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ChromaPure User Manual

1. 25 3 Click the radio button next to the desired meter to select it 4 Click Initialize The Initialize button will turn into Apply Mode 5 Set the desired mode Note Some meters only have one operating mode 6 If the meter requires a dark reading place against a flat surface to block out all light For more information about the dark reading requirements of various color analyzers refer to Dark Reading Requirements p 84 7 Click Apply Mode TIP If the selected meter relies on a serial connection such as the Klein K 10 you will have to set the serial port settings This usually involves only setting the correct port which you can determine by looking in the Windows Device Man ager Click the button to the right of the operating mode drop down to access the serial port settings 8 Close the Select Initialize Meter window Setting Calibration Options Before beginning your calibration session you will probably want to set the options that you desire To do this click the Options button on the toolbar For detailed information about the vari ous options refer to Selecting Calibration Options p 29 below 26 RECORDING DISPLAY SETTINGS Overview You may wish create a detailed recording of the display s settings as part of the calibration pro cess What you record here will be available in the Settings Report For more information about running reports refer to Running a Calibration Report p 69 To
2. 41 SETTING WHITE AND BLACK LEVEL Overview Properly setting black level generally labeled as Brightness and white level generally labeled as Contrast or Picture of the display is a prerequisite for all other calibration adjustments You should do this first To properly set black level brightness 1 Display a pluge pattern that contains video information just above and below video black against a fully black background 2 Lower the brightness control until the just above black bar fades into the background and becomes invisible 3 Raise the brightness control until the just above black bar just becomes clearly visible NOTE Video black is digital 16 on a 0 255 scale Video white is 235 on the same scale Everyone agrees that information below 16 should be invisible and that every thing between 16 235 should be visible There is some controversy as to whether we should be concerned about above white material 236 255 and if so to what extent To properly set white level contrast Display a test pattern that contains video information that is just below white and just above white against a fully white background The correct white level setting is that setting at which 3 conditions are met e The peak white output is consistent with the display type e The just below white bar is clearly visible e The color of full white is neutral Use the White Balance tool to check the color of white For more infor
3. 100 90 80 70 60 4 50 Output 40 30 20 10 0 0 10 20 30 40 50 60 70 80 90 100 Input Luminance is a linear unit of intensity that can be expressed in absolute or relative terms e Absolute luminance is expressed in raw cd m2 or ft L e Relative luminance is expressed as a number between 0 0 1 0 where 1 0 is equal to the absolute luminance of the white reference The Color Management module uses lightness The Color Decoding module uses relative lumi nance The Pre Post Calibration Grayscale modules and the Pre Post Calibration Color Gamut modules use both relative and absolute luminance One of the obvious consequences of the difference between lightness and luminance is that the difference in lightness between a bright color green and a dim color blue is much smaller than it would be if expressed in luminance relative or absolute Green luminance is approximately 71 of reference white whereas blue luminance is approximately 8 a ratio of nine to one However the same difference in expressed lightness is a ratio of less than three to one One way to think of this is that the intensity of green measures 9 times brighter than blue but green only appears to the eye as 2 7 times brighter than blue This is what we mean by when we say that perception of the intensity of light is non linear 86
4. 35 5 Plug in your field meter and initialize it For information about how to setup a meter see Installing and Configuring ChromaPure for Initial Use p 18 6 Return to the Meter Correction module The reference fields will be populated with the values you already measured 7 Select the Field Meter radio button and then take a series of WRGB measurements ChromaPure will automatically calculate the correction between the Reference and Field meters 8 Once all of the corrections have been calculated click the Apply button The correction will now be applied to all measurements for this session and the field meter will emulate the performance of the reference meter 36 TAKING PRE CALIBRATION GRAYSCALE MEA SUREMENTS Overview The Pre Calibration Grayscale module allows you to measure the ability of the display to track a neutral color of white from black all the way to peak white The initial grayscale reading provides a snapshot of the display s pre calibration performance for both white balance and gamma You should take pre calibration grayscale readings for every calibration session This data is crucial if you wish to generate a before after report To take an Pre Calibration Grayscale measurement 1 Click the Pre calibration Grayscale button The Pre calibration Grayscale module will appear Pre Calibration Grayscale StartPage Help Measurement Mode 10 C 40 Ca C 2 C 50 90 C 3 C
5. The Spyder3 4 does not require a dark reading The basICColor Discus does not require a dark reading The Display 2 and DTP 94 require a single dark reading at the beginning of the calibration session The i1Pro requires an initial dark reading at the beginning and subsequent periodic dark readings throughout the calibration session The Hubble requires an initial dark reading at the beginning and subsequent periodic dark readings throughout the calibration session The Klein K 10 does not require a dark reading The Minolta CS 200 does not require a dark reading Reference spectroradiometers such as the JETI and Photo Research units automatically take dark readings as part of the measurement process 83 REFERENCE GAMUTS Red Green Blue Yellow Cyan Magenta White Red Green Blue Yellow Cyan Magenta White Red Green Blue Yellow Cyan Magenta White Red Green Blue Yellow Cyan Magenta White SMPTE C x y 0 6300 0 3400 0 3100 0 5950 0 1550 0 0700 0 4209 0 5067 0 2306 0 3262 0 3144 0 1606 0 3127 0 3290 Rec 709 x y 0 6400 0 3300 0 3000 0 6000 0 1500 0 0600 0 4193 0 5053 0 2246 0 3287 0 3209 0 1542 0 3127 0 3290 EBU x y 0 6400 0 3300 0 2900 0 6000 0 1500 0 0600 0 4172 0 5018 0 2197 0 3287 0 3271 0 1576 0 3127 0 3290 DCI x y 0 6800 0 3200 0 2650 0 6900 0 1500 0 0600 0 4248 0 5476 0 2048 0 3602 0 3424 0 1544 0 3140 0 3510 Y 0 2124 0 7011 0 0866 0 9134 0 7876 0
6. z Back Cancel Click Finish Your meter is now ready to use in Windows XP Installing a Driver in Windows 7 1 Plug in the meter to an available USB port A bubble message will appear in the task tray informing you that Windows did not install this device Close this message Open the Windows Control Panel In the Control Panel navigate to System and Security System Device Manager The Windows Device Manager will appear 22 plit Computer gt ca Disk drives BG Display adapters Ai DVD CD ROM drives wang IDE ATA ATAPI controllers IEEE 1394 Bus host controllers gt gt Keyboards D Mice and other pointing devices 1C Modems b Monitors gt Network adapters Ip Other devices Ji Calibrator KR Portable Devices gt Processors BI SD host adapters 4 Sound video and game controllers ZB System devices Universal Serial Bus controllers You should see an item with a yellow exclamation point probably under Other Devices indicating that the driver is not installed the example above shows the Chroma 5 Right click that item and then select Update Driver Software An Update Driver Software window will appear 23 17 Update Driver Software Calibrator Browse for driver software on your computer Search for driver software in this location gram Files Display Calibrations LLC ChromaPure Drivers il Pro D2 ER V Include subfolders O gt Let me
7. Take a series of WRGBCYM readings to create a baseline Display a red test pattern Select the Red radio button Click the Continuous button a uh WN Click Measure ChromaPure will take readings and update the error chart in real time 7 Adjust the Color control until the Red Color bar shows as close to 0 error as possible 8 When finished click Stop NOTE The goal here is to minimize the brightness error for all of the primaries not just red After adjusting red with the Red Color control you may want to con tinue and repeat the process for the Blue Color and Green Color controls to get the lowest possible average percentage error for all three primaries 46 SETTING THE MAIN TINT HUE CONTROL Overview The main Tint of Hue control affects the position of the secondary colors on the color wheel Use the Tint Hue control to align the secondary colors to their correct position Use the main Tint Hue control only if your display has no color management system If it does then usually adjusting Tint Hue is unnecessary adjustments to Tint Hue For more information about setting the white balance TIP Always adjust the white balance of the display before attempting to make d refer to Setting White Balance p 44 To adjust Tint Hue 1 Click the Color Decoding button on the main tool bar The Color Decoding module will appear Take a series of WRGBCYM readings to create a baseline Select the Cyan radio
8. This is available for any PC that has a HDMI out port that you can connect to your display Then you only need to take advantage of Windows extended display feature 1 Click the Options button on the navigation toolbar and then click Signal Generators 30 The Signal Generator window will appear ChromaPure Options EU El Environment Auto Recovery Jh Enable Signal Generator Support Calibration d E Meters Add Signal Generators C lx Reports Built In Select Color Format Select Pattern Type Select Resolution Select Signal Intensity v v Cancel 2 Check Enable Signal Generator Support Click the Built in option 4 Plug in an HDMI cable into your workstation that connects to your display This allows you to take advantage of Windows extended display feature 5 Configure the extended display so that the video card provides it with its native resolution which will usually be 1920x1080 and ensure that both the extended display and your workstation display are both active Your workstation should be the primary display 6 Click OK With the Built in signal generator activated the proper test patterns will now appear automatically as you use various features in the application You may also now call up any one of the many spe cialized test patterns from the drop down on the Signal Generator Toolbar The following signal generators are supported by ChromaPure Professional only es Accu
9. 12 2 08 2 1 2 08 2 11 2 04 2 05 2 12 2 19 Help Contrast 128 If you see any problems in the readings then return to the White Balance and or Gamma modules and make further adjustments 67 TAKING POST CALIBRATION COLOR GAMUT MEASUREMENTS Overview Taking measurements in the Post Calibration Color Gamut module works just like the Pre Calibra tion Color Gamut module Its only function is to measure the results obtained from your calibration session You can then compare the pre and post measurements in the calibration report For more information about taking a color gamut measurement refer to Taking Pre calibration Color Gamut Measurements p 39 Post Calibration Color Gamut StartPage Help Measurement Mode White Red Green Blue Yellow Cyan Magenta White S x 0 31 0 659 0 296 0 136 0 426 0216 6 321 bl ae y oam 0 337 nen 0 079 0 512 nam om C Green C cyan t CR CH S 0 214 0 705 0 098 0 942 0 822 0 332 cdm2 50 522 10 81 35 6 4 95 47 58 4 55 16 79 CIE94 5 6 na 101 1 6 an 4 6 Save Chromaticity Image Save Luminance Image Reset Form Help If you see any problems in the readings then return to the Color Management and or Color Decoding modules and make further adjustments 68 RUNNING A CALIBRATION REPORT Overview Once you have completed your calibration session it is useful to have a permanent
10. Overview Before beginning the calibration you should first set the desired options Just click the Options button on the toolbar and then select the desired values The selected value will be in effect dur ing the calibration session and will become the default for future calibration sessions unless subse quently changed ChromaPure offers the following settings in the Options module Color Luminance Use this option to select whether you wish the color luminance targets in the Pre Post Color Gamut modules to be determined by reference to the selected gamut or to be calculated from the mea sured primaries You should use Fixed Target from Gamut if the display has a CMS that allows you to adjust the primary colors or if the primary colors naturally match your desired gamut Use Calculated target if the primary colors significantly deviate from your desired gamut and you cannot adjust them with a CMS Reference Gamut Each of these options has an effect on the results that your calibration will produce When calibrating a display you need to have a reference gamut Each gamut specifies the hue and saturation for the primary colors red green and blue and a white point From this is calculated the saturation and hue of the secondary colors and the luminance of all of the colors ChromaPure offers four reference gamuts e SMPTE C e Rec 709 e EBU e DCI Use SMPTE C for NTSC standard definition Rec 709 for NTSC and PAL based high def
11. a test pattern but you must have a recorded source of broadcast material either from a DVR or DVD 1 Record a television source that includes a fade to black sequence that typically occurs in between commercials or between commercials and network programming 2 Play back the sequence and pause at the fade to black section Using a colorimeter or a light meter measure the light output of the black screen 4 Adjust the black level up and down You will find a place where additional downwards adjustments of the Brightness setting will not affect the light output of the panel That point just where the panel s light output becomes unresponsive to decreases in the Bright ness setting is the correct setting for black Setting Sharpness 10 This should also be adjusted by eye Use a sharpness test pattern which is generally a series of horizontal and vertical lines to look for ringing or faint outlines along the edges of the lines in the test pattern Set the Sharpness control to the highest point you can that minimizes ringing you may not be able to eliminate it entirely On some sets the sharpness should be set to zero But for most it is usually at about the 1 3 point Adjusting White Balance Briefly white balance adjustment simply involves adjusting specialized controls that allow a display to track a neutral white throughout its entire range from the blackest black to the whitest white Unlike a good color management
12. and remeasure black white levels gray scale color decoding saturation tint and gamma because there may have been interaction between these adjustments You may have to go through two or three rounds of measurements until all are correct Calibrating a Front Projector Calibrating front projectors poses some special issues primarily concerned with the fact that unlike flat panels you can measure projectors in two ways off the screen or directly from the lamp SMPTE recommends that all critical measurements should be taken at the viewing position from the center of the screen Because of the limitations of most consumer color analyzers mea surements should generally be taken closer to screen say a foot or two Also angle the meter slightly so it does not read its own shadow If you have a high gain screen then you should be careful to keep this angle as small as possible This is because high gain screens will color shift off axis This is good advice but there are some circumstances in which measurements directly from the lamp are useful e Contrast Since the light reflected off the screen is minimal when projecting black you will probably get a more accurate reading by taking measurements directly from the lamp Compare this to a measurement of full white to get contrast ratio To ensure accuracy do not move the sensor between the two readings A standard camera tripod is useful for this e Peak output Since you don t have to wo
13. button Click the Continuous button ue P WN Display a cyan test pattern 6 Click Measure ChromaPure will take readings and update the error chart in real time 7 Adjust the Tint Hue control until the Blue Hue bar shows as close to 0 error as possible 8 When finished click Stop NOTE The goal here is to minimize the hue error for all of the secondaries not just cyan After adjusting cyan with the Blue Hue control you may want to con tinue and repeat the process for the Red Hue magenta and Green Hue yellow controls to get the lowest possible average percentage error for all three second aries 47 USING COLOR MANAGEMENT Overview Use the Color Management module if the display includes a color management system CMS that provides control over the hue saturation and lightness of the primary and secondary colors You can also select the desired color space in which to work Select the color space that best corre sponds to the human interface in the CMS controls For example Select HSL for CMS s that rely on these adjustment parameters such as the JVC LCoS pro jectors Select RGB for CMS s that rely on these adjustment parameters such as the Samsung flat panels and the Lumagen Radiance external video processors Select xyY for CMS s that rely on these adjustment parameters such as the iScan DVDO Duo external video processor To use Color Management 1 5 6 7 Click Color Management on the ma
14. changed by moving a color towards or away from the white point hue is changed by revolving a color around the white point When a color s hue is off its appearance will seem contami nated by other colors For example red that is too yellowish will begin to seem orange Blue that is too reddish will begin to appear purplish Human vision is very sensitive to changes in hue e Color Luminance This is the brightness or intensity of color Often confused with satu ration the luminance of any color or even white can be measured by a simple light meter Color luminance comes in two types absolute luminance and relative luminance Absolute uminance is the value typically expressed in cd m2 or foot lamberts metric or imperial units of luminance that is reported directly by the color analyzer Absolute lumi nance is useful for determining peak output black level and gamma e Relative luminance is the luminance of a color expressed as a percentage of the luminance of white at the same level of stimulus The relative luminance of reference white is always represented as 1 0 and colors are shown as some percentage of that For example the high definition standard for the luminance of red is 0 2126 That means that red should measure 21 26 as bright as white at the same level of stimulus Relative luminance is useful for gamut specifications and calculating the dE of color For more information about dE refer to dE Method p 30 To sum up a
15. commercially available CMS solution for consumer gear that can correct non linear performance throughout the entire color space Nonetheless this tool is useful for determining how well a CMS functions and whether it is advisable to calibrate your display at say the 75 saturation point of the gamut Doing so may result in lower average color errors when measured in the Advanced Color Management module 50 Saturations 0 900 0 850 0 800 0 750 0 700 0 650 0 600 0 550 0 500 gt 0 450 0 400 0 350 0 300 0 250 0 200 0 150 0 100 0 050 0 000 0 000 0 050 0 100 0 150 0 200 0 250 0 300 0 350 0 400 0 450 0 500 0 550 0 600 0 650 0 700 0 750 0 800 x The saturation scale at 25 increments In addition to different levels of saturation we can also think of the six primary and secondary col ors at different levels of amplitude or stimulus Just like we measure white at different levels of stimulus when calibrating the grayscale we can also measure any color at different levels of stim ulus as well So too just like white should remain x0 3127 y0 329 throughout the grayscale a HD red should remain x0 640 y0 330 at different levels of stimulus NOTE You can use this module only if you have access to the proper test patterns Chro maPure s built in patterns offer a saturation and amplitude scale in 25 increments as do the HDG 4000 and DVG 5000 AccuPel external signal generators
16. instru ment using offsets built in to the ChromaPure license file No change is made to the hardware device itself The following color analyzers are supported by ChromaPure Professional only e X Rite Hubble Sencore OTC 1000 non contact colorimeter e Klein K 10 non contact colorimeter e Minolta CS 200 colorimeter e Photo Research PR 650 655 670 spectroradiometer e JETI 1201 1211 spectroradiometers We continually review the hardware options available and add new meter support when appropri ate These meters measure both the chromaticity and luminance of light The measurements are reported in xyY format xy coordinates describe the chromaticity of the light and Y describes its luminance in either in candelas per square meter cd m2 or foot lamberts ft L Luminance is the diffuse light we receive from flat panels or projector screens If you wish to read light directly from a front projector s lens you must attach a diffuser to the meter For more information about cali brating a front projector refer to Calibrating a Front Projector p 15 To prepare a meter for a calibration session 1 Attach the meter to your PC s USB port 2 From the main ChromaPure window click Select Initialize Meter The Select Initialize Meter module will appear with the licensed meter s displayed H I Select Initialize Meter 10 x e Initialize Display3 Disconnected SN OE 11 4 02 100747 08 Select serial port settings here
17. of the screen 11 Select the gain of the screen 12 Click Calculate 13 ChromaPure will return the equivalent value in e ft L e cd m2 e lumens e lux Manufacturers routinely report gain figures that are inflated from the actual value 76 Raw Data Module Overview Use the Raw Data module for a wide variety of calibration tasks You can take either single mea surements or continuous measurements that appear in large xyY format If you are using the Off set feature or a signal generator be sure to click the radio button to indicate the type of measurement WRGBCYM that you plan to take prior to clicking Measure The data you measure will appear in the grid on the right You can export that data to a CVS file for analysis simply by clicking the Export button Data Conversion Tool Overview You may have a need to do some data modeling of potential measurements of one or more dis plays This involves providing sample xyY data to determine what performance images based on that data would provide To support this ChromaPure includes a Data Conversion tool Simply pro vide your own XyY test data and this utility will convert it into several other color spaces including e XYZ e Lab e Luv e RGB e RGB 77 You can also supply a sample test and reference color to obtain a dE value from the major dE for mulas as well as information about the percent of deviation from the tes
18. pick from a list of device drivers on my computer This list will show installed driver software compatible with the device and all driver software in the same category as the device O E a Cancel 6 Click the Browse button and then browse to the following location on your hard drive C Program Files Display Calibrations LLC ChromaPure Drivers lt select the correct folder gt TIP There are several sub folders under Drivers Select the one that contains the driver for your device For example if you are installing the X Rite i1Pro or Display 2 then select the i1Pro D2 sub folder If you are installing the X Rite Chroma 5 then select the Chromad sub folder 7 Click Next A final Update Driver Software window will appear 8 Click Close You are now ready to begin using the meter in Windows 7 Selecting and Initializing the Meter Overview Prior to any calibration session you must have a color analyzer connected ChromaPure Standard currently supports the following devices X Rite OEM i1 Display Pro III Display 3 Display 3 PRO X Rite Display 2 Lt colorimeter X Rite Chroma 5 colorimeter X Rite DTP 94 colorimeter X Rite i1Pro spectrophotometer basICColor Discus colorimeter 24 e DataColor Spyder3 4 colorimeter e Minolta CS 100A colorimeter NOTE Any of the colorimeters can be upgraded to a PRO version This indi cates that the colorimeter s response has been corrected by a reference
19. record of the results ChromaPure provides four calibration reports A simple one page results report A multi page comprehensive results report A settings report A customizable multi page comprehensive results report in Microsoft Excel format The reports contain both raw xyY data and charts and graphs displaying the pre and post calibra tion performance of your display To run 1 a calibration report Click Calibration Report on the main navigation toolbar A page will appear that allows you to select the desired report Calibration Report Start Page Help Select a Report C Simple Calibration Report C Excel Report Detailed Calibration Report Calibration Settings Report Run Report Click the desired report type You can select e Simple Calibration Report This is internally generated and shows basic grayscale and gamut data only e Detailed Calibration Report This is internally generated and shows a wide variety of calibration data e Calibration Settings Report This is internally generated and shows the information e Excel Report This is an externally generated report and requires you to have Micro soft Excel install on your PC For those with ChromaPure Professional licences these reports can be customized to your specifications 3 Click Run Report A printable calibration report will appear You can then export the report pdf to make it sharable with others Interpreting
20. record the display s settings 1 From the main navigation tool bar select Settings A Session Parameters page will appear Session Paramters ba Start Page e Help m Customer Information Television Technician Name SEH Ir Make gt Name Eh Address Ir Tl Model Ir Phone Number Ir City Ena a Serial Number Email EE state f Phone Normal Mode park Mode Input 1 Input 2 Pre Calibration Post Calibration Pre Calibration Post Calibration Picture Mode sd LO o Picture Mode Ir KH Picture Temperature o Picture Temperature IT gt Contrast Picture RE Contrast Picture 5353s ee Brightness Blacks D TEE Brightness Blacks D IEN Color Saturation Spee Color Saturation Hue Tint Phase aasa eessen Hue Tint Phase LO rt Sharpness Detail HU IT Sharpness Detail ti eee Backight _ Baot ee Red Drive Gain High EU ia Red Drive Gain High emeng Keel Green Drive Gain High l II Green Drive Gain High i egen Blue Drive Gain High O Ir Blue Drive Gain High LU aaa Red Cutoff Bias Offset TT Red Cutoff Bias Offset TT Green Cutoff Bias Offset Een eeng Green Cutoff Bias Offset Kees TI Blue Cutoff Bias Offset HU Ir Blue Cutoff Bias Offset IT a Comments Comments na H y 2 Type the various settings on this page 27 SELECTING CALIBRATION OPTIONS
21. system CMS which is relatively rare virtually all displays have white balance controls Sometimes they are in the user menu or they may be buried in a service menu that can only be accessed by a specific key sequence on the remote The goal is to get an xy measurement as close as possible to x0 3127 y0 329 or when red green and blue are each at 100 relative intensity Since white is the combination of all three primary colors neutral white is achieved when those colors are in relative balance The calibration software will provide these raw numbers and a graphical representation of RGB relative to the target white point To calibrate the white balance 1 Aim the meter at the display 2 Select a 80 gray test pattern 3 Adjust the RGB Contrast controls until RGB is balanced or until you read x0 3127 y0 329 4 Select a 20 gray test pattern and use the RGB Brightness controls until RGB is balanced or until you read x0 3127 y0 329 5 Repeat the last two steps as many times as necessary until both the 80 gray and the 20 gray test patterns measure a neutral shade of white This may take several sets of measurements 6 Finally take an entire series of grayscale measurements at 10 intervals from 10 to 100 to ensure that the display tracks white accurately throughout the entire range Consider the example below This is not a neutral shade of white because there is too much red and insufficient blue and green You would adjust your di
22. used to represent the luminance of a color Luminance is not plotted by on the CIE chart because it cannot be represented by xy coordinates It must be represented separately Saturation This is the colorfulness of the color relative to its own brightness A color s saturation is represented on the CIE chart as the distance from the white point As a color moves closer to the white point it loses saturation As it moves away from the white point towards the gamut boundary this defines the limits of visible light it becomes more deeply saturated Add saturation to a color and it will begin to appear more deep and rich Reduce saturation of a color and it will begin to appear more pale and less colorful at their same level of brightness There has been an unfortunate tendency in the popular press to refer to saturation as though it were an unqualified positive aspect of a display s color reproduction and that the more of it the better In reality there is only one correct amount of saturation for any color and that is the amount defined by the gamut being used For all practical purposes this gamut you should always calibrate to is the high definition standard known as Rec 709 For more information about calibrating to different gamuts refer to Reference Gamut p 29 Hue This is the primary characteristic of color that allows us to distinguish one color from another A color s hue is measured by its angle to the white point If saturation is
23. you should take when calibrating your display For specific instruc tions on how to make these adjustments using ChromaPure software refer to Chapter 3 Video Calibration using ChromaPure p 41 However if you do not have a good background on how the process works read this section first Setting White Level Contrast The Contrast control determines the peak output your display will provide Set it too low and you lose image punch and lower the contrast ratio Set this too high and you lose color accuracy and detail in bright scenes peak output set too high can also cause eye strain image noise and pre mature aging of the display The standard method for setting Contrast requires that you look at a test pattern that has a just below white stripe against a white background You are supposed to set Contrast as high as you can without losing the ability to distinguish the just below white stripe from full white However there are a couple of problems with this method e Many modern digital displays will never suffer from loss of high level detail even with Con trast set to 100 This method will recommend a setting that is much too high e This method does not take into consideration color performance Many displays will lose their ability to track a neutral grayscale at very high output levels when Contrast set as high as this method recommends Thus a better method for setting Contrast is to set it at a level consistent with
24. your color using 75 saturation targets You may use the standard Color Management module for this For more information refer to Using Color Management p 48 53 ADJUSTING COLOR DECODING Overview Use the Color Decoding module when your display lacks a full featured CMS Some displays have color decoding controls that allow you to independently adjust the brightness of each primary color and the hue of each secondary color Most displays however only have a universal Color and Tint or Hue control To adjust a display s color decoding performance 1 Click Color Decoding on the main navigation tool bar The Color Decoding module will appear Color Decoding Start Page Measurement Mode Red Color Green Color Blue Color Red Hue Green Hue Blue Hue C White IT Continuous C Red C Yellow C Green C cyan C Blue Magenta Prmaries E Red E Green x 0 98 y 0 659 Y 45 46 DI Magenta x 0 358 R y 0 172 Y 49 146 Y 19 277 O White 2 Take an initial measurement of White Red Green Blue Yellow Cyan and Magenta to get a baseline The percentage error in RGB Color and RGB Hue will appear on the graph RGB Color measures the percentage error of the luminance of each primary color RGB Hue measures the percentage hue error of each secondary color magenta red hue yellow green hue and cyan blue hue 3 Display a red test pattern 4 Select the Red radio button 5 Click the Continuous check box and then
25. 2989 1 0000 0 2126 0 7152 0 0722 0 9278 0 7874 0 2848 1 0000 0 2220 0 7067 0 0713 0 9287 0 7780 0 2933 1 0000 0 2095 0 7216 0 0689 0 9311 0 7905 0 2784 1 0000 84 UNDERSTANDING DELTA E Overview Delta E dE is a measurement of color error relative to a known standard Thus the goal in cali bration is to get the dE of the measured color as low as possible There are several different dE formulas e CIELAB e CIELUV e CIE94 e CIEDE2000 Each formula produces somewhat different results and has different tolerances We recommend using CIE94 though CIELUV is also a good choice for grayscale When using CIE94 or CIEDE2000 strive for a value of 1 5 or less 1 0 and below is visually perfect for color and 4 0 or less 2 0 or less is visually perfect for grayscale If using CIELAB or CIELUV strive for 4 0 or less for all readings 85 LIGHTNESS AND LUMINANCE Overview Both are a measure of the intensity of light Lightness is a non linear perceptually weighted unit of intensity that is approximately the inverse of display gamma Human vision is very sensitive to even small changes in the intensity of light under dim conditions but less sensitive to similar changes under bright conditions As the graph below shows at only 18 of the total level of intensity we already perceive approximately half of the difference between black and peak output Lightness vs Luminance Luminance Lightness
26. 326 om 0 057 SE 0 499 0 315 0 156 C Blue Magenta KR 5 ee oS SE e sah aaa a a lala ee CIE94 FEN Save Chromaticity Image Save Luminance Image J Reset Form Quick Report 2 Display a white test pattern 3 Click Measure ChromaPure will take a measurement of the xyY values of white and automatically advance to the next color red 4 Display a red test pattern 5 Click Measure 39 Repeat these steps until you complete all of the remaining readings When you have fin ished the gamut readings several data elements are available e You can review the E value for each color e You can review the raw xyY data for each color e You can review the provided CIE graph and color luminance bar chart of the measured gamut e You can also save those graphs as image files by clicking the associated Save Image button TIP If at any point you make a mistake you can always go back and remeasure one of the colors 40 YaLdVHD ChromaPure Calibration Procedures Setting White Balance p 44 Setting the Main Color Control p 46 Setting the Main Tint Hue Control p 47 Using Color Management p 48 Using Advanced Color Management p 50 Adjusting Color Decoding p 54 Setting Gamma p 56 Measuring Contrast p 59 Using Auto Calibrate p 61 Using the Video Processor Control Panel p 65 What s Inside W Setting White and Black Level p 42
27. 4 10 4 0 967 PAA AT ces MO c4 36 47 10 4 20 Yo 4 30 4 40 x Red Green Blue Yellow Cyan Magenta 2 You can export the report as an image PDF or Word file 71 CALIBRATION TOOLS Sharing Data When you have completed your calibration you may wish to share the data with others Click one of the Save Image buttons found on several of the modules to save a graph to your local PC as an image file Export the entire calibration to a session file These files have a calx extension and can be opened by any other ChromaPure user Export xyY data from the Before After Grayscale and Color Gamut modules in CSV format This raw data can be opened by Excel Generate a comprehensive calibration report This can be printed and shared as hard copy or converted to PDF and then e mailed or posted online Importing and Exporting Calibration Data Overview It is important that you are able to export the results of a calibration session so you can open the data in ChromaPure later or share with other ChromaPure users It is also useful to export raw cal ibration data to use with other data analysis tools or to share with those who are not ChromaPure users To export a calibration session 1 Click Save on the main navigation tool bar An Export Results window will appear Export results Save in C3 CalibrationData sl B220 Favoites Desklup Gi My Documents a Production Pa Home
28. 60 C 100 C 70 10 20 30 40 50 60 70 80 90 100 Average x 0 335 0 290 0 285 0 285 0 285 0 285 0 285 0 286 0 286 0 286 y 0 318 0 289 0 287 0 286 0 286 0 287 0 287 0 288 0 288 0 290 Y 0 333 2 455 7 831 18 816 36 426 55 299 75 574 97 832 120 473 140 844 CIE94 17 4 22 0 23 5 23 9 23 9 23 5 23 2 22 9 22 7 21 6 23 0 CET 5366 8934 9462 9522 9586 9518 9458 9402 9386 9240 9390 Gamma 2 63 2 52 2 40 2 20 1 95 1 83 1 75 1 63 1 48 2 04 Output 0 24 1 7 5 6 13 4 25 9 39 3 53 7 69 5 85 5 100 0 2 Display a 10 test pattern 3 Click Measure ChromaPure will take a measurement of the xyY values at that level of stimulus and auto matically advance to the next level 37 4 Display the next gray pattern in the series 5 Click Measure 6 Repeat these steps until you complete the 100 reading When you have finished the grayscale readings several data elements are available You can review the dE values You can review the gamma values You can review the Correlated Color Temperature CCT values You can review both the gamma response and the RGB values at each level of stimulus from the provided graphs You can also save those graphs as image files by clicking the associated Save Image but ton TIP If at any point you make a mistake you can always go back and re measure one of the levels Also you can display gamma d
29. 75 or 100 white test pattern Measure the Y value luminance of white Display a 75 or 100 Red test pattern and measure the Y value here as well You will notice that as you move the Color control up and down the Y value of Red increases and decreases but white stays the same Set the color control at the point where Red Y measures closest to 21 of the white read ing TIP It is not really important whether you use 75 or 100 patterns in this test so long as you use the SAME level of intensity for both red and white If you have not already done so adjust the gray scale and get it as close to D65 x 0 3127 y 0 329 across the entire range as possible Point the colorimeter towards the screen and display a cyan test pattern Put the Tint control at its neutral mid setting Use the software controls to plot the hue of cyan Adjust Tint up or down until the reading places the hue of cyan as close to the target 0 error as possible If you had to substantially adjust Tint from the neutral point to get an accurate hue of cyan then check the other secondaries yellow and magenta as well You may have to 12 select another setting that gets the average error in hue of the three secondaries as low as possible TIP If your display has a full featured CMS then adjusting the main Color and Yy Tint controls is not necessary Adjusting Color using a Color Management System CMS 1 2 Point your c
30. C hroma P u re Video Calibration Software ChromaPure User Manual 6 14 14 Table of Contents Introduction The Basics ccccccceeseeeeeeeeeeeeeeeeeeeeeeeeeeeeseeeaaeeeeeeeees 3 What To Expect From Calibration un masasama rr nrntnterrnnrnrennnrn rnrn rtnn nnerrreeenne 4 What Bo NET KE 5 Calibration Procedures E 6 Essential ee nn paaa AGA AA 6 Basie Lee 6 Essential Terminology E 8 Calibration Order ed 9 Calibration E 9 Setting White Level Contrast c ccccceeceeeesseeeceeeeeeeeeesceeeeeseeeeenensceneceeeesneneeseseenens 9 Setting Black Level Brightness 1 1 ama aaa amahan 10 Setting SN MESS AA AA AA 10 Adjusting White Balance aaa ANA tenes viva AA 11 Setting Colon TN EE 12 Adjusting Color using a Color Management System CMS 13 Adj sting GaMMa E 13 Calibrating a Front Projector maa AA AA 14 ChromaPure Pre Calibration Procedures ssceeeeeeeeeeeeeeees 16 Installing and Configuring ChromaPure for Initial Use 000000000 17 istal NEO sats taincaeuansins sasdcacasatiaanndesdaceante aaa a adaa aa a a aa a aa eiia 17 Install ChromaPure Goftware aaa 17 Import the License TE 17 Install a Driver for the Color Analvyzer AAA 18 Installing a Driver in Windows XP EE 18 Installing a Driver in WiINdoOwWS EEN 22 Selecting and Initializing the Meter 2 cccccccccccesseceeeeeeeeeseeeseeeeeceeceeeneenes 24 Setting Calibration ge 26 Recording EE En e EE 27 ee ee tee le e en Si
31. Pel HDG 3000 e AccuPel HDG 4000 e AccuPel DVG 5000 e DVDO TPG e Sencore VP 40x e Quantum Data 780 e Quantum Data 701 e Quantum Data 882c 31 e Sencore MP 500 Using any of these options ChromaPure will automatically display the correct test pattern required by the feature you access within the application No user intervention is required Using automation with a video test pattern generator 1 Plug in the signal generator connect it to the PC via serial or USB depending on the unit and then connect the signal generator s output to the display you wish to calibrate Click the Options button on the navigation toolbar and then click Signal Generators The Signal Generator window will appear ChromaPure Options et El Environment Auto Recovery Jh Enable Signal Generator Support Calibration M DI Add eters Signal Generators Reports Built In PS sl EH E E Select Color Format Select Pattern Type Select Resolution Select Signal Intensity Y v Cancel 2 Check Enable Signal Generator Support 3 From the drop down list select the desired generator and then click Add The selected generator will appear in a list of enabled devices 32 ChromaPure Options N Environment Auto Recovery IV Enable Signal Generator Support Calibration fAccupel Dvg5000 d Meters perps ngaa Signal Generators A Reports Built In kal Ki C Accupel DYG 5000 KS EZ DI DR Port Settings Butto
32. T 1eater Save as type La Session File D Cancel VA 72 2 Select XML Session File from the Save as type box 3 Type a desired name for the file in the File name box 4 Select a desired location in the Save in box 5 Click Save A file with the specified name will save in the specified location It will have a calx extension You or any other ChromaPure user can subsequently open this file view the data and associated charts and run a report on the data This file includes all of the basic calibration data including customer information and calibration settings NOTE ChromaPure includes a fail safe feature in case you forget to save the calibration data Whenever you attempt to exit the program you will be prompted to save a calibration file first Also if for whatever reason the program shuts down abnormally when you re start you will be prompted to restore the calibration data from the previous session To export raw calibration data 1 Click Save on the main navigation tool bar An Export Results window will appear Export Results pI 2 xj Save in CalibrationD ata Di O Ce P Favoites Desklup Na My Documents Ge Production Pa Home 1eater Save as type csv File DI Cancel 2 Select CSV File from the Save as type box 3 Type a desired name for the file in the File name box 4 Select a desired location in the Save in box e 79 5 Click Save A file with the spe
33. The Advanced Color Management module is designed to measure these parameters No commer cially available consumer color management system will correct these errors However if calibrat ing at full saturation results in significant errors in the rest of the color space then you can try to calibrate at 75 saturation using the Color Management module This may provide better over all results For more information refer to Using Color Management p 48 To measure the amplitude and saturation scale 1 Click the Advanced CM button The Advanced Color Management module will appear 51 Advanced Color Management Start Page Help x TEE w Measurement Mode Select Measurement Mode Save Chart Image White Baseline Measurements v Save CSV Data C Red CT Yellow Select Char Green Cyan Help Saturations CIE Chart Pe C Blue C Magenta Reset Form Select Pattern Intensity Ca pantay White Red Green Blue Yellow Cyan Magenta x 900 oo oo o0 oo oa 00 y oo oo oo oo 0 0 oo oa o0 o o oo oo oo cdm2 oo oo oo of oo oo o0 dE oo oo oo og oo og 2 Select White and ensure that Baseline Measurements is the selected Measurement Mode 3 Select the desired Pattern Intensity TIP It can be useful to measure the saturation scale at different levels of inten sity You may find that it measures differently at different levels of inte
34. UV e CIELAB e CIE94 e CIE2000 Both CIELUV and CIELAB were endorsed by CIE in 1976 The underlying formula in each is the same but they rely on different color spaces Because Luv offers a linear chromaticity diagram it is more commonly used for video applications but Lab is a perfectly acceptable alternative In fact SMPTE has recently endorsed CIELAB as the color difference metric for its Digital Cinema Ini tiative CIE94 was developed by CIE in 1994 and is based on Lab only It is a more complicated formula than the 1976 alternatives and arguably provides more accurate results especially with color CIE2000 endorsed in 2000 by CIE is an even more complicated formula that has never gained widespread acceptance outside of the textile industry It is also Lab based It is important to understand that these different measurements of color error scale somewhat dif ferently so when comparing results obtained by different dE formulas use the following equiva lence scales For white e CIELUV 4 0 e CIELAB CIE94 CIE2000 3 0 For color e CIELUV 4 0 e CIELAB 3 0 e CIE94 1 5 e CIE2000 1 5 Which dE formula you use is to a certain extent a matter of personal preference However we rec ommend using CIE94 for primary secondary color grading For simplicity s sake you could use CIE94 for grayscale also It will return the same results as CIELAB However many prefer CIELUV for grayscale as it is somewhat more sensitive to small color er
35. active Lumagen configuration e Gamma Set the Lumagen Gamma factor 65 NILAVH ChromaPure Calibration Procedures Taking Post Calibration Color Gamut Measurements p 68 Running a Calibration Report p 69 Quick Reports p 71 Calibration Tools p 72 What s Inside W Taking Post Calibration Measurements p 67 66 TAKING POST CALIBRATION MEASUREMENTS Overview Taking measurements in the Post Calibration Grayscale module works just like the Pre Calibration Grayscale module Its only function is to measure the results obtained from your calibration ses sion You can then compare the pre and post measurements in the calibration report For more information about taking a grayscale measurement refer to Taking Pre calibration Grayscale Mea surements p 37 Post Calibration Grayscale Start Page Help Measurement Mode C 0 C 40 C 80 10 C 50 C 90 C 20 C 60 100 C 30 70 Measure Save Gamma Image Reset Form Save Grayscale Image 0 10 20 30 40 50 60 70 80 90 100 Average x 0 428 0 142 0 277 0 297 0 302 0 307 0 309 0 309 0 311 0 312 0 313 y 0 347 0 169 0 322 0 331 0 332 0 337 0 337 0 339 0 34 0 338 0 34 Y 0 418 0 057 1 762 4 38 7 806 12 592 18 13 25 739 33 73 42 667 53 333 CIES4 22 1 10 3 6 8 5 4 5 4 4 9 5 7 5 6 4 8 5 2 6 CCT 2620 0 8899 7362 7048 6725 6657 6628 6511 6463 6416 6968 Gamma 2 97 2
36. al ibrating to the 75 Rec 709 reference gamut 49 USING ADVANCED COLOR MANAGEMENT Overview The standard color management module allows the user to adjust the primary and secondary col ors of the display to match as closely as possible the selected gamut Unfortunately the color per formance of consumer displays is not always entirely linear To see what this means think of the gamut not just in terms of six colors and a white point but also think of the same six colors falling distributed throughout the gamut at different levels of saturation and amplitude Saturation is just the distance from the white point The selected gamut defines where a fully sat urated color should fall relative on the outside edge of the selected gamut However we can also think of the same color closer to the white point and thus less saturated A perfectly linear display assuming the HD gamut would produce a fully saturated red at x0 640 y0 330 It would also produce a 50 saturated red half way towards the white point at x0 476 y0 330 Unfortunately displays are not always perfectly linear A fully calibrated red at 100 saturation may measure perfectly while a 50 saturation red can show substantial errors These errors if large enough are easily visible Nonetheless they remain completely unmeasured by the standard CIE chart The Advanced Color Management module measures these errors This tool is for diagnostic purposes only There is no
37. ance of the reference spectroradiometer The result is the best of both worlds You can now cal ibrate displays with a device that is fast easy to use color accurate and good at low light levels You can also use the Meter Correction feature with front projectors when you wish to measure directly from the projector lens Use measurements taken off the screen to correct the readings taken directly from the lens To create and use a meter correction 1 Select and Initialize the reference meter TIP You may use the Meter Correction feature even if ChromaPure does not support the reference device In this case simply measure RGBW with the refer ence meter record the results and then manually type the xy values into the appropriate reference fields in the Meter Correction module Then proceed with Step 4 below 2 Click the Meter Correction button The Meter Correction module will appear Meter Correction Start Page Help a Measurement Mode White Red Reference Meter NAY Kr Kr Kr C Field Meter Measurement Mode Ce White C Red O wes Field x fo fo fo fo C Blue Field y fo fo fo fo SESCH 3 Select the Reference Meter radio button and then take a series of WRGB measure ments 4 Open the Select Initialize Meter module and then disconnect the reference meter TIP If you are using an ilPro Display 2 combination be sure to physi cally unplug the bro before initializing the Display 2
38. ata either as a curve chart as shown above or as a line chart You select this in the Options Grayscale window Taking Grayscale Measurements in 5 Increments Overview You may wish to take grayscale measurements with more granularity than what is provided by 10 increments To meet this need we offer the option to take grayscale measurements in 5 increments For more information about setting this option refer to Grayscale p 29 The process works exactly as described above except that the charts appear on separate tabs 38 TAKING PRE CALIBRATION COLOR GAMUT MEA SUREMENTS Overview The Pre Calibration Color Gamut module allows you to measure the ability of the display to track accurate primary and secondary colors relative to the target gamut The initial gamut reading pro vides a snapshot of the display s pre calibration performance for the hue saturation and lumi nance of the primary and secondary colors You should take a pre calibration gamut reading for every calibration session This data is crucial if you wish to generate a before after report To take a pre calibration color gamut measurement 1 Click the Pre Calibration Color Gamut button on the navigation bar The Pre Calibration Color Gamut module will appear Pre Calibration Color Gamut Ha Page Help Measurement Mode j White Hi Red Green E Blue io Bes geg C Yel oso oss waa om1 040 oz 0x GEN O cm y 0314 0
39. attern from a external disc If you are using a test pattern gener ator or ChromaPure s own internal test patterns click the Please select a pattern drop down box in the upper right hand corner from which to select a full white test pattern A luminance value will appear in either ft L or cd m2 This is your display s white level or peak out put and a number will appear below This is your display s sequential contrast To measure simultaneous contrast 1 Display a checkerboard test pattern using the drop down list for test pattern generators or from an external disc Place your sensor on one of the black squares Click a black square A luminance value will appear in either ft L or cd m2 Place your sensor on one of the white squares Click a white square 59 A luminance value will appear and a number will appear below This is the display s simultaneous contrast NOTE You can repeat this for as many or as few of the squares as you wish to mea sure so long as you have measured at least one black and one white square Any additional measurements will be averaged 60 USING AUTO CALIBRATE Overview ChromaPure offers an auto calibration tool as an optional add on to the main program Chroma Pure Standard users may purchase this add on For ChromaPure Professional users Auto Calibrate is provided free of charge This tool only works in conjunction with either the DVDO Duo or Luma gen Radiance family
40. can communicate with it The procedures vary somewhat depending upon whether you use Windows XP or Windows 7 The instructions below cover both Installing a Driver in Windows XP 1 Plug the meter into an available USB port A Found New Hardware Wizard window will appear 18 Found New Hardware Wizard Welcome to the Found New Hardware Wizard Windows will search for current and updated softwere by looking on your computer on the hardware installation CD or on the Windows Update Web site with your permission Read our privacy policy Can Windows connect to Windows Update to search for software Yes this time only C Yes now and every time connect a device Ge No not tiis time Click Next to continue c Back Cancel 2 Select No not at this time and then click Next A second Found New Hardware Wizard window will appear 19 Found New Hardware Wizard This wizard helgs you install software for Chroma Calibrator If your hardware came with an installation CD lt 6 or floppy disk insert it now What do you want the wizard to do C Install the software automatically Recommended Install from a list or specific location Advanced Click Next to continue lt Back Cancel 3 Select Install from a list or specific location Advanced and then click Next Another Found New Hardware Wizard window will appear 20 Found New Hardware Wizard 4 Please ch
41. ce you setup in the previous step 62 6 Click the Test Device button If your calibration device has been successfully setup and selected then a red test pattern will appear 7 Manually adjust the brightness contrast and sharpness of your display Clicking the rele vant buttons will bring up the appropriate test patterns Since these image parameters must be set by eye they cannot be included in the automated session 8 Manually calibrate white balance at 100 video using the display s controls 9 Click Next The second ChromaPure Auto Calibration window will appear Select desired calibration functions m General Settings C Use current settings Reset calibration settings to the default Reset the Lumagen to factory default Reference Gamut ec 709 e Gamma Method R 22 v T Use manual white black readings for BT 1886 Whitey C0 cd m2 Blacky 2 0 cd m2 E Grayscale Gamma E AA a M Color Gamut T Advanced Color Gamut p Advanced Color Gamut Settings Passes T Measure post calibration 125 729 colors IV Generate Calibration Report Start Auto Calibration Cancel Auto Calibration 10 Select the desired calibration functions You can choose between Grayscale Gamma Color Gamut and Advanced Color Management available as a separate add on If you select Color Gamut or Advanced Color Gamut then you must also choose the reference gamut from the Referenc
42. cified name will save in the specified location It will have a csv extension You can open this file format in Excel for data analysis The file includes raw xyY data from the Pre Post Grayscale and Color Gamut modules All calibration information can be derived from these values To import a session file 1 Click Load from the main navigation tool bar An Import window will appear LM Ais Look in o CalibrationD ata D e b4 Ce P Favoites Desklup Gi My Documents bal AA Produztion a Home 1eater mern TOO zl Files of type XML Session File 7 Cancel 2 Navigate to the location where the desired ChromaPure calx session file was saved 3 Select the file and then click Open ChromaPure will import all of the pre and post calibration data from that saved session TIP You can also import a calibration session by simply double clicking a calx file Chro Yy maPure will open and automatically load the information contained in that session Also get in the habit of saving all of your calibration data in a single place Use some naming con vention such as date of calibration name of client or both that will allow you to easily call up specific data from past calibration sessions 74 Calculating Lumens for a Front Projector Overview The Lumens Calculator module should be used for front projectors to calculate the peak output of the projector by an illuminance or a luminance reading Y
43. click Measure ChromaPure will measure changes to the to the luminance of red in real time 6 Adjust the color decoding control or the main color control to achieve the smallest per centage error as possible 7 Click Stop 54 8 Repeat 4 7 for the other two primary colors 9 Display a magenta test pattern 10 Click the Magenta radio button 11 Click the Continuous check box 12 Click Measure ChromaPure will measure changes to the red hue in real time 13 Adjust the color decoding control or the main hue control to achieve the smallest percent age error as possible Repeat 9 13 for the remaining secondary colors What s the difference between Color Decoding and Color Management Both modules measure the luminance of the primary colors and the hue of the secondary colors However there are three important differences between them e By default the Color Management and Advanced Color Management modules use a fixed set of references However the references for the Color Decoding module are calcu lated from the measured values of the primary colors a standard white point is assumed e The Color Management module uses lightness to display the percentage color lumi nance error whereas the Color Decoding module uses relative luminance to display the percentage color luminance error For more information on the difference between lumi nance and lightness refer to Lightness and Luminance p 86 e Depending on the selected co
44. comprehensive analysis of the ColorChecker data then click Report This will automatically generate an Excel based report This report requires both pre and post cal ibration data 80 YaLdVHD Video Calibration Concepts What s Inside Color Wheel p 82 Dark Reading Requirements p 83 Reference Gamuts p 84 Understanding Delta E p 85 Lightness and Luminance p 86 81 COLOR WHEEL The primary and secondary colors shown in 360 degrees on the color wheel 120 60 240 300 Placement on the color wheel defines the hue of a color Hue is the primary characteristic by which we distinguish one color from another 82 DARK READING REQUIREMENTS The sensors in all color analyzers have their own level of noise The ratio between the inherent noise of the sensor and the level of the signal being measured is the signal to noise ratio This number should be as high as possible The way the color analyzers attempt to minimize the effect of inherent noise is to take a dark reading Since there is no external signal being measured any data will be from the noise floor of the instrument itself Once measured this can be subtracted from all subsequent readings All color analyzers use this technique However some simply build a sample of the noise floor into the unit s firmware so it doesn t have to be measured The Display 3 does not require a dark reading The Chroma 5 does not require a dark reading
45. device Test Device If you see a red test pattern on your display device then the calibration device has been properly setup If not then troubleshoot the connection to the device Repeat steps 2 4 until you see a red test pattern Select the optimal picture preset on your display device There is no standard terminology for this but itis often named Movie or Cinema mode Properly adjust the display device s black level brightness Show Test Pattern Get Help Properly adjust the display device s white level contrast Show Test Pattern Get Help Properly adjust the display device s sharpness Show Test Pattern Get Help Pre Calibrate White Balance at 100 This will provide the best post calibration results Open White Balance Get Help Next 3 Select and initialize the meter you wish to use TIP If you wish to use meter correction ensure that you do this now before the auto calibrate session begins For more information about meter correction refer to Creating A Meter Correction p 35 4 Ifyou have not already done so setup the desired Calibration Device Auto Calibrate cur rently supports either the DVDO Duo or the Lumagen family of processors TIP ChromaPure saves information about selected signal generators between cali bration sessions Thus if in your previous session you setup the desired device this should not have to be done again 5 Select the calibration device This should be the same devi
46. display offer to the calibrator to obtain a good image This varies wildly among displays Some are better candidates for calibration than others sim ply because they offer a wealth of calibration controls At a minimum a display should offer custom white balance controls in addition to the standard Contrast Brightness Color Tint and Sharpness adjustments found on all displays The best candidates also offer adjustments for gamma color decoding and or color management What is the quality of the calibration equipment hardware and software Even those dis plays that are the best candidates for calibration will see little improvement if the calibra tor uses sub standard equipment Finally there is a purely subjective element to this How sensitive are you to changes in color and luminance The best candidates for calibration are those who have a good eye for accurate reproduction If you are not sensitive to this then may not notice much of a difference regardless of the changes made WHAT Do I NEED In addition to ChromaPure software and a PC or laptop you will need A color analyzer to read the light and color that your display produces Some way to get test patterns into your display The most common method is with a cali bration DVD or Blu ray disc There are many options to choose from including a disc that ChromaPure offers If you have an HDMI output on your PC then you can also use test patterns built in to ChromaPure Fina
47. e Gamut drop down 11 You must also select a gamma target You can select a fixed power law gamma value from 2 2 2 6 or select BT 1886 gamma See instructions below for using BT 1886 gamma We recommend that you select either 2 22 or BT 1886 12 If you select Advanced Color Gamut you must also select the size of the color matrix to be used The Advanced Color Gamut is only available from Lumagen processors and the 63 sizes available are 125 729 or 4913 colors A larger color matrix will yield better results but will take much longer to complete 125 colors is adequate for the great majority of applications 13 Select whether you wish the application to generate a calibration report when auto cali brate has completed 14 If you wish to see a calibration report you should probably also select Measure post calibration125 729 colors Leaving this unchecked will speed up the process somewhat but will leave you without any post calibration colors to display in the report 15 Click Start Auto Calibration The process will begin and display activity in the window You can cancel the session at any time When it has completed it will generate a calibration report if you selected that option and turn off the test patterns so normal viewing can continue BT 1886 Gamma This option allows you to calibrate to a dynamic gamma target that varies depending on the level of stimulus and the white and black levels of your display Ge
48. e generates the needed test patterns automatically The user doesn t have to worry about selecting the correct pattern before taking a reading because the software does that for you ChromaPure supports sev eral of these devices Once you have the items in this list you are ready to calibrate your display Basic Principles Display performance is measured in several ways e White and black levels The most basic aspect of video calibration is getting the correct white and black levels White level the intensity of light the display produces when the video signal is at 100 strength is adjusted by the contrast control Black level the intensity of light the display produces when the video signal is a 0 strength is adjusted by the brightness control For more information on setting white and black levels refer to Setting White and Black Level p 42 e Sharpness This adjustment is a holdover from the days of analog video and generally should be turned down considerably or simply left at its default setting On many modern digital displays the sharpness control has very little effect on the image e White Balance This is the aspect of color performance that gets the most attention It concerns the display s ability to provide a neutral shade of white The shade of white all the way from darkest gray to the brightest white is called the grayscale If the display can t reproduce a neutral white then it will add an unnatural color cast
49. easingly more intense signals As a signal gets more intense if the display rises out of black very fast then it has a low gamma If it rises out of black slowly then it has a low gamma The optimal gamma is expressed numerically Aim for a gamma in the 2 2 2 35 range For more information on adjusting gamma in ChromaPure refer to Setting Gamma p 56 It is important to understand two things about these aspects of display performance These are independent aspects of image quality You can have good gray scale tracking and poor color decoding You can have good color decoding and a very inaccurate color gamut The bottom line is that each needs to be adjusted separately Adjusting them is a reiterative process Although these aspects of image performance are independent adjusting them often has interactive effects This means that after you finish adjusting one area of performance it is a good idea to go back and look at areas you have already worked on to see how adjustments in one area may have affected other areas or performance generating a calibration report is a useful tool for checking this For more information on generating a calibration report refer to Running a Calibration Report p 69 Essential Terminology xyY This is a common method for precisely measuring color performance x and y are coordinates on the triangular CIE chromaticity chart mentioned above that plot out how colors measure relative to their reference points Y is
50. eeen 68 Running a Calibration EE 69 Interpreting the Calibration Report 69 QUICK REPOS AA AA 71 Calibration Re 72 Sharing Data E 72 Importing and Exporting Calibration Data 72 Calculating Lumens for a Front Proiechor naaawa aaa waaaanaaannnnnns 75 Raw Dala Modus aaa a NAA BANA AALALA 77 Data Conversion Tool AN NAA LANGAN Ae eee nent 77 Using the ele 78 Video Calibration Concepts cccccceeseeeeeeeeeseeeeeeeeseeeeseeeeseeneeees 81 Color Auer eege 82 Dark Reading Requirements nanasa 83 Reference Gamuts haaa AN ANA ANAN ANA eee 84 Understanding Deltas Bre mm Cont aaa aran a esi cesaemieo tees 85 Lightness and LUMINANCE gege ege EEN 86 YaLdVHD Introduction The Basics What s Inside What To Expect From Calibration p 4 What Do I Need p 5 Calibration Procedures p 6 Use ChromaPure software to calibrate your plasma LCD flat panel or projector to industry stan dards For technical support for issues not covered in this document contact support chromapure com WHAT TO EXPECT FROM CALIBRATION Calibration can make either a very large or very small difference to the quality of the image on your display Which result you get depends on several variables How far from industry standards is your display out of the box If it is properly setup at the factory it almost never is then calibration will make little difference Otherwise it can make a profound difference How much control does the
51. good color perfor mance and reasonable light output for a given display device What s a reasonable level e CRT tubes plasmas digital rear projection and LCD flat panels 120 cd m2 35 ft L e Digital front projection 48 cd m2 14 ft L These values comes from the SMPTE standard which is always useful in such matters Setting Black Level Brightness You should set black level by eye using test patterns The purpose of these test patterns are the same You want to set the black level of the display as low as you can without losing the ability to see video information that is just above black intensity If you set black level too low then you will lose shadow detail this is sometimes referred to as crushed blacks If you set black level too high then you lower the display s contrast and realism in dark scenes The typical method for setting black level is to use a test pattern that displays a 2 below black stripe and a 2 above black stripe against a black background You set brightness so that the 2 above black is barely visible and the 2 below black is invisible However more recent disc based test patterns allow for finer adjustments than a standard 2 pluge pattern and should be used to set brightness There is one problem with the method just described How do we set black level for broadcast sources where no test pattern is available Fortunately there is one approach that will get a cor rect black level even without
52. here are two types of contrast Sequential Contrast Otherwise known as on off contrast this indicates the difference between the black level of the display and its peak output when each is measured one after the other Use a 0 and then a 100 white test pattern for this Simultaneous Contrast This indicates the difference between 100 black and 100 white when both are displayed at the same time Use a checkerboard test pattern for this Because the white squares will affect the black squares on a checkerboard pattern simultaneous contrast is always considerably lower than sequential contrast To measure sequential contrast 1 1 You may want to take contrast readings both before and after the calibration When tak ing a post calibration reading ensure that you have already properly set the display s black level and white level For more information about this refer to Setting White and Black Level p 42 Click Contrast on the main navigation bar The Contrast module will appear Display a full black test pattern from a external disc If you are using an external test pat tern generator or ChromaPure s own internal test patterns click the Please select a pat tern drop down box in the upper right hand corner from which to select a full black test pattern Click inside the large black square on the left A luminance value will appear in either ft L or cd m2 This is your display s black level Display a full white test p
53. ified by the target gamut Remember these Y values are relative luminance so they are just percentages of refer ence white You ll have to measure the luminance of white first and then check the lumi nance of the colors to see how close they are to the specified value in the gamut For more information about various reference gamuts refer to Reference Gamuts p 85 NOTE The human eye is not equally sensitive to all colors and all color differences For example it is more important to get red and green right than blue It is also more important to get correct hues than correct saturation Adjusting Gamma You want to ensure that your display has a gamma response that is both within the accepted range and that it is reasonably linear I suggest 2 22 as a good gamma value to aim for but you can experiment with somewhat higher gammas if you like Above 2 35 you will likely find that the image loses shadow detail and begins to appear somewhat contrasty 1 Display a 100 white test pattern and record the Y brightness value 13 2 Display a 90 white test pattern and record the Y brightness value Repeat until you have recorded the intensity of white all the way down to 10 4 ChromaPure will plot the gamma values at each of these levels Use your display s controls to make necessary adjustments to achieve a gamma value as close to 2 22 as possible at every point throughout the grayscale That s it Now you should go back
54. in tool bar The Color Management module will appear Select the desired color space Select the desired Reference Gamut Take an initial measurement of white red green blue yellow cyan and magenta to obtain a baseline reading The following data will appear e Percentage error in each of the three poles of the selected color space for each color on the graph e The dE error for each color on the graph e The raw xyY data for each color below the measurement panel Luminance data is presented both in absolute luminance cd m2 and relative luminance Y For more information about absolute and relative luminance refer to Lightness and Luminance p 86 Display a test pattern for the target color Select the radio button for that same color Click the Continuous check box and then click Measure ChromaPure will measure changes in percentage errors in the selected color space in real time 8 9 Adjust your display s CMS controls to bring the percentage error of the selected color to as close to zero as possible It is useful to pay close attention to the dE value shown below the error bars to determine what mix of errors in the selected color space offers the most accurate color Click Stop 48 10 Repeat steps 4 7 for whatever color or colors require correcting NOTE You may want to use the Advanced Color Management module to determine if more accurate color through the color space can be obtained by c
55. inition in Europe and EBU for PAL based SD material in Europe DCI Digital Cinema Initiative is an expanded gamut for which consumer material is not currently available For more information about the standard gamuts refer to Reference Gamuts p 85 Grayscale Standard grayscale readings are taken in 10 increments However in the Options Calibration panel you can select 5 increments if you like If you select this option the charts in the Pre Post Calibration Grayscale modules will appear on separate tabs in order to accommodate 20 mea surement points You can also select between a gamma curve graph levels of stimulus and percentage output or a gamma line graph levels of stimulus and gamma response 28 Luminance The two options provided are cd m2 candelas per meter squared or ft L footlamberts Either provides a standard of measurement for the absolute luminance of the signal Cd m2 sometimes called nits is a metric unit and ft L is an Imperial unit 1 cd m2 equals 0 2919 ft L and 1 ft L equals 3 426 cd m2 The choice here is a merely a matter of preference It does not affect the substantive results but only how they are displayed dE Method Delta E dE is a measurement of color error relative to a standard Thus the goal in calibration is to get the dE of the measured color as low as possible There are different dE formulas that pro vide somewhat different results ChromaPure offers four options e CIEL
56. is indicates both that the gamma response is consis tent at all levels of stimulus and that the gamma function is neither too high or too low A gamma function that is too high will offer great image depth and deep blacks but you will lose shadow detail and the image may appear contrasty A gamma function that is too low will provide great shadow detail but contrast will suffer and the image may lack depth To measure and adjust gamma 1 Click the Gamma button on the main navigation tool bar The Gamma module will appear 56 Gamma Start Page Help Measurement Mode EN C 100 65 C 30 Target Gamma 2 22 5 e SCH CCT 6205 C aah C em C Z557 Y 0 199 AE 11 6 C one C seeb C 20 eee Sam P C 85 C 50 C 15 ey kan o f 95 103 06 2 25 L03 24 C 80 enk 10 30 92 25 2 15 91 57 Tak C 0 GC 5 85 82 42 2 16 80 65 C 70 352617 IT Continuous 80 72 29 2 17 70 50 75 62 43 2 14 61 09 65 45 96 2 14 44 46 RFO 60 38 60 2 15 37 22 55 32 00 2 15 30 68 Help 50 26 71 2 11 24 83 45 22 17 2 13 19 65 OOO Swem 40 16 56 2 12 15 13 35 12 65 2 11 11 25 132 0 88 4 120 6 30 976 2 10 7 99 25 6 42 2 09 5 33 2095 361 2 15 3 25 15 1 90 2 17 L71 1096 0 75 2 19 0 70 5 0 20 2 13 0 15 sa 0 0 q 00 0 0 0 0 0 9 0 0o 2 Display a 100 white stimulus pattern 3 Click Measure ChromaPure will take a measurement and then automatically advance to the next level 4 Displa
57. ite balance at the high end again and vice versa This is necessary because changes in one are likely to effect the response in the other The goal is to get a good white bal ance at both ends of the grayscale at the same time There is no standard industry wide terminology for white balance controls You may see RGB Contrast Brightness RGB Gain Bias RGB Gain Offset RGB Drives Cuts They all mean the same thing Bright end of the grayscale e Contrast e Gains e Drives Dark end of the grayscale e Brightness e Biases e Offsets e Cuts The display s white balance controls may be easily accessible in the user menu or they may be hidden in a special service menu accessible only through a unique key combination on the remote 45 SETTING THE MAIN COLOR CONTROL Overview The main Color control affects the luminance of all of the colors and to a lesser degree their satu ration Use the Color control to adjust the primary colors luminance to their correct position TIP Use the main Color and Tint control only if your display has no color management system If it does then usually adjusting the Color control is unnecessary However even if your display does have a CMS you may find it useful to adjust the main Color control to provide extra adjustment room for the color luminance parameter To adjust Color 1 Click the Color Decoding button on the main toolbar The Color Decoding module will appear
58. ity Performance This section shows the dE performance of the primary sec ondary colors relative to the target gamut You should aim for a post calibration result in which the primary secondary colors have a dE of no more than 1 5 CIE94 and CIE2000 4 0 CIELAB or 5 0 CIELUV Unless your display includes an effective color manage ment system you will unlikely be able to achieve results this good Lightness Saturation and Hue Error This section shows the same information as above but breaks out the contributions to the before after color errors in terms of per centage errors in lightness saturation and hue You should aim for no more than 2 error in any component Unless your display includes an effective color management sys tem you will unlikely be able to achieve results this good CIE Chart This section shows a subset of the same information as above plotted on a familiar CIE chart These charts plot saturation and hue errors only The report includes the 1931 xy version which is less perceptually uniform than the 1976 u v chart but more familiar to most users Gamma This section plots luminance performance of the display This includes gamma which is the display s ability to properly increase signal output as signal input increases The relationship between them is summarized mathematically and referred to a gamma You should aim for a gamma value that is a flat as possible in the range of 2 2 2 35 This section also show
59. lly you can use an external test signal generator ChromaPure supports several If you have a front projector I would recommend an illuminance meter and a camera tri pod to mount your meter on The AEMC CA813 is a good reasonably priced illuminance meter CALIBRATION PROCEDURES Essential Equipment e Color analyzer This is a USB device that you point at the display so it can read the color and light output of the display and then connect to a laptop computer The best color ana lyzer for most people is the X Rite i1 Display Pro ChromaPure supports both the retail ver sion and a special calibrated version that offers enhanced accuracy called the Display 3 PRO e Calibration Software You need ChromaPure to interpret the data that the meter pro vides analyze the data and plot the results on easy to read charts graphs e Video Test Patterns Finally you ll need some way to get a test pattern on the screen on your display The easiest way to do this is with a DVD or Blu ray If you prefer something more automated you can also use the built in test patterns generated by the PC s video card For more information about this option refer to Using automation with a video test_pattern generator p 32 You can also use an external test pattern generator such as the DVDO Duo or AccuPel For more information about this option refer to Using automation with a video test pattern generator p 32 This is an appealing option because ChromaPur
60. lor space the Color Management module gives the calibrator three axes of adjustment e Hue Saturation and Lightness HSL e Red Green and Blue RGB e x y and Y xyY for each of the six primary and secondary colors Color decoding offers only one axis of adjustment for the primary colors luminance and one axis of adjustment for the secondary colors hue These adjustments are the only ones offered because these are where the overwhelming majority of color decoding errors occur 55 SETTING GAMMA Overview All displays have gamma which is a number that reflects the relationship between the intensity of signal input relative to the intensity of measurable output This relationship between input and output is not linear There are two reasons for this e CRTs the devices traditionally used for image reproduction and video production have a voltage input to signal output relationship that is itself non linear e Second and quite coincidentally human perception is nonlinear as well in approximately the inverse of CRTs Thus all display devices must exhibit gamma to accommodate both of these phenomenon Gamma can be displayed as a non linear curve on a graph plotting input and output or as a more or less horizontal line on a graph indicating the gamma function at each level of stimulus By default ChromaPure documents gamma in the latter way Ideally you would want a perfectly flat line somewhere in the 2 2 2 35 range Th
61. mation about the White Balance tool refer to Setting White Balance p 44 Raise the contrast as high as you can within the recommended limit without the just below white bar disappearing and without the color of white becoming distorted Use the Raw Data Module to check the peak white output Light Output Targets for Various Display Types e CRT Plasma LCD Flat Panel Rear Projector 35 ft L 120 cd m2 e Digital front projector 14 ft L 48 cd m2 Just set the contrast as high as you can within the recommended limit so long as the other two cri teria are also both met Your display may not be able to achieve the minimum recommended light output This is fine Just get as close as you can However going much over the recommended value is not recommended Higher peak output will only cause eye strain excessive image noise and lessened operating life of the display 42 Black and White Pluge ChromaPure s built in test patterns includes a Black Pluge and a White Pluge test pattern for set ting black level brightness and white level contrast You can access the patterns from the Sig nal Generator drop down View Toolbars Signal Generators You can also use the pluge patterns in the AccuPel test pattern generator A Black Pluge test pattern contains two vertical stripes a just above video black 21 on the right and a just below video black 11 on the left against a video black 16 background 1 Adjust the Brightness control o
62. n Select Color Format Select Pattern Type Select Resolution Select Signal Intensity Cancel Dk 4 Click the radio button next to the desired generator and then click the port setup button A Serial Port Configuration window will appear Serial Port Configuration i Meter l Serial Port Number coma e Baud Rate 3600 e Parity None be Data Bits fe v Stop Bits One e Cancel 5 Select the correct serial port parameters You can check the Windows Device Manager to ensure that you have the correct settings for the device 33 6 Click Apply The Serial Port Configuration window will close and you will return to the Signal Generator win dow 7 Select all of the desired display options such as e Color Format e Resolution e Signal Intensity e Pattern Type 8 Check Enable Auto Advance if you want the readings to advance automatically through the Pre Post Grayscale and the Pre Post Color Gamut modules you can select the desired interval 9 Click OK You are now ready to begin calibrating your display TIP In addition to automatically providing the desired patterns during a calibration Y session external signal generators all provide a large number of test patterns that can be called up by activating the Test Pattern Toolbar Just click View Toolbars Signal Generators Auto Recovery To ensure data integrity ChromaPure includes an auto recovery feature This featu
63. n the display to its minimum 2 Display the Black Pluge test pattern 3 Slowly raise the brightness setting until you just clearly see the stripe on the right If you also see the stripe on the left then you have raised it too far A White Pluge test pattern contains two vertical stripes a just above video white 240 on the right and a just below video white 230 on the left against a video white 235 background 1 Adjust the display s contrast control until you achieve the recommended output for the display 2 Display the White Pluge test pattern 3 Ensure that you can see the stripe on the left Seeing the stripe on the right is desirable but not essential 4 If you cannot see the stripe on the left then lower the contrast control until you can even if this means less light output than the recommended level Y TIP The brightness and contrast settings are usually interactive so you should go back and forth between them to ensure that both parameters are correctly set 43 SETTING WHITE BALANCE Overview Setting the white balance is arguably the most important step in calibration Getting the color of white correct affects all viewing material even black and white content The correct white balance is achieved when white contains equal amounts of red green and blue of the target gamut As it turns out all of the gamuts commonly used SMPTE C Rec 709 and EBU use the same white point x0 3127 y0 329 To
64. nerally this will result in power law values in the 2 3 2 4 range at the top end of the grayscale which will gradually slope downwards until 10 stimulus is in the 2 1 2 2 range In order for BT 1886 to function correctly the system must be provided with information about the white and black level of the display If you are confident that you meter can measure these levels accurately then just select BT 1886 as the gamma option and it will read these automatically dur ing the calibration process However if you have a display with a very low black level that you can not measure through regular means and or you are measuring a front projector directly from the lens you should click the Override check boxes and supply the correct white and black values in cd m2 in the Options Calibration BT 1886 panel The system will then use these values rather than attempting to measure them For example if you have Pioneer Kuro or a local dimming LCD whose black level is too low to reli ably measure then I would type 0 003 in the black level box If you have a JVC projector whose black level you cannot read then simply measure the contrast ratio by pointing the probe at the lens using a diffuser Once you have the ratio between black and white just take a reading from the screen for 100 white then you can calculate the black level from this 64 USING THE VIDEO PROCESSOR CONTROL PANEL Overview The DVDO Duo and Lumagen Radiance video processo
65. nsity 4 Click Measure Continue to measure RGBYCM just as in the standard color management module Each measurement returns values in xyY absolute luminance in cd m2 and dE 5 Select Primary Saturations from the Measurement Mode drop down box 6 Measure red green and blue each at 25 50 and 75 saturation 7 Select Secondary Saturations from the Measurement Mode drop down box 52 8 Measure yellow cyan and magenta each at 25 50 and 75 saturation 9 You may also take similar measurements of amplitude in 25 increments 10 When finished you can share the results in several ways View and save a CIE Chromaticity chart View and save a Saturations dE chart View and save a Saturations Luminance chart Export raw xyY and dE data in csv format Generate an Advanced Color Management Report that can be saved in pdf format What do I look for The goal of these measurements is diagnostic What you want to see is that the measured satura tion level for each color is a close to the targets on the CIE chart and luminance chart as possible and the dEs for the colors are as low as possible across the entire range Ideally the colors will be as accurate inside the color space as they are at its outside boundary Also ideally the amplitude measurements will show very little deviation on the CIE chart and relatively constant dEs The Advanced Color Management module will also help you to determine if perhaps you should calibrate
66. nt controls that operate on red magenta and green yellow indepen dently Then you can use the main Color Tint controls to adjust blue cyan For more infor mation on resolving color decoding errors refer to Adjusting Color Decoding p 54 Color Gamut This is the range of colors that the display is capable of rendering The gamut is most often represented as a triangular pattern plotted on a standard tongue shaped chart as shown below Chromaticity 0 1 02 NT 4 E G6 NA as CIE Chromaticity Chart The gamut is defined by the xy coordinates of the primary colors red green and blue and the white point The secondary colors cyan magenta and yellow are derived from them These color points have specific definitions for both standard and high definition signals All commercially available video material is mastered according to these stan dards If the display cannot reproduce the gamut accurately then the image will visibly suffer Digital displays used to offer especially poor performance in this regard but recently they seem to have gotten better The only way to fix errors in the gamut is with a Color Management System CMS A CMS can make a profound difference to the perfor mance of the display but few offer one and of those that do not all work properly For more information on using a CMS with ChromaPure refer to Using Color Management p 51 Gamma This performance parameter describes how the display responds to incr
67. ode has its own averaging built in so Measurement Smoothing is not needed here e This feature is also accessible directly from the White Balance module If you enable Measurement Smoothing from the Options module the effects are global so you will not need to enable it from the White Balance module as well But if you do leave it engaged in the White Balance module the effects will be global as well Signal Generator If you have test patterns on a Blu ray disc you can provide test patterns manually However you may want to automate your calibration sessions You can do this by using a signal generator Chro maPure Standard currently supports the following devices as signal generators e PC s video card e DVDO iScan Duo e Lumagen Radiance A signal generator will provide both standard color and grayscale test patterns and specialized test patterns requiring visual inspection such as a pluge crosshatch and multiburst To enable access to the special test patterns click View Toolbars Signal Generators A drop down list will appear at the top of the screen from which specialized test patterns can be accessed You will also now have access to the Video Processor Control Panel For more information about the Video Pro cessor Control Panel refer to Using the Video Processor Control Panel p 65 Using automation with the PC s video card The easiest way to use automation is to take advantage of ChromaPure s Built in signal generator
68. of external video processors It allows the user to set some basic options and then just click a button and the system will fully calibrate the display and even generate a compre hensive calibration report without any additional user input Calibrations take from 5 10 minutes to complete depending on the speed of the color analyzer you use If you are a Lumagen user you can also add an additional advanced auto calibrate feature This allows you to calibrate not just six colors along the gamut boundary but 124 colors all throughout the color space Using this feature takes an additional 15 20 minutes to complete and results in studio quality color performance Before running Auto Calibrate Getting good results from auto calibrate is largely dependent upon the starting point Follow these tips to get the best out of the auto calibrate session e If you are an international user close ChromaPure open the Windows Control Panel and change the Language Preference to U S English This is the preference for the PC not the keyboard e Ensure that Measurement Smoothing is set to 1 Off For more information refer to Mea surement Smoothing p 30 e Take a full set of Pre Calibration Grayscale and Pre Calibration Color Gamut measure ments Select whatever preset on your display that yields the best results for grayscale gamma and color The smaller the errors when you begin the better the results when you finish For more information refer
69. of the display in a way that has consequences for the color of natural objects in the real world To use the ColorChecker 1 From the main navigation bar click ColorChecker The ColorChecker module will open ColorChecker Raw Data Module Start Page Help Measure White White re Calibration Report Help Gamma 2 25 aoe BER 0 00 0 00 0 00 0 00 2 Select Pre Calibration or Post Calibration depending on where you are in the work flow 79 3 Click Measure White This displays a white test pattern and takes a measurement A reference white value is necessary for calculating the CIE94 value for each of the color patches TIP Clicking Measure White and any of the color patches displays a test pattern from the active signal generator and then takes a measure ment If you are using a Blu ray or DVD disc for test patterns then ensure that the appropriate test pattern is displayed before clicking the associated color patch If you are using the Built in test patterns then you must click twice for every measurement 4 Select the desired gamma This selection will have a small effect on the color of the test pattern displayed If you are using an external test pattern source then test patterns will generally require a 2 2 gamma 5 Click each of the color patches A test pattern will appear a measurement will be taken and the dE in CIE94 units will appear in the patch 6 If you wish to see an
70. olorimeter towards the screen display a white window and then take a xyY measurement Repeat the step above for all of the primary and secondary colors red green blue yel low cyan magenta Use the controls on your calibration software to plot the amount of error in hue satura tion and brightness each color shows relative to the chosen standard I would select the Rec 709 High Definition standard Your software should allow you to set that as the tar get gamut Use the CMS on the display to adjust the colors so that they show the lowest error in each of the 3 dimensions as possible dE is a good single numerical metric for judging the amount of color error The lower the dE value the better For more information about dE refer to dE Method p 30 You probably won t be able to get all of the colors lined up perfectly but get them as close as you can It is important to understand that some poorly designed CMSs are such that as you change the xy values to get correct hue saturation of a color and a good looking CIE chart the Y value luminance will change as well Since the CIE chart doesn t show lumi nance it is very important that you check this after making these changes Otherwise you could have made the color worse without knowing it If your software doesn t support direct read outs of color luminance then you ll have to do it manually The luminance of each color should be a close as possible to the Y value spec
71. oose your search and installation options Ng Waa FT Seach tor the best driver in these locations Use the check boxes below to limit or expand the default search which includes local paths and removable media The best diver found will be installed T Search removable media floppy CD ROM IW Include this location in the searck C Program Files4Display Calibrations LLE4ChromaPu sl Dor t search will choose the driver to nstall Choose this option to select the device driver from a list Windows does not guarantee that the driver you choose will be the best match for your hardware lt Back Next gt Cancel 4 Select Include this location in the search and then click the Browse button 5 Browse to the following location on your hard drive C Program Files Display Calibrations LLC ChromaPure Drivers lt select the correct folders TIP There are several sub folders under Drivers Select the one that contains the driver for your device For example if you are installing the X Rite i1Pro or Dis play 2 then select the i1Pro D2 sub folder If you are installing the X Rite Chroma 5 then select the Chromab sub folder 6 Click Next A final Found New Hardware Wizard window will appear 21 7 Found New Hardware Wizard Completing the Found New eS Hardware Wizard The wizard has finished installing the software for e Chroma Calibrator Click Finish to cose the wizard
72. ou can input several data formats into the calculator including e lux e lumens e foot lamberts e cd m2 In addition to providing the necessary data input you must also provide information about your screen Once all of the information has been supplied you may calculate the output of your pro jector in the same four data formats listed above To use the Lumens Calculator 1 Display a 100 white test pattern 2 Either turn on an illuminance meter such as the AEMC CA813 and place up against the screen facing the projector lens or position a standard color analyzer facing the center of the screen with a minimal degree of offset 3 Take a reading The illuminance meter will read in lux and the color analyzer will read in ft L or cd m2 4 Makea note of the value returned from the reading 5 Start the Lumens Calculator module 75 Lumens Calculator Start Page Help Measurenent Type D Measurenent Value Select Dimension D Enter Scrzen Size inches eet Sep TS Select Gain Calculate Screen Area feet 0 0 Screen Area meters 0 0 Diagonal 0 0 Height 0 0 Width 0 0 fl 0 0 cd m2 0 0 Lux 0 0 Lumens 0 0 te Type the value you recorded in the Measurement Value field Select the correct Measurement Type lumens lux ft L or cd m2 Type the screen size in inches o ONG Select the dimension in which the screen size is measured diagonal or width 10 Select the correct aspect ratio
73. re automatically saves a copy of your calibration session information on a regular basis every 2 minutes is the default Also if the program ever shuts down unexpectedly then upon restart you will be prompted to load the most recent session file Finally upon normal exit you will be prompted to save a session file Report Settings You can customize your report by inserting a logo image and information about the name of the calibration technician and the company at the top of the report To add a custom logo 1 Create your logo It should be a relatively small size It must fit in the report s header 2 Save the file as a Logo jpg it must be this name in the following folder c Program Files Display Calibrations LLC ChromaPure Reports Images To add custom text type the desired information about the name of the technician and the company 34 CREATING A METER CORRECTION Overview Meter correction is an optional feature that allows a calibrator to use a reference meter to correct the response of a faster but less accurate field device Many low cost colorimeters are easy to use and offer very good low light sensitivity but lack pre cise color accuracy especially for certain types of displays At the same time many spectroradiom eters offer reference color accuracy but can be slow and often have poor low light sensitivity The Meter Correction feature allows you to adjust the response of the colorimeter to match the perfor m
74. rors The targets for color measure ments when using the newer formulas are different because of the manner in which the newer formulas treat luminance in the calculation which is ignored for grayscale Luminance perfor mance with resect to grayscale tracking is part of the gamma response of the display and plays no role in dE calculations 29 BT 1886 Gamma BT 1886 is a recent attempt to try and standardize the gamma function Selecting and using this gamma requires the user to supply information about the display s white and black level in cd m2 Once you do this the gamma at each level of stimulus will appear These values will be used throughout the application whereever BT 1886 is selected as the desired gamma function including in auto calibrate Measurement Smoothing With some meters you will notice that in Continuous mode the results will bounce around consid erably making it difficult to determine with any precision the value of the reading The Measure ment Smoothing option addresses this problem Simply select a method either Average or Median and a number of measurements as few as 3 will significantly improve readings There are couple of issues to consider when using Measurement Smoothing e It will slow the application s ability to return data The higher the number of readings you select the longer the application will require to return xyY values e This feature only works for single readings The Continuous m
75. rosoft Net 4 0 framework if your PC does not already have this The Net 4 0 installation file may be downloaded from the ChromaPure web site 2 Once Net 4 0 is installed just double click the exe file Install ChromaPure Software To install ChromaPure just double click the setup exe file you were provided and follow the on screen instructions A ChromaPure icon will appear on your desktop Import the License File You will now need to install the license file that you were provided when you purchased the soft ware This file includes the serial number of the color analyzer you were licensed to use with Chro maPure To import a license file 1 To begin start ChromaPure by double clicking the desktop icon The first time ChromaPure runs you will be prompted for a license file 17 ChromaPure Licensing Ei Licenses Starting Version Ending Version m Licensed Meters Import License Close 2 Click Import License and then browse to the location where your license file has been saved 3 Select it and then click Open Your license file will be installed TIP If you ever need to install a new license you can access the Licensing Util Y ity from the Tools menu Install a Driver for the Color Analyzer Overview Before you can use your color analyzer whether it is a trichotomously colorimeter or a spectroradi ometer you will have to install a driver so that Microsoft Windows
76. rry about angle of acceptance or screen gain reading the light output directly from the lamp is generally easier than reading reflected light off the screen e Exotic screens Projection screens with a very high gain cannot be measured reliably off axis which makes reading from the screen difficult If you have such a screen it may be best to read directly from the lens Some additional points to consider e Use a diffuser Whenever you take readings directly from the projector lamp you must install a diffuser on the meter All of ChromaPure s supported meters are luminance devices and do not support reading directly from a projector lens without the use of a dif fuser e Consider an illuminance meter Alternatively you can use an illuminance meter such as the AEMC CA813 for contrast and gamma readings but not for readings that require color information Illuminance meters read in lux rather than in ft L or nits ChromaPure includes a lumens calculator for calculating ft L nits and lumens from lux measurements from such a device For more information on the lumens calculator refer to Calculating Lumens for a Front Projector p 75 e Use Color Correction Finally if you do take color readings directly from the lamp using a meter and diffuser you should also take readings with the same meter off the screen and use those to create a reference to color correct the direct from lamp readings For more information on creating an offset u
77. rs offer built in calibration controls Use ChromaPure s Video Processor Control Panel to use these controls without resorting to either pro cessor s remote control and on screen display To use the Video Processor Control Panel 1 Ensure that the Lumagen or Duo has been setup and configured Also ensure that the Sig nal Generator Toolbar is active For more information about the Signal Generator Toolbar refer to Signal Generator p 30 2 Click the small icon just to the left of the test pattern drop down Video Processor Control Panel access File View Tools Help Jb a Er nw Zar Bo Select a Test Pattern Pre Calibration Grayscale Auto Calibration Start Page Settings Measurement Mode SE o0 Ca C 80 The Video Processor Control Panel will appear Lumagen version shown Manual Control g 3 a xj Color R G B Y Radiance Select a Value ma Na Gamma 1 00 wel Increment 5 DEST we TC Save 3 Select a color or grayscale point to adjust 4 Select an increment size for the adjustment 5 Adjust R G B or Y up or down while measuring the desired color patch in continuous mode This panel also provides the following controls e Export Export the adjustments as a XML file e Import Subsequently import the adjustments previously exported to an XML file e Help Open the Help file e Reset Reset all of the adjustments to their defaults e Save Save the adjustments made to the
78. s AA AA 28 EH 28 FRELENENCE SSI eegene Ee 28 Grayscale siea ne te eee or ne a Ronee eee ee eee e ee AA 28 ue 29 dE Method ME 29 B1 1886 CANG ka 30 Measurement Smoothing 30 ll CI RED EE 30 Using automation with the PC s video Cardo eee ceteteeeeeeeeeeeeeeeeeeeeeeeeeeeeeenaaaeees 30 Using automation with a video test pattern oeneraior 32 EHNEN adeleg EE 34 R port due EE 34 Creating A Meter Correction ula aaa 35 Taking Pre calibration Grayscale Measurements ssssssssssssnnnnrnnnrrtrrrreereeeen 37 Taking Grayscale Measurements in 5 Increments snannaaannnneneneeeneeeeean 38 Taking Pre calibration Color Gamut Measurements 39 ChromaPure Calibration Procedures 1 0011111 nenne 41 Setting White and Black Level 42 Black leie hl PG EE 43 Setting White EE 44 Setting the Main Color Gontrol EE 46 Setting the Main Tint Hue Control aaa 47 Using Color Management sscl2 sn PAA enol bond aia ins 48 Using Advanced Color Management 50 Adjusting Color Decoding age 54 What s the difference between Color Decoding and Color Management 55 ele ul EE 56 Measuring COMmlaS GE 59 USING AULO C ee 61 BT 1886 GaMMa mpre ES ee Kg 64 Using the Video Processor Control Panel 65 ChromaPure Calibration Procedures aaa 66 Taking Post Calibration Measurements a aaannnanananaaanananasanaanssnasnnnnnnn nanan 67 Taking Post Calibration Color Gamut Measurements sssssessnnnnnnnnnereeereere
79. s the contrast and white level black level performance of the display For comfortable viewing you should aim for a white level of 30 40 ft L for flat panels and 12 16 ft L for front projection The black level should be as low as possible without losing shadow detail SMPTE recommends an on off contrast ratio of no lower than 2000 1 70 QUICK REPORTS Overview In addition to the standard reports you can run on your calibration session ChromaPure also includes Quick Reports within the application These are available in the Pre Post Calibration Gray scale and Pre Post Calibration Color Gamut modules They offer a simple and fast method for obtaining a quick snapshot of the pre and post calibration data To run a Quick Report 1 From within the Pre Post Calibration Grayscale or Color Gamut modules click the Quick Report button A Quick Report will be generated from the data in the module HE FrmQuickColorGamutReportViewer E Je oj gt Export As Imagaaed Export as Image Export as PDF or Word D aU 100 H peal laka ChromaPure Pre Calibration Color Gamut Quick Report Date 6 2 2011 Meter Unknown Gamut Rec709 dE Type CIE94 White Red Green Blue Yellow Cyan Magenta 0 300 0 713 0 291 0 143 0 431 0 200 0 305 0 329 0 287 0 683 0 053 0 550 0 300 0 130 1 000 0 177 0 704 0 067 0 906 0 779 0 254 cdim2 546 97 384 37 49 4 42 5 13 9 dE 7A 61 5 9 17 5 5 66 44 Primary Secondary Chromaticity 1931 Luminance 40 4 30 4 20
80. s we have seen each color can be expressed by xy coordinates on a chromaticity chart that establishes its saturation and hue The Y value defines its luminance The correct xy coordinates for all primary and secondary colors are defined by reference points on the triangular CIE chromaticity chart shown as described above on p 8 If the color deviates from the reference point by appearing shifted towards other colors on the chart then its hue is wrong and needs cor recting If a color is shifted closer to or father from the white point in the center of the chart rela tive to the reference then its saturation is wrong and needs correcting Finally if the color is too bright or too dim relative to the established standard not shown on the chart but determined mathematically then its luminance is wrong and needs correcting Calibration Order Adjustments should be made in the following order 1 Select the optimum Picture Mode in the display Set Black and White levels Set Sharpness Calibrate White Balance Adjust Color Tint color decoding a uh WN Calibrate the color gamut If your display has a CMS then Color and Tint adjustments are not necessary The display s CMS will take care of this 7 Gamma You will need to remeasure white balance Changes in gamma will effect the grayscale Remember changes in one area may have affected others Video calibration is a reiterative pro cess Calibration Steps List below are the main steps
81. set the white point 1 Click the White Balance module button on the main tool bar The White Balance tool will appear Measurement Mode x 0 320 C 10 C 50 C 90 C 20 C 60 C 100 y 0 341 CCT 6051 C am C 70 C 40 30 l Continuous Y 52 895 AE 5 0 Measurement Smoothing Number of Measurements A Method Mean 1 Median 101 2 100 7 89 7 2 If necessary enable Measurement Smoothing For more information about Measure ment Smoothing refer to Measurement Smoothing p 30 If you enable Measurement Smoothing in this module it will be active in all modules so remember to return it to 1 when you are finished calibrating the white point 3 Display a 80 gray test pattern 4 Click Measure The application will return information for 44 e dE e Raw xyY data e CCT e RGB balance This initial measurement provides a snapshot of the white balance at that level of stimulus 5 Click Continuous The application will show the data listed above as it changes in real time 6 Adjust your display s white balance controls to get the RGB balance as close to 100 for red green and blue as possible Between 98 and 102 or no more than 2 dE is a good goal 7 When finished click Stop Display a 20 gray test pattern 9 Repeat steps 4 7 as necessary TIP Setting white balance is a reiterative process Whenever you adjust the white balance at the low end of the grayscale you must then recheck the wh
82. sing ChromaPure refer to Creating a Meter Cor 14 rection p 35 Of course this assumes that you can take a good reading from the screen and you may not be able to if you have an exotic screen see above Meter Placement When reading from the screen place the meter 1 2 feet from the screen angled slightly to the right or left to avoid reading the meter s shadow When read ing from the lens place the meter close enough it can measure black but not so close that full white overloads the meter Test Patterns For all digital front projectors use full field test patterns For CRT projec tors only use window test patterns 15 ILAYHI ChromaPure Pre Calibration Procedures What s Inside Installing and Configuring ChromaPure for Initial Use p 17 Recording Display Settings p 27 Selecting Calibration Options p 28 Creating A Meter Correction p 35 Taking Pre calibration Grayscale Measurements p 37 Taking Pre calibration Color Gamut Measurements p 39 16 INSTALLING AND CONFIGURING CHROMAPURE FOR INITIAL USE Overview To get ChromaPure fully up and running you need to accomplish six tasks Install Net 4 0 Install ChromaPure Software Import the license file Install a driver for your color analyzer Select and Initialize your color analyzer Select the desired options Each of these steps is covered below Install Net 4 0 To install Chroma video calibration software 1 Install the Mic
83. splay s white balance controls until these three bars all measured as close to 100 as possible 118 3 95 8 87 5 Sometimes you may find that even though 80 and 20 stimulus are neutral white the mid range 40 60 stimulus is not This means that your display won t track a good grayscale and you have 11 to make some compromises The general rule of thumb is to focus on getting the mid range to track neutral white Then get the low end right Sacrifice accuracy at the top end if you have to NOTE There is no industry wide accepted terminology for white balance controls You may see RGB Contrast Brightness RGB Gain Bias RGB Gain Offset RGB Drives Cuts They all mean the same thing Contrast Gain or Drive is for adjusting the bright end of the grayscale and Brightness Bias Offset or Cut is for adjusting the dark end of the gray scale Setting Color Tint The standard method for adjusting color and tint involves looking at a SMPTE color bar test pat tern through a blue filter This method has 2 drawbacks First at best it is an approximation of the correct setting Second and more importantly for some displays it simply does NOT work On some plasmas in particular I have noticed that this method will recommend a grossly inaccurate setting Here s a foolproof method for setting Color Tint that does not use filters Color 1 Tint ue kh WN Point the colorimeter or light meter towards the screen and display a
84. t color shows from the reference color in lightness saturation and hue To use the Data Conversion tool 1 On the main navigation bar click Data Conversion The Data Conversion Utility will appear xy Color Difference x y Y S EH Reference HUN Hl Hl pooo O O Test Calculate Calculate CIELUY CIE94 CIELAB CIEDE2000 H 5 L 2 Type the xyY values of the color you wish to model 3 Click Calculate The corresponding equivalent values in the provided color spaces will appear You can obtain different R G B values by selecting a different reference gamma 4 To obtain color difference information type xyY values in the Reference and Test boxes and then click Calculate Delta E information will appear along with information about percentage difference in lightness saturation and hue Using the ColorChecker Overview The ColorChecker was introduced in a 1976 paper by McCamy et al The chart s color patches are designed to mimic natural objects such as human skin green foliage flowers and sky The pre cise colors in ChromaPure s ColorChecker came from measurements made in 1993 from a new 78 ColorChecker chart Also the chart uses illuminant D65 and the Cyan patch has been slightly mod ified to fit within the Rec 709 gamut The ColorChecker module is useful for testing how much your calibration efforts have improved the color performance
85. the Calibration Report The calibration report summarizes data gathered from the calibration session It includes several different sections each showing before and after performance 69 Grayscale Performance This section shows raw xy data dE and CCT for the gray scale It also graphs the before after dE performance You should aim for grayscale results in which dE is no larger than 4 0 CIELAB CIE94 or CIE2000 or 5 0 CIELUV You can select your preference for which dE color difference model you wish to use RGB Bar Chart This section shows the same grayscale data as above but breaks the results out by the contributions of red green and blue A perfectly neutral white for the selected gamut will have 100 values for all three primary colors Aim for no more than 4 RGB error Color Temperature This section again shows grayscale performance but this time using Correlated Color Temperature CCT as the standard A neutral shade of white is 6505k Lower than that is too red and higher than that is too blue CCT is a deprecated metric because the measurement is imprecise This is because CIE never endorsed a spe cific method for calculating CCT there are several and more importantly it ignores the contribution of green You can have two very different shades of white that share the same color temperature For this reason dE RGB balance or even the raw xy coordinates are all better measures of the color of white Chromatic
86. to Taking Pre calibration Grayscale Measurements p 37 and Taking Pre calibration Color Gamut Measurements p 39 able to raise color luminance by raising the main color control Also if the gamma response falls off dramatically at the high end that generally means that the contrast is set too high In such cases lower the contrast control on the dis play until the gamma response at 90 is at least 1 6 TIP In particular select a Picture preset that does NOT include either undersat Yy urated colors or colors whose luminance is too low If necessary you may be To use Auto Calibrate 1 Ensure that Auto Calibrate is enabled This requires a specific setting in the license file If your license does not support Auto Calibrate then the Auto Calibrate button will be grayed out 2 Click the Auto Calibrate button A Welcome to ChromaPure Auto Calibration window will appear 61 Welcome to ChromaPure Auto Calibration Before you can begin an auto calibrate session you need to complete several steps Select and initialize your meter Test Report If you have not yet done this do it now and then return to Auto Calibrate Select Initialize Meter Get Help Setup your external calibration device ChromaPure supports the DVDO Duo and the Lumagen Radiance If you have not yet done this do it now and then return to Auto Calibrate Setup Calibration Device Get Help Select your calibration device D Test your calibration
87. to all images For this reason it is absolutely essential to correctly calibrate the display s grayscale For more information on calibrating white balance refer to Setting White Balance p 44 e Color Decoding This term refers to a process that is used to lower bandwidth require ments by encoding the native RGB signal into YPbBr analog or YCbCr digital which must then be decoded back to RGB prior to display There are different encoding decoding standards so sometimes a poor design in the television may lead to color decoding errors These errors are primarily seen as primary colors red green or blue with incorrect lumi nance and or secondary colors yellow cyan or magenta with incorrect hues All com mercial displays include a Color and Tint control These are basically controls designed to resolve color decoding errors though their effectiveness is extremely limited because Color adjusts the luminance of ALL of the colors and Tint effects hue of ALL of the second aries The problem is that typically displays have color decoding errors that effect the col ors differently For example you could adjust Color Tint to get the correct luminance of blue and the correct hue of cyan but the luminance of green and red may still be inaccu rate You could adjust the color control to get red right but then blue and green would be inaccurate See the problem A full set of color decoding controls addresses this problem by offering color ti
88. y a 90 gray test pattern 5 Click Measure The application will take a measurement return a gamma value for that level and then automati cally advance to the next level 6 Repeat steps 4 5 until you have finished measuring 1096 You may also take an additional readings at 5 increments by checking the desired boxes next to each level Checking the gamma response at 5 in particular can help with precisely tuning shadow detail NOTE Only the values above 0 and below 100 stimulus have gamma 100 is only used as a reference from which gamma at the other levels of stimulus are calculated 0 is not measured at all Displays offer three ways of adjusting gamma to achieve the flattest gamma response possible within the prescribed range e Adjust Brightness and Contrast 57 e Select from various gamma presets e Adjust the luminance output at each level of stimulus You can use any of the these methods to adjust your gamma response It all depends on what controls your display offers If you put the Gamma module into continuous mode you can see changes in real time to the gamma response at any level of stimulus When the measurements are complete you will have gamma values at each level of stimulus and an average gamma value 58 MEASURING CONTRAST Overview Contrast the difference between the luminance of the display s black level and its peak output is one of the most important indicators of image quality T

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