Spectra Colour Services Ltd.
Contents
1. use larger or smaller pixels to form tl Resolution r All of the LaserJet printers are capable of printing raster graphics at 75 100 150 or 300 dots per inch In addition the LaserJet 4 and later 600 dpi printers are also capable of 200 as well as 600 dpi The physical size of the printed image is totally dependent on the resolution used to print it The image in Figure 1 was printed at 300 dpi If it were printed at 150 dpi the resulting image would be twice the size an effective enlargement of 200 but without any increase in the size of the output file The identical image could be had at 300 dpi using a s 200 flag on the command Page 4 MKPCL line except the print file would be four times the size If it works out that a change in the printing resolution will create the exact size that is needed then a resolution change would generally be preferable to using a scale command You would either get a smaller file in the case of an enlargement or finer detail in a reduction On the other hand printer resolution isn t a terribly practical means of image scaling because the choices are so limited which means that most of the time none of the available resolutions would produce the wanted im Figure 3 Resolution Variations The effect of change in printer resolution is demonstrated in Figure 3 where the identical bitmap image is printed at 600 300 200 150 dpi on the top row and2. any image that would trim without inversion will not trim with ming of the Crop Image CH 8 The C option crops the image per the user s specifications The flag takes four comma separated arguments that are the desired coordinates in pixels that represent the area of interest of the image in the form C x begin a end y begin y end No spaces are permitted within the argument The values are in pixels measuring from the top left of the image Consider the image to be a two dimensional array of pixels We can specify the desired crop area by defining the beginning column on the left followed by the ending column on the right and then similarly the first and last row The first element on either axis is 1 For example assume our original BMP is 1200 pixels wide by 700 pixels high If we want to crop out of that pixels 280 1050 on the X axis and rows 40 640 on the Y axis the command mkpel C 230 1050 40 640 inputfle outputfile would produce the desired output To establish the desired coordinates first print out a copy of the uncropped image on the printer at 300 dpi the mkpel default Issue mkpel inputfile outputfile and then print the output file Print the file included in the distribution named ruler pel a ruler with a 300 dpi measuring scale With the 300 dpi ruler you can very quickly establish the crop parameters Laminate and trim the ruler if you can All subsequent sizing of the image is based on the cr
3. as a permanent macro and be available to all users throughout the day There is always the danger that the printer is shut off for some reason during the day or the macro itself is deleted In addition macros occupy printer memory and if memory is tight you certainly don t want it filled up with everybodys Cursor Positioning x ty 44 Without intervention from the application the graphic file will be printed on the page wherever the printer cursor happens to be atthe time In most applications it is quite likely that the cursor would first be purposefully positioned and then the graphic image would be printed No cursor positioning commands are necessary within the graphics file itself I the graphic is being enabled as an overlay i e the printer is going to automatically print it on each page then a cursor positioning sequence will need to be contained in the macro to locate the image atthe desired spot on the page The x and y flags provide a mechanism to insert positioning codes into the print file The argument to the x flag is the desired location of the image along the horizontal or X axis and likewise the y flag s argument defines the vertical or Y axis location If the argument to either flag mned no or then it will be interpreted as an absolute position that is x dots to the right dots down from the top left margin That is a very likely scenario in the case of an automatic overlay Lets say the logo wa
4. be printed the variables aa dd would be nulled while ee hh would be loaded with the relevant values Assuming that the format was defined to NOT print blank lines then the graphic should print as desired An additional check would be needed in processing to make sure that the print code was executed on the last line of the report if the lst page isnt filled If it is necessary to print a lank line define another format line only containing a single character variable When a blank line is wanted load the variable with chr 13 otherwise make it null The use of this technique and others no doubt permits the filePro programmer to generate very sophisticated reports that might seem impossible with filePro at first glance Certainly the usefulness goes far beyond conditionally executing a print code Getting Help The best way to leam is through experimentation Because of the flexibility afforded both by filePro s output formats and the PCL language itself there is usually more than one way to accomplish your print requirements There is a wealth of information in the PCL Technical Reference Manual Set available fom Hewlett Packard If you are stuck send email to jimi spectracolorservices com and describe what you are trying to do and where you are having a problem Page 29
5. be wrapped with the save and restore cursor codes but that is easily done with the d flag on the command line The only drawback to that approach is the file is made inflexible for other uses In this regard though there is a public domain vi clone called vir has some useful attributes It has a binary mode and will not swallow 0x00 characters line len of several megabytes are allowed and line wrap can be disabled These three features make minor surgery on a PCL bitmap very eas You will find that it is most practical to test the positioning codes ete by editing the file and printing with the Ip command Put the image into filePro only when you are certain that you have what you want It will save you a lot of time in development FilePro and PCL Macros To demonstrate the ease of implementing printer macros with flePro we will setup the letterhead macro previously created for use in any of your output formats It is assumed that PFDLDIR has already been set in the environment This is short and sweet First define a printeode to download Ihead mae and logo mae to the printer let s say code 65 Define it as requiring no space in the first field and then for the business part of the code enter Ihead mae logo mae Now quote code 65 as the form init code on the F8 options page in define output on the target format This will download the macros to the printer at the beginning of the job All that remai
6. bytes and the with the added PCL overhead needed to print the file on a LaserJet we get an actual print file of 74 339 bytes As the HP printers have evolved over the last few years different compression schemes have become available to reduce the amount of data that needs to be sent to the printer for a given image But because not all printers support all compression methods we cant simply have a flag to tum compression on or off How we choose to compress the image data will be dependent on the printer to be used to print it There are four different levels of compression Level Type Supported by File Size o None Llll and earlier 74 339 bytes 2 TIFF Lup 34674 3 TIFF Delta Row LIM 22444 4 TIFF Dela Row LJIP 4 and later 21 009 The table above shows the file length actually achieved for the image in Figure 1 using the four different types of compression You can see from the byte count that compressing the graphie is usually worthwhile The compressed file doesn t actually save any printer memory in imaging the graphic because the file is uncompressed within the printer but the time saved to transmit the file to the printer is significant In this example levels 3 and 4 both have a better than 3 to 1 compression ratio Some images will compress more than 10 to 1 The bigger the file the greater the potential resource saving Line drawings will tend to compress more effectively than halftone photographic images To creat
7. file Togo pel that is located in the default download directory Further we would like to print the logo at location 200X 400Y on every page If print code number 75 for example is defined as Sb amp 10S 1b p200x400Y logo pel SIb amp fIS you could put print code 75 anywhere on the output format and the logo would be properly positioned and subsequent filePro data would be located correctly as well Note that the above code is what would literally be entered into the print code table and would be defined as non printing or not requiring a space to be allowed for it Now an explanation Page 25 MKPCL SIb amp 0S is the PCL sequence to store the CAP or to push itself does not change the CAP it onto the stack Saving the CAP in SIb p200x400Y moves the CAP to locate the graphic on the page logo pel downloads the logo pel file to the printer At this point the CAP is at the bottom of the logo SIb amp MIS restores the CAP to the address previously saved or pops the previous address off the stack At this point the cursor is now located back to where it was before the print code was encountered so subsequent filePro data will be unaffected by virtue of the logo having been printed AIL of the cursor positioning code can be added to the graphie file itself thus requiring only the download command to appear on the print code table The x and y flags can be used in mkpel for this purpose It would need to
8. lt ese gt amp fIS restores the cursor to the last previously saved address This means that you could embed X Y coordinates in the bitmap itself or you could supply the positioning codes from within your application If macro 1636 contains X Y code within lt ese gt amp f0S lt ese gt amp f1636y3X lt ese gt amp fIS would save the cursor run the macro and restore the cursor back to the point we started at Let s say we wanted to print at location 400X 1200Y Rather than have the XY code in the macro we could position it within the application but remember to save the cursor beforehand In this case we could issue lt ese gt GeS lt ese gt p4 0051 200Y lt ese gt amp I1636yIX lt ese gt KA1S and the image would be positioned as desired Sometimes the print location is determined by the data on the page and can only be established at runtime For example this could be a signature at the end of some text of 1d length In this ease we probably always want to print at the same X location but the location is relative to the end of text If our PCL command is issued right at the end of text we can use a relative positioning code for the Y axis The code lt ese gt S10S lt ese gt p400x S0Y lt ese gt S1636y3N lt ese gt SI1S will position the image 50 dis below the point the macro call was encountered with the cursor eventually restored to the calling poi Macros can be nested so if you have a macro to overlay an invoi
9. stream although that probably is t practical most of the time The graphic file itself is sent to the printer using the download feature available in printer maintenance which is implemented as a printer code on the print code table You define in printer maintenance a print code in the form pel filename The quotes are required and the filename can be either a complete path to the file or a relative path fiom the download directory By default the current directory is used but you can change the default by setting the environment variable PFDLDIR The print code for the download can be located anywhere on the output format from the printer standpoint however if the graphic was to only appear on the first page of the job then the download would have to be executed during the format init or some other creative method would have to be implemented to insure the file was only sent tothe printer the one time Once the printer has imaged the graphic the cursor remains at the bottom left of the image In most cases this will have put the cursor out of syne with the regular filePro data The most straightforward approach to restoring the cursor is to simply use PCL codes to save the cursor address before the graphic is downloaded and then restore the cursor back to that position after it is printed An example should make this clea Assume that we have created PCL printable file of our logo and it resides in the
10. MKPCL Bitmap to PCL File Converter for Unix DOS Spectra Colour Services Ltd Works on any character based terminal Simple command line user interface Creates HP compatible print fle Supports BMP PCX and JPG image file formats Image scaling compression and rotation Cuspurimage relocatable on page Easy integration into forms and reports www_spectracolorservi Installation Judy 1 2012 Dos Copy MKECL EXE from the distribution to an appropriate directory in your path and the other sample files to any convenient directory for testing The program 1s Bot dependent on any other config files for proper operation It iz however necessary to create a directory where mkpei will write ite temp files By default the program expects the directory IMP to exist Make it a shared folder if you put iton a network drive Create WIMP or if you prefer another location for the tenp UNIX untar the files from distribution to any convenient directory and then move to that directory Copy the mkpel executable to a directory in your PATH as appropriate to your needs Set the ownership and permissions to suit Copy the Sampie files to the directory of your choosing for testing PCLTEMP The program respects the environment variable PCLTEMP and you can set it to contain the path to the temp directory of your choosing For exemple if you prefer the temp files to be written to u tap tem
11. after the bitmap has been imaged the CAP is restored to the previously saved address The save will happen before any x or y values are encountered This is very useful if you are printing the image with other tex It means you can specify an absolute address for the image without disturbing the location of your current text This scenario is most likely to play out when you are calling the image as a macro Effectively the image is printed but the underlying application is unaware of it See the discussion on macro execution in Application Guidelines Watermark W The watermark flag defines a gray level to reproduce the black in a bi level file Instead of printing your logo as solid black you can print it in any shade of gray you select The argument to the fl the desired pixel intensity in the range 1 to 254 Remember O represents pure black and 255 is pure white Values outside the 1 254 range will cause the flag to be ignored Page 12 MKPCL Often you will find that a graphic reproduced as black will be too overpowering and rendering it as a shade of gray will give a more pleasing image Figure 11 below shows our Spectra logo at the indicated shading levels both at 300 dpi and 600 dpi mkpel W 120 inputfile outputfile would seta gray level of 120 at 300 dpi mkpel r 600 s 200 W 120 inputfile outputfile would be in order at 600 dpi s 200 is included to preserve the image si
12. alculations are made Figure 9 Trimming the image The T option is used in conjunction with the t flag to set a trim threshold on grayscale images ie both the t and T are used together on the command line The trim function processes the original image before any highlight adjustments are made and likely would not be effective on a grayscale image because the brightest tone or intensity in the image is something less than pure White Similar to the highlight threshold command the argument to the T flag defines the pixel intensity considered pure white for trim purposes This has no effect on the rendering of the image itself just the criterion used to trim off excess background This is very useful when working with signatures that have been scanned in color Signatures in particular are much easier to position and size with all the overscan removed Invariably the background tone is something less than white and it will not trim with the t flag alone however the addition of T 210 to the command line may do the wick A litle experimentation will give you a feel for the needed value For example try mkpel t T210 b inputfile outputfle If the border still includes background beyond the signature on any of the four sides use a lower threshold and try again Of course you would remove the b from the command line once the result was satisfactory Once in a while you will find a blob of some kind in the oversc
13. an area that prevents the trim function from operat wanted In that ease take the original file into a paint program and erase the offending mark Page 11 MKPCL Rotate R 84 The entire image can be rotated to 0 90 180 and 270 degrees in the clockwise direction where 0 degrees would be considered with the top of the image pointing north Likewise rotating the image to the 90 degree position puts the top to the east 180 has the top pointing south and finally the 270 degree position puts the top to the west See Figure 10 ese Wl rA o oo aso amwe Figure 10 Image Rotation The argument to the R flag isthe angle of rotation Note first that the flag is a capital letter and shouldn t be confused with the lower ease counterpart used for image resolution Second 0 90 180 and 270 are the only valid arguments They represent the four compass positions and any other Values will result in an error mkpel R 90 inputfile outputfile would be the required command to rotate the image to 90 degrees The default is O degrees The width specified on the command line will refer to the image width before the rotation takes place and likewise for the height SavelRestore Cursor d4 I the d flag without argument is included on the command line the program will add the appropriate PCL code to the output that saves the current active position or CAP before the image is printed Then
14. and Width 1 HH andlor w st Rather than specifying the desired image size as a percentage of the original the user can supply an absolute width or height on the command line and the program will make the necessary calculations taking into account the resolution to create the appropriately sized image Usually the h or w flags would be mutually exclusive on the command line i e if the width is supplied then the height is calculated proportionally and vice versa This is called sealing where units or dots are the same size both horizontally and vertically I both a width and a height are supplied on the command line then there is a good chance that to fit the image to the specified rectangle it will have to be scaled to different proportions on the width and height This would be anisotropic scaling where the horizontal and vertical units of measure are different Basically the effect is to shrink or stretch the image in one direction or another This is shown in Figure 4 where the image on the left side was generated using the command mkpel u px w 925 inputfile outputfile The resulting image is 925 dots wide as specified and the height scaled to 770 dots The command mkpel u px w 925 h 600 inputfile outputfile produced the corresponding image on the right The second drawing has not been cropped in the sense of clipping off part of the image but rather it has been squeezed together from top to bottom to conform to
15. at 100 and 75 dpi on the bottom row This particular logo with its curved lines is a good example to show what can happen to a drawing When printed at a coarser resolution The original image was scanned at 300 dpi so the imag second from the left on the top row represents the original size and resolution The ruggedness that comes with a lower resolution is quite apparent Note that this is only a concern when dealing with i nal or curved lines Page 5 MKPCL One way to keep curves and diagonals as smooth as possible assuming a 300 dpi scanner is to scan the original at 200 of the size needed for printing but use 600 dpi when actually printing the image Of course a 600 dpi printer is required When printing a large raster image or several smaller ones on the same page there is always the real danger of running out of printer memory The situation can be remedied by cutting the resolution in half e g from 300 to 150 and then using the s 50 flag on the command line to preserve the original size The effect of this is to reduce the required printer memory to one fourth of what had been needed at the higher resolution The program will default to a 300 dpi resolution if the r flag is absent from the command line Ifa different default resolution is wanted the environment variable PCLRES can be set to the desired value An r flag on the command line will override the resolution setting in the er Height
16. ce form you would have the invoice macro execute the logo macro as part of the form The logo macro would have no internal positioning codes This way a single logo macro could be used on any number of forms and only require a single download Also an image can be repeated on the same page just by executing the macro at different locations An automatic overlay that contains all of the static information on the printed page can immensely reduce the complexity of the application as the overlay might be able to relieve the application of font changes and other PCL overhead Page 22 MKPCL A Macro Example To tie all of this together we will create a letterhead macro that will be used as an automatic overlay The entire demonstration will require a total of three files 1 thead mae the main letterhead macro 2 logo mae a logo macro executed by head mac 3 demo the application that calls Ihead mac Although it is not shown at actual size below is a copy of the completed macro You can see that there are three elements the logo some text and a line ox 2 10688 King icorpe Hwy Suey B C VST AWA Tal G04 584 0077 Spectra Colour Services Ltd The entire operation is controlled by the Ihead mac file With the exception of the logo all of the PCL code in the macro can be entered with a text editor The escape character is shown as in the listing below This is how it is represented by the vi editor R
17. d by amp f1X which is the end macro definition command The last sequence declares macro 1636 as permanent Page 23 MKPCL Logo Macro Create the logo macro with mkpel using the supplied logo bmp file as the source Enter the command as follows mkpel e4 t m 100 p logo bmp logo mac This will create logo mac with a macro ID of 100 and will be marked as permanent when it is sent to the printer Test File Using your text editor enter the following into a file called demo gt eer6a6yax gt p825x1200vTest of letterhead macro L Remember that the represents the escape character Save the file and we can go on to test the macro The first line enables macro 1636 for overlay and the second is just frivolous text with ated positioning code At the end there is a formf ed shown as L You would enter L in vi but do whatever you need to with your editor to get char 12 Putting it to Work Direct both logo mae and Ihead mae to your laser printer using the appropriate print command for your computer system While these macros are in separate files here several macros could be contained in a single file thus requiring only a single download for all of them Now print the demo file and you should have the letterhead nicely printed at the top and the sample text down towards the center of the page Change the text and print it again If you haven t shut off the printer in betw
18. e skpel caldera bep caldera pel Bkpel B 30 caldera bap caldera pel Skpel B 30 A 220 caldera bap caldera pel EKPI g 100 caldera bap caidera per Mote Unix users may need to add o zav to the 1p comand line to successfully print bitmap images MKPCL Overview Mkpel is a UNIX DOS program that converts a BMP PCX or JPG raster graphic file directly to a file that can be printed on an HP compatible laser printer The program automatically determines the type of input file and proceeds accordingly This software should be of interest to database or other users who find that their application provides no support for raster graphics and require a method to insert logos or other graphic images in their forms and reports New with Version 2 the input BMP PCXIIPG file can contain a color black amp white or grayscale image Images with a pixel depth of 1 4 8 or 24 bits per pixel are all supported Color images when processed by mkpel are first converted to grayscale to await further processing If you are scanning a new color image it may be in your interest to output a grayscale file directly from the scanner This will make the input file about one third the size of its color counterpart Figure 1 The program is very easy to use In general usage you would type at the UNIX prompt mkpel options inputfile outputfile where inputfile is the source BMP PCX PG file and outputfile is the resulting
19. e a compressed print file simply supply the desired compression level as an argument to the e flag on the command line For example mkpel e 3 inputfile outputfile instructs the program to create the output using level 3 compression While level 2 only uses TIFF to encode the image data levels 3 and 4 use both TIFF and delta row compression The HP compression routines are applied intelligently i e each raster row is examined beforehand and Page 2 MKPCL the most efficient compression method is used for that particular row Therefore it is very unlikely that using a lower compression level than your printer is capable of handling would ever be to your advantage other than to make the file printable on as many printers as possible In that ease the lowest common denominator would be level 0 The program will default to level 0 if the e flag is omitted from the command line however if you want to set up a different default 3 or 4 set the environment variable PCLCOMP to the appropriate value For example from the prompt UNIX users type PCLCOMPs4 export PCLCOMP DOS users type set PCLCOMP 4 From that point on your new default compression level would be 4 If you ate only producing print files for one printer you might set PCLCOMP in your profile file If PCLCOMP has been set it can still be overridden by a e flag entry on the command line Image Sealing s The flag takes as an argu
20. eeds to send a short PCL command to either execute the macro or enable it for automatic overlay We will look at each of these altematives in detail in a moment Your application must have the facility to permit PCL code to be inserted in the middle of the job In addition as part of the PCL code you have to be able to enter the escape character chrS 27 in basic OxIB in hex 1033 in octal and of course 27 in decimal In the examples here the escape is shown simply as lt ese gt in the code but it still refers to the real escape character Fortunately the balance of the PCL code is all ASCII characters A macro can contain any valid PCL code as wel as bitmaps From this point forward it is assumed that macro 1636 has already been downloaded and was declared as permanent when mkpel created the macro As long as they each have a unique ID several macros can be resident in the printer simultaneously largely limited only by the amount of printer memory Automatic Overlay When enabled as an automatic overlay the macro code will be run as the very last thing before the page is actually printed and ejected from the printer To enable a macro as automatic we need to insert somewhere on the page lt ese gt amp f y4X where represents the Macro ID number that was assigned when mkpel was run So in the example at hand we would issue lt ese gt amp f1636y4X Once enabled the overlay will be run on every page until the overlay is exp
21. een the letterhead should print again without a reload con You can create sophisticated applications that require little PCL code to implement Consider that you can have several macros downloaded and resident in the printer Then some logic in the application can execute the overlay containing the logo or form that is appropriate based on some criterion contained within the user data A simple example might be an invoicing routine that overlays an invoice form for positive amounts but overlays a eredit note for negative amounts Start out with modest goals and build on it from there This discussion is largely beyond the scope of mkpel itself which is simply another tool used to achieve your intended goal Page 24 MKPCL FilePro Usage Inserting a bitmap graphic into filePro output requires three general steps Fits the CAP must be moved to the position on the page where the graphic is to be printed The initial postion marks the top left corner of the bitmap image Then the file containing the image is sent to the printer and finally the CAP may need to be relocated on the page to continue printing the balance of the page To position the cursor simply send the appropriate PCL escape sequence to the printer that sets the CAP as desired It is possible that the CAP may already be where you want the image printed by Virtue of having the graphic downloaded at an opportune time in the filePro data
22. emember that this is a single character in the file The line numbers are for display here and are not part of the file 1 6 1636y0x 616d0e66F 51p20v0s0b4197T 2 o p475x285ySpectra Colour Ser Ltd s12v 3 s pa75x352 Box 2 10688 King George Hwy Surrey a 5 A P300x385Y c1960aTbP M p60x85 amp 100y3X 1X f1636y10x The first line begins amp f1636y0X This is a begin macro definition command The value preceding the y is the macro ID and OX indicates begin macro definition Next is a page formatting command The Oe in the middle of the string specifies there is NO top margin This format is only for the macro itself and not the page format for the application that will later use the macro This is done so we can print overlay items in the application s margins if desired The final item on the line is the sequence to call up 20 pt Garamond for the company Line 2 positions the cursor prints the company name and reduces the poi address and phone numbers which are positioned and printed on the third line Some of the actual address text has been deleted here to make it fit on one line The complete text is in the Ihead mac file The fourth line positions and prints the horizontal line with a PCL sequence size to 12 pt for the Finally on the fifth line the logo is positioned and then printed by executing macro 100 which we will create in a moment This is followe
23. error number and a brief descriptive message of the problem is displayed Below is a list of the error codes and descriptions Error No Description o Too few arguments on command line 1 Bad command line syntax Invalid option or missing argument 2 valid program option 3 me name for input and output file 4 valid program option 5 10 Boundary limit error valid unit of measure R walid landscape specification B valid trim threshold 4 Gamma value out of range 15 Macro ID out of range 16 Size specification too small n Foreground color out of range 18 walid compression number 19 walid rotation angle 2 walid resolution 21 walid watermark value 2 Cannot open input file 23 25 Memory allocation error 26 Cannot create temp file 2 Cannot create temp file 28 PCX plane count Must be L or 3 29 PCX file or memory error 30 34 Output size out of bounds 35 Cannot open output file 36 43 Memory allocation error 4 Unknown input file type 45 52 Bad cropping parameter 33 mpatible BMP compression or plane count When an error is encountered thee lines are displayed a timestamp a copy of the command line and the error message While this may seem to be an over abundance of information to display a simple error it is useful if you run mkpel from a seript and save errors to a file The command mkpel options inputfile outputfile 2 gt gt tmplerrlog would redirect and accumulate error messages
24. ge and is useful to determine the limits of a scanned image that has a white surround To add the border to the image put the b flag on the command line without argument Figure 5 was created with mkpel b inputfile outputfile Figure 5 Adding a border Page 8 MKPCL Grayseale Tone Manipulation Unlike the black amp white two color images we have looked at thus far grayscale files are far more susceptible to differences in resolution printer density settings and other variations from printer to printer The same image will probably be darker if printed at 600 dpi vs 300 dpi on the same printer Printer dots tend to bleed some and this is proportionately greater at higher resolutions Mkpel offers some command line options to modify the printed output Brightness B Similar to the brightness control on your monitor the brightness flag will lighten or darken the image Note thatthe flag is a capital B The argument is an integer and is a relative move from the current density Positive values will lighten the picture and negative values will darken it Grayscale files are capable of 255 intensities and the value in the B argument is added to the pixel value The images in Figure 6 below had B values 1 to r of 30 0 and 30 respectively Brightness defaults to a value of 0 if the B flag is absent from the command line CALDERA CALDERA CALDERA a o se Figure 6 B
25. hown at the top The information displayed is determined by the command line contents Input and output image sizes are shown first followed by the applicable program functions as they are executed This culminates with Generating Output that builds to 100 The output file is complete at this point The final three lines contain a timestamp a copy of the command line and a message confirming the successful execution ofthe program If the program encounters an error while running an error message will be shown in the third line Page 18 MKPCL The v fag allows the user to suppress the top bottom or both sections altogether from being displayed on the sereen The flag takes a numeric argument from 0 3 that has the following effect 0 Display both top and bottom sections default 1 Suppress all display 2 Display only top section Suppress bottom 3 Display only bottom section Suppress top the argument to the flag is outside the 0 3 range the program will print a warning and revert to its default of O display both sections and carry on as normal If you prefer a default gt O the program respects the environmental variable PCLQUIET Set it to 1 2 or 3 as needed and this will become your new default To set the new default to 1 UNIX users type PCLQUIET 1 export PCLQUIET DOS users type set PCLQUIET 1 A command line option overrides an environment setting For those of you creating logfiles the t
26. hreshold may save some thin lines or small text in an image that has been lightened It may take a bit of trial and error to establish the needed value If you are one point too high in the white threshold value you get no effect at all If you are too low you modify pixels that you didn t want to The inverse applies when working with a shadow threshold The main thing is to set your threshold right at the breakpoint so you don t change any pixels wecessarily Program default values are 255 for the highlight threshold and O for the shadow threshold No effect for either Page 10 MKPCL Trim t Trim Threshold T The trim option when invoked by the t flag on the command line will tim off any surrounding white overscan from the image if it is there Bytes are physically deleted from the output file if there is extra white around the image Aside from removing some excess baggage from the file the trimmed image is potentially easier to size to a specifie dimension than its untrimmed counterpart No argument is required to the flag on the command line The command mkpel t b inputfile outputfile produced Figure 9 below Compare that to the untrimmed version in Figure S The border has been included for comparison purposes only Note that when the t flag is used together with the w or h flags the image will be sized based on the trimmed image i e the image is trimmed before any size c
27. ils To create a macro file simply add the m flag to the command line with an integer from 1 to 32767 as the argument This number will be the Macro ID unique to this macro that is referenced later when it is run For example mkpel m 1636 inputfile outputfile would create a PCL file that would store macro number 1636 in the printer s memory once it was downloaded Then at the appropriate time the underlying application would issue the execute macro 1636 command at which time the graphic would be integrated into the current page being printed If the macro option is used the Following is sent to the file using m 1636 cited as the example 1 Delete macro 1636 if it exists tion of macro 1636 3 Image data 4 End macro 1636 definition Without the m flag only the image data 3 would go into the output file and with it commands 1 2 and 4 are added Once downloaded the macro will exist in the printer until it is powered off or eset A normal print job would reset the printer when finished and the macro would cease to exist I the p flag is added to the command line then one more command is tagged on to the end of the file The p lag is ignored in the absence of the m flag 5 Make macro 1636 permanent Page 16 MKPCL A permanent macro will survive a printer reset however it will disappear if the printer is powered off The company logo could be downloaded to the printer in the morning
28. landscape page without intervention the image would still print in portrait orientation appearing sideways on the landscape page PCL code can be added to the stream that instructs the printer to rotate the image to the current orientation automatically or the image can be rotated so when it is printed as portrait it stil reads properly when viewing the landscape page It is most efficient for the printer if an image is printed in portrait orientation The 1 ell flag can be included on the command line to let you choose the preferred behavior Only Values of O or 1 are permitted An argument of 0 will eave the image untouched and a 1 will cause the image to follow the orientation The default is 1 which means that it is unlikely you would ever have a problem if you ignored this flag altogether Runtime Display v At runtime various messages are displayed on the screen that track the program s execution progress This is pretty standard and what we expect For most users this flag can probably be ignored The text below shows a typical display mkpcl c4 s 135 logo bmp logo pel Reading Source File ogo bmp 1ogo pe1 current Width Width at 135 408 Dots 551 Dots Current Height Height at 134 321 Dots 433 Dots Scaling Image Dithering Generating output 100 Complete Sun Oct 2 11 13 55 2005 mkpel c4 s 135 logo bmp logo pel No Errors Normal program termination p For reference the command line is s
29. le to the printer S0C is si sly the hex code for a formfeed that ejects the page from the printer Page 27 MKPCL The DeskJet printers do not support the save and restore cursor commands as do the LaserJets so the recommended procedure is to send the formfeed immediately after the graphic has been imaged This creates a problem for filePro not on the page that was just printed but rather any subsequent pages Consider the timing of the execution of our print code with the code placed on the last character of the last line Once the code is finished filePro still has to print the final character as well as the LFICR for the last line The problem is that the print code has already had the printer eject the page thus the trailing LF CR ete end up on the next page The last character is eliminated by defining the print code as occupying space on the format but that still is no help on the trailing LICR Define the printcode as occupying a space The solution to this dilemma is to add another print code to the format that homes the cursor to postion 1 1 on the format Put the code at 1 1 and define it in printer maintenance as follows Sib amp a0R Stb pOx SIb S amp a0R moves the CAP vertically to the baseline of the top row SIb pOX moves the CAP to the left margin There seems to be a bug in the PCL3 DeskJet firmware Where SIb amp a0R is supposed to locate the cursor on the first row below the t
30. licitly disabled a different macro is enabled or the printer is reset To disable the overlay issue lt ese gt amp SX anytime The ID is not required to disable as only one macro can be enabled at any given time Page 21 MKPCL Because the overlay is run after the PCL page has been imaged you must supply PCL coordinates to position the bitmap on the page Do this with the x and y flags on the mkpel command line when the macro is created One advantage of the automatic overlay is that you needn t concern yourself with the curso s position once the image has been laid down as the cursor is reset when the page is printed The overlay is particularly ideal where you have a logo or some other item that is displayed at the same location on every page Macro Execution When a macro is executed it is immediately run at the location where the execute command was encountered on the page A macro is executed with the command lt ese gt Sfiy3X where sis the macro ID thus the command for the image at hand would be lt ese gt amp f1636y3X Once the macro has been run the cursor remains at the bottom left ofthe image and this has probably put the cursor out of syne with the application What we can do is save the cursor address before the image is laid down and then restore the cursor back to its original location when done Our application is none the wiser The command lt ese gt SM0S saves the current cursor location and
31. lighter colors here WITHOUT the W flag that you would use in black and white If you need to reproduce an image that is monochrome but a colo there are immense savings in image size printing it this way rather than as a full color image Page 15 MKPCL Limit L 8 The limit option came as the result of a customer request It specifies two dimensions in the form L mavwidth maxheight This represents the maximum size the image is to be in either direction ie if the image is sized to maxwidth and the height scales to greater than maxheight then it will bbe resized to fit the depth with a correspondingly narrower width The parameters are comma separated and no spaces ate allowed The values are stated in user units and fractional components are permitted where applicable Given a 2 75 wide x 1 75 inch high area printing mkpel u in L 2 75 75 inputfile outputfile will always produce an output image that fits the allocated area so it could be run from a script and process a number of originals without operator intervention If you have to contend with a variety of sizes and shapes of originals mkpel will insure the image fits within the limits of the defined box Printer Macro m p The output file can be formatted for downloading to the printer as a macro and then later executed by the application or enabled as an automatic overlay See the macro example later in this manual for macro deta
32. ment the percentage size of the original bitmap that is desired for the printed image where 100 is the same size values less than 100 indicate a reduction and values greater than 100 indicate an enlargement The program will permit percentages from as small as 10 with the upper limit being an image with a width or depth of about 8400 dots The latter cover a legal size sheet at 600 dpi That is undoubtedly a bigger image than your printer s memory can handle and it is very unlikely that the limits at either end will even come close to being tested Ar positive value is valid otherwise The method used for sealing the image size is to duplicate or delete exis image so you are NOT gaining any detail when you enlarge the image We are effectively gaining image size at the expense of image resolution That said the image quality is pretty good overall and very good at relatively small magnifications of up to 150 or so The image to the right is the same as Figure 1 but is reduced to 50 in size The command line was mkpel 50 inputfile outputfile Compare this to the fll size image and you will see that the drawing has held together quite well considering that 3 4 of the pixels in the original file have been deleted pixels from the original rast the image in Figure 2 is the same drawing except that the scaling has now enlarged the to 175 of the original size Again compare the enlargement to the original and you will see that i
33. ncrease in contrast when rendered in grayscale The color image can derive its perceived bounce from contrasting colors where the grayscale image must ely entirely on tonal variations Threshold H 4 S 44 The threshold command can specify two different pixel intensities There is a highlight as well as a shadow level defined by the H and S flags respectively The highlight threshold defines a pixel value and any pixel in the image with a greater value will be promoted to pure white 255 Similarly the shadow threshold also defines a pixel value but values below it will be demoted t0 pure black 0 Referring back now to the dark image in Figure 6a itis shown a we run the same mkpel command but add the H flag to the command line we can restore the white pixels back to their original values without affecting the darker pixels In this example we had lowered the value of all pixels by 30 points so considering that the maximum pixel value is 255 lets set our threshold to 220 and see if that cleans up the background See Figure 8b amp CALDERA CALDERA sa Figure 8 Highlight Threshold This can very useful whe with ballpoint pen signatures that have been scanned in color Ballpoint may not reproduce very well as the line work tends to be broken and uneven You can easily darken the signature and then clean up the background by setting a highlight threshold While maybe not as common a shadow t
34. ns is to put a variable on the output format that enables or disables the macro for overlay on the page Call the variable o 10 g and in processing make the following assignments 1 you want the letterhead to be printed on the current page set ol ehr 27 amp f1636y4X Once ol has been sent to the printer the letterhead will appear on every page To disable the overlay set Page 26 MKPCL ol ehr 27 amp ISX Depending on the contents of ol you can elect to print the letterhead or not There is a good chance that you only want the leterhead on the first page In the case of a report you would need to keep track of the current page number and then populate the variable as is appropriate Once disabled the overlay will remain disabled until it is explicitly enabled again On a full page form place ol anywhere that is convenient On a report format put ol somewhere in the heading and it will only appear once on the page The variable only needs to be set when you are changing the state of the overlay The processing should be designed to make ol null on any page where you aren t enabling or disabling the overlay HP DeskJet Printers The key to successfully merging graphic images into filePro output formats is maintaining the corect alignment of the filePro data on the printed page afier the graphic has been imaged This is relatively easy with a laser printer because the entire page is stored in the printer s memo
35. nts to be located one inch from the left margin and two inches down from the top margin Assuming a 300 dpi addressing scheme in the printer mkpel x 300 y 600 inputfile outputfile would create an output file with the correct positioning code inserted in front of the graphic If a printer macro is the desired output then mkpel m 1636 x 300 y 600 inputfile outputfile would be an appropriate command I the argument to either flag is preceded by a or sign it will be interpreted to mean that cursor is to be positioned relative to the current cursor position CAP It is quite common to have an absolute postion on one axis and a relative position on another mkpel x 1050 y 50 inputfile outputfile moves the cursor 1050 dots from the left margin and SO dots up the page from the CAP Absolute positioning on the X axis is commonly used to preserve column alignment Relative positioning codes are very useful to slightly tweak the general location on the page where the graphie will be printed This location is largely determined by whatever else is being printed on the page For relative moves on the X axis values move the cursor left and values move it right On the Y axis values move up the page and values move the cursor down the page Page 17 MKPCL Presentation Mode 1 Raster graphics are printed in portrait orientation regardless of the orientation of the logical page So if you print an image on a
36. op and not the original Page 14 MKPCL Color Index 1 H is possible with a PCLS color printer to print a monochrome image in a color other than black Note that this includes all of the PCLS color LaserJets and all of the PCLS DeskJet printers These Deskets include the 2250 2280 2300 This will NOT work on the PCL3 DeskJets which includes the vast majority of HP inkjet printers Included in the files in the distribution is colors pel which is reproduced in Figure 15 below Print the file on your PCLS color printer It is shown here purely for reference and any judgment of color fidelity and accuracy should be made from your printed copy In any ease you wili se that the sheet contains 100 copies of our Spectra logo individually numbered 0 99 There are 10 different colors each at 10 different densities The number below each logo is the argument required for the C flag fon the command SoboeonLL bbbobobooi ose Sooooood gt RRR RRR Vvooooooooo a a a od voooooee gt boboooooboor bbobbot Sooo bbbbbboo boooooonn boooooou Figure 15 MKPCL Color Indexes mkpel 1 57 inputfile outputfile would produce a green image similar to logo 57 above OF course the color accuracy would be 100 when compared to the color sheet that you had printed for reference This could be an excellent method for creating watermarks Ifyou want to make a tinted watermark use ane of the
37. op margin as it does on a LaserJet on every DeskJet we have tested it positions relative to the top of the physical page rather than the top margin You may find that 1b amp a3R is wanted when working with a default half inch top margin A little experimentation will quickly show the needed value The actual implementation in real output formats is quite likely much simpler that it may read here particularly when defining a form as opposed to a report Report formats present a problem in that the print code to download the graphic ete must only be executed at the end of the last text line of the format Even if the graphic is to appear in the heading area of the page the print code to create it must still be placed at the end of the text Because the code cannot be placed in the page heading some means to conditionally execute the code using LC in conjunction with not printing blank lines perhaps will have to be implemented in processing For example assume that two data lines in a report format were defined as Page 28 MKPCL Each of these lines is formatted to contain identical data except that the second line would have the graphic print code placed at the end of the line and would only be used when the final line on the page was being processed As the page was being printed the variables aa dd would be loaded with the appropriate values while ee hh would be null However when the last line was to
38. op section of the display is sent to stdout while the bottom section is directed to stderr All error messages are sent to stderr as wel so a logfile can be derived from the output of stderr Now if you don t want to include a record of successful program executions simply put v 2 on the command line and those messages will not be generated Help To get help online mkpel without argument will display the following USAGE mkpel options input ile outputfile Yakpel without argument foz help Sb ut border around image TE Mh Brightness adjustment Jea Compress 0 2 3 4 Output as macro PAN Make macro permanent Resolution in dots per inch MALALA Crop imac Rotate image 0 90 180 or 270 Save Restore cursor CAP Seale to MiNt of original size o Flop image left to right 5 AMN Shadow threshold Ig Mt Set gamma value TETHNN Teim overscan Trim Threshold J AM Iesge height in user unite lu User units px in mm pt cm pe HAMN Highlight threshold TEM avert to negative image Limit runtime display messages Image width in user unite Watermark Tone 1 254 k aris positioning in dote Page 19 MKPCL Error Logging There are roughly 50 error conditions that can cause mkpel to abort its execution Most of these are pilot error where a bad or illegal argument is given to an option on the command line consequently errors are relatively rare When an error is encountered an
39. p then enter the command from DOS set FCLTEMP u tmp temp from UNIX PCLTEMP u tmp tenp export PCLTEMP Note that there is a trailing or depending on the OS This IS required and further you must create all of the components in the directory path if they don t exist already Put the set PCLTEMP string in autoexec bat or another suitable bat file on bos systeme On UNIX systems ete profile or your profile files are the Likely locations Quick Start The file logo bap is a scan of our Spectra logo and can be used to Genonstrate mkpel operation First enter skpel logo bap 1ogo pel Now print the 1ogo pcl file using the appropriate Ip command to direct the fiie to your LaserJet The top left comer of the image is at location 0 0 X Y in the PCL coordinate aystem Now ty sakpel x 2000 loge bap 1ogo pel Print logo pel again and you will see that the image is now over towards the right side of the sheet but still at the top This time kpel x 1025 y 1350 Logo tep logo pel When the file is printed this time the logo will be roughly centered on the page As the coordinate aystem is 300 unite per inch you can place the image very accurately fon the page by supplying the necessary X Y values to akpel The caldera bap file is a full color image and the output from it can be manipulated as per the instructions on p 9 10 of the manual Print each of these You create the pel fil
40. printable PCL file to be used with your application There is no restriction on the file naming placed by mkpel however any rules imposed by the operating system will have to be followed Mkpel provides a number of command line option flags that will modify the behavior of the program to change the printed image to suit your purpose Note that none of these options in any way will change the BMP PCX JPG input file so you can experiment quite freely without fear of damaging the original file While there are several options available most of the time it is quite likely that you won t need any of them and once in a while maybe just one or two As a baseline reference the image in Figure 1 required no options when the file was created just the command mkpel inputfile outputfile Page 1 MKPCL A bitmap or raster graphic image is composed of successive rows of dots that in the case ofa laser printer are either black or white The state of a dot is stored in one bit where if the bit is on it prints black on the page Thus one byte can store only 8 different dots from the image The number of data bytes required to store a given image then is row width 8 aumber of rows Assuming a 300 dot per inch resolution even a small image will require several thousand bytes to describe it This leads us to the first of the options compression File Compression The raster data for the image in Figure is 70 751
41. rightness Variations You can clearly see the effect of the command Also note that the darkening of the image in 6a has created some unintended and unwanted tone in the background In this instance the B 30 was probably a bit heavy handed for this illustration but there are many occasions where you want to darken the image as much as possible while still retaining pure whites This is addressed on the next page in the threshold description The brightness option will NOT change pixels that have an original value of O or 255 so pure whites and pure blacks are still retained after a brightness change Gamma or Contrast g 44 The gamma flag permits the user to adjust the contrast of the printed image Integer values in the range from 1 200 are allowed with a default value of 75 Generally lowering the gamma value will render the image lighter and lower in contrast and conversely raising the gamma value will produce a darker image with increased contrast Contrast adjustments may be used in tandem with brightness changes Very often you may find you need both an increase in contrast as well as a lightening of the image In Figure 7 on the following page the Caldera logo is shown with gamma Values 1 to r of 0 75 and 100 respectively Page 9 MKPCL CALDERA CALDERA CALDERA n w te Figure 7 Gamma Variations Again the effect is readily apparent Some color images may require a significant i
42. ry before the page is physically printed and the cursor can be relocated at any time Note that PCL3 printers do not support printer macros Mkpel was written specifically with LaserJet printers in mind and traditionally merging text and graphics using one of the less expensive DeskJet printers was tedious at best and probably impossible in practicalities in the context of filePro The newer DeskJet models give the filePro user a means to insert graphies and still maintain alignment with the database data This applies to the DeskJet 540 6xx Series and the 8xx Series and later only For other models in the Sxx Series this simply won t work Sorry While these DeskJet models cannot store in memory an entire page of text and graphics they can and do store the entire page of text before the page is printed This presents the opportunity to position the cursor anywhere on the page and print a graphic after the text has been processed Duplicating the example used previously with the LaserJet to print the logo on the DeskJet printer we would first need to create the following print code in printer maintenance SIb p200x400Y logo pel SOC This code is placed on the output format on the last character of the last lir print just as it did with the LaserJet Briefly the codes do the following and the page should SIb p200x400Y moves the CAP to posit the graphic on the page M logo pel downloads the logo pel fi
43. ssumes 25 4 mmm to the inch 5 pe Pica Assumes six picas to the inch exactly 6 pt Point Assumes 72 points to the inch exactly Page 7 MKPCL If the u flag is absent from the command line the program will default to using the inch as the unit of measure Note that the size of pixel is determined by the resolution used and thus can vary from one invocation of the program to the next whereas all of the other scales are absolute factions of an inch The tem pixel is used here to avoid confusion with the term dot that may be used in the same frame of reference when defining a cursor location Traditionally there were 300 dots to the inch and we don t want to confuse that with the image pixel which may or may not be 300 dpi Foran image 4 25 inches wide ype mkpel w 4 25 inputfile outputfile Foran image 10 cm wide type mkpel u em w 10 inputfile outputfile Substitute the appropriate mnemonic on the command line for the other measuring scales The program recognizes the environment variable PCLUNIT and it will be recognized as the default unit of measure when set To make the centimeter the default at the prompt UNIX users ype PCLUNIT em export PCLUNIT DOS userstype set PCLUNIT em An argument to the u flag on the command line will override the environment setting Border b This flag simply instructs the program to make all the perimeter pixels of the image black This can greatly enhance the look of a grayscale ima
44. t stands up pretty well Its command line was mkpel 175 inputfile outputfile Enlarged images compress very well Although the 175 magnification more than tripled the amount of image data the print file only grew by about one third Page3 MKPCL Figure 2 I you have the resources you can always rescan the drawing or resize the or image of some kind That obviously may not always be possible but more to the point scali image when creating the print file is very fast and you can change your mind and resize it again with litte effort This is especially useful if you are trying to fit an image into a very tight space Very quickly three or four slightly different sized print files ean be created and tested for the best fit Corporate logos would be typical of the kind of thing that may need to be printed regularly at a varity of sizes The size of a bitmap can grow rapidly when enlarging an image At 200 the bitmap has grown to four times its original size and there is always concem about the execution speed of the print file once in the printer This is particularly important to database applications that may be printing the same image repeatedly in a single print run A 200 image has both the number of rows and columns doubled so that each pixel in the old drawing is now represented by four pixels 2x2 grid in the new one There is another way to enlarge or reduce the image by simply having the printer
45. the 600 dot height specified on the command line Depending on how you want to look at it you could also say that the 600 dot height was specified and the image width was stretched to conform to the 925 dot width that was indicated The scaling of the image height and width are two completely separate operations internally and one is not dependent on the other The u flag will be explained momentarily The default unit of measure used in the argument to the h or w flag is the inch but other units are available and they are discussed in the description of the u flag The argument may contain a Page 6 MKPCL decimal point indicating some fractional part of a user unit However all measurements are ultimately converted back to pixels so to be meaningful the fractional component of the argument will have to represent a least one pixel Figure 4 User Units u The unit of measure specified as an arg in more convenient terms perhaps than printer pixels This flag only has meaning when used when specifying an absolute image size on the command line in conjunction with the h and or w flags There are six different measuring scales available each of which has a mnemonic abbreviation that will be used as the u flag argument ment to the flag permits the user to define the 1 i Inch 2 px Pixel or printer dot 3 a Centimeter Assumes 2 54 em to the inch 4 mm Millimeter A
46. to the file Implertlog Program success will also be posted to the display or logfile Page 20 MKPCL Application Guidelines A raster file is either imaged by the printer immediately as the data is received or it is downloaded to the printer as a macro and is then processed at some later time In most instances itis not very practical to download a file in the middle of the data stream Further many applications do not provide the functionality to make timely downloads to the printer Ideally all necessary macros would be downloaded to the printer at the beginning of the job A macro provides alternatives for the application to utilize the bitmap and would most likely be the preferred approach In the macro scenario the image is sent to the printer with its embedded unique Macro ID This download of the image to the printer ean happen at the be it could be first thing in the morning for a job that is going to be printed sometime later I the macro was defined as permanent then only a loss of power to the printer or an expli or replace macro command will change the macro s status In the worst case where the application provides no way to send a file to the printer on demand you can simply use your standard prin command to direct the macro to the printer before your application is started Nothing will physically print at this point Once the macro has been sent to the printer your application only n
47. ze bob Obobo Figure 11 Wartermark Variations Note how coarsely the dithering algorithm has rendered the lighter shadings of 220 and 240 whereas the the same shading at 600 dpi significantly beter This provides a simple mechanism to ghost an image in the background of an invoice or purchase order ete Altematively you ean start with a black image and have PCL use a gray or some other pattem as the fill Flop Image f This option flops the image over left to right and is invoked by including the f flag without an argument on the command line If the flop option is used with an image rotation the image is first rotated and then flipped over Figure 12 Flopped Image Page 13 MKPCL Invert Image i The invert option reverses the state of each bit in the image effectively creating a negative of the original Ifthe i flag is present on the command line the image will be inverted This option may be more useful than would be immediately apparent primarily because bitmap files are typically written for video display where a bit that is on will display as white just the opposite of the printers behavior Programs like mkpel normally invert the image as a matter of course Figure 13 Inverted image When the i flag is present on the command line the image is inverted before any ti image that may be called for Image inversion directly affects the trimability of any image and
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