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Newsgroups: comp.sources.misc From: Rich Burridge <richb@Aus.Sun.COM> Subject: v22i048: popi - The Digital Darkroom, Part09/09 Message-ID: <1991Aug22.153235.16057@sparky.IMD.Sterling.COM> X-Md4-Signature: 22482ffbd26278b746541d38feb3fe43 Date: Thu, 22 Aug 1991 15:32:35 GMT Approved: kent@sparky.imd.sterling.com Submitted-by: Rich Burridge <richb@Aus.Sun.COM> Posting-number: Volume 22, Issue 48 Archive-name: popi/part09 Environment: Xlib, Xview, SunView Supersedes: popi: Volume 9, Issue 47-55 #! /bin/sh # 1. Remove everything above the #! /bin/sh line # 2. Save the resulting text in a file. # 3. Execute the file with /bin/sh to create the files: # FILES # MANIFEST # CHANGES # popi.man.text # This archive created: Wed Aug 21 10:36:13 EST 1991 # # export PATH; PATH=/bin:$PATH # if [ -f FILES ] then echo shar: will not over-write existing file FILES else echo shar: extracting 'FILES', 2998 characters cat > FILES <<'Funky_Stuff' @(#)FILES 1.2 91/01/03 This file describes all the files that make up the Reve distribution. README - describes what popi is, and how to get started. Makefile.dist - master Makefile used to build popi on most systems. TODO - bugs and suggested enhancements. Volunteers? popi.msc - Make file for Microsoft braindamaged make. popi.prj - Popi project file (for PC compilers). powerc.prj - Project file for Mix Software's Power C Compiler popitopgm.c - small filter to convert old popi format images to pgm. debug.c - debug routines used by popi. expr.c - parser routines used by popi. io.c - file handling routines used by popi lex.c - lexical routines used by popi main.c - main routine and declarations used by popi. polar.c - polar coordinate handling routines used by popi. libpbm.c - PBM/PGM/PPM routines used by popi in io.c libpbm.h - definitions used by the PBM/PGM/PPM routines. run.c - run time interpreter used by popi. special.c - special transformations used by popi. popi.icon - popi icon used when the popi window is iconifed. gl.c - special version of the gl initialisation routines. g_init.c - graphics device driver for the gl window system. amiga.c - graphics device driver for the Amiga. apollo.c - graphics device driver for the Apollo. atariterm.c - graphics device driver for Atari TERM windows. graphics.c - independent graphics routines used by popi. hp.c - graphics device driver for an HP 8+ plane display. kerterm.c - graphics driver for kermit TERM windows. ibmpc.c - graphics driver for the IBM PC's. mgr.c - graphics driver used the MGR window system. news.c - C wrappers for the NeWS graphics routines. next.m - graphics driver for the NeXT machine. nulldev.c - device driver for a null device. sunview.c - Sun SunView graphics routines. x11.c - X11 (Xlib) graphics routines. xview.c - X11 XView toolkit graphics routines. popi.ps - NeWS graphics routines used by popi. popi.h - definitions and constants used by popi. graphics.h - optional graphics external variables and definitions. patchlevel.h - current patchlevel for this release of popi. lex.h - definitions used by the popi lexical parser. popi.man - the popi manual page (troff/nroff -man format). FILES - what you're reading now. MANIFEST - tells you what archive part each file was in. CHANGES - change history. Updated with each new patch. popi.man.text - plain text version of the popi manual pages. Funky_Stuff len=`wc -c < FILES` if [ $len != 2998 ] ; then echo error: FILES was $len bytes long, should have been 2998 fi fi # end of overwriting check if [ -f MANIFEST ] then echo shar: will not over-write existing file MANIFEST else echo shar: extracting 'MANIFEST', 2232 characters cat > MANIFEST <<'Funky_Stuff' @(#)MANIFEST 1.4 91/01/03 This file tells you in which part of the popi distribution each file appeared. Filename. | Part # -------------------------------------------------- README | 1 Makefile.dist | 1 TODO | 1 popi.msc | 1 popi.prj | 1 powerc.prj | 1 popitopgm.c | 1 debug.c | 2 expr.c | 2 io.c | 2 lex.c | 2 main.c | 2 polar.c | 2 libpbm.c | 3 libpbm.h | 3 run.c | 3 special.c | 3 popi.icon | 3 gl.c | 4 g_init.c | 4 amiga.c | 5 apollo.c | 5 atariterm.c | 5 graphics.c | 5 hp.c | 5 kerterm.c | 5 ibmpc.c | 6 mgr.c | 6 news.c | 6 next.m | 6 nulldev.c | 7 sunview.c | 7 x11.c | 7 xview.c | 7 popi.ps | 8 popi.h | 8 graphics.h | 8 patchlevel.h | 8 lex.h | 8 popi.man | 8 FILES | 9 MANIFEST | 9 CHANGES | 9 popi.man.text | 9 Funky_Stuff len=`wc -c < MANIFEST` if [ $len != 2232 ] ; then echo error: MANIFEST was $len bytes long, should have been 2232 fi fi # end of overwriting check if [ -f CHANGES ] then echo shar: will not over-write existing file CHANGES else echo shar: extracting 'CHANGES', 12961 characters cat > CHANGES <<'Funky_Stuff' Popi change history. -------------------- v3.1 - patchlevel 0. - 21st August 1991. ---------------------------------------- * Added mention of the popi mailing list to the README file. * Popi can now correctly handle the reading of compressed image files from the command line. * From Stephen Frede <stephenf@softway.sw.oz.au> - trunc() in special.c is a library routine on some machines, and the declaration in the header files conflicts. Changed name to "imtrunc". - signed is an ANSI keyword, and so should not be used as a function name in special.c - I have changed it to "dosigned()". * Added all known problems, suggestions and comments received, to the TODO file. * Ran the X11 version of popi through Saber-C fixing up compile time inconsistencies. - The color variable was being used before it was set in the oil() routine in special.c - various variables no longer used. * From Adrian F. Clark <alien@essex.ac.uk> Backspacing/deleting back pass the beginning of input, caused a core dump. * Range checking has been added to the OP_CRVAL case in prun() in run.c. This now allows examples like: -> :read "dmr" -> new[x,y]=dmr[x,y]+(Z/2 -dmr[x+2,y+2]) -> :r "dmr" -> new[x,y]=dmr[x*2,y*2] to correctly work. * The X11 (Xlib) and XView graphics drivers now build an image offscreen, so that they can correctly restore the image canvas for repaint events. * All references to revtable in x11.c and xview.c have been removed. * Prepared popi distribution for release to comp.sources.misc. v3.0 - patchlevel 7. - 25th March 1991. --------------------------------------- * Fixed up the % operator in the op_op table. * Fixed up handling of the Images array in the OP_CRVAL case in the switch table in prun(). v3.0 - patchlevel 6. - 17th January 1991. ----------------------------------------- * From Russ Nelson <nelson@sun.soe.clarkson.edu> Makefile.dist changes for DOS. Borland's Make doesn't grok .keep_changes, nor the lint_*:; lint ... lines. I commented out .keep_changes, and split out the line_*:; lines into more vanilla dependencies * Fixed up color support for the XView graphics driver. Still needs to be tested on a TrueColor display. * Added in PBM support when reading images. PBM files are simply converted to a grayscale image that has two values; 0 or 1. The nature of PBMPLUS is such that ppm automatic should support pgm and pbm. v3.0 - patchlevel 5. - 14th January 1991. ----------------------------------------- * From Rich Morin <cfcl!rdm@apple.com> - polar.c, main.c, popi.h Tidied up a bit. Couldn't find any basic speed up, unfortunately... The calculation takes ~120 seconds on my Sun-3/60. Hypot's time could be cut almost in half, but it takes only 25% of the time, so the gain would be only 12.5%, and the kludge is pretty hairy. Set up a control flag named tcache; it controls caching of trig values for all four quadrants in "/usr/tmp/popi.<Xsize>.<Ysize>". Might want to save only quadrant 2 (the cache file for 512x512 is currently 1MB). N.B. FREAD and FWRITE were defined in popi.h, but never used. They conflicted with definitions in <fcntl.h>, so I killed them. - special.c, io.c, popi.h Set :ofmt up as a command, like :signed. It corresponds to the -o flag. v3.0 - patchlevel 4. - 9th January 1991. ---------------------------------------- * popi will now attempt to read the old format image file auto-magically if it detects that the image file is not in pgm or ppm format. Even if it read a grayscale image in the old format, it will still write it out in pgm format, unless the user has given the -o command line option. The manual pages have been updated to mention all this. * The command line options at the beginning of the manual pages have been rearranged in alphabetical order. v3.0 - patchlevel 3. - 3rd January 1991. ---------------------------------------- * From Rich Morin <cfcl!rdm@apple.com> The basic SunView interface seems to be functional. The following glitches were fixed: :l - didn't show possibilities on ambiguous abbreviations fixed: special (special.c) ? - printed specials as #w..., not :w... fixed: HelpMsg, help (special.c) ^D - hung popi input, generated huge error log fixed: disp_getchar (sunview.c) **<<May want to check for similar bugs in other drivers>>** popi -\? - usage message was incomplete fixes: filled out usage table a bit: UsageMsg (main.c) also sorted option parsing switch: get_options (main.c) popi -d - dumped core if no argument was given popi -g - dumped core if no argument was given kludged: get_options (main.c) Fixed some minor fluff in the manual page: magic cookie for specials is now :, not #. magic cookie (?) for color I/O is no longer needed. Its "it's" was wrong, now it's "its"... CFCL is only one laboratory (if that). New files: * popitopgm.c - a small filter to convert old format popi image files to pgm format. See the README and manual pages for more details. v3.0 - patchlevel 2. - 31st December 1990. ------------------------------------------ * Converted the image reading/writing routines to use pgm (portable graymap) for greyscale images, and ppm (portable pixmap) for color images. The manuals pages have been updated to include a new section describing the image formats. The README file had been modified to included the appropriate copyright messages. The FILES and MANIFEST files have been modified to mention the new files. * From Russ Nelson <nelson@sun.soe.clarkson.edu> The command line is now too long for DOS compilers. All DOS compilers will have this problem: Turbo C, MS-C, MS-Quick C, and Mix C. The solution used, has been to put all the object files but main into a library, and link using that library. This keeps the Makefile the same for everyone, but it makes it slightly harder to maintain because of the addition of library commands. New files: * libpbm.c - the PBM/PGM/PPM routines needed by popi. These have been taken from the PBMPLUS package, and modified appropriately for popi. * libpbm.h - definitions and declaration for the PBM/PGM/PPM routines used by popi. Used in libpbm.c and io.c. v3.0 - patchlevel 1. - 28th December 1990. ------------------------------------------ * The X11 (Xlib) version was creating a pixmap of the full image size every time it was drawing a scanline. The pixmap only needed to be one pixel high. * Rewrote the XView version in the same style as the SunView driver. v3.0 - patchlevel 0. - Started 21st December 1990. -------------------------------------------------- * From Russ Nelson <nelson@image.soe.clarkson.edu> Incorporated various efficiency changes. * From Rich Morin <cfcl!rdm@apple.com> - Added a -c flag - color (RGB) calculation, display, and I/O (NTSC luma display on non-24-bit monitors) - Added a -s flag, #signed - signed I/O - Added 24-bit monitor support under SunView - Added smallest unambiguous name recognition for special commands (eg, #r) - Added table-driven messages about special commands in #help - Assorted bug fixes * Generated a Makefile.dist, which will need to be copied over to Makefile. This saves stomping on everybodies toes when changes to the Makefile need to be made. * Reversed the order of information in the CHANGES file. The latest entries are now first. * Created MANIFEST and FILES files for popi. Moved the troffable manual pages to popi.man, and the plain text version to popi.man.text. Updated the TODO file with a list of all the new problems and suggested enhancements since the previous version was posted to the net. The README file has been reordered into various sections, with a contents at the front. * Indented the code in debug.c, expr.c, io.c, lex.c main.c, polar.c, run.c, special.c and popi.h to the same style. * Replaced the threshold half-toning with floyd-steinberg error diffusion dithering (taken from xloadimage). v2.1 - patchlevel 6. - Posted to comp.sources.bugs (May 1990). -------------------------------------------------------------- * From Russ Nelson <nelson@image.soe.clarkson.edu> Previously most tokens were represented as their character equivalents. These have been changed to numeric defines so that many compilers can generate better code for the switch statement in prun(). * Added some debugging to help trace tokens. * From K. Palaniappan <palani@uirvld.csl.uiuc.edu> Fixed the out of range problem at CRVAL in prun(). v2.1 - patchlevel 5. - Posted to comp.sources.bugs (January 1990). ------------------------------------------------------------------ * There is now an optional compilation parameter. If DEF_SIZE is defined, the image will be square and that size by default. If DEF_X and/or DEF_Y are defined, the image will be the size given by the definitions. Makefile has been modified to add a definition of -DDEF_SIZE=128 for the PC versions. New files: * gl.c - a graphics driver for the public domain gl graphics package from Glenn Geers <glenn@extro.ucc.su.oz>. Glenn has used this to port to the 386 Xenix box. See the comments at the beginning of the gl graphics driver for more information on just what devices and O/S's are supported. * g_init.c - a new version of the g_init.c file that comes with the gl graphics package, which includes 386 mods. v2.1 - patchlevel 4. Posted to comp.sources.bugs (January 1990). ---------------------------------------------------------------- * The size of the input buffer for typing has been changed from 80 to 256 characters. * The SunView driver has been completely rewritten. It now has a scrollable text window for command input, and a canvas window of the correct size for displaying the images. There is a panel with a "% done" slider which is displayed as it is generating the next image. The SunView driver therefore no longer uses graphics.c. * The comment for the exportable routines in each graphics driver has been changed from "ten routines" to "the routines". There are now only nine routines. * The declaration for the variable total in getpix in file io.c was in the wrong position, and prevented the file from successfully compiling. This problem was introduced in patch #3. * Added disp_percentdone(100) calls to the oil and tile routines in special.c. * In disp_perecentdone in graphics.c, a check is now made that the new percent value is different from the old one, otherwise the routine returns immediately. This dramatically improves the performance of server based graphics drivers. * The routine ImgAlloc in io.c was incorrectly mallocing an area based on the variable Xsize. This should have been Ysize. * Two small adjustments to the HP graphics driver. * Introduces the : operator to denote special functions. This replaces the # operator, which is currently retained for backward compatibility, but with no guarantee that this will always remain so. The manual page has been updated to reflect this change. * The popi help message has been updated to include several missing functions plus the new functions. * Inclusion of the :quit, :exit and :q functions. Guess what they do! New files: * next.m - a graphics driver for the NeXT from Joe Freeman of NeXT. Note that a different OCFLAGS value in the Makefile should be used. * CHANGES - documented history of the changes made with each new popi patch. v2.1 - patchlevel 3. - Posted to comp.sources.bugs (December 1989). ------------------------------------------------------------------- * Checking has been added to prevent constructs such as: dmr[x+1,y+1]=.... causing a segmentation fault. * The X11 driver has been fixed to correctly display on monochrome screens where the black pixel isn't 1. * New commands #create and #run have been added. * ungetc is now handled in the main popi code, so the graphics routine disp_ungetc is no longer needed. * Fixed a few typos in the manual page. * Adjusted a few inefficiencies found in expr.c, io.c and main.c * Several changes to allow a potential change in the image data structure. New files: * popi.man - this is a plain text version of the popi manual page (popi.1) for those people who do not have the ability to format popi.1. * hp.c - a graphics driver for an HP display from Eric Haines - 3D/Eye Inc, Ithaca, NY. v2.1 - patchlevel 2. - Released to comp.sources.misc (December 1989). --------------------------------------------------------------------- Funky_Stuff len=`wc -c < CHANGES` if [ $len != 12961 ] ; then echo error: CHANGES was $len bytes long, should have been 12961 fi fi # end of overwriting check if [ -f popi.man.text ] then echo shar: will not over-write existing file popi.man.text else echo shar: extracting 'popi.man.text', 37480 characters cat > popi.man.text <<'Funky_Stuff' POPI(1L) MISC. REFERENCE MANUAL PAGES POPI(1L) NAME popi - perform interactive digital image transformations SYNOPSIS popi [option] ... [file] ... DESCRIPTION Popi is a program which allows arbitrary transformations to be interactively applied to digital images. It is based on the program described in "Beyond Photography - The Digital Darkroom" by Gerald J. Holzmann. The meanings of the avail- able command line options are as follows: -a- Turn auto-display off. Equivalent to the :display - command. Images can still be displayed explicitly with the :display image command. -a+ Turn auto-display on. After each image transformation, the image will be displayed. Equivalent to the :display + command (default). -c+ Set the colour mode flag on. Do all work in RGB. Grayscale displays present NTSC Luma values. -c- Turn the colour mode flag off. Use grayscale (default). -l[logfile] Enables logging of all input, error messages, and some responses. Logging is done on the named file, or the file "popi.log" if no name is given. The :logfile com- mand may also be used to turn logging on and off. -o Save images to disk in the old popi format. -p[ncpus] On a Sequent multiprocessor, use the specified number of cpus to perform the transform. If this option is given without a number, the maximum number available is used. This option has no effect on uniprocessor com- puters. -s+ Set the signed I/O flag on. Do signed I/O. -s- Turn the signed I/O flag off. Do unsigned I/O (default). -t+ Set the trig caching flag on. Cache trig values in /usr/tmp/popi.X.Y, where X and Y are the size limits for the current popi run. (This speeds up the first use of polar co-ordinates in each run.) Sun Release 4.1 Last change: 20 December 1989 1 POPI(1L) MISC. REFERENCE MANUAL PAGES POPI(1L) -t- Turn the trig caching flag off. Don't do trig caching (default). -V Print program version identification message and exit. -v+ Set the verbose flag on. Be chatty about a number of things. -v- Turn the verbose flag off. Be silent about everything except error messages (default). -xWidth Set the image width (number of pixels per scanline) to Width (default 512). -yHeight Set the image height (number of scanlines) to Height (default 512). SYNTAX An image transform is described by a transform statement. The statement basically takes the form dest = expression where dest indicates the new image and expression describes a transformation. This statement is executed over the range of image coordinates. For a 512 x 512 image, it will be executed 262144 times. An image is normally referenced in a statement by its name and an index. A cartesian index is specified by using the x and y coordinates in square brack- ets after the image name. Thus dmr[0,0] is the top left pixel in the image named dmr. Polar coordinates may be specified by giving a radius and angle (in degrees) in curly brackets. Thus dmr{0,0} refers to the centre pixel in the image. The symbols x and y may appear in the transform statement. These take on values corresponding to a dif- ferent pixel each time the transform is executed. Inter- nally the algorithm is as follows for y varying from 0 to Y for x varying from 0 to X execute transform statement where Y is the maximum y coordinate and X is the maximum x coordinate. The image size can be set on the command line as described later. The value of a pixel varies from 0 to 255 in the current implementation. Any value outside this range is treated as modulo 256 when being stored in an image (ie. it wraps around). Low numeric values represent dark colours, while large values represent light colours. A Sun Release 4.1 Last change: 20 December 1989 2 POPI(1L) MISC. REFERENCE MANUAL PAGES POPI(1L) simple transform statement to set an image to completely black would be new[x,y] = 0 ; set image to black The name new is one of the two default images always main- tained internally. The other is old. The images referred to by these names are swapped after each operation, so a suc- cession of transforms may modify the "old" image to produce a "new" image. Thus the statement new[x,y] = old[x,y] / 2 ; darken image will reduce all the pixel intensity values by a half, dark- ening the existing image. The semicolon (`;') character introduces a comment. Anything from this to the end of the line is ignored. All the standard arithmetic, relational and boolean operators from the C language are available, with precedence generally as per the C language. Some addi- tional operators, predefined variables and math functions are also available. Here is a listing of the available sym- bols and their meanings. name Refers to an image name. If not followed by index brackets, the index [x,y] is assumed. The currently available names are those shown by the :list display, and also old and new. $n Where n is a digit, this is an alternative method of referring to an image. In fact this may be the only method if the image name contains punctuation charac- ters. The :list command shows the correspondence between image names and this form of reference. X The maximum x coordinate value. This is one less than the number of pixels per scanline (image width), which may be set with the -x command line option. Y The maximum y coordinate value. This is one less than the number of scanlines (the height of the image), which may be set with the -y command line option. x The current cartesian x coordinate. Varies from 0 (left of image) to X (right of image). y The current cartesian y coordinate. Varies from 0 (top of image) to Y (bottom of image). r The radius component of the polar coordinate which corresponds to the current cartesian (x,y) coordinate. This is equivalent to sqrt(x*x + y*y) with a transla- tion of the origin. Sun Release 4.1 Last change: 20 December 1989 3 POPI(1L) MISC. REFERENCE MANUAL PAGES POPI(1L) a The angle component of the polar coordinate which corresponds to the current cartesian (x,y) coordinate. This is equivalent to (and a shorthand for) atan(y/x). Note that the first time in a popi session you use an expression with either r or a in it, you may notice an extra delay before the image transformation begins. This is due to precalculation of an array of polar coordinates that happens the first time you use one. R The maximum radius value of a polar coordinate. A The maximum angle value of a polar coordinate (this is just 360). Z The maximum intensity value of a pixel (corresponding to white). Currently, this is always 255. ** The exponentiation (raise to the power) operator. The expression x ** 2 means x squared (x * x). * The multiplication operator. This has a higher pre- cedence than division to avoid underflow in expressions with multiplication and division, since normally expressions are evaluated as integers. / Integer division. If the divisor is 0, the result is set to Z. % Modulo. If the divisor (right hand operand) is 0, the result is set to 0. + Addition. - Subtraction. This may be a unary or a binary operator. << Left shift. The left operand is shifted left the number of bits specified by the right operand. >> Right shift. The left operand is shifted right the number of bits specified by the right operand. > Greater than. As with all the relational operators, if the specified relation between the operands is true, the result is 1, otherwise the result is 0. < Less than. >= Greater than or equal to. <= Less than or equal to. Sun Release 4.1 Last change: 20 December 1989 4 POPI(1L) MISC. REFERENCE MANUAL PAGES POPI(1L) == Test for equality. != Not equal to. & Bitwise (arithmetic) AND operator. ^ Bitwise exclusive OR (XOR) operator. | Bitwise (arithmetic) OR operator. && Logical AND operator. The result is 1 if both of the operands are true (non-zero); otherwise the result is 0. Unlike the && operator of the C language, this operator is currently not conditional. Both operands are always evaluated. || Logical OR operator. The result is 1 if both either (or both) of the operands are true (non-zero); other- wise the result is 0. Unlike the || operator of the C language, this operator is currently not conditional. Both operands are always evaluated. sin(expr) This gives the value of the trigonometric sine of the expression, multiplied by Z. This is required because all operations are performed with integers. cos(expr) This gives the value of the trigonometric cosine of the expression, multiplied by Z. This is required because all operations are performed with integers. atan(y-expr,x-expr) This returns the trigonometric arctangent (inverse tangent) of y-expr/x-expr in degrees (ie the value returned will be between 0 and 360). hypot(x,y) This returns the hypotenuse (x*x + y*y). log(expr) Returns the natural logarithm of the expression. sqrt(expr) Returns the square root of the expression. abs(expr) Returns the absolute value of the expression. rand() Returns a positive random number. This will usually be used with the modulo or bitwise AND operator to Sun Release 4.1 Last change: 20 December 1989 5 POPI(1L) MISC. REFERENCE MANUAL PAGES POPI(1L) restrict the range of the result. For example, new[x,y] = old[x,y] + rand() % 20 - 10 will adjust the brightness levels of each pixel in the old image by a random amount (up to 10 levels brighter or darker). SPECIAL COMMANDS Popi supports a number of special commands, each starting with a : character. The current set of commands includes: debug, display, free, genepson, genps, help, list, logfile, matte, melt, ofmt, oil, read, shear, signed, slice, tile, truncate, undo, verbose, version, and write. They may be abbreviated to the minimum unambiguous length (e.g., :r). Their definitions follow: :read "filename" [image-name] Read a raw data file into the named image. If no image name is specified, the name is derived from the base name component of the filename. If the name already exists, that image is overwritten in memory, otherwise a new image is created. If the filename does not exist, but the same name with a ".Z" suffix does exist, it is assumed that the file is compressed and the "zcat" program is used to read the compressed image. Note that when the image name defaults to the file name, only the basename (portion after the last '/' character, if any) is used to name the image. If this resulting name starts with a digit, or contains any characters other than alphabetic, digits and the under- score, you will not be able to reference the image by name, but will have to use the alternative "$n" syntax. :write "filename" [image-name] Write a raw data file from the named image. The image name is optional, and if not specified, image "old" is used. If the first character of the filename is `|', the rest of the filename is interpreted as a command to be run, with the raw image data being fed to it as standard input. :list All the named images (other than "old" and "new" are listed). :genps "filename" [image-name] Generate postscript to produce the image. The image name is optional, and if not specified, image "old" is used. The image will be scaled to fit whatever paper size is being used. As with the :write command, if the Sun Release 4.1 Last change: 20 December 1989 6 POPI(1L) MISC. REFERENCE MANUAL PAGES POPI(1L) first character of the filename is a `|' symbol, the rest of the string will be treated as a command to be executed, with the postscript being piped to its stan- dard input. This is convenient for printing images on a PostScript printer. :undo The old and new images are swapped. This has the effect of restoring the image that existed before the last transformation. :genepson "filename" [image-name] Generate data for an Epson (or compatible) printer to produce the image. The image name is optional, and if not specified, image "old" is used. Under MSDOS, the device name can be used directly (eg "PRN"). The existing code is for a 24-pin printer such as the LQ-500. To generate data for an 8-pin printer requires a couple of minor modifications to function genepson() in file special.c. :undo The old and new images are swapped. This has the effect of restoring the image that existed before the last transformation. :display image-name The named image will be displayed. This is the fastest way to display an image, and works regardless of the state of auto-display. :display + Turn auto-display on (equivalent to the command-line option -a+ ). :display - Turn auto-display off (equivalent to the command-line option -a- ). :truncate + All assignments to an image with values outside the range 0 to Z will be truncated to the appropriate boun- dary, instead of wrapping as described in the book. An example of using this feature would be for a simplistic lightening of an image by adding a constant value. Normally, very white areas would wrap around and become black, but enabling truncation prevents this. :truncate - All assignments to an image will be done modulo (Z+1). This is the default. Sun Release 4.1 Last change: 20 December 1989 7 POPI(1L) MISC. REFERENCE MANUAL PAGES POPI(1L) :truncate Report whether truncation is currently in effect or not. :verbose + Turn on verbose mode. Equivalent to the -v+command Certain warning messages will be printed. This turns on the "percent done" feature of some drivers (on oth- ers it is always active). :verbose - Turn off verbose mode. Equivalent to the -v-command :verbose Report the state of the verbose flag. :signed + All file I/O is done in signed (2's complement) mode. :signed - All file I/O is done in unsigned mode. This is the default. :signed Report the state of the signed I/O flag. :ofmt + The old popi format is used for output files. :ofmt - The new popi format is used for output files. This is the default. :ofmt Report the state of the output format flag. :logfile + Enable logging on the current log file (default "popi.log"). If logging is already enabled, the file is closed and re-opened with a new timestamp appended. :logfile - Disable logging" :logfile "filename" Enable logging on the specified file. Whenever a log file is opened, it is always opened in append mode, so existing data is never truncated. Upon opening a log file, a timestamp is written. All user input is logged, along with error messages and some program responses. Sun Release 4.1 Last change: 20 December 1989 8 POPI(1L) MISC. REFERENCE MANUAL PAGES POPI(1L) :create imagename Memory is allocated for a new image. This image is then swapped with the current image (the result of the last transformation). :run "filename" Commands are read and executed from the given filename. :free imagename The memory associated with the named image is freed. Any further access to this image becomes impossible. This command may be useful in situations where memory is very limited, such as a PC. TRANSFORMATIONS The remaining special commands are used to obtain special built-in transformations, as described in Chapter 6 of "Beyond Photography". In each of these cases, the image name is optional, and defaults to "old". In each case (except for :melt), the result is stored in "new", and then "old" and "new" are swapped as usual. In the case of :melt, the transformation is done in place and no swap occurs. :oil [image-name] :shear [image-name] :slice [image-name] :tile [image-name] :melt [image-name] :matte [image-name [gamma]] In this case, gamma is an optional floating point number (defaults to 7.5). See the book for details. DIFFERENCES There are a number of differences between the Pico inter- preter, for which the examples in the book are written, and the Popi interpreter as implemented here. Integer evalua- tion stack. The current version of the interpreter has an integer evaluation stack. For this reason, the sin() and cos() functions, have their results multiplied by Z automat- ically in order to be significant. A future version of the interpreter will provide the option for a floating point stack, and a syntax which will handle both cases. Polar coordinates. In the book, both cartesian and polar coordi- nates are specified with square brackets. The decision of whether to interpret the indices as polar or cartesian is based on context; if the symbols r and a are used in the index expressions, the coordinates are interpreted as polar, Sun Release 4.1 Last change: 20 December 1989 9 POPI(1L) MISC. REFERENCE MANUAL PAGES POPI(1L) otherwise they are interpreted as rectangular. Thus, in order to use a radius or angle in a cartesian coordinate expression, it must be cast, as is done on page 48 of the book. By providing a separate syntax for polar and carte- sian coordinate references, the problem never occurs. EXAMPLES These examples are mainly taken from the book, with syntax modifications where required. The images in the book are usually 1000 x 1000 pixels. To produce the same results on a smaller image, you may need to multiply any occurences of x, y and r by an appropriate scaling factor. The first example image generation in the book is new[x,y] = x + y ; page 17 (3.1) which produces a number of diagonal stripes, each fading from black to white. On a 512 x 512 image, to get the same number of stripes, use the transform new[x,y] = x*2 + y*2 A series of ripples can be produced with new[x,y] = (x * y) % (Z + 1) ; page 18 (3.2) or more simply, because all brightness values are inherently modulo (Z + 1) unless truncation is turned on new[x,y] = x * y A single smooth transition can be accomplished with new[x,y] = (Z * x * y) / ((X-1) * (Y-1)) ; page 18 (3.3) The transformation new[x,y] = x % y is the same as new[x,y] = x when x < 0 (ie in the lower left triangle of the image, with a different effect in the upper right half. The trig functions allow transforms such as new[x,y] = y + sin(x) / 2 ; page 19 (3.5) which produce a series of sine waves (remember that the range of sin(x) is +-Z. An image reminiscent of a radar sweep can be produced by new[x,y] = atan(y - Y/2, x - X/2) * Z / 360 ; page 19 (3.6) The atan() function has a range of 0 .. 360, so the *Z/360 Sun Release 4.1 Last change: 20 December 1989 10 POPI(1L) MISC. REFERENCE MANUAL PAGES POPI(1L) rescales to 0 .. Z. This transform is overall providing an intensity relative to the angle of a point in polar coordi- nates. The transform language provides the current angle as the variable a, so this statement can be rewritten as new[x,y] = a * Z / 360 Polar coordinates can be used to produce an image which varies from black in the centre to white on the outside new[x,y] = r * Z / R ; page 21 (3.11) or a spiraling effect new[x,y] = (((a + r) % 16) - 8) * Z / 16 + Z/2 ; page 21 (3.12) The conditional operator can be used to provide a filled black circle new[x,y] = r > R/2 ? 0 : Z or black and white patterns such as new[x,y] = ((x % (5 + y/25)) > 5) ? 0 : Z ; page 20 (3.9) new[x,y] = (Z * abs(x % sin(y)) > 10) ? 0 : Z ; page 20 (3.10) We can also modify existing images using these transforms. The previous image can always be referred to as old, or an explicitly named image can be used. We can read an image (eg of Dennis Ritchie) using :read "dmr" ; read the image in the file "dmr" and name it dmr. and then use it in a transform, such as new[x,y] = Z - dmr[x,y] ; page 22 (3.13) This produces a negative, which can be written to a file with :write "dmr_neg" or converted to PostScript and printed with :genps "| lp -dalw" Since the new image built during a transformation becomes the old image of the following transform, the negative image can be re-reversed to produce the original with new[x,y] = Z - old[x,y] ; reverse the process Sun Release 4.1 Last change: 20 December 1989 11 POPI(1L) MISC. REFERENCE MANUAL PAGES POPI(1L) In the following examples, we will use old in most of the transforms, rather than a particular image name. In prac- tice, you would probably use a specifically named image instead. Provide a circular frame for an image new[x,y] = r > R/2 ? 0 : old[x,y] A solarisation process, that fades in from left to right new[x,y] = (old[x,y] > (Z*x) / (2 * X)) ? old[x,y] : Z-old[x,y] ; page 22 (3.16) Generate a relief map new[x,y] = old[x,y] + (Z/2 - old[x+2,y+2]) ; page 24 (3.19) Shrink an image new[x,y] = old[x*2,y*2] ; page 25 (3.24) An interesting caricature is produced by new[x,y] = old{sqrt(r * R),a} ; page 34 Note the use of polar coordinates. The reverse transform gives a fisheye lens effect: new[x,y] = old{(r*r)/R, a} ; page 60 The following transform illustrates how an expression can be used for the indices of the destination matrix. new[x, y-old[x,y]/4] = old[x,y] ; page 40 An image can be swirled about the centre with new[x,y] = old{r, a + r/3} The following transform uses polar coordinate values in a cartesian reference, resulting in something that looks like what you'd see in a cylindrical mirror new[x,y] = old[a * X/A, r * Y/R] ; page 48 The image generated by new[x,y] = old{ (r/16)*16, (a/16)*16 } ; page 72 is very interesting, in that it is completely unrecognisable when viewed up close, but from a distance of a few metres it will resolve into the original. new[x,y] = old{r, a + old{r,a}/8} ; page 68 Sun Release 4.1 Last change: 20 December 1989 12 POPI(1L) MISC. REFERENCE MANUAL PAGES POPI(1L) This image is a swirl, but with the skew dependant on the brightness of the current point. new[x,y] = x < X/2 ? old[x,y] : old[X-x,y] new[x,y] = x > X/2 ? old[x,y] : old[X-x,y] These transformations do a horizontal mirror reversal about the centre of the image. Because faces are usually close to, but not exactly, centered, this transform of a face can be interesting. new[x,y] = old[x+(x%32)-16, y] ; page 58 new[x,y] = old[x+((a+r/10)%32)-16, y] These transforms applied to a face produce what looks like someone peering through a bathroom window. DRIVERS nulldev The null device driver is mainly for people with no graphics display device for which a driver exists. Using this device, data for a PostScript or Epson printer can still be generated. atariterm The atari driver is for use with "TERM", a multiplexing terminal program for the Atari ST, written by Peter Collinson of the University of Kent at Canterbury. It is not a driver for running native on an atari. kermit This is a driver for MS-Kermit 2.32 on an IBM PC, which is capable of emulating a Tektronix 4010. This provides three levels of contrast (nothing, normal and bold). MGR This driver is for the Bell Core MGR window system. It is visually identical to the SunView version, but is currently hardwired to monochrome. NeWS This is the driver that will work with NeWS v1.1 and OpenWindows v1.0. It is also visually identical to the SunView version. pcturbo This is a driver for running popi native on a PC with Borland's Turbo C compiler. It uses the graphics library supplied with Turbo C, which auto-detects most types of graphics display. No attempt at using a colourmap is done - a single display dot is used for each image pixel, with simple dithering. Only directly accesible memory is used, which drastically restricts the size of images that can be handled. Sun Release 4.1 Last change: 20 December 1989 13 POPI(1L) MISC. REFERENCE MANUAL PAGES POPI(1L) SunView This driver works with the SunView graphics package available on Sun workstations. This uses a scrollable command window which allows line editing, cutting and pasting. The image canvas is a separate window on the correct size. The output is in colour on 24-bit colour machines, in 256 grayscale on 8-bit colour machines, and an 8x8 dither on monochrome screens. X11 This driver is the initial version to work with MIT's X11 window system. This currently has minimal func- tionality. The output is in 256 grayscales on colour machines, and an 8x8 dither on monochrome screens. XView A conversion of the original SunView graphics driver to use the XView X11 toolkit. This driver is visually identical to the X11 version. This driver will be rewritten to be identical with the new SunView graphics driver. IMAGE FORMAT popi use the portable graymap file format for the grayscale images, and the portable pixmap file format for its color images. These image formats are an integral part of the PBMPLUS extended portable bitmap toolkit distributed by Jef Poskanzer. See the README file, for the copyright notices associated with this package. popi will automagically read images in the old format, but if you have any such images, it is recommended that they be converted to pgm files using the small popitopgm filter included with this package, as this format may no longer be supported in future releases. It is also recommended that you get a copy of the PBMPLUS toolkit. popitopgm takes an old popi image on standard input, and writes a pgm file to standard output. There are two command line options that might be applicable for your image conversion: -x nnn - the width of the image in pixels. -y nnn - the height of the image in pixels. The program defaults these values to 512 if they aren't given. The definition of the portable graymap format is as follows: - A "magic number" for identifying the file type. A pgm file's magic number is the two characters "P2". - Whitespace (blanks, TABs, CRs, LFs). Sun Release 4.1 Last change: 20 December 1989 14 POPI(1L) MISC. REFERENCE MANUAL PAGES POPI(1L) - A width, formatted as ASCII characters in decimal. - Whitespace. - A height, again in ASCII decimal. - Whitespace. - The maximum gray value, again in ASCII decimal. - Whitespace. - Width * height gray values, each in ASCII decimal, between 0 and the specified maximum value, separated by whi- tespace, starting at the top-left corner of the graymap, proceding in normal English reading order. A value of 0 means black, and the maximum value means white. - Characters from a "#" to the next end-of-line are ignored (comments). - No line should be longer than 70 characters. Here is an example of a small graymap in this format: P2 # feep.pgm 24 7 15 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3 3 3 3 0 0 7 7 7 7 0 0 11 11 11 11 0 0 15 15 15 15 0 0 3 0 0 0 0 0 7 0 0 0 0 0 11 0 0 0 0 0 15 0 0 15 0 0 3 3 3 0 0 0 7 7 7 0 0 0 11 11 11 0 0 0 15 15 15 15 0 0 3 0 0 0 0 0 7 0 0 0 0 0 11 0 0 0 0 0 15 0 0 0 0 0 3 0 0 0 0 0 7 7 7 7 0 0 11 11 11 11 0 0 15 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Programs that read this format should be as lenient as pos- sible, accepting anything that looks remotely like a gray- map. There is also a variant on the format, available by setting the RAWBITS option at compile time. This variant is dif- ferent in the following ways: - The "magic number" is "P5" instead of "P2". - The gray values are stored as plain bytes, instead of ASCII decimal. - No whitespace is allowed in the grays section. Sun Release 4.1 Last change: 20 December 1989 15 POPI(1L) MISC. REFERENCE MANUAL PAGES POPI(1L) - The files are smaller and many times faster to read and write. Note that this raw format can only be used for maxvals less than or equal to 255. The definition of the portable pixmap format is as follows: - A "magic number" for identifying the file type. A ppm file's magic number is the two characters "P3". - Whitespace (blanks, TABs, CRs, LFs). - A width, formatted as ASCII characters in decimal. - Whitespace. - A height, again in ASCII decimal. - Whitespace. - The maximum color-component value, again in ASCII decimal. - Whitespace. - Width * height pixels, each three ASCII decimal values between 0 and the specified maximum value, starting at the top-left corner of the pixmap, proceding in normal English reading order. The three values for each pixel represent red, green, and blue, respectively; a value of 0 means that color is off, and the maximum value means that color is maxxed out. - Characters from a "#" to the next end-of-line are ignored (comments). - No line should be longer than 70 characters. Here is an example of a small pixmap in this format: P3 # feep.ppm 4 4 15 0 0 0 0 0 0 0 0 0 15 0 15 0 0 0 0 15 7 0 0 0 0 0 0 0 0 0 0 0 0 0 15 7 0 0 0 15 0 15 0 0 0 0 0 0 0 0 0 Programs that read this format should be as lenient as pos- sible, accepting anything that looks remotely like a pixmap. Sun Release 4.1 Last change: 20 December 1989 16 POPI(1L) MISC. REFERENCE MANUAL PAGES POPI(1L) There is also a variant on the format, available by setting the RAWBITS option at compile time. This variant is dif- ferent in the following ways: - The "magic number" is "P6" instead of "P3". - The pixel values are stored as plain bytes, instead of ASCII decimal. - Whitespace is not allowed in the pixels area. - The files are smaller and many times faster to read and write. Note that this raw format can only be used for maxvals less than or equal to 255. SEE ALSO ipscript(1L), imavg(1L). AUTHOR Gerald J. Holzmann, AT&T Bell Laboratories, Murray Hill, New Jersey. Modifications and additional functionality, Atari, PC, PostScript, Epson and null drivers by Stephen Frede, Softway Pty Ltd, Australia. Popi maintainance, SunView, X11, NeWS, MGR and XView graph- ics drivers by Rich Burridge, Sun Microsystems, Australia. Kermit graphics driver by Frank Crawford, Q.H. Tours. Amiga graphics driver by Peter Chubb, Softway Pty Ltd, Aus- tralia. Apollo driver by Tim Lambert, University of New South Wales. HP driver by Eric Haines, 3D/Eye Inc, Ithaca, NY. Popi efficiency changes and improvements to the PC driver by Russ Nelson, Clarkson University. Color support, signed/unsigned i/o and 24 bit SunView sup- port by Rich Morin, Canta Forda Computer Laboratory. Dithering code taken from xloadimage, which is copyright (c) 1989-1990 by Kirk L. Johnson, Jim Frost and Steve Losen. See the README file for the copyright notices associated with this code. Popi image i/o routines are based on the PBM/PGM/PPM rou- tines from the PBMPLUS package, which is copyright (c) 1989 by Jef Poskanzer. See the README file for the copyright notices associated with this code. BUGS Functions which require popen() (ie auto reading of compressed files and writing to pipes) don't work in the sequent multiprocessor version. Reading of compressed images in the old format will no longer work, because you Sun Release 4.1 Last change: 20 December 1989 17 POPI(1L) MISC. REFERENCE MANUAL PAGES POPI(1L) can't seek on the pipe from zcat. Probably more - please notify richb@Aus.Sun.COM of any found, if it's not already listed in the TODO file. Sun Release 4.1 Last change: 20 December 1989 18 Funky_Stuff len=`wc -c < popi.man.text` if [ $len != 37480 ] ; then echo error: popi.man.text was $len bytes long, should have been 37480 fi fi # end of overwriting check exit 0 # Just in case...