Usenet 1994 January/usenetsourcesnewsgroupsinfomagicjanuary1994.iso/sources/misc/volume34/imagemagick/part08

Text File | 1992-12-14 | 57.0 KB | 1,643 lines

Newsgroups: comp.sources.misc
From: [e-mail] (John Cristy)
Subject:  v34i036:  imagemagick - X11 image processing and display v2.2, Part08/26
Message-ID: <[e-mail]>
X-Md4-Signature: 4741345e10680ae21b1746a8b2adcdff
Date: Sun, 13 Dec 1992 20:27:50 GMT
Approved: [e-mail]

Submitted-by: [e-mail] (John Cristy)
Posting-number: Volume 34, Issue 36
Archive-name: imagemagick/part08
Environment: UNIX, VMS, X11, SGI, DEC, Cray, Sun, Vax

#!/bin/sh
# this is Part.08 (part 8 of a multipart archive)
# do not concatenate these parts, unpack them in order with /bin/sh
# file ImageMagick/import.c continued
#
if test ! -r _shar_seq_.tmp; then
    echo 'Please unpack part 1 first!'
    exit 1
fi
(read Scheck
 if test "$Scheck" != 8; then
    echo Please unpack part "$Scheck" next!
    exit 1
 else
    exit 0
 fi
) < _shar_seq_.tmp || exit 1
if test ! -f _shar_wnt_.tmp; then
    echo 'x - still skipping ImageMagick/import.c'
else
echo 'x - continuing file ImageMagick/import.c'
sed 's/^X//' << 'SHAR_EOF' >> 'ImageMagick/import.c' &&
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%                 IIIII  M   M  PPPP    OOO   RRRR    TTTTT                   %
%                   I    MM MM  P   P  O   O  R   R     T                     %
%                   I    M M M  PPPP   O   O  RRRR      T                     %
%                   I    M   M  P      O   O  R R       T                     %
%                 IIIII  M   M  P       OOO   R  R      T                     %
%                                                                             %
%                                                                             %
%             Import X11 image to a machine independent format.               %
%                                                                             %
%                                                                             %
%                                                                             %
%                           Software Design                                   %
%                             John Cristy                                     %
%                              July 1992                                      %
%                                                                             %
%                                                                             %
%  Copyright 1992 E. I. du Pont de Nemours & Company                          %
%                                                                             %
%  Permission to use, copy, modify, distribute, and sell this software and    %
%  its documentation for any purpose is hereby granted without fee,           %
%  provided that the above Copyright notice appear in all copies and that     %
%  both that Copyright notice and this permission notice appear in            %
%  supporting documentation, and that the name of E. I. du Pont de Nemours    %
%  & Company not be used in advertising or publicity pertaining to            %
%  distribution of the software without specific, written prior               %
%  permission.  E. I. du Pont de Nemours & Company makes no representations   %
%  about the suitability of this software for any purpose.  It is provided    %
%  "as is" without express or implied warranty.                               %
%                                                                             %
%  E. I. du Pont de Nemours & Company disclaims all warranties with regard    %
%  to this software, including all implied warranties of merchantability      %
%  and fitness, in no event shall E. I. du Pont de Nemours & Company be       %
%  liable for any special, indirect or consequential damages or any           %
%  damages whatsoever resulting from loss of use, data or profits, whether    %
%  in an action of contract, negligence or other tortious action, arising     %
%  out of or in connection with the use or performance of this software.      %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Import is an X Window System window dumping utility.  Import allows X
%  users to store window images in a specially formatted dump file.  This
%  file can then be read by the Display utility for redisplay, printing,
%  editing, formatting, archiving, image processing, etc.  The target
%  window can be specified by id or name or be selected by clicking the
%  mouse in the desired window.  The keyboard bell is rung once at the
%  beginning of the dump and twice when the dump is completed.
%
%  The import program command syntax is:
%
%  Usage: import [options ...] file
%
%  Where options include:
%    -border          include image borders in the output image
%    -compress type   RunlengthEncoded or QEncoded
%    -delay seconds   pause before selecting target window
%    -display server  X server to contact
%    -frame           include window manager frame
%    -monochrome      transform image to black and white
%    -scene value     image scene number
%    -screen          select image from root window
%    -verbose         print detailed information about the image
%    -window id       select window with this id or name
%
%  Change '-' to '+' in any option above to reverse its effect.
%  For example, +frame means do not window manager frame.
%
%  By default, 'file' is written in the MIFF image format.  To specify
%  a particular image format, precede the filename with an image format
%  name and a colon (i.e. mtv:image) or specify the image type as the
%  filename suffix (i.e. image.mtv).  Specify 'file' as '-' for standard
%  input or output.
%
%
*/
X
/*
X  Include declarations.
*/
#include "display.h"
#include "image.h"
#include "alien.h"
#include "X.h"
X
/*
X  Global declarations.
*/
char
X  *application_name;
X
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   E r r o r                                                                 %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Function Error displays an error message and then terminates the program.
%
%  The format of the Error routine is:
%
%      Error(message,qualifier)
%
%  A description of each parameter follows:
%
%    o message: Specifies the message to display before terminating the
%      program.
%
%    o qualifier: Specifies any qualifier to the message.
%
%
*/
void Error(message,qualifier)
char
X  *message,
X  *qualifier;
{
X  (void) fprintf(stderr,"%s: %s",application_name,message);
X  if (qualifier != (char *) NULL)
X    (void) fprintf(stderr," (%s)",qualifier);
X  (void) fprintf(stderr,".\n");
X  exit(1);
}
X
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   U s a g e                                                                 %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Procedure Usage displays the program usage;
%
%  The format of the Usage routine is:
%
%      Usage()
%
%
*/
static void Usage()
{
X  char
X    **p;
X
X  static char
X    *options[]=
X    {
X      "-border          include image borders in the output image",
X      "-compress type   RunlengthEncoded or QEncoded",
X      "-delay seconds   pause before selecting target window",
X      "-display server  X server to contact",
X      "-frame           include window manager frame",
X      "-monochrome      transform image to black and white",
X      "-scene value     image scene number",
X      "-screen          select image from root window",
X      "-verbose         print detailed information about the image",
X      "-window id       select window with this id or name",
X      (char *) NULL
X    };
X  (void) fprintf(stderr,"Usage: %s [options ...] file\n",application_name);
X  (void) fprintf(stderr,"\nWhere options include:\n");
X  for (p=options; *p != (char *) NULL; p++)
X    (void) fprintf(stderr,"  %s\n",*p);
X  (void) fprintf(stderr,
X    "\nChange '-' to '+' in any option above to reverse its effect.\n");
X  (void) fprintf(stderr,
X    "For example, +frame means do not include window manager frame.\n");
X  (void) fprintf(stderr,
X  "\nBy default, 'file' is written in the MIFF image format.  To specify a\n");
X  (void) fprintf(stderr,
X    "particular image format, precede the filename with an image format\n");
X  (void) fprintf(stderr,
X    "name and a colon (i.e. mtv:image) or specify the image type as the\n");
X  (void) fprintf(stderr,
X    "filename suffix (i.e. image.mtv).  Specify 'file' as '-' for standard\n");
X  (void) fprintf(stderr,"input or output.\n");
X  exit(1);
}
X
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%    M a i n                                                                  %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%
*/
int main(argc,argv)
int
X  argc;
X
char
X  *argv[];
{
X  char
X    *filename,
X    *option,
X    *resource_value,
X    *server_name,
X    *target_window;
X
X  Display
X    *display;
X
X  Image
X    *image;
X
X  int
X    i,
X    x;
X
X  time_t
X    start_time;
X
X  unsigned int
X    borders,
X    compression,
X    frame,
X    scene,
X    screen,
X    verbose;
X
X  XResourceInfo
X    resource_info;
X
X  XrmDatabase
X    resource_database,
X    server_database;
X
X  /*
X    Display usage profile if there are no command line arguments.
X  */
X  application_name=(*argv);
X  if (argc < 2)
X    Usage();
X  /*
X    Connect to X server.
X  */
X  server_name=(char *) NULL;
X  for (i=1; i < argc; i++)
X  {
X    /*
X      Check command line for server name.
X    */
X    option=argv[i];
X    if (((int) strlen(option) > 1) && ((*option == '-') || (*option == '+')))
X      if (strncmp("dis",option+1,3) == 0)
X        {
X          /*
X            User specified server name.
X          */
X          i++;
X          if (i == argc)
X            Error("missing server name on -display",(char *) NULL);
X          server_name=argv[i];
X          break;
X        }
X  }
X  display=XOpenDisplay(server_name);
X  if (display == (Display *) NULL)
X    Error("unable to connect to X server",XDisplayName(server_name));
X  /*
X    Set our forgiving error handler.
X  */
X  XSetErrorHandler(XError);
X  /*
X    Initialize resource database.
X  */
X  XrmInitialize();
X  resource_database=XrmGetDatabase(display);
X  resource_value=XResourceManagerString(display);
X  if (resource_value == (char *) NULL)
X    resource_value="";
X  server_database=XrmGetStringDatabase(resource_value);
X  XrmMergeDatabases(server_database,&resource_database);
X  /*
X    Get user defaults from X resource database.
X  */
X  XGetResourceInfo(resource_database,application_name,&resource_info);
X  resource_value=XGetResource(resource_database,application_name,"borders",
X    (char *) NULL,"False");
X  borders=IsTrue(resource_value);
X  resource_value=XGetResource(resource_database,application_name,
X    "compression",(char *) NULL,"Runlength");
X  if (Latin1Compare("qencoded",resource_value) == 0)
X    compression=QEncodedCompression;
X  else
X    compression=RunlengthEncodedCompression;
X  resource_value=XGetResource(resource_database,application_name,"frame",
X    (char *) NULL,"False");
X  frame=IsTrue(resource_value);
X  resource_value=XGetResource(resource_database,application_name,"scene",
X    (char *) NULL,"0");
X  scene=atoi(resource_value);
X  resource_value=XGetResource(resource_database,application_name,"screen",
X    (char *) NULL,"False");
X  screen=IsTrue(resource_value);
X  resource_value=XGetResource(resource_database,application_name,"verbose",
X    (char *) NULL,"False");
X  verbose=IsTrue(resource_value);
X  /*
X    Check command syntax.
X  */
X  filename=(char *) NULL;
X  target_window=(char *) NULL;
X  for (i=1; i < argc; i++)
X  {
X    option=argv[i];
X    if (((int) strlen(option) < 2) || ((*option != '-') && (*option != '+')))
X      filename=argv[i];
X    else
X      switch(*(option+1))
X      {
X        case 'b':
X        {
X          borders=(*option == '-');
X          break;
X        }
X        case 'c':
X        {
X          compression=NoCompression;
X          if (*option == '-')
X            {
X              i++;
X              if (i == argc)
X                Error("missing type on -compress",(char *) NULL);
X              if ((*argv[i] == 'R') || (*argv[i] == 'r'))
X                compression=RunlengthEncodedCompression;
X              else
X                if ((*argv[i] == 'Q') || (*argv[i] == 'q'))
X                  compression=QEncodedCompression;
X                else
X                  Error("invalid compression type on -compress",(char *) NULL);
X            }
X          break;
X        }
X        case 'd':
X        {
X          if (strncmp("delay",option+1,2) == 0)
X            {
X              resource_info.delay=0;
X              if (*option == '-')
X                {
X                  i++;
X                  if ((i == argc) || !sscanf(argv[i],"%d",&x))
X                    Error("missing seconds on -delay",(char *) NULL);
X                  resource_info.delay=atoi(argv[i]);
X                }
X              break;
X            }
X          if (strncmp("display",option+1,3) == 0)
X            {
X              server_name=(char *) NULL;
X              if (*option == '-')
X                {
X                  i++;
X                  if (i == argc)
X                    Error("missing server name on -display",(char *) NULL);
X                  server_name=argv[i];
X                }
X              break;
X            }
X          Error("unrecognized option",option);
X          break;
X        }
X        case 'h':
X        {
X          Usage();
X          break;
X        }
X        case 'f':
X        {
X          frame=(*option == '-');
X          break;
X        }
X        case 'm':
X        {
X          resource_info.monochrome=(*option == '-');
X          break;
X        }
X        case 's':
X        {
X          if (strncmp("scene",option+1,4) == 0)
X            {
X              i++;
X              if ((i == argc) || !sscanf(argv[i],"%d",&x))
X                Error("missing scene on -scene",(char *) NULL);
X              scene=atoi(argv[i]);
X              break;
X            }
X          if (strncmp("screen",option+1,4) == 0)
X            {
X              screen=(*option == '-');
X              break;
X            }
X          Error("unrecognized option",option);
X          break;
X        }
X        case 'w':
X        {
X          i++;
X          if (i == argc)
X            Error("missing id, name, or 'root' on -window",(char *) NULL);
X          target_window=argv[i];
X          break;
X        }
X        case 'v':
X        {
X          verbose=(*option == '-');
X          break;
X        }
X        default:
X        {
X          Error("unrecognized option",option);
X          break;
X        }
X      }
X  }
X  if (filename == (char *) NULL)
X    Error("missing an image file name",(char *) NULL);
X  /*
X    Read image from X server.
X  */
X  if (resource_info.delay > 0)
X    (void) sleep(resource_info.delay);
X  start_time=time((time_t *) 0);
X  image=ReadXImage(target_window,server_name,frame,screen,borders);
X  if (image == (Image *) NULL)
X    exit(1);
X  image->scene=scene;
X  if (resource_info.monochrome)
X    QuantizeImage(image,2,8,False,GRAYColorspace,True);
X  if (compression != UndefinedCompression)
X    image->compression=compression;
X  (void) strcpy(image->filename,filename);
X  (void) WriteAlienImage(image);
X  if (verbose)
X    {
X      /*
X        Display detailed info about the image.
X      */
X      if (image->class == DirectClass)
X        image->colors=NumberColors(image);
X      (void) fprintf(stderr,"[%u] %s %ux%u",image->scene,image->filename,
X        image->columns,image->rows);
X      if (image->class == DirectClass)
X        (void) fprintf(stderr," DirectClass ");
X      else
X        (void) fprintf(stderr," PseudoClass ");
X      (void) fprintf(stderr,"%dc %s %ds\n",image->colors,image->magick,
X        time((time_t *) 0)-start_time+1);
X    }
X  DestroyImage(image);
X  XCloseDisplay(display);
X  return(False);
}
SHAR_EOF
echo 'File ImageMagick/import.c is complete' &&
chmod 0644 ImageMagick/import.c ||
echo 'restore of ImageMagick/import.c failed'
Wc_c="`wc -c < 'ImageMagick/import.c'`"
test 16580 -eq "$Wc_c" ||
    echo 'ImageMagick/import.c: original size 16580, current size' "$Wc_c"
rm -f _shar_wnt_.tmp
fi
# ============= ImageMagick/import.man ==============
if test -f 'ImageMagick/import.man' -a X"$1" != X"-c"; then
    echo 'x - skipping ImageMagick/import.man (File already exists)'
    rm -f _shar_wnt_.tmp
else
> _shar_wnt_.tmp
echo 'x - extracting ImageMagick/import.man (Text)'
sed 's/^X//' << 'SHAR_EOF' > 'ImageMagick/import.man' &&
.ad l
.nh
.TH IMPORT 1 "10 October 1992" "ImageMagick"
.SH NAME
import - capture some or all of an X server screen and save to file in the
MIFF image format.
.SH SYNOPSIS
.B "import"
[ \fIoptions\fP ... ] \fIfile\fP
.SH DESCRIPTION
.PP
.I Import
reads an image from any visible window on an X server and outputs it as
an image file.  You can capture a single window, the entire screen, or any
rectangular portion of the screen.  You can use \fIdisplay\fP (see
\fBdisplay(1)\fP) utility for redisplay, printing, editing, formatting,
archiving, image processing, etc. of the captured image.
.PP
The target window can be specified by id, name, or may be selected by
clicking the mouse in the desired window.  If you press a button and
then drag, a rectangle will form which expands and contracts as
the mouse moves.  To save the portion of the screen  defined by the
rectangle, just release the button.  The keyboard bell is rung once at
the beginning of the screen capture and twice when it completes.
.PP
.SH EXAMPLES
.PP
To select an X window with the mouse and save it in the MIFF image
format to a file on disk titled window.miff, use:
.PP
X     import window.miff
.PP
To select an X window and save it in the MIFF image format to a file on
disk titled figure.miff to include in another document, use:
.PP
X     import -geometry +0+0 figure.miff
.PP
To capture the entire X server screen as the MIFF image format in a file on
disk titled root.miff, use:
.PP
X     import -window root root.miff
.SH OPTIONS
\fIImport\fP options can appear on the command line or in your X resources
file (see \fBX(1)\fP).  Options on the command line supersede values specified
in your X resources file.
.TP 5
.B "-border"
include image borders in the output image.
.TP 5
.B "-compress \fItype\fP"
the type of image compression: \fIQEncoded\fP or \fIRunlengthEncoded\fP.
See \fBMIFF(5)\fP for details.
X
Specify \fB\+compress\fP to store the binary image in an uncompressed format.
The default is the compression type of the specified image file.
.TP 5
.B "-delay \fIseconds\fP"
pause before selecting target window.
X
This option is useful when you need time to ready the target window before
it is captured to a file.
.TP 5
.B "-display \fIhost:display[.screen]\fP"
specifies the X server to contact; see \fBX(1)\fP.
.TP 5
.B "-frame"
include window manager frame.
.TP 5
.B "-monochrome"
transform image to black and white.
.TP 5
.B "-scene \fIvalue\fP"
image scene number.
.TP 5
.B "-screen"
This option indicates that the GetImage request used to obtain the image
should be done on the root window, rather than directly on the specified
window.  In this way, you can obtain pieces of other windows that overlap
the specified window, and more importantly, you can capture menus or other
popups that are independent windows but appear over the specified window.
.TP 5
.B -verbose
print detailed information about the image.
X
This information is printed: image scene number;  image name;  image size;
the image class (\fIDirectClass\fP or \fIPseudoClass\fP);  the total
number of unique colors;  and the number of seconds to read and write the
image.
.TP 5
.B "-window \fIid\fP"
select window with this id or name.
X
With this option you can specify the target window by id or name rather
than using the mouse.  Specify 'root' to select X's root window as the
target window.
.PP
Change \fI-\fP to \fI+\fP in any option above to reverse its effect.  For
example \fB+frame\fP means do include window manager frame.
.PP
\fIfile\fP specifies the image filename.  By default, the image is
written in the MIFF image format (see \fBMIFF(5)\fP).  To specify a
particular image format, precede the filename with an image format name
and a colon (i.e.  mtv:image) or specify the image type as the filename
suffix (i.e. image.mtv).  See \fBCONVERT(1)\fP for a list of valid
image formats.  Specify \fIfile\fP as \fI-\fP for standard input or
output.  If \fIfile\fP has the extension \fB.Z\fP, the file is encoded
with \fIcompress\fP.
.SH ENVIRONMENT
.PP
.TP 5
.B DISPLAY
To get the default host, display number, and screen.
.SH SEE ALSO
display(1), animate(1), mogrify(1), convert(1), Quantize(9), X(1)
MIFF(5)
.SH COPYRIGHT
Copyright 1992 E. I. du Pont de Nemours & Company
.PP
Permission to use, copy, modify, distribute, and sell this software and
its documentation for any purpose is hereby granted without fee,
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in
supporting documentation, and that the name of E. I. du Pont de Nemours
& Company not be used in advertising or publicity pertaining to
distribution of the software without specific, written prior
permission.  E. I. du Pont de Nemours & Company makes no representations
about the suitability of this software for any purpose.  It is provided
"as is" without express or implied warranty.
.PP
E. I. du Pont de Nemours & Company disclaims all warranties with regard
to this software, including all implied warranties of merchantability
and fitness, in no event shall E. I. du Pont de Nemours & Company be
liable for any special, indirect or consequential damages or any
damages whatsoever resulting from loss of use, data or profits, whether
in an action of contract, negligence or other tortious action, arising
out of or in connection with the use or performance of this software.
.SH AUTHORS
John Cristy, E.I. du Pont De Nemours & Company Incorporated
SHAR_EOF
chmod 0644 ImageMagick/import.man ||
echo 'restore of ImageMagick/import.man failed'
Wc_c="`wc -c < 'ImageMagick/import.man'`"
test 5476 -eq "$Wc_c" ||
    echo 'ImageMagick/import.man: original size 5476, current size' "$Wc_c"
rm -f _shar_wnt_.tmp
fi
# ============= ImageMagick/images/README ==============
if test ! -d 'ImageMagick/images'; then
    echo 'x - creating directory ImageMagick/images'
    mkdir 'ImageMagick/images'
fi
if test -f 'ImageMagick/images/README' -a X"$1" != X"-c"; then
    echo 'x - skipping ImageMagick/images/README (File already exists)'
    rm -f _shar_wnt_.tmp
else
> _shar_wnt_.tmp
echo 'x - extracting ImageMagick/images/README (Text)'
sed 's/^X//' << 'SHAR_EOF' > 'ImageMagick/images/README' &&
The aquarium image was rendered with rayshade from a script written
by [e-mail] and Jerome A. Farm.
X
Image `montage.miff' was created with this command:
X
X  montage -colors 256 -gravity center -title "Image Montage"
X    -geometry 128x128+5+5 dna.miff swan.miff aquarium.miff montage.miff
SHAR_EOF
chmod 0644 ImageMagick/images/README ||
echo 'restore of ImageMagick/images/README failed'
Wc_c="`wc -c < 'ImageMagick/images/README'`"
test 295 -eq "$Wc_c" ||
    echo 'ImageMagick/images/README: original size 295, current size' "$Wc_c"
rm -f _shar_wnt_.tmp
fi
# ============= ImageMagick/quantize.c ==============
if test -f 'ImageMagick/quantize.c' -a X"$1" != X"-c"; then
    echo 'x - skipping ImageMagick/quantize.c (File already exists)'
    rm -f _shar_wnt_.tmp
else
> _shar_wnt_.tmp
echo 'x - extracting ImageMagick/quantize.c (Text)'
sed 's/^X//' << 'SHAR_EOF' > 'ImageMagick/quantize.c' &&
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%           QQQ   U   U   AAA   N   N  TTTTT  IIIII   ZZZZZ  EEEEE            %
%          Q   Q  U   U  A   A  NN  N    T      I        ZZ  E                %
%          Q   Q  U   U  AAAAA  N N N    T      I      ZZZ   EEEEE            %
%          Q  QQ  U   U  A   A  N  NN    T      I     ZZ     E                %
%           QQQQ   UUU   A   A  N   N    T    IIIII   ZZZZZ  EEEEE            %
%                                                                             %
%                                                                             %
%              Reduce the Number of Unique Colors in an Image                 %
%                                                                             %
%                                                                             %
%                                                                             %
%                           Software Design                                   %
%                             John Cristy                                     %
%                              July 1992                                      %
%                                                                             %
%  Copyright 1992 E. I. du Pont de Nemours & Company                          %
%                                                                             %
%  Permission to use, copy, modify, distribute, and sell this software and    %
%  its documentation for any purpose is hereby granted without fee,           %
%  provided that the above Copyright notice appear in all copies and that     %
%  both that Copyright notice and this permission notice appear in            %
%  supporting documentation, and that the name of E. I. du Pont de Nemours    %
%  & Company not be used in advertising or publicity pertaining to            %
%  distribution of the software without specific, written prior               %
%  permission.  E. I. du Pont de Nemours & Company makes no representations   %
%  about the suitability of this software for any purpose.  It is provided    %
%  "as is" without express or implied warranty.                               %
%                                                                             %
%  E. I. du Pont de Nemours & Company disclaims all warranties with regard    %
%  to this software, including all implied warranties of merchantability      %
%  and fitness, in no event shall E. I. du Pont de Nemours & Company be       %
%  liable for any special, indirect or consequential damages or any           %
%  damages whatsoever resulting from loss of use, data or profits, whether    %
%  in an action of contract, negligence or other tortious action, arising     %
%  out of or in connection with the use or performance of this software.      %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Realism in computer graphics typically requires using 24 bits/pixel to
%  generate an image.  Yet many graphic display devices do not contain
%  the amount of memory necessary to match the spatial and color
%  resolution of the human eye.  The QUANTIZE program takes a 24 bit
%  image and reduces the number of colors so it can be displayed on
%  raster device with less bits per pixel.  In most instances, the
%  quantized image closely resembles the original reference image.
%
%  A reduction of colors in an image is also desirable for image
%  transmission and real-time animation.
%
%  Function Quantize takes a standard RGB or monochrome images and quantizes
%  them down to some fixed number of colors.
%
%  For purposes of color allocation, an image is a set of n pixels, where
%  each pixel is a point in RGB space.  RGB space is a 3-dimensional
%  vector space, and each pixel, pi,  is defined by an ordered triple of
%  red, green, and blue coordinates, (ri, gi, bi).
%
%  Each primary color component (red, green, or blue) represents an
%  intensity which varies linearly from 0 to a maximum value, cmax, which
%  corresponds to full saturation of that color.  Color allocation is
%  defined over a domain consisting of the cube in RGB space with
%  opposite vertices at (0,0,0) and (cmax,cmax,cmax).  QUANTIZE requires
%  cmax = 255.
%
%  The algorithm maps this domain onto a tree in which each node
%  represents a cube within that domain.  In the following discussion
%  these cubes are defined by the coordinate of two opposite vertices:
%  The vertex nearest the origin in RGB space and the vertex farthest
%  from the origin.
%
%  The tree's root node represents the the entire domain, (0,0,0) through
%  (cmax,cmax,cmax).  Each lower level in the tree is generated by
%  subdividing one node's cube into eight smaller cubes of equal size.
%  This corresponds to bisecting the parent cube with planes passing
%  through the midpoints of each edge.
%
%  The basic algorithm operates in three phases: Classification,
%  Reduction, and Assignment.  Classification builds a color
%  description tree for the image.  Reduction collapses the tree until
%  the number it represents, at most, the number of colors desired in the
%  output image.  Assignment defines the output image's color map and
%  sets each pixel's color by reclassification in the reduced tree.
%
%  Classification begins by initializing a color description tree of
%  sufficient depth to represent each possible input color in a leaf.
%  However, it is impractical to generate a fully-formed color
%  description tree in the classification phase for realistic values of
%  cmax.  If colors components in the input image are quantized to k-bit
%  precision, so that cmax= 2k-1, the tree would need k levels below the
%  root node to allow representing each possible input color in a leaf.
%  This becomes prohibitive because the tree's total number of nodes is
%  1 + sum(i=1,k,8k).
%
%  A complete tree would require 19,173,961 nodes for k = 8, cmax = 255.
%  Therefore, to avoid building a fully populated tree, QUANTIZE: (1)
%  Initializes data structures for nodes only as they are needed;  (2)
%  Chooses a maximum depth for the tree as a function of the desired
%  number of colors in the output image (currently log2(colormap size)).
%
%  For each pixel in the input image, classification scans downward from
%  the root of the color description tree.  At each level of the tree it
%  identifies the single node which represents a cube in RGB space
%  containing the pixel's color.  It updates the following data for each
%  such node:
%
%    n1 : Number of pixels whose color is contained in the RGB cube
%    which this node represents;
%
%    n2 : Number of pixels whose color is not represented in a node at
%    lower depth in the tree;  initially,  n2 = 0 for all nodes except
%    leaves of the tree.
%
%    Sr, Sg, Sb : Sums of the red, green, and blue component values for
%    all pixels not classified at a lower depth. The combination of
%    these sums and n2  will ultimately characterize the mean color of a
%    set of pixels represented by this node.
%
%  Reduction repeatedly prunes the tree until the number of nodes with
%  n2 > 0 is less than or equal to the maximum number of colors allowed
%  in the output image.  On any given iteration over the tree, it selects
%  those nodes whose n1  count is minimal for pruning and merges their
%  color statistics upward. It uses a pruning threshold, ns, to govern
%  node selection as follows:
%
%    ns = 0
%    while number of nodes with (n2 > 0) > required maximum number of colors
%      prune all nodes such that n1 <= ns
%      Set ns to minimum n1 in remaining nodes
%
%  When a node to be pruned has offspring, the pruning procedure invokes
%  itself recursively in order to prune the tree from the leaves upward.
%  n2,  Sr, Sg,  and  Sb in a node being pruned are always added to the
%  corresponding data in that node's parent.  This retains the pruned
%  node's color characteristics for later averaging.
%
%  For each node, n2 pixels exist for which that node represents the
%  smallest volume in RGB space containing those pixel's colors.  When n2
%  > 0 the node will uniquely define a color in the output image. At the
%  beginning of reduction,  n2 = 0  for all nodes except a the leaves of
%  the tree which represent colors present in the input image.
%
%  The other pixel count, n1, indicates the total number of colors
%  within the cubic volume which the node represents.  This includes n1 -
%  n2  pixels whose colors should be defined by nodes at a lower level in
%  the tree.
%
%  Assignment generates the output image from the pruned tree.  The
%  output image consists of two parts: (1)  A color map, which is an
%  array of color descriptions (RGB triples) for each color present in
%  the output image;  (2)  A pixel array, which represents each pixel as
%  an index into the color map array.
%
%  First, the assignment phase makes one pass over the pruned color
%  description tree to establish the image's color map.  For each node
%  with n2  > 0, it divides Sr, Sg, and Sb by n2 .  This produces the
%  mean color of all pixels that classify no lower than this node.  Each
%  of these colors becomes an entry in the color map.
%
%  Finally,  the assignment phase reclassifies each pixel in the pruned
%  tree to identify the deepest node containing the pixel's color.  The
%  pixel's value in the pixel array becomes the index of this node's mean
%  color in the color map.
%
%  For efficiency, QUANTIZE requires that the reference image be in a
%  run-length encoded format.
%
%  With the permission of USC Information Sciences Institute, 4676 Admiralty
%  Way, Marina del Rey, California  90292, this code was adapted from module
%  ALCOLS written by Paul Raveling.
%
%  The names of ISI and USC are not used in advertising or publicity
%  pertaining to distribution of the software without prior specific
%  written permission from ISI.
%
%
*/
X
/*
X  Include declarations.
*/
#include "display.h"
#include "image.h"
X
/*
X  Define declarations.
*/
#define color_number  number_colors
#define MaxNodes  266817
#define MaxShift  8
#define MaxTreeDepth  8  /* Log2(MaxRGB) */
#define NodesInAList  2048
X
/*
X  Structures.
*/
typedef struct _Node
{
X  struct _Node
X    *parent,
X    *child[8];
X
X  unsigned char
X    id,
X    level,
X    children,
X    mid_red,
X    mid_green,
X    mid_blue;
X
X  unsigned long int
X    number_colors,
X    number_unique,
X    total_red,
X    total_green,
X    total_blue;
} Node;
X
typedef struct _Nodes
{
X  Node
X    nodes[NodesInAList];
X
X  struct _Nodes
X    *next;
} Nodes;
X
typedef struct _Cube
{
X  Node
X    *root;
X
X  ColorPacket
X    color,
X    *colormap;
X
X  unsigned int
X    depth;
X
X  unsigned long int
X    colors,
X    pruning_threshold,
X    next_pruning_threshold,
X    distance,
X    shift[MaxTreeDepth+1],
X    squares[MaxRGB+MaxRGB+1];
X
X  unsigned int
X    nodes,
X    free_nodes,
X    color_number;
X
X  Node
X    *next_node;
X
X  Nodes
X    *node_queue;
} Cube;
X
/*
X  Global variables.
*/
static Cube
X  cube;
X
/*
X  External declarations.
*/
extern char
X  *application_name;
X
/*
X  Forward declarations.
*/
static Node
X  *InitializeNode _Declare((unsigned int,unsigned int,Node *,unsigned int,
X    unsigned int,unsigned int));
X
static unsigned int
X  DitherImage _Declare((Image *));
X
static void
X  ClosestColor _Declare((Node *)),
X  Colormap _Declare((Node *)),
X  PruneLevel _Declare((Node *));
X
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%  A s s i g n m e n t                                                        %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Procedure Assignment generates the output image from the pruned tree.  The
%  output image consists of two parts: (1)  A color map, which is an
%  array of color descriptions (RGB triples) for each color present in
%  the output image;  (2)  A pixel array, which represents each pixel as
%  an index into the color map array.
%
%  First, the assignment phase makes one pass over the pruned color
%  description tree to establish the image's color map.  For each node
%  with n2  > 0, it divides Sr, Sg, and Sb by n2 .  This produces the
%  mean color of all pixels that classify no lower than this node.  Each
%  of these colors becomes an entry in the color map.
%
%  Finally,  the assignment phase reclassifies each pixel in the pruned
%  tree to identify the deepest node containing the pixel's color.  The
%  pixel's value in the pixel array becomes the index of this node's mean
%  color in the color map.
%
%  The format of the Assignment routine is:
%
%      Assignment(image,dither,optimal)
%
%  A description of each parameter follows.
%
%    o image: Specifies a pointer to an Image structure;  returned from
%      ReadImage.
%
%    o dither: Set this integer value to something other than zero to
%      dither the quantized image.  The basic strategy of dithering is to
%      trade intensity resolution for spatial resolution by averaging the
%      intensities of several neighboring pixels.  Images which suffer
%      from severe contouring when quantized can be improved with the
%      technique of dithering.  Severe contouring generally occurs when
%      quantizing to very few colors, or to a poorly-chosen colormap.
%      Note, dithering is a computationally expensive process and will
%      increase processing time significantly.
%
%    o optimal: An unsigned integer value greater than zero indicates that
%      the optimal representation of the reference image should be returned.
%
%
*/
static void Assignment(image,dither,optimal)
Image
X  *image;
X
unsigned int
X  dither,
X  optimal;
{
X  register int
X    i;
X
X  register Node
X    *node;
X
X  register RunlengthPacket
X    *p;
X
X  register unsigned int
X    id;
X
X  /*
X    Allocate image colormap.
X  */
X  image->alpha=False;
X  image->class=PseudoClass;
X  if (image->colormap != (ColorPacket *) NULL)
X    (void) free((char *) image->colormap);
X  image->colormap=(ColorPacket *)
X    malloc((unsigned int) cube.colors*sizeof(ColorPacket));
X  if (image->colormap == (ColorPacket *) NULL)
X    {
X      Warning("unable to quantize image","memory allocation failed");
X      exit(1);
X    }
X  if (image->signature != (char *) NULL)
X    (void) free((char *) image->signature);
X  image->signature=(char *) NULL;
X  cube.colormap=image->colormap;
X  cube.colors=0;
X  Colormap(cube.root);
X  image->colors=(unsigned int) cube.colors;
X  /*
X    Create a reduced color image.  For the non-optimal case we trade
X    accuracy for speed improvements.
X  */
X  if (dither)
X    dither=!DitherImage(image);
X  p=image->pixels;
X  if (!dither)
X    if (!optimal)
X      for (i=0; i < image->packets; i++)
X      {
X        /*
X          Identify the deepest node containing the pixel's color.
X        */
X        node=cube.root;
X        do
X        {
X          id=(p->red > node->mid_red ? 1 : 0) |
X            (p->green > node->mid_green ? 1 : 0) << 1 |
X            (p->blue > node->mid_blue ? 1 : 0) << 2;
X          if ((node->children & (1 << id)) == 0)
X            break;
X          node=node->child[id];
X        } while (True);
X        p->index=(unsigned short) node->color_number;
X        p++;
X      }
X    else
X      for (i=0; i < image->packets; i++)
X      {
X        /*
X          Identify the deepest node containing the pixel's color.
X        */
X        node=cube.root;
X        do
X        {
X          id=(p->red > node->mid_red ? 1 : 0) |
X            (p->green > node->mid_green ? 1 : 0) << 1 |
X            (p->blue > node->mid_blue ? 1 : 0) << 2;
X          if ((node->children & (1 << id)) == 0)
X            break;
X          node=node->child[id];
X        }
X        while (True);
X        /*
X          Find closest color among siblings and their children.
X        */
X        cube.color.red=p->red;
X        cube.color.green=p->green;
X        cube.color.blue=p->blue;
X        cube.distance=(~0);
X        ClosestColor(node->parent);
X        p->index=cube.color_number;
X        p++;
X      }
}
X
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%  C l a s s i f i c a t i o n                                                %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Procedure Classification begins by initializing a color description tree
%  of sufficient depth to represent each possible input color in a leaf.
%  However, it is impractical to generate a fully-formed color
%  description tree in the classification phase for realistic values of
%  cmax.  If colors components in the input image are quantized to k-bit
%  precision, so that cmax= 2k-1, the tree would need k levels below the
%  root node to allow representing each possible input color in a leaf.
%  This becomes prohibitive because the tree's total number of nodes is
%  1 + sum(i=1,k,8k).
%
%  A complete tree would require 19,173,961 nodes for k = 8, cmax = 255.
%  Therefore, to avoid building a fully populated tree, QUANTIZE: (1)
%  Initializes data structures for nodes only as they are needed;  (2)
%  Chooses a maximum depth for the tree as a function of the desired
%  number of colors in the output image (currently log2(colormap size)).
%
%  For each pixel in the input image, classification scans downward from
%  the root of the color description tree.  At each level of the tree it
%  identifies the single node which represents a cube in RGB space
%  containing It updates the following data for each such node:
%
%    n1 : Number of pixels whose color is contained in the RGB cube
%    which this node represents;
%
%    n2 : Number of pixels whose color is not represented in a node at
%    lower depth in the tree;  initially,  n2 = 0 for all nodes except
%    leaves of the tree.
%
%    Sr, Sg, Sb : Sums of the red, green, and blue component values for
%    all pixels not classified at a lower depth. The combination of
%    these sums and n2  will ultimately characterize the mean color of a
%    set of pixels represented by this node.
%
%  The format of the Classification routine is:
%
%      Classification(image)
%
%  A description of each parameter follows.
%
%    o image: Specifies a pointer to an Image structure;  returned from
%      ReadImage.
%
%
*/
static void Classification(image)
Image
X  *image;
{
X  register int
X    i;
X
X  register Node
X    *node;
X
X  register RunlengthPacket
X    *p;
X
X  register unsigned int
X    bisect,
X    count,
X    id,
X    level;
X
X  p=image->pixels;
X  for (i=0; i < image->packets; i++)
X  {
X    if (cube.nodes > MaxNodes)
X      {
X        /*
X          Prune one level if the color tree is too large.
X        */
X        PruneLevel(cube.root);
X        cube.depth--;
X      }
X    /*
X      Start at the root and descend the color cube tree.
X    */
X    count=p->length+1;
X    node=cube.root;
X    for (level=1; level < cube.depth; level++)
X    {
X      id=(p->red > node->mid_red ? 1 : 0) |
X        (p->green > node->mid_green ? 1 : 0) << 1 |
X        (p->blue > node->mid_blue ? 1 : 0) << 2;
X      if (node->child[id] == (Node *) NULL)
X        {
X          /*
X            Set colors of new node to contain pixel.
X          */
X          node->children|=1 << id;
X          bisect=(unsigned int) (1 << (MaxTreeDepth-level)) >> 1;
X          node->child[id]=InitializeNode(id,level,node,
X            node->mid_red+(id & 1 ? bisect : -bisect),
X            node->mid_green+(id & 2 ? bisect : -bisect),
X            node->mid_blue+(id & 4 ? bisect : -bisect));
X          if (node->child[id] == (Node *) NULL)
X            {
X              Warning("unable to quantize image","memory allocation failed");
X              exit(1);
X            }
X          if (level == (cube.depth-1))
X            cube.colors++;
X        }
X      /*
X        Record the number of colors represented by this node.  Shift by level
X        in the color description tree.
X      */
X      node=node->child[id];
X      node->number_colors+=count << cube.shift[level];
X    }
X    /*
X      Increment unique color count and sum RGB values for this leaf for later
X      derivation of the mean cube color.
X    */
X    node->number_unique+=count;
X    node->total_red+=p->red*count;
X    node->total_green+=p->green*count;
X    node->total_blue+=p->blue*count;
X    p++;
X  }
}
X
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%  C l o s e s t C o l o r                                                    %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Procedure ClosestColor traverses the color cube tree at a particular node
%  and determines which colormap entry best represents the input color.
%
%  The format of the ClosestColor routine is:
%
%      ClosestColor(node)
%
%  A description of each parameter follows.
%
%    o node: The address of a structure of type Node which points to a
%      node in the color cube tree that is to be pruned.
%
%
*/
static void ClosestColor(node)
register Node
X  *node;
{
X  register unsigned int
X    id;
X
X  /*
X    Traverse any children.
X  */
X  if (node->children > 0)
X    for (id=0; id < 8; id++)
X      if (node->children & (1 << id))
X        ClosestColor(node->child[id]);
X  if (node->number_unique > 0)
X    {
X      register ColorPacket
X        *color;
X
X      register unsigned int
X        blue_distance,
X        green_distance,
X        red_distance;
X
X      register unsigned long int
X        distance;
X
X      /*
X        Determine if this color is "closest".
X      */
X      color=cube.colormap+node->color_number;
X      red_distance=(int) color->red-(int) cube.color.red+MaxRGB;
X      green_distance=(int) color->green-(int) cube.color.green+MaxRGB;
X      blue_distance=(int) color->blue-(int) cube.color.blue+MaxRGB;
X      distance=cube.squares[red_distance]+cube.squares[green_distance]+
X        cube.squares[blue_distance];
X      if (distance < cube.distance)
X        {
X          cube.distance=distance;
X          cube.color_number=(unsigned short) node->color_number;
X        }
X    }
}
X
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%  C o l o r m a p                                                            %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Procedure Colormap traverses the color cube tree and notes each colormap
%  entry.  A colormap entry is any node in the color cube tree where the
%  number of unique colors is not zero.
%
%  The format of the Colormap routine is:
%
%      Colormap(node)
%
%  A description of each parameter follows.
%
%    o node: The address of a structure of type Node which points to a
%      node in the color cube tree that is to be pruned.
%
%
*/
static void Colormap(node)
register Node
X  *node;
{
X  register unsigned int
X    id;
X
X  /*
X    Traverse any children.
X  */
X  if (node->children > 0)
X    for (id=0; id < 8; id++)
X      if (node->children & (1 << id))
X        Colormap(node->child[id]);
X  if (node->number_unique > 0)
X    {
X      /*
X        Colormap entry is defined by the mean color in this cube.
X      */
X      cube.colormap[cube.colors].red=(unsigned char)
X        ((node->total_red+(node->number_unique >> 1))/node->number_unique);
X      cube.colormap[cube.colors].green=(unsigned char)
X        ((node->total_green+(node->number_unique >> 1))/node->number_unique);
X      cube.colormap[cube.colors].blue=(unsigned char)
X        ((node->total_blue+(node->number_unique >> 1))/node->number_unique);
X      node->color_number=cube.colors++;
X    }
}
X
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%  D i t h e r I m a g e                                                      %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Procedure DitherImage uses the Floyd-Steinberg algorithm to dither the
%  image.  Refer to "An Adaptive Algorithm for Spatial GreySscale", Robert W.
%  Floyd and Louis Steinberg, Proceedings of the S.I.D., Volume 17(2), 1976.
%
%  First find the closest representation to the reference pixel color in the
%  colormap, the node pixel is assigned this color.  Next, the colormap color
%  is subtracted from the reference pixels color, this represents the
%  quantization error.  Various amounts of this error are added to the pixels
%  ahead and below the node pixel to correct for this error.  The error
%  proportions are:
%
%            P     7/16
%      3/16  5/16  1/16
%
%  The error is distributed left-to-right for even scanlines and right-to-left
%  for odd scanlines.
%
%  The format of the DitherImage routine is:
%
%      DitherImage(image)
%
%  A description of each parameter follows.
%
%    o image: Specifies a pointer to an Image structure;  returned from
%      ReadImage.
%
%
*/
static unsigned int DitherImage(image)
Image
X  *image;
{
X  typedef struct _ScaledColorPacket
X  {
X    int
X      red,
X      green,
X      blue;
X  } ScaledColorPacket;
X
X  Image
X    *dithered_image;
X
X  int
X    *cache,
X    odd_scanline;
X
X  register int
X    blue_error,
X    green_error,
X    red_error,
X    step;
X
X  register Node
X    *node;
X
X  register RunlengthPacket
X    *p,
X    *q;
X
X  register ScaledColorPacket
X    *cs,
X    *ns;
X
X  register unsigned int
X    id;
X
X  register unsigned short
X    index;
X
X  ScaledColorPacket
X    *scanline;
X
X  unsigned char
X    *range_limit,
X    *range_table;
X
X  unsigned int
X    i,
X    x,
X    y;
X
X  /*
X    Initialize dithered image attributes.
X  */
X  image->orphan=True;
X  dithered_image=CopyImage(image,image->columns,image->rows,False);
X  image->orphan=False;
X  if (dithered_image == (Image *) NULL)
X    {
X      Warning("unable to dither image","memory allocation failed");
X      return(True);
X    }
X  /*
X    Allocate the cache & scanline buffers to keep track of quantization error.
X  */
X  cache=(int *) malloc((1 << 18)*sizeof(int));
X  range_table=(unsigned char *) malloc(3*(MaxRGB+1)*sizeof(unsigned char));
X  scanline=(ScaledColorPacket *)
X    malloc(2*(image->columns+2)*sizeof(ScaledColorPacket));
X  if ((cache == (int *) NULL) || (range_table == (unsigned char *) NULL) ||
X      (scanline == (ScaledColorPacket *) NULL))
X    {
X      Warning("unable to dither image","memory allocation failed");
X      return(True);
X    }
X  /*
X    Initialize tables.
X  */
X  for (i=0; i < (1 << 18); i++)
X    cache[i]=(-1);
X  for (i=0; i <= MaxRGB; i++)
X  {
X    range_table[i]=0;
X    range_table[i+(MaxRGB+1)]=(unsigned char) i;
X    range_table[i+(MaxRGB+1)*2]=MaxRGB;
X  }
X  range_limit=range_table+(MaxRGB+1);
X  /*
X    Preload first scanline.
X  */
X  p=image->pixels;
X  image->runlength=p->length+1;
X  cs=scanline+1;
X  for (i=0; i < image->columns; i++)
X  {
X    if (image->runlength > 0)
X      image->runlength--;
X    else
X      {
X        p++;
X        image->runlength=p->length;
X      }
X    cs->red=p->red;
X    cs->green=p->green;
X    cs->blue=p->blue;
X    cs++;
X  }
X  odd_scanline=False;
X  for (y=0; y < image->rows; y++)
X  {
X    if (y < (image->rows-1))
X      {
X        /*
X          Read another scanline.
X        */
X        ns=scanline+1;
X        if (!odd_scanline)
X          ns+=(image->columns+2);
X        for (i=0; i < image->columns; i++)
X        {
X          if (image->runlength > 0)
X            image->runlength--;
X          else
X            {
X              p++;
X              image->runlength=p->length;
X            }
X          ns->red=p->red;
X          ns->green=p->green;
X          ns->blue=p->blue;
X          ns++;
X        }
X      }
X    if (!odd_scanline)
X      {
X        /*
X          Distribute error left-to-right for even scanlines.
X        */
X        q=dithered_image->pixels+image->columns*y;
X        cs=scanline+1;
X        ns=scanline+(image->columns+2)+1;
X        step=1;
X      }
X    else
X      {
X        /*
X          Distribute error right-to-left for odd scanlines.
X        */
X        q=dithered_image->pixels+image->columns*y+(image->columns-1);
X        cs=scanline+(image->columns+2)+(image->columns-1)+1;
X        ns=scanline+(image->columns-1)+1;
X        step=(-1);
X      }
X    for (x=0; x < image->columns; x++)
X    {
X      q->red=range_limit[cs->red];
X      q->green=range_limit[cs->green];
X      q->blue=range_limit[cs->blue];
X      i=(q->red >> 2) << 12 | (q->green >> 2) << 6 | q->blue >> 2;
X      if (cache[i] < 0)
X        {
X          /*
X            Identify the deepest node containing the pixel's color.
X          */
X          node=cube.root;
X          do
X          {
X            id=(q->red > node->mid_red ? 1 : 0) |
X              (q->green > node->mid_green ? 1 : 0) << 1 |
X              (q->blue > node->mid_blue ? 1 : 0) << 2;
X            if ((node->children & (1 << id)) == 0)
X              break;
X            node=node->child[id];
X          }
X          while (True);
X          /*
X            Find closest color among siblings and their children.
X          */
X          cube.color.red=q->red;
X          cube.color.green=q->green;
X          cube.color.blue=q->blue;
X          cube.distance=(~0);
X          ClosestColor(node->parent);
X          cache[i]=cube.color_number;
X        }
X      index=(unsigned short) cache[i];
X      red_error=(int) q->red-(int) cube.colormap[index].red;
X      green_error=(int) q->green-(int) cube.colormap[index].green;
X      blue_error=(int) q->blue-(int) cube.colormap[index].blue;
X      q->index=index;
SHAR_EOF
true || echo 'restore of ImageMagick/quantize.c failed'
fi
echo 'End of  part 8'
echo 'File ImageMagick/quantize.c is continued in part 9'
echo 9 > _shar_seq_.tmp
exit 0
exit 0 # Just in case...