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ChromaPure User Manual

1. Measurement Mode White Red Green Blue Yellow Cyan Magenta A white 2 x 0 31 0 659 0 296 0 136 0 426 0 216 0 321 ked Tolon y 0 337 0 337 0 613 0 079 0 512 0 339 0 172 Green O Cyan Y j Bite brota 0 214 0 705 aos 0 942 0 822 0 332 cdm2 50 522 10 81 35 6 4 95 47 58 41 55 16 79 EA 7 A E Save Chromaticity Image Save Luminance Image Reset Form Help 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 Taking Pre Calibration Color Gamut Measurements 39 ChromaPure Pre Calibration Procedures 4 Display a red test pattern 5 Click Measure 6 Repeat these steps until you complete all of the remaining readings When you have finished the gamut readings several data elements are avail able gt You can review the E value for each color You can review the raw xyY data for each color gt You can review the provided CIE graph and color luminance bar chart of the measured gamut gt 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 y and re measure one of the colors Taking Pre Calibration Color Gamut Measurements 40 VIDEO CALIBRATION USING CHROMAPURE CHAPTER What s Inside Setting White and B
2. 6 Return to the Meter Correction module The reference fields will be populated with the values you already mea sured 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 but ton The correction will now be applied to all measurements for this session and the field meter will emulate the performance of the reference meter Creating a Meter Correction 36 ChromaPure Pre Calibration Procedures TAKING PRE CALIBRATION GRAYSCALE MEASUREMENTS 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 Start Page Help Measurement Mode 10 04 C8 C 2 5 90 00 90 C 30 60 C 100 80 C 70 70 60 50 40 30 Save Gamma Image 2
3. TIP You can also import a calibration session by simply double Y clicking a calx file ChromaPure 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 convention such as date of calibration name of client or both that will allow you to easily call up specific data from past calibration sessions Calibration Tools 77 ChromaPure Post Calibration Procedures 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 You can input several data formats into the calculator including gt lux gt lumens gt foot lamberts gt cd m2 In addition to providing the necessary data input you must also provide infor mation about your screen Once all of the information has been supplied you may calculate the output of your projector 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 stan dard 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
4. C hroma P u re Video Calibration Software User Manual June 2011 TABLE OF CONTENTS Chapter 1 Introduction The Basics s s ssssssnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn 3 What to Expect from Calibrati N seria corral n 4 What Do I Need ii ca 5 Calibration Procedures ic AA di 6 Essential EQUIP d ies 6 Basic PANA IS dt DARA DE AR 6 Essential TEMO cia 9 Calibration DAS aia 10 Calibration StS 05 score 10 Calibrating a Front Projector micras 15 Chapter 2 ChromaPure Pre Calibration Procedures ssssssssssnnnnnnnnnnnnnnnnnnn 17 Installing and Configuring ChromaPure for Initial Use cccooonncnccnnoncnnnnnnnnnnnnonannnnnnnnonnns 18 Install Net A EEE 18 Install ChromaPure SoftWare ccomonococconoconanaconanaconnanaronancarononaronronarennnnnrarnnararennnnnnns 18 Import your License File nica 18 Install a Driver for your Color ANalyZF occcccoccccconocinnnnconnnonnrononnnnnnnnnrnnronnrnnnnnareronanenes 19 Selecting and Initializing the Meter sui occ in uaa 25 Setting Calibration OPtiONS sesion 27 Recording Display Senos sarao ea 28 Selecting Calibration OPtONS asii 29 Color LUMINANCE criar das ib ode 29 Referente Camara 29 Grayscale A O aaaseas pa cemanaanmiamacune 29 LUmMNAN CE PP en e O PE 0 tune 30 GEE o A e e PR ON O EE En E E 30 Measurement SMOOthING rd edici 31 Signal Generator rr A A a 31 AUTO REGCOVELY ici A A ai 34 al ys rarene PP eo a a e a 34 Creating a Meter COMEN ai o 35 Taking Pre Calibration Gra
5. Comments Po o g g 2 Type the various settings on this page Recording Display Settings 28 ChromaPure Pre Calibration Procedures SELECTING CALIBRATION OPTIONS 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 during the calibration session and will become the default for future calibration sessions unless subsequently 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 measured 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 pro duce 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 sec ondary colors a
6. 10 Click the Magenta radio button 11 Click the Continuous checkbox 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 percentage error as possible Repeat 9 13 for the remaining secondary colors What s the difference between the Color Decoding and Color Management modules All modules measure the luminance of the primary colors and the hue of the secondary colors However there are three important differences between them gt By default the Color Management and Advanced Color Manage ment modules use a fixed set of references However the references for the Color Decoding module are calculated from the measured val ues of the primary colors a standard white point is assumed gt The Color Management module uses lightness to display the percent age color luminance error whereas the Color Decoding module uses relative luminance to display the percentage color luminance error For more information on the difference between luminance and lightness refer to Lightness and Luminance p 87 gt Depending on the selected color space the Color Management mod ule 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 prima
7. 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 correcting If a color is shifted closer to or father from the white point in the center of the chart relative to the reference then its satura tion 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 Black and White levels Sharpness White Balance Color Tint Color decoding n bh WN Color gamut If your display has a CMS then Color and Tint adjust ments are not necessary The display s CMS will take care of this 6 Gamma When finished go back and remeasure each parameter because changes in one may have affected the readings for another Remember video calibration is a reiterative process Calibration Steps List below are the main steps you should take when calibrating your display For specific instructions on how to make these adjustments using ChromaPure software refer to Chapter 3 Video Calibration using ChromaPure p 41 How ever if you do not have a good background on how the process works read this section first Calibration Procedures 10 Introduction The Basics Setting White Level Contrast The Contrast control determine
8. Overview Once you have completed your calibration session it is useful to have a per manent record of the results ChromaPure provides four calibration reports gt A simple one page results report gt A multi page comprehensive results report gt A settings report gt A customizable multi page comprehensive results report in Microsoft Excel format The results reports contain both raw xyY data and charts and graphs display ing the pre and post calibration performance of your display To run a calibration report 1 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 Simple Calibration Report C Excel Report Detailed Calibration Report Calibration Settings Report Run Report 2 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 you entered in the Settings module e Excel Report This is an externally generated report and requires you to have Microsoft Excel install on your PC For those with Chro maPure Professional licences these reports can be customized to your specifications
9. 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 gt Adjusting them is a reiterative process Although these aspects of image performance are independent adjusting them often has interac tive effects This means that after you finish adjusting one area of per formance 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 70 Essential Terminology gt xyY This is a common method for precisely measuring color perfor mance x and y are coordinates on the triangular CIE chromaticity chart mentioned above that plot out how colors measure relative to their ref erence points Y is used to represent the luminance of a color Lumi nance is not plotted by on the CIE chart because it cannot be represented by xy coordinates It must be represented separately gt 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 satura
10. 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 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 Bright ness Bias Offset or Cut is for adjusting the dark end of the grayscale Setting Color Tint The standard method for adjusting color and tint involves looking at a SMPTE color bar test pattern through a blue filter This method has 2 drawbacks First at best it is an approximation of the correct setting Second and more impor tantly for some displays it simply does NOT work On some plasmas in partic ular 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 fil ters Color 1 Point the colorimeter or light meter towards the screen and display a 75 or 100 white test pattern 2 Measure the Y value luminance of white 3 Display a 75 or 100 Red test pattern and
11. 3 Click Run Report A printable calibration report will appear You can then export the report pdf to make it sharable with others Running a Calibration Report 70 ChromaPure Post Calibration Procedures Interpreting the Calibration Report The calibration report summarizes data gathered from the calibration session It includes several different sections each showing before and after perfor mance gt Grayscale Performance This section shows raw xy data dE and CCT for the grayscale 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 pref erence for which dE color difference model you wish to use gt 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 gt Color Temperature This section again shows grayscale performance but this time using Correlated Color Temperature CCT as the stan dard 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 impor tantly it ig
12. 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 standards 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 Manage ment System CMS A CMS can make a profound difference to the per formance 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 increasingly 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 59 It is important to understand two things about these aspects of display perfor mance Calibration Procedures 8 Introduction The Basics
13. Display Calibrations LLC ChromaPure Drivers lt select the correct folder gt TIP There are several subfolders 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 1Pro D2 subfolder If you are installing the X Rite Chroma 5 then select the Chromad subfolder 6 Click Next A final Found New Hardware Wizard window will appear Installing and Configuring ChromaPure for Initial Use 21 ChromaPure Pre Calibration Procedures Found New Hardware Wizard Completing the Found New y Hardware Wizard SS The wizard has finished installing the software for e Chroma Calibrator Click Finish to close the wizard lt Back Cancel 7 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 Win dows did not install this device 2 Close this message 3 Open the Windows Control Panel 4 In the Control Panel navigate to System and Security System Device Manager The Windows Device Manager will appear Installing and Configuring ChromaPure for Initial Use 22 ChromaPure Pre Calibration Procedures gt AE Display adapters gt DVD CD ROM drives b lt q IDE ATA ATAPI controllers IEEE 1394 Bus host controllers Keyboards F Mice an
14. Found New Hardware Wizard This wizard helps you install software for Chroma Calibrator If your hardware came with an installation CD 42 or floppy disk insert it now What do you want the wizard to do Install the software automatically Recommended Install from a list or specific location Advanced Click Next to continue lt Back Cancel Installing and Configuring ChromaPure for Initial Use 20 ChromaPure Pre Calibration Procedures 3 Select Install from a list or specific location Advanced and then click Next Another Found New Hardware Wizard window will appear Found New Hardware Wizard Please choose your search and installation options SS Y Search for 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 driver found will be installed Search removable media floppy CD ROM IV Include this location in the search C Program Files Display Calibrations LLC ChromaPu y C Don t search will choose the driver to install 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
15. are primarily seen as primary colors red green or blue with incorrect luminance and or secondary colors yellow cyan or magenta with incorrect hues All commercial 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 secondaries The problem is that typically dis plays have color decoding errors that effect the colors 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 inaccurate 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 tint controls that operate on red magenta and green yellow inde pendently Then you can use the main Color Tint controls to adjust blue cyan For more information on resolving color decoding errors refer to Adjusting Color Decoding p 57 gt 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 Calibration Procedures 7 Introduction The Basics Chromaticity 0 1 07 ES 44 05 6 Ay a CIE Chromaticity
16. 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 techni cian and the company Selecting Calibration Options 34 ChromaPure Pre Calibration Procedures CREATING A METER CORRECTION Overview Meter correction is an optional feature that allows a calibrator to use a refer ence 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 sen sitivity but lack precise color accuracy especially for certain types of displays At the same time many spectroradiometers offer reference color accuracy but can be slow and often have poor low light sensitivity The Meter Correc tion feature allows you to adjust the response of the colorimeter to match the performance of the reference spectroradiometer The result is the best of both worlds You can now calibrate 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
17. device has been properly setup If not then troubleshootthe 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 butitis 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 Next Using Auto Calibrate 64 Video Calibration using ChromaPure 3 Select and initialize the meter you wish to use TIP If you wish to use meter correction ensure that you do this y now before the auto calibrate session begins For more informa tion about meter correction refer to Creating a Meter Correc tion p 35 4 If you have not already done so setup the desired Calibration Device Auto Calibrate currently supports either the DVDO Duo or the Lumagen family of processors TIP ChromaPure saves information about selected signal gen Y erators between calibration 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 device you setup in the previous step 6 Click the Test Device button If your calibration device has been suc cessfully setup and selected t
18. is a measurement of color error relative to a known standard Thus the goal in calibration is to get the dE of the measured color as low as possible There are several different dE formulas gt CIELAB gt CIELUV gt CIE94 gt CIEDE2000 Each formula produces somewhat different results and has different toler ances We recommend using CIE94 though CIELUV is a reasonable 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 per fect for grayscale If using CIELAB or CIELUV strive for 4 0 or less for all readings Understanding Delta E 86 Video Calibration Concepts LIGHTNESS AND LUMINANCE 100 90 80 70 50 40 30 20 10 0 Output Both are a measure of the intensity of light Lightness is a non linear percep tually 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 low light 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 60 0 10 20 30 40 50 60 70 50 90 100 Input Luminance is a linear unit of intensity th
19. 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 Calibration Procedures 13 Tint Introduction The Basics Set the color control at the point where Red Y measures closest to 21 of the white reading TIP It is not really important whether you use 75 or 100 pat terns 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 pat tern 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 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 y main Color and Tint controls is not necessary Adjusting Color using a Color Management System CMS 1 Point your colorimeter towards the screen display a white window and then take a
20. space in which to work Select the color space that best corresponds 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 projectors gt 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 Scan DVDO Duo external video processor To use Color Management 1 Click Color Management on the main tool bar The Color Management module will appear Measurement Mode Select Reference Gamut Select Color Space Rec 709 y E White Red Green Blue Yelow Cyan Magenta E White IE Continuous x 0 000 0 000 0 000 0 000 0 000 0 000 0 000 Red amp Yellow y 0 000 0 000 0 000 0 000 0 000 0 000 0 000 a aT E e ly 0 000 0 000 0 000 0 000 0 000 0 000 cd m2 0 000 0 000 0 000 0 000 0 000 0 000 0 000 i Reset Help dE Method CIE94 O Lightness MI Saturation Mi Hue Lightness 0 Saturation 0 Hue 0 AE 0 Using Color Management 51 9 Video Calibration using ChromaPure 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
21. 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 col ors neutral white is achieved when those colors are in relative balance The calibration software will provide these raw numbers and a graphical represen tation 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 inter vals from 10 to 100 to ensure that the display tracks white accu rately throughout the entire range Calibration Procedures 12 Introduction The Basics 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 display s white balance controls until these three bars all measured as close to 100 as possible
22. that contains video information that is just below white and just above white against a fully white background TIP We recommend that you use the test pattern contained on the y AVSHD disc or the Spears and Munsil High Definition Benchmark disc to set white and black level The correct white level setting is that setting at which 3 conditions are met The peak white output is consistent with the display type The just below white bar is clearly visible gt The color of full white is neutral Use the White Balance tool to check the color of white For more information 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 gt CRT Plasma LCD Flat Panel Rear Projector 30 40 fL 103 137 cd m gt Digital front projector 12 16 fL 41 55 cd m Setting White and Black Level 42 Video Calibration using ChromaPure Just set the contrast as high as you can within the recommended limit so long as the other two criteria 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 recom mended Higher peak output w
23. the three poles of the selected color space for each color on the graph The dE error for each color on the graph The raw xyY data for each color below the measurement panel Luminance data is presented both in absolute luminance cd m and relative luminance Y For more information about absolute and relative luminance refer to Lightness and Luminance p 87 Display a test pattern for the target color Select the radio button for that same color Click the Continuous checkbox and then click Measure ChromaPure will measure changes in percentage errors in the selected color space in real time 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 10 Repeat steps 4 7 for whatever color or colors require correcting NOTE You may want to use the Advanced Color Manage ment module to determine if more accurate color through the color space can be obtained by calibrating to the 75 Rec 709 reference gamut Using Color Management 52 Video Calibration using ChromaPure USING ADVANCED COLOR MANAGEMENT Overview The standard color management module allows the user to adjust the primary and secondary colors of the display to match as closely as possible the selected gamu
24. 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 Using Advanced Color Management 53 Video Calibration using ChromaPure 0 900 y 0 300 0 700 0 600 0 500 0 400 0 300 0 200 0 100 0 000 0 000 0 100 0 200 0 300 0 400 0 500 0 600 0 700 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 colors 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 stimulus 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 ChromaPure 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 The Advanced Color Management module is designed to measure these parameters No commercially available color management system will correct these errors However if calibrating at full saturation results in significant errors in the rest of the color space then you can try to calibrate at 75 sa
25. xyY measurement Repeat the step above for all of the primary and secondary colors red green blue yellow cyan magenta Use the controls on your calibration software to plot the amount of error in hue saturation and brightness each color shows relative to the chosen standard 1 would select the Rec 709 High Definition stan dard Your software should allow you to set that as the target 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 Calibration Procedures 14 Introduction The Basics as well Since the CIE chart doesn t show luminance it is very impor tant 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 possi ble to the Y value specified by
26. you have finished measuring 10 You may also take an additional readings at 5 increments by checking the desired 60 Video Calibration using ChromaPure boxes next to each level Checking the gamma response at 5 in par ticular 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 gt Adjust Brightness and Contrast Select from various gamma presets gt 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 Setting Gamma 61 Video Calibration using ChromaPure 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 There are two ways to measure contrast gt Sequential Contrast Otherwise known as on off contrast this ind
27. 0 10 Reset Form 0 Save Grayscale Image 10 20 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 CIES4 17 4 22 0 23 5 23 9 23 9 23 5 23 2 22 9 22 7 21 6 23 0 CCT 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 Taking Pre Calibration Grayscale Measurements 37 ChromaPure Pre Calibration Procedures ChromaPure will take a measurement of the xyY values at that level of stimulus and automatically advance to the next level 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 gt 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 gt 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 y and re measure one of the l
28. APURE FOR INITIAL USE Overview To get ChromaPure fully up and running you need to accomplish four tasks gt Install Net 4 0 Install ChromaPure Software Import you license file Install a driver for your color analyzer vy vV vv Select and Initialize your color analyzer gt Select the desired options Each of these steps is covered below Install Net 4 0 To install Chroma video calibration software 1 Install the Microsoft 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 your License File You will now need to install the license file that you were provided when you purchased the software This file includes the serial number of the color ana lyzer you were licensed to use with ChromaPure 1 To begin start ChromaPure by double clicking the desktop icon The first time ChromaPure runs you will be prompted for a license file Installing and Configuring ChromaPure for Initial Use 18 ChromaPure Pre Calibration Procedures ChromaPure Licensing a x Licensee Starting Version Ending Version M Licensed Meters Import License 2 Click Impor
29. Chro maPure Professional users Auto Calibrate is provided free of charge This tool only works in conjunction with either the DVDO Duo or Lumagen Radiance family 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 dis play and even generate a comprehensive calibration report without any addi tional user input Calibrations take from 5 10 minutes to complete depending on the speed of the color analyzer you use 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 Welcome to ChromaPure Auto Calibration Before you can begin an auto calibrate session you need to complete several steps Select and initialize your meter 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 y Test your calibration device Test Device Ifyou see a red test pattern on your display device then the calibration
30. Yellow Green Cyan C Blue Magenta Primaries 0 669 x 0 28 322 y 0 659 13 44 Y 45 46 M Red E Green x y Y n 0 0 0 1 Secondaries O Yellow Cyan E Magenta x 0 441 x 0 212 x 0 358 y 0 52 y 0 359 y 0 172 Y 60 396 Y 49 146 Y 19 277 Reset Help O White x 0 332 y 0 347 Y 66 26 Select the Cyan radio button Click the Continuous button Display a cyan test pattern au AUN Click Measure Take a series of WRGBCYM readings to create a baseline ChromaPure will take readings and update the error chart in real time Setting the Main Tint Hue Control 49 Video Calibration using ChromaPure 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 continue 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 sec ondaries Setting the Main Tint Hue Control 50 Video Calibration using ChromaPure 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
31. ability to properly increase sig nal 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 shows the contrast and white level black level perfor mance of the display For comfortable viewing you should aim for a Running a Calibration Report 71 ChromaPure Post Calibration Procedures white level of 30 40 fL for flat panels and 12 16 fL 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 Running a Calibration Report 72 ChromaPure Post Calibration Procedures QUICKREPORTS Overview In addition to the standard reports you can run on your calibration session ChromaPure also includes QuickReports within the application These are avail able in the Pre Post Calibration Grayscale 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 QuickReport 1 From within the Pre Post Calibration Grayscale or Color Gamut mod ules click the Quick Report button A QuickReport will be generated from the data in the module lol xi _ Export As mage Export as Image Export as PDF or Word Ga EG gt 100 Fin ChromaPure Pre Ca
32. ancel Selecting Calibration Options 33 ChromaPure Pre Calibration Procedures 6 Select the correct serial port parameters You can check the Windows Device Manager to ensure that you have the correct settings for the device 7 Click Apply The Serial Port Configuration window will close and you will return to the Signal Generator window 8 Select all of the desired display options such as e Color Format e Resolution e Signal Intensity e Pattern Type 9 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 10 Click OK You are now ready to begin calibrating your display TIP In addition to automatically providing the desired patterns during a y calibration session external signal generators all provide a large num ber 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 feature 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
33. and subse quent periodic dark readings throughout the calibration session The Hubble requires an initial dark reading at the beginning and subse quent 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 Dark Reading Requirements 84 Video Calibration Concepts REFERENCE GAMUTS SMPTE C x y Y Red 0 6300 0 3400 0 2124 Green 0 3100 0 5950 0 7011 Blue 0 1550 0 0700 0 0866 Yellow 0 4209 0 5067 0 9134 Cyan 0 2306 0 3262 0 7876 Magenta 0 3144 0 1606 0 2989 White 0 3127 0 3290 1 0000 Rec 709 x y Y Red 0 6400 0 3300 0 2126 Green 0 3000 0 6000 0 7152 Blue 0 1500 0 0600 0 0722 Yellow 0 4193 0 5053 0 9278 Cyan 0 2246 0 3287 0 7874 Magenta 0 3209 0 1542 0 2848 White 0 3127 0 3290 1 0000 EBU x y Y Red 0 6400 0 3300 0 2220 Green 0 2900 0 6000 0 7067 Blue 0 1500 0 0600 0 0713 Yellow 0 4172 0 5018 0 9287 Cyan 0 2197 0 3287 0 7780 Magenta 0 3271 0 1576 0 2933 White 0 3127 0 3290 1 0000 DCI x y Y Red 0 6800 0 3200 0 2095 Green 0 2650 0 6900 0 7216 Blue 0 1500 0 0600 0 0689 Yellow 0 4248 0 5476 0 9311 Cyan 0 2048 0 3602 0 7905 Magenta 0 3424 0 1544 0 2784 White 0 3140 0 3510 1 0000 Reference Gamuts Video Calibration Concepts UNDERSTANDING DELTA E Overview Delta E dE
34. at can be expressed in absolute or rel ative terms Absolute luminance is expressed in raw cd m2 or fL 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 measures lightness The Color Decoding module uses relative luminance The Pre Post Calibration Grayscale mod ules 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 lumi nance relative or absolute Green luminance is approximately 71 of refer ence 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 is meant by the claim that our perception of the intensity of light is non linear Lightness and Luminance 87
35. 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 C White I Continuous C Red C Yellow C Green O Cyan C Blue Magenta Primaries M Red E Green x 0 669 y 0 322 Y 13 44 Secondaries 49 146 Y 19 277 Reset Help 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 Select the Red radio button 5 Click the Continuous checkbox and then click Measure ChromaPure will measure changes to the to the brightness of red in real time Adjusting Color Decoding 57 Video Calibration using ChromaPure 6 Adjust the color decoding control or the main color control to achieve the smallest percentage error as possible 7 Click Stop 8 Repeat 4 7 for the other two primary colors 9 Display a magenta test pattern
36. 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 Setting Gamma 59 Video Calibration using ChromaPure N Setting Gamma Gamma StartPage Help Measurement Mode C 100 C 65 C 30 Target Gamma 2 22 CCT 6205 Cos 60 C 25 3 C 90 C ss C 20 E Gamma Taraet Y C ase C 50 C 15 ecg 103 06 2 25 103 24 C a 45 C 10 90 92 25 2 15 91 57 C 75 IV 40 5 y 85 81 42 2 16 80 65 C 70 C 35 7 Continuous 80 71 29 2 17 70 50 75 62 43 2 14 61 09 70 53 52 2 16 52 41 65 45 96 2 14 44 46 60 38 60 2 15 37 22 55 32 00 2 15 30 68 50 26 71 2 11 24 83 45 21 17 2 13 19 65 40 16 56 2 12 15 13 35 12 65 2 11 11 25 132 0 88 4 120 6 30 9 26 2 10 7 99 25 6 42 2 09 5 33 20 3 61 2 15 3 25 15 1 90 2 17 1 71 10 0 75 2 19 0 70 5 0 20 2 13 0 15 o e ee 0o 00o eee Display a 100 white stimulus pattern Click Measure ChromaPure will take a measurement and then automatically advance to the next level Display a 90 gray test pattern Click Measure The application will take a measurement return a gamma value for that level and then automatically advance to the next level Repeat steps 4 5 until
37. d other pointing devices Ej Modems i gt ME Monitors AP Network adapters Ly Other devices dy Calibrator KB Portable Devices l gt D Processors ii Ei SD host adapters Sound video and game controllers Mi System devices f gt 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 5 Right click that item and then select Update Driver Software An Update Driver Software window will appear Installing and Configuring ChromaPure for Initial Use 23 ChromaPure Pre Calibration Procedures O i Update Driver Software Calibrator Browse for driver software on your computer Search for driver software in this location pram Files Display Calibrations LLC ChromaPure Drivers il Pro D2 Ad V Include subfolders EE gt Let me 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 IE 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 subfolders under Drivers Select the one that contains the driver for your device For example if you are i
38. e ware versions to choose from You can also use internal test patterns generated from your PC that ChromaPure controls Finally you can use external test signal generators gt If you have a front projector I would recommend an illuminance meter and a camera tripod to mount your meter on The AEMC CA813 is a good illuminance meter What Do I Need 5 Introduction The Basics CALIBRATION PROCEDURES Essential Equipment 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 most accurate device under 1000 is the X Rite iiPro though it can be tedious to use A close second is the X Rite Chroma 5 A much less expensive option that is somewhat less accu rate is the X Rite Display 2 also sold as the Pantone Eye One Display LT for less than 150 These meters are the same distinguished only by the packaging and the included X Rite software aimed towards pho tography applications ChromaPure also offers optional software enhancements to the Chroma 5 and Display 2 LT that substantially increases their accuracy beyond that even of the i1Pro gt Calibration Software You need ChromaPure to interpret the data that the meter provides analyze the data and plot the results on easy to read charts graphs gt Video Test Patterns Finally you ll need some way to get a test pat tern on the screen on your display The easies
39. er 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 diffuser gt Consider an illuminance meter Alternatively you can use an illumi nance meter such as the AEMC CA813 for contrast and gamma read ings but not for readings that require color information Illuminance meters read in lux rather than in fL or nits ChromaPure includes a lumens calculator for calculating fL nits and lumens from lux measure ments from such a device For more information on the lumens calcula tor refer to p 77 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 using ChromaPure refer to Creating a Meter Correc tion p 35 Calibration Procedures 16 CHROMAPURE PRE CALIBRATION PROCEDURES CHAPTER What s Inside Installing and Configuring ChromaPure for Initial Use p 18 Recording Display Settings p 28 Creating a Meter Correction p 35 Taking Pre Calibration Grayscale Measurements p 37 Taking Pre Calibration Color Gamut Measurements p 39 ChromaPure Pre Calibration Procedures 17 ChromaPure Pre Calibration Procedures INSTALLING AND CONFIGURING CHROM
40. esssaseessoas 71 UN DOS A O O estore samediumalbnts 73 Calibration LOS A dai dad 74 SHAPING AA A 74 Importing and Exporting Calibration Data coonccinccnncnnccnnnnnnnnnnnnnnnrnnnnnaranonarannnnannnnnns 74 Calculating Lumens for a Front ProjecCtOr cscccssseccessseressssecensseceesssseesseseesseseenesanes 78 Raw Date Mod a aia 80 Data Conversion TOO laminas ienei e aa 80 Chapter 5 Video Calibration Concepts sssssssssnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnna 82 o NEE E ET E E E E E E 83 Dark Reading Requirements anita Obi 84 RETENCIONES A 85 Understanding Delta E airada rad aldo ali 86 Lightness and LUIS vinnousevadudes dune sathadudude sand i ea aa a aN E 87 Table of Contents 1 INTRODUCTION THE BASICS CHAPTER What s Inside What to Expect from Calibration p 4 What Do Need p 5 Calibration Procedures p 6 Use this software to calibrate your television flat panel or projector to indus try standards For technical support for issues not covered in this document contact support chromapure com Ww Introduction The Basics Introduction The Basics 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 vari ables gt 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 calib
41. evels Also you can display gamma data 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 Taking Pre Calibration Grayscale Measurements 38 ChromaPure Pre Calibration Procedures TAKING PRE CALIBRATION COLOR GAMUT MEASUREMENTS 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 provides a snapshot of the display s pre calibration performance for the hue saturation and luminance of the pri mary 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 StartPage Help
42. ft A luminance value will appear in either fL or cd m2 This is your dis play s black level Display a full white test pattern from a external disc If you are using an external test pattern generator 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 fL or cd m2 This is your dis play s white level or peak output and a number will appear below This is your display s sequential contrast To measure simultaneous contrast 1 Measuring Contrast 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 fL or cd m2 Place your sensor on one of the white squares Click a white square 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 measure so long as you have measured at least one black and one white square Any additional measurements will be averaged Video Calibration using ChromaPure USING AUTO CALIBRATE Overview ChromaPure offers an auto calibration tool as an optional add on to the main program ChromaPure Standard users may purchase this add on For
43. ful 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 back ground You set brightness so that the 2 above black is barely visible and the 2 below black is invisible However more recent test patterns such as the ones found on the Spears and Munsul calibration disc and the AVSHD disc are much more accurate 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 correct black level even without a test pattern but you must have a recorded source of broadcast material either from a DVR or DVD Calibration Procedures 11 Introduction The Basics 1 Record a television source that includes a fade to black sequence
44. hen a red test pattern will appear 7 Manually adjust the brightness contrast and sharpness of your dis play Clicking the relevant buttons will bring up the appropriate test patterns Since these image parameters must be set by eye they can not be included in the automated session 8 Click Next The second ChromaPure Auto Calibration window will appear ChromaPure Auto Calibration Select desired calibration functions M Gamma M Grayscale IM Color Gamut Select reference gamut Rec 709 X Would you like a calibration report upon completion Yes Start Auto Calibration This process will require a few minutes You can dick Cancel at any time Cancel Auto Calibration Using Auto Calibrate 65 Video Calibration using ChromaPure 9 Select the desired calibration functions If you select Color Gamut then you must also choose the correct gamut from the Select Refer ence Gamut drop down 10 Select whether you wish the application to generate a calibration report when auto calibrate has completed 11 Click Start Auto Calibration The process will begin and display activity in the window below You can cancel the session at any time When it has completed it will gen erate a calibration report if you selected that option and turn off the test patterns so normal viewing can continue Using Auto Calibrate 66 CHROMAPURE PosT CALIBRATION PROCEDURES CHAPTER What s Inside Taking Post Calib
45. icates the difference between the black level of the display and its peak out put when each is measured one after the other Use a 0 and then a 100 white test pattern for this gt 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 pat tern simultaneous contrast is always considerably lower than sequential con trast To measure sequential contrast 1 You may want to take contrast readings both before and after the cali bration When taking 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 2 Click Contrast on the main navigation bar The Contrast module will appear Contrast Start Page Help Please select a pattern Y 54 657 Sequential Contrast Simultaneous Contrast Measuring Contrast 62 3 Video Calibration using ChromaPure Display a full black test pattern from a external disc If you are using an external test pattern generator or ChromaPure s own internal test pat terns click the Please select a pattern 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 le
46. ich dE formula you use is to a certain extent a matter of personal prefer ence However we recommend using CIE94 for primary secondary color grad ing 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 errors The targets for color mea surements when using the newer formulas are different because of the man ner in which the newer formulas treat luminance in the calculation which is ignored for grayscale Luminance performance with resect to grayscale track ing is part of the gamma response of the display and plays no role in dE calcu lations Measurement Smoothing With some meters you will notice that in Continuous mode the results will bounce around considerably making it difficult to determine with any precision the value of the reading The Measurement Smoothing option addresses this problem Simply select a method either Average or Median and a number of measure ments as few as 3 will significantly improve readings There are couple of issues to consider when using Measurement Smoothing gt It will slow the application s ability to return data The higher the num ber of readings you select the longer the application will require to return xyY values This feature is also accessible directly from the White Balance mod ule If you enable Measurement Smoothing from the Options m
47. ill only cause eye strain excessive image noise and lessened operating life of the display Black and White Pluge ChromaPure s built in test patterns includes a Black Pluge and a White Pluge test pattern for setting black level brightness and white level contrast You can access the patterns from the Signal Generator drop down View Toolbars Signal Generators The 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 PC black 0 background 1 Adjust the Brightness control on 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 The 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 PC white 255 background 1 Adjust the display s contrast control until you achieve the recom mended 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 recom mended level TIP The brightness and cont
48. in fL or cd m2 4 Make a note of the value returned from the reading 5 Start the Lumens Calculator module Calibration Tools 78 ChromaPure Post Calibration Procedures Lumens Calculator StartPage Help Measurement Type Measurement Value Select Dimension Enter Screen Size inches Select Aspect Ratio 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 teo Type the value you recorded in the Measurement Value field Select the correct Measurement Type lumens lux fL or cd m2 Type the screen size in inches VON OA Select the dimension in which the screen size is measured diagonal or width 10 Select the correct aspect ratio of the screen 11 Select the gain of the screen 12 Click Calculate 13 ChromaPure will return the equivalent value in e fL e cd m2 e lumens e lux Calibration Tools 79 ChromaPure Post Calibration Procedures Manufacturers routinely report gain figures that are inflated from the actual value Raw Data Module Overview Use the Raw Data module for a wide variety of calibration tasks You can take either single measurements or continuous measurements that appear in large xyY format If you are using the Offset 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 t
49. is also useful to export raw calibration 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 Export on the main navigation tool bar An Export Results window will appear Calibration Tools 74 ChromaPure Post Calibration Procedures Export Results lo Save in E CalibrationD ata F fale Favorites Desktop My Documents g Production a al HomeTheater File name z Save as type XML Session File y Cancel Select XML Session File from the Save as type box Type a desired name for the file in the File name box Select a desired location in the Save in box 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 subse quently 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 n A UN NOTE ChromaPure includes a fail safe feature in case you for get 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 abnor mally when you re start you will be prompted to restore the cal ibration data from the previous session To export raw calibration da
50. k Measure The application will return information for gt dE gt Raw xyY data gt CCT gt 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 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 4 dE is a good goal When finished click Stop Display a 20 gray test pattern 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 white 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 balance 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 gt gt gt Contrast Gains Drives Dark end of the grayscale gt gt gt gt Brightness Biases Offsets Cuts Setting White Balance 45 Video Calibration using ChromaPure The display s white balance controls may be easily accessible i
51. lack Level p 42 Setting White Balance p 44 Setting the Main Color Control p 47 Setting the Main Tint Hue Control p 49 Using Color Management p 51 Using Advanced Color Management p 53 Adjusting Color Decoding p 57 Setting Gamma p 59 Measuring Contrast p 62 Using Auto Calibrate p 64 Video Calibration using ChromaPure 41 Video Calibration using ChromaPure 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 Ww 235 on the same scale Everyone agrees that information below 16 should be invisible and that everything 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
52. libration 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 0 254 546 97 38 4 3 7 49 4 42 5 13 9 7 1 6 1 5 9 1 7 5 5 66 4 1 Primary Secondary Chromaticity 1931 Luminance E 06 29 04 MN 36 47 T T T T Blue Yellow Cyan Magenta 2 You can export the report as an image PDF or Word file QuickReports 73 ChromaPure Post Calibration Procedures 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 gt Export xyY data from the Before After Grayscale and Color Gamut mod ules in CSV format This raw data can be opened by Excel gt 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
53. lorimeter Installing and Configuring ChromaPure for Initial Use 25 ChromaPure Pre Calibration Procedures Klein K 10 non contact colorimeter Minolta CS 200 colorimeter Photo Research PR 655 670 spectroradiometer Orb Optronics SP100 JETI Specbos 1201 spectroradiometer gt JETI Specbos 1211 spectroradiometer v v v Yy We continually review the hardware options available and add new meter sup port when appropriate These meters measure both the chromaticity and luminance of light The mea surements are reported in xyY format xy coordinates describe the chromatic ity of the light and Y describes its luminance in either in candelas per square meter cd m or foot lamberts fL 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 infor mation about calibrating a front projector refer to Calibrating a Front Projec tor 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 Select serial port settings here 10 x EN Select Initialize Meter Disconnected SN 119052 3 Click the radio button next to the desired meter to select it 4 Click Initialize The Initialize button will turn i
54. n the user menu or they may be hidden in a special service menu accessible only through a unique key combination on the remote Setting White Balance 46 Video Calibration using ChromaPure SETTING THE MAIN COLOR CONTROL Overview The main Color control affects the luminance of all of the colors and to a lesser degree their saturation Use the Color control to adjust the primary col ors 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 Color Decoding Start Page Measurement Mode Red Color Green Color Blue Color Red Hue Green Hue Blue Hue C White I Continuous C Red C Yellow C Green Cyan C Blue Magenta Primaries M Red E Green x 0 28 y 0 659 Y 13 44 Y 45 46 Secondaries O Yellow O Cyan x 0 441 x 0 212 y 0 52 y 0 359 Y 60 396 Y 49 146 O White 2 3 4 5 6 Take a series of WRGBCYM readings to create a baseline Display a red test pattern Select the Red radio button Click the Continuous button Click Measure ChromaPure will take readings and upda
55. n using ChromaPure 8 You may also take similar measurements of amplitude in 25 incre ments 9 When finished you can share the results in several ways e View and save a CIE Chromaticity chart e View and save a Saturations dE chart e View and save a Saturations Luminance chart e Export raw xyY and dE data in csv format e Generate an Advanced Color Management Report that can be saved in pdf format What do I look for The goal of these measurements is mostly diagnostic What you want to see is that the measured saturation 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 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 51 Using Advanced Color Management 56 Video Calibration using ChromaPure 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
56. nd the luminance of all of the colors ChromaPure offers four reference gamuts gt SMPTE C gt Rec 709 gt EBU gt DCI Use SMPTE C for NTSC standard definition Rec 709 for NTSC high definition and EBU for PAL based material in Europe DCI Digital Cinema Initiative is an expanded gamut for which consumer material is not widely 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 Selecting Calibration Options 29 ChromaPure Pre Calibration Procedures do so the charts in the Pre Post Calibration Grayscale modules will appear on separate tabs in order to accommodate 20 measurement points You can also select between a gamma curve graph levels of stimulus and per centage output or a gamma line graph levels of stimulus and gamma response Luminance The two options provided are cd m candelas per meter squared or fL foot lamberts Either provides a standard of measurement for the absolute lumi nance of the signal Cd m sometimes called nits is a metric unit and fL is an Imperial unit 1 cd m equals 0 2919 fL and 1 fL equals 3 426 cd m The choice here is a merely a matter of preference It does not affect the substan tive results but only how they are reported dE Method Delta E dE or AE is a measuremen
57. nores 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 gt Chromaticity Performance This section shows the dE performance of the primary secondary 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 management system you will unlikely be able to achieve results this good gt 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 percentage errors in lightness saturation and hue You should aim for no more than 2 error in any compo nent Unless your display includes an effective color management sys tem you will unlikely be able to achieve results this good gt 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
58. nstalling the X Rite i1Pro or Display 2 then select the i1Pro D2 subfolder If you are installing the X Rite Chroma 5 then select the Chromad subfolder 7 Click Next A final Update Driver Software window will appear Installing and Configuring ChromaPure for Initial Use 24 ChromaPure Pre Calibration Procedures 5 Update Driver Software Chroma Calibrator Windows has successfully updated your driver software Windows has finished installing the driver software for this device ei J Chroma Calibrator LD i 2 e a E as B n 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 gt X Rite Display 2 Lt colorimeter X Rite Chroma 5 colorimeter X Rite DTP 94 colorimeter X Rite 1 Pro spectrophotometer v v vv DataColor Spyder3 colorimeter NOTE Any of the colorimeters can be upgraded to a PRO ver sion This indicates that the colorimeter s response has been corrected by a reference instrument 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 gt X Rite Hubble Sencore OTC 1000 non contact co
59. nto Apply Mode Installing and Configuring ChromaPure for Initial Use 26 ChromaPure Pre Calibration Procedures 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 require ments 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 Manager 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 various options refer to Selecting Calibra tion Options p 29 below Installing and Configuring ChromaPure for Initial Use 27 ChromaPure Pre Calibration Procedures RECORDING DISPLAY SETTINGS Overview You may wish create a detailed recording of the display s settings as part of the calibration process What you record here will be available in the Settings Report For more information about r
60. o back 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 mea surements should be taken from the center of the screen This is good advice but there are a couple of circumstances in which measure ments directly from the lamp are useful gt Contrast Since the light reflected off the screen is minimal when pro jecting black you will probably get a more accurate reading by taking measurements directly from the lamp Compare this to a measurement Calibration Procedures 15 Introduction The Basics 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 Peak output Since you don t have to worry about angle of acceptance or screen gain reading the light output directly from the lamp is gener ally easier than reading reflected light off the screen Some additional points to consider Use a diffuser Whenever you take readings directly from the projec tor lamp you must install a diffus
61. o calibrate If you wish to use the Built in test pattern generator then no initial steps are necessary 2 Click the Options button on the navigation toolbar and then click Sig nal Generators The Signal Generator window will appear ChromaPure Options 3 Environment Auto Recovery MV Enable Signal Generator Support Calibration m las Meters ada ag Signal Generators c z Reports Built In Select Color Format Select Pattern Type Select Resolution Select Signal Intensity v Cancel 3 Check Enable Signal Generator Support Selecting Calibration Options 32 ChromaPure Pre Calibration Procedures 4 From the drop down list select the desired generator and then click Add The selected generator will appear in a list of enabled devices ChromaPure Options i E Environment Auto Recovery V Enable Signal Generator Support Calibration ccupeLDva5000 y Meters Accupel_Dvg5000 v Signal Generators Reports C Built In w xl C Accupel DVG 5000 ef Port setup button Select Color Format Select Pattern Type Select Resolution Select Signal Intensity z 5 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 ii Meter Serial Port Number coma y Baud Rate a600 y Parity None y Data Bits je Y Stop Bits One X C
62. o clicking Measure Raw Data Module Start Page Help m Measurement Mode Export C Red C 0 C 60 C Green C 10 C 70 C Blue C 20 C 80 ESTA liaas las C Yelow 30 C 90 Sioana 55 3895 Cyan C 40 C 100 11 7420 Magenta 50 IT Continuous 37 2725 Blue 5 3147 Yellow 50 1802 Cyan 43 4097 Magenta 17 7120 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 displays 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 provide your own xyY test data and this utility will convert it into several other color spaces includ ing gt XYZ gt Lab Calibration Tools 80 ChromaPure Post Calibration Procedures gt Luv gt RGB gt RGB You can also supply a sample test and reference color to obtain a dE value from the major dE formulas as well as information about the percent of devia tion from the test 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 xyY Colo
63. od ule 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 You may want to automate your calibration sessions You can do this by using a signal generator ChromaPure Standard currently supports the following devices as signal generators PC s video card gt DVDO Scan Duo gt Lumagen Radiance The following signal generators are available in ChromaPure Professional only gt AccuPel HDG 3000 gt AccuPel HDG 4000 gt AccuPel DVG 5000 Selecting Calibration Options 31 ChromaPure Pre Calibration Procedures gt Sencore VP 40x gt Quantum Data 780 gt 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 TIP Only the PC video card and the AccuPel HDG 4000 DVG 5000 y support custom colors that are required for the Advanced Color Man agement module If you want to use this module and you don t have these external generators then you must use either the PC generated signals or a DVD Blu ray disc 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 t
64. or Luminance This is the brightness or intensity of color Often confused with saturation 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 Calibration Procedures 9 Introduction The Basics e Absolute luminance is the value typically expressed in cd m or foot lamberts metric or imperial units of luminance that is reported directly by the color analyzer Absolute luminance is useful for determining peak output black level and gamma e Relative luminance is the luminance of a color expressed as a per centage 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 spec ifications and calculating the dE of color For more information about dE refer to dE Method p 30 To sum up aS 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
65. ou see any problems in the readings then return to the White Balance and or Gamma modules and make further adjustments Taking Post Calibration Grayscale Measurements 68 ChromaPure Post Calibration Procedures TAKING POST CALIBRATION COLOR GAMUT MEASUREMENTS Overview Taking measurements in the Post Calibration Color Gamut module works just like the Pre Calibration Color Gamut module Its only function is to measure the results obtained from your calibration session You can then com pare the pre and post measurements in the calibration report For more infor mation about taking a color gamut measurement refer to Taking Pre Calibration Color Gamut Measurements p 39 Post Calibration Color Gamut Start Page Help Measurement Mode White Red Green Blue Yellow Cyan Magenta 2 white E x 0 31 0 659 0 296 0 136 0 426 0 216 0 321 ped oor y 0 337 0 337 0 613 0 079 0 512 0 339 0 172 Green O Cyan Y i Ole cia 0 214 0 705 0 098 0 942 0 822 0 332 cdm2 50 522 10 81 35 6 4 95 47 58 41 55 16 79 CIE94 5 6 0 9 10 1 156 39 4 6 Save Chromaticity Image Save Luminance Image Reset Form Help If you see any problems in the readings then return to the Color Manage ment and or Color Decoding modules and make further adjustments Taking Post Calibration Color Gamut Measurements 69 ChromaPure Post Calibration Procedures RUNNING A CALIBRATION REPORT
66. r Difference x y Y o Reference pooo E m Test o Calculate Calculate CIELUY CIE94 CIELAB CIEDE2000 H 5 E 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 dE information will appear along with information about percentage dif ference in lightness saturation and hue Calibration Tools 81 VIDEO CALIBRATION CONCEPTS CHAPTER What s Inside Color Wheel p 83 Dark Reading Requirements p 84 Reference Gamuts p 85 Understanding Delta E p 86 Lightness and Luminance p 87 Video Calibration Concepts 82 Video Calibration Concepts COLOR WHEEL The primary and secondary colors shown in degrees on the color wheel 120 60 240 300 Placement on the color wheel defines the hue of a color Color Wheel Video Calibration Concepts DARK READING REQUIREMENTS The Chroma 5 does not require a dark reading The Spyder3 does not require a dark reading The Display 2 and DTP 94 require a single dark reading at the begin ning of the calibration session gt The iPro requires an initial dark reading at the beginning
67. rast settings are usually interactive y so you should go back and forth between them to ensure that both parameters are correctly set Setting White and Black Level 43 Video Calibration using ChromaPure 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 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 e 50 90 C 20 60 C 100 y 0 341 CCT 6051 C 30 C 70 Y 5 2 89 5 AE 5 E 0 40 80 FT Continuous Measurement Smoothing Number of Measurements 1 a Method Mean Median 101 2 100 7 89 7 2 If necessary enable Measurement Smoothing For more information about Measurement Smoothing refer to Measurement Smoothing p 31 If you enable Measurement Smoothing in this module it will be Setting White Balance 44 Video Calibration using ChromaPure active in all modules so remember to return it to 1 when you are fin ished calibrating the white point 3 Display a 80 gray test pattern 4 Clic
68. ration Grayscale Measurements p 68 Taking Post Calibration Color Gamut Measurements p 69 Running a Calibration Report p 70 QuickReports p 73 Calibration Tools p 74 ChromaPure Post Calibration Procedures 67 ChromaPure Post Calibration Procedures TAKING POST CALIBRATION GRAYSCALE 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 session 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 Measurements p 37 Measurement Mode Post Calibration Grayscale Start Page Help C 0 C 40 80 C 10 50 90 20 60 100 O 30 70 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 12 2 08 21 2 08 2 11 2 04 2 05 2 12 2 19 Help Contrast 128 If y
69. ration will make little difference Otherwise it can make a profound difference gt How much control does the display offer to the calibrator to obtain a good image This varies wildly among displays Some are better candi dates for calibration than others simply 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 candi dates also offer adjustments for gamma color decoding and or color management What is the quality of the calibration equipment hardware and soft ware Even those displays that are the best candidates for calibration will see little improvement if the calibrator uses sub standard equip ment Finally there is a purely subjective element to this How sensitive are you to changes in color and luminance The best candidates for calibra tion 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 What to Expect from Calibration 4 Introduction The Basics WHAT Do NEED In addition to ChromaPure software and a PC or laptop you will need gt 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 calibration DVD There are many commercial and fre
70. rol Black level the intensity of light the display produces when the video signal is a 0 strength is Calibration Procedures 6 Introduction The Basics adjusted by the brightness control For more information on setting white and black levels refer to Setting White and Black Level p 42 gt 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 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 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 gt Color Decoding This term refers to a process that is used to lower bandwidth requirements 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
71. ry 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 Adjusting Color Decoding 58 Video Calibration using ChromaPure 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 gt CRTs the devices traditionally used for image reproduction and video production have a voltage input to signal output relationship that is itself non linear 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 This indi cates both that the gamma response is consistent 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
72. s 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 premature aging of the display The standard method for setting Contrast requires that you look at a test pat tern 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 distin guish the just below white stripe from full white I included such a pattern on the calibration DVD However there are a couple of problems with this method Many modern digital displays will never suffer from loss of high level detail even with Contrast set to 100 This method will recommend a setting that is much too high 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 good color performance and reasonable light output for a given display device What s a reasonable level CRT tubes plasmas digital rear projection and LCD flat panels 120 cd m 35 fL gt Digital front projection 48 cd m 14 fL These values comes from the SMPTE standard which is always use
73. t Unfortunately the color performance of consumer displays is not 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 fall ing not just on the edge of the color space but distributed throughout at dif ferent levels of saturation and amplitude Saturation is just the distance from the white point The selected gamut defines where a fully saturated color should fall relative to the white point 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 generally not perfectly linear A fully calibrated red at 100 saturation may measure per fectly while a 50 saturation red shows substantial errors These errors if large enough are easily visible Nonetheless they remain completely unmea sured by the standard CIE chart The Advanced Color Management module measures these errors At present the tool is for diagnostic purposes only There is no commercially available CMS solution for consumer gear that can correct non linear perfor mance throughout the entire color space Nonetheless this tool is useful for determining how well a CMS functions and
74. t 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 y the Licensing Utility from the Tools menu Install a Driver for your Color Analyzer Overview Before you can use your color analyzer whether it is a tristimulus colorimeter or a spectroradiometer you will have to install a driver so that Microsoft Win dows 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 Installing and Configuring ChromaPure for Initial Use 19 ChromaPure Pre Calibration Procedures Found New Hardware Wizard ia Welcome to the Found New Hardware Wizard Windows will search for current and updated software 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 Yes now and every time connect a device No not this time Click Next to continue 2 Select No not at this time and then click Next A second Found New Hardware Wizard window will appear
75. t 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 provide somewhat different results ChromaPure offers four options gt CIELUV gt CIELAB gt CIE94 gt CIE2000 Both CIELUV and CIELAB were endorsed by CIE in 1976 The underlying for mula 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 appli cations but Lab is a perfectly acceptable alternative In fact SMPTE has recently endorsed CIELAB as the color difference metric for its Digital Cinema Initiative 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 differently so when comparing results obtained by different dE formulas use the following equivalence scales For white gt CIELUV 4 0 gt CIELAB CIE94 CIE2000 3 0 For color gt CIELUV 4 0 gt CIELAB 3 0 Selecting Calibration Options 30 ChromaPure Pre Calibration Procedures gt CIE94 1 5 gt CIE2000 1 5 Wh
76. t way to do this is with a DVD The GetGray video calibration disc which can be downloaded and burned to DVD works well and sells for 25 AVS members have cre ated a very nice set of HD patterns for Blu ray called AVSHD Finally 1 have created a very simple calibration disc that provides all the pat terns necessary for the steps in this guide 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 ChromaPure 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 several 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 gt 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 cont
77. ta 1 Click Export on the main navigation tool bar An Export Results window will appear Calibration Tools 75 ChromaPure Post Calibration Procedures Export Results 2 x Save in o CalibrationData o a gt fie Favorites E Desktop My Documents Mo pr Production nn HomeT heater Fiename El Save as type csv File Cancel Select CSV File from the Save as type box 2 3 Type a desired name for the file in the File name box 4 Selecta 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 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 Import from the main navigation tool bar An Import window will appear Calibration Tools 76 ChromaPure Post Calibration Procedures Import 2 xi Look in o CalibrationD ata Q F gt a Favorites Desktop My Documents a Production a ie HomeT heater S Files of type XML Session File Cancel Zi 2 Navigate to the location where the desired ChromaPure calx session file was saved 3 Select the file and then click Open 4 ChromaPure will import all of the pre and post calibration data from that saved session
78. te the error chart in real time Setting the Main Color Control 47 Video Calibration using ChromaPure 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 prima ries not just red After adjusting red with the Red Color control you may want to continue and repeat the process for the Blue Color and Green Color controls to get the lowest possible average percentage error for all three pri maries Setting the Main Color Control 48 Video Calibration using ChromaPure 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 cor rect 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 unneces sary white balance refer to Setting White Balance p 44 Y TIP Always adjust the white balance of the display before attempting to make adjustments to Tint Hue For more information about setting the To adjust Tint Hue 1 Click the Color Decoding button on the main tool bar The Color Decoding module will appear Color Decoding Start Page Measurement Mode Red Color Green Color Blue Color Red Hue Green Hue C White I Continuous C Red C
79. 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 3 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 addi tional 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 Brightness setting is the correct setting for black Setting Sharpness 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 the White Balance Briefly white balance adjustment simply involves adjusting specialized con trols 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 system CMS which is relatively rare virtu ally all displays have white balance controls Sometimes they are in the user menu or they may be buried in a service menu
80. the target gamut Remember these Y values are relative luminance so they are just percentages of reference white You ll have to measure the luminance of white first and then check the luminance of the colors to see how close they are to the specified value in the gamut For more information about various refer ence 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 gam mas 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 2 Display a 90 white test pattern and record the Y brightness value 3 Repeat until you have recorded the intensity of white all the way down to 10 4 Your calibration software should plot the gamma values at each of these levels Use your display s controls to make necessary adjust ments to achieve a gamma value as close to 2 22 as possible at every point throughout the grayscale That s it Now you should g
81. tion 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 stan dard known as Rec 709 For more information about calibrating to dif ferent gamuts refer to Reference Gamut p 29 gt Hue This is the primary characteristic of color that allows us to distin guish one color from another A color s hue is measured by its angle to the white point If saturation is 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 con taminated by other colors For example red that is too yellowish will begin to seem orange Blue that is too reddish will begin to appear pur plish Human vision is very sensitive to changes in hue gt Col
82. tu ration using the Color Management module This may provide better overall results For more information refer to Using Color Management p 51 To measure the amplitude and saturation scale 1 Click the Advanced CM button The Advanced Color Management module will appear Using Advanced Color Management 54 Video Calibration using ChromaPure Advanced Color Management StartPage Help Measurement Mode White C Red Green C Blue Save Chart Image Select Measurement Mode 57 Save CSV Data O Yellow Cyan Select Chart ACI IEA C Magenta y Reset Form ACM Report White Red Green Blue Yellow Cyan Magenta 0 0 0 0 0 0 0 0 0 0 0 0 0 0 y 0 0 0 0 0 0 0 0 0 0 0 0 0 0 F 0 0 0 0 0 0 0 0 0 0 0 0 cd m2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 dE 0 0 0 0 0 0 0 0 0 0 0 0 Select White and ensure that Baseline Measurements is the selected Measurement Mode 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 Select Primary Saturations from the Measurement Mode drop down box Measure red green and blue each at 25 50 and 75 saturation Select Secondary Saturations from the Measurement Mode drop down box Measure yellow cyan and magenta each at 25 50 and 75 satu ration Using Advanced Color Management 55 Video Calibratio
83. unning reports refer to Running a Cali bration Report p 70 To record the display s settings 1 From the main navigation tool bar select Settings A Session Parameters page will appear Session Paramters Start Page loa Help Customer Information Name o A Address an 4 state apf Phone Television Make Model Technician A Name Po gt 7 o Phone Mumber ft tw Serial Number Email Normal Mode Dark Mode Input 1 Comments Pre Calibration Post Calibration Picture Mode sd A o y O Picture Temperature IS Po Contrast Picture gt po gt Brightness Blacks po 7 oOo Color Saturation oOo 7 o Hue Tint Phase gt Po gt Sharpness Detail Po gt Po gt Backlight Poo gt O Red Drive Gain High Pp Po gt Green Drive Gain High pa Pp Blue Drive Gain High 7 Red Cutoff Bias Offset Green Cutoff Bias Offset gt Po gt Blue Cutoff Bias Offset O Input 2 Pre Calibration Post Calibration Picture Mode az sd Picture Temperature po lc Contrast Picture i po Brightness Blacks pp 7 tn 7 Color Saturation gp 7 y 7 Hue Tint Phase Po Po gt Sharpness Detail po i Backight AA Red Drive Gain High po po 7 Green Drive Gain High ti po Blue Drive Gain High po A i Red Cutoff Bias Offset Green Cutoff Bias Offset o ls Blue Cutoff Bias Offset
84. 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 Chro maPure does not support the reference device In this case simply measure RGBW with the reference meter record the results and then manually type the xy values into the appropri ate reference fields in the Meter Correction module Then pro ceed with Step 4 below 2 Click the Meter Correction button The Meter Correction module will appear Meter Correction Start Page Help Measurement Mode white Red Green Blue Reference Meter as Ref x fo fo fo jo Field Meter Rar y b b b b Measurement Mode White C Green nda fo fo fo fo C Red C Blue Field y jo jo fo lo rep ay 3 Select the Reference Meter radio button and then take a series of WRGB measurements Creating a Meter Correction 35 ChromaPure Pre Calibration Procedures 4 Open the Select Initialize Meter module and then disconnect the reference meter TIP If you are using an i1Pro Display 2 combination be sure to Y physically unplug the i1Pro before initializing the Display 2 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
85. yscale Measurements cooncccccncccnnnoncnnnonnnononnncrnnnnnrnnnonarnrnnnnnnnns 37 Taking Grayscale Measurements in 5 Increments ccooocccnccccnocnnonononanonaninnnncnonanenanon 38 Taking Pre Calibration Color Gamut Measurements cccceccsecesseeeceeeeeeeeesaeeeaeeesseeesaeeeees 39 Chapter 3 Video Calibration using ChromaPure s ssssssssnnnnnnnnnnnnnnnnnnnnnnnnn 41 Setting White and Black Level conca ii doin 42 Black and White PILES sicario 43 Setting White Balance misa aiii 44 Setting the Mal Color Control dado dica 47 Setting the Main Tint Hue Control nosiipaiaaala 49 Using Color Management sssrinin AO 51 Table of Contents i Using Advanced Color Management insano a de 53 Adjusting Color Decoding var A A EEN Ad 57 What s the difference between the Color Decoding and Color Management modules 58 A pie doovadeitumaudny ie eaeyt sonntin E E 59 ME ASUPIIG COMA A ass aa a cae GES tala ies thts oes 62 Using AUTO CIDE sta cd oca 64 Chapter 4 ChromaPure Post Calibration Procedures sscssessessssesssesseees 67 Taking Post Calibration Grayscale Measurements cccceecesececeeeecaeeeseeeesaeeeeaeeeseeesaeeeees 68 Taking Post Calibration Color Gamut Measurements ccccceceeceeeeeeeseeeeseeessaeesseessaeeees 69 Running a Calibration Report c cssccccssssesessssececsencensseceessessesesaseesenesareeseuasesssaseesenagas 70 Interpreting the Calibration Report sscescsssercsssseressssecessseseeseseeesssseeessee

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