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598 lines
20 KiB
C
598 lines
20 KiB
C
#include "xp_core.h" //used to make library compile faster on win32 do not ifdef this or it wont work
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/* taken from libppm3.c - ppm utility library part 3
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**
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** Colormap routines.
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**
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** Copyright (C) 1989, 1991 by Jef Poskanzer.
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**
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** Permission to use, copy, modify, and distribute this software and its
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** documentation for any purpose and without fee is hereby granted, provided
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** that the above copyright notice appear in all copies and that both that
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** copyright notice and this permission notice appear in supporting
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** documentation. This software is provided "as is" without express or
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** implied warranty.
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*/
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#include <stdio.h>
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#include <memory.h>
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#include <malloc.h>
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#include <process.h>
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#include <search.h>
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#include <stdlib.h>
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#include "xp_core.h"/*defines of int32, etc.*/
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#include "xp_mem.h"/*defines of XP_ALLOC, etc.*/
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#include "xp_str.h"/*defines of XP_MEMCPY, etc.*/
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#include "xpassert.h"
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#include "xp_qsort.h"
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#include "ntypes.h" /* for MWContext to include libcnv.h*/
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#include "libcnv.h"
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#include "pbmplus.h"
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#include "ppm.h"
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#include "ppmcmap.h"
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#include "colorqnt.h"
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#define LARGE_NORM 1
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#define REP_AVERAGE_COLORS 1
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#define MAXCOLORS 256
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#define FLOYD_DEFAULT 1/*use floyd algorithm*/
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#define FS_SCALE 1024
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typedef struct box* box_vector;
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struct box
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{
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int16 ind;
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int16 colors;
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int32 sum;
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};
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static colorhist_vector mediancut ARGS(( colorhist_vector chv, int16 colors, int32 sum, pixval maxval, int16 newcolors ));
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static int redcompare ARGS(( const colorhist_vector ch1, const colorhist_vector ch2 ));
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static int greencompare ARGS(( const colorhist_vector ch1, const colorhist_vector ch2 ));
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static int bluecompare ARGS(( const colorhist_vector ch1, const colorhist_vector ch2 ));
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static int sumcompare ARGS(( const box_vector b1, const box_vector b2 ));
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/*used for quick sort of color table*/
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typedef int (* qsortprototype)(const void *, const void *);
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/*EFFECTS:modifies imagearray to reflect colors in colorhistogram
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MODIFIES:imagearray, pchv,maxcolorvalue,colors
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RETURNS:CONV_OK if success
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INPUT:
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imagearray= RGB tripples
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imagewidth= width of image
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imageheight=height of image
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maxcolorvalue=passed in as maximum value for each R,G or B
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colors= valid pointer to int16
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maxcolorvalue= valid pointer to int16
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OUTPUT:
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maxcolorvalue=leaves with what was assigned as the maximum value
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colors= number of colors in the mapping
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pchv= leaves pointing to the new color table. calling function reponsible for deleting!
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SPECIAL NOTE!
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the returned color table is in the range of 0 to maxcolorvalue.
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you must divide my maxcolorvalue and multiply times the input maxcolorvalue to get
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colors in the range of 0-MAXCOLORS-1
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*/
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CONVERT_IMAGERESULT
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quantize_colors(CONVERT_IMG_ARRAY imagearray,int16 imagewidth,int16 imageheight,int16 *maxcolorvalue,int16 *colors,colorhist_vector *pchv)
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{
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pixval newmaxval=0;
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int16 row=0;
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colorhist_vector chv=NULL;
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colorhist_vector colormap=NULL;
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pixel *pP=NULL;
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pixval maxval=(pixval)(MAXCOLORS-1);
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colorhash_table cht=NULL;
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int32* thisrerr=NULL;
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int32* nextrerr=NULL;
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int32* thisgerr=NULL;
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int32* nextgerr=NULL;
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int32* thisberr=NULL;
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int32* nextberr=NULL;
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int32* temperr=NULL;
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int16 usehash,floyd=FLOYD_DEFAULT;
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int16 fs_direction;
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register int16 col, limitcol;
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register int32 sr, sg, sb, err;
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register int16 ind;
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pixel** copy = 0;
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*pchv=NULL;
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XP_ASSERT(colors);
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XP_ASSERT(maxcolorvalue);
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/*
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** Step 1: attempt to make a histogram of the colors, unclustered.
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** If at first we don't succeed, lower maxval to increase color
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** coherence and try again. This will eventually terminate, with
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** maxval at worst 15, since 32^3 is approximately MAXCOLORS.
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*/
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/* Make a copy of the image pixels */
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copy = XP_ALLOC(sizeof(pixel*) * imageheight);
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{
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int i;
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pixel* pixelRow;
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pixel* sourceRow;
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for(i = 0; i < imageheight; i++){
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pixelRow = XP_ALLOC(imagewidth*sizeof(pixel));
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copy[i] = pixelRow;
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sourceRow = (pixel*) imagearray[i];
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/* XP_MEMCPY(pixelRow, sourceRow, sizeof(pixel)*imagewidth); */
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{
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int j;
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for(j = 0; j < imagewidth; j++){
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pixelRow[j] = sourceRow[j];
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}
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}
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}
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}
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for ( ; ; )
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{
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chv = ppm_computecolorhist(
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(pixel **)copy, imagewidth, imageheight, MAXCOLORS, colors );
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if ( chv != (colorhist_vector) 0 )
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break;
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newmaxval = maxval / 2;
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for ( row = 0; row < imageheight; ++row )
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for ( col = 0, pP = (pixel *)copy[row]; col < imagewidth; ++col, ++pP ){
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PPM_DEPTH( *pP, *pP, maxval, newmaxval );
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}
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maxval=newmaxval;
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}
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/* Free copy of image */
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{
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int i;
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for(i = 0; i < imageheight; i++){
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XP_FREE(copy[i]);
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}
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XP_FREE(copy);
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}
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/* we now have the maximum # of colors*/
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/*
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** Step 2: apply median-cut to histogram, making the new colormap.
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*/
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colormap = mediancut( chv, (int16)*colors, (int32)(imageheight * imagewidth), (pixval)maxval, (int16)*maxcolorvalue );
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free( chv );
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{ /* Crank up colors in color map */
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int i;
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for(i = 0; i < *colors; i++ ) {
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PPM_DEPTH( colormap[i].color, colormap[i].color, maxval, MAXCOLORS-1 );
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}
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maxval = MAXCOLORS-1;
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}
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/*
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** Step 3: map the colors in the image to their closest match in the
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** new colormap, and write 'em out.
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*/
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cht = ppm_alloccolorhash( );
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usehash = 1;
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if ( floyd )
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{
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/* Initialize Floyd-Steinberg error vectors. */
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thisrerr = (int32*) malloc( (imagewidth + 2)* sizeof(int32) );
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nextrerr = (int32*) malloc( (imagewidth + 2)* sizeof(int32) );
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thisgerr = (int32*) malloc( (imagewidth + 2)* sizeof(int32) );
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nextgerr = (int32*) malloc( (imagewidth + 2)* sizeof(int32) );
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thisberr = (int32*) malloc( (imagewidth + 2)* sizeof(int32) );
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nextberr = (int32*) malloc( (imagewidth + 2)* sizeof(int32) );
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if (!nextberr||!thisberr||!nextgerr||!thisgerr||!nextrerr||!thisrerr)
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return CONVERR_OUTOFMEMORY; /*memory allocation failed*/
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srandom( (int16) ( time( 0 ) ^ getpid( ) ) );
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for ( col = 0; col < imagewidth + 2; ++col )
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{
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thisrerr[col] = random( ) % ( FS_SCALE * 2 ) - FS_SCALE;
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thisgerr[col] = random( ) % ( FS_SCALE * 2 ) - FS_SCALE;
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thisberr[col] = random( ) % ( FS_SCALE * 2 ) - FS_SCALE;
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/* (random errors in [-1 .. 1]) */
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}
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fs_direction = 1;
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}
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for ( row = 0; row < imageheight; ++row )
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{
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if ( floyd )
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for ( col = 0; col < imagewidth + 2; ++col )
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nextrerr[col] = nextgerr[col] = nextberr[col] = 0;
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if ( ( ! floyd ) || fs_direction )
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{
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col = 0;
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limitcol = imagewidth;
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pP = (pixel *)imagearray[row];
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}
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else
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{
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col = imagewidth - 1;
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limitcol = -1;
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pP = &((pixel **)imagearray)[row][col]; /*(pixel *)&(imagearray[row][col*3]); times 3 because a CONV_IMAGE_ARRAY IS A char ** not a pixel ** */
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}
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do
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{
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if ( floyd )
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{
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/* Use Floyd-Steinberg errors to adjust actual color. */
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sr = PPM_GETR(*pP) + thisrerr[col + 1] / FS_SCALE;
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sg = PPM_GETG(*pP) + thisgerr[col + 1] / FS_SCALE;
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sb = PPM_GETB(*pP) + thisberr[col + 1] / FS_SCALE;
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if ( sr < 0 ) sr = 0;
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else if ( sr > maxval ) sr = maxval;
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if ( sg < 0 ) sg = 0;
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else if ( sg > maxval ) sg = maxval;
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if ( sb < 0 ) sb = 0;
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else if ( sb > maxval ) sb = maxval;
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PPM_ASSIGN( *pP, (pixval)sr, (pixval)sg, (pixval)sb );
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}
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/* Check hash table to see if we have already matched this color. */
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ind = ppm_lookupcolor( cht, pP );
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if ( ind == -1 )
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{ /* No; search colormap for closest match. */
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register int16 i, r1, g1, b1, r2, g2, b2;
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register int32 dist, newdist;
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r1 = PPM_GETR( *pP );
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g1 = PPM_GETG( *pP );
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b1 = PPM_GETB( *pP );
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dist = 2000000000;
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for ( i = 0; i < *maxcolorvalue; ++i )
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{
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r2 = PPM_GETR( colormap[i].color );
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g2 = PPM_GETG( colormap[i].color );
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b2 = PPM_GETB( colormap[i].color );
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newdist = ( r1 - r2 ) * ( r1 - r2 ) +
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( g1 - g2 ) * ( g1 - g2 ) +
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( b1 - b2 ) * ( b1 - b2 );
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if ( newdist < dist )
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{
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ind = i;
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dist = newdist;
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}
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}
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if ( usehash )
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{
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if ( ppm_addtocolorhash( cht, pP, ind ) < 0 )
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{
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usehash = 0;
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}
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}
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}
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if ( floyd )
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{
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/* Propagate Floyd-Steinberg error terms. */
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if ( fs_direction )
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{
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err = ( sr - (int32) PPM_GETR( colormap[ind].color ) ) * FS_SCALE;
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thisrerr[col + 2] += ( err * 7 ) / 16;
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nextrerr[col ] += ( err * 3 ) / 16;
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nextrerr[col + 1] += ( err * 5 ) / 16;
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nextrerr[col + 2] += ( err ) / 16;
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err = ( sg - (int32) PPM_GETG( colormap[ind].color ) ) * FS_SCALE;
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thisgerr[col + 2] += ( err * 7 ) / 16;
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nextgerr[col ] += ( err * 3 ) / 16;
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nextgerr[col + 1] += ( err * 5 ) / 16;
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nextgerr[col + 2] += ( err ) / 16;
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err = ( sb - (int32) PPM_GETB( colormap[ind].color ) ) * FS_SCALE;
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thisberr[col + 2] += ( err * 7 ) / 16;
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nextberr[col ] += ( err * 3 ) / 16;
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nextberr[col + 1] += ( err * 5 ) / 16;
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nextberr[col + 2] += ( err ) / 16;
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}
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else
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{
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err = ( sr - (int32) PPM_GETR( colormap[ind].color ) ) * FS_SCALE;
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thisrerr[col ] += ( err * 7 ) / 16;
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nextrerr[col + 2] += ( err * 3 ) / 16;
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nextrerr[col + 1] += ( err * 5 ) / 16;
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nextrerr[col ] += ( err ) / 16;
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err = ( sg - (int32) PPM_GETG( colormap[ind].color ) ) * FS_SCALE;
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thisgerr[col ] += ( err * 7 ) / 16;
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nextgerr[col + 2] += ( err * 3 ) / 16;
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nextgerr[col + 1] += ( err * 5 ) / 16;
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nextgerr[col ] += ( err ) / 16;
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err = ( sb - (int32) PPM_GETB( colormap[ind].color ) ) * FS_SCALE;
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thisberr[col ] += ( err * 7 ) / 16;
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nextberr[col + 2] += ( err * 3 ) / 16;
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nextberr[col + 1] += ( err * 5 ) / 16;
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nextberr[col ] += ( err ) / 16;
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}
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}
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*pP = colormap[ind].color;
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if ( ( ! floyd ) || fs_direction )
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{
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++col;
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++pP;
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}
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else
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{
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--col;
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--pP;
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}
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}
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while ( col != limitcol );
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if ( floyd )
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{
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temperr = thisrerr;
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thisrerr = nextrerr;
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nextrerr = temperr;
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temperr = thisgerr;
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thisgerr = nextgerr;
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nextgerr = temperr;
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temperr = thisberr;
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thisberr = nextberr;
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nextberr = temperr;
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fs_direction = ! fs_direction;
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}
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/* ppm_writeppmrow( stdout, (pixel *)imagearray[row], imagewidth, maxval, 0 );*/
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}
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ppm_freecolorhash(cht);
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free(thisrerr);
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free(nextrerr);
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free(thisgerr);
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free(nextgerr);
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free(thisberr);
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free(nextberr);
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(*maxcolorvalue)=maxval;
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(*pchv)=colormap;
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return CONV_OK;
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}
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/*
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** Here is the fun part, the median-cut colormap generator. This is based
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** on Paul Heckbert's paper "Color Image Quantization for Frame Buffer
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** Display", SIGGRAPH '82 Proceedings, page 297.
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*/
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static colorhist_vector
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mediancut( colorhist_vector chv, int16 colors, int32 sum, pixval maxval, int16 newcolors )
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{
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colorhist_vector colormap;
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box_vector bv;
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register int16 bi, i;
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int16 boxes;
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bv = (box_vector) malloc( sizeof(struct box) * newcolors );
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colormap = (colorhist_vector) malloc( sizeof(struct colorhist_item) * newcolors );
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if ( bv == (box_vector) 0 || colormap == (colorhist_vector) 0 )
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return NULL;
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for ( i = 0; i < newcolors; ++i )
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PPM_ASSIGN( colormap[i].color, 0, 0, 0 );
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/*
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** Set up the initial box.
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*/
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bv[0].ind = 0;
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bv[0].colors = colors;
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bv[0].sum = sum;
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boxes = 1;
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/*
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** Main loop: split boxes until we have enough.
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*/
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while ( boxes < newcolors )
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{
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register int32 indx, clrs;
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int32 sm;
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register int32 minr, maxr, ming, maxg, minb, maxb, v;
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int32 halfsum, lowersum;
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/*
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** Find the first splittable box.
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*/
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for ( bi = 0; bi < boxes; ++bi )
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if ( bv[bi].colors >= 2 )
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break;
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if ( bi == boxes )
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break; /* ran out of colors! */
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indx = bv[bi].ind;
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clrs = bv[bi].colors;
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sm = bv[bi].sum;
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/*
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** Go through the box finding the minimum and maximum of each
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** component - the boundaries of the box.
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*/
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minr = maxr = PPM_GETR( chv[indx].color );
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ming = maxg = PPM_GETG( chv[indx].color );
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minb = maxb = PPM_GETB( chv[indx].color );
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for ( i = 1; i < clrs; ++i )
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{
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v = PPM_GETR( chv[indx + i].color );
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if ( v < minr ) minr = v;
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if ( v > maxr ) maxr = v;
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v = PPM_GETG( chv[indx + i].color );
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if ( v < ming ) ming = v;
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if ( v > maxg ) maxg = v;
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v = PPM_GETB( chv[indx + i].color );
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if ( v < minb ) minb = v;
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if ( v > maxb ) maxb = v;
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}
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/*
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** Find the largest dimension, and sort by that component. I have
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** included two methods for determining the "largest" dimension;
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** first by simply comparing the range in RGB space, and second
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** by transforming into luminosities before the comparison. You
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** can switch which method is used by switching the commenting on
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** the LARGE_ defines at the beginning of this source file.
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*/
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#ifdef LARGE_NORM
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if ( maxr - minr >= maxg - ming && maxr - minr >= maxb - minb )
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XP_QSORT(
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(char*) &(chv[indx]), clrs, sizeof(struct colorhist_item),
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(qsortprototype)redcompare );
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else if ( maxg - ming >= maxb - minb )
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XP_QSORT(
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(char*) &(chv[indx]), clrs, sizeof(struct colorhist_item),
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(qsortprototype)greencompare );
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else
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XP_QSORT(
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(char*) &(chv[indx]), clrs, sizeof(struct colorhist_item),
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(qsortprototype)bluecompare );
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#endif /*LARGE_NORM*/
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#ifdef LARGE_LUM
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{
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pixel p;
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float rl, gl, bl;
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PPM_ASSIGN(p, maxr - minr, 0, 0);
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rl = PPM_LUMIN(p);
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PPM_ASSIGN(p, 0, maxg - ming, 0);
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gl = PPM_LUMIN(p);
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PPM_ASSIGN(p, 0, 0, maxb - minb);
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bl = PPM_LUMIN(p);
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if ( rl >= gl && rl >= bl )
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XP_QSORT(
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(char*) &(chv[indx]), clrs, sizeof(struct colorhist_item),
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redcompare );
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else if ( gl >= bl )
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XP_QSORT(
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(char*) &(chv[indx]), clrs, sizeof(struct colorhist_item),
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greencompare );
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else
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XP_QSORT(
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(char*) &(chv[indx]), clrs, sizeof(struct colorhist_item),
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bluecompare );
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}
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#endif /*LARGE_LUM*/
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/*
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** Now find the median based on the counts, so that about half the
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** pixels (not colors, pixels) are in each subdivision.
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|
*/
|
|
lowersum = chv[indx].value;
|
|
halfsum = sm / 2;
|
|
for ( i = 1; i < clrs - 1; ++i )
|
|
{
|
|
if ( lowersum >= halfsum )
|
|
break;
|
|
lowersum += chv[indx + i].value;
|
|
}
|
|
|
|
/*
|
|
** Split the box, and sort to bring the biggest boxes to the top.
|
|
*/
|
|
bv[bi].colors = i;
|
|
bv[bi].sum = lowersum;
|
|
bv[boxes].ind = indx + i;
|
|
bv[boxes].colors = clrs - i;
|
|
bv[boxes].sum = sm - lowersum;
|
|
++boxes;
|
|
XP_QSORT( (char*) bv, boxes, sizeof(struct box), (qsortprototype)sumcompare );
|
|
}
|
|
|
|
/*
|
|
** Ok, we've got enough boxes. Now choose a representative color for
|
|
** each box. There are a number of possible ways to make this choice.
|
|
** One would be to choose the center of the box; this ignores any structure
|
|
** within the boxes. Another method would be to average all the colors in
|
|
** the box - this is the method specified in Heckbert's paper. A third
|
|
** method is to average all the pixels in the box. You can switch which
|
|
** method is used by switching the commenting on the REP_ defines at
|
|
** the beginning of this source file.
|
|
*/
|
|
for ( bi = 0; bi < boxes; ++bi )
|
|
{
|
|
#ifdef REP_CENTER_BOX
|
|
register int16 indx = bv[bi].ind;
|
|
register int16 clrs = bv[bi].colors;
|
|
register int16 minr, maxr, ming, maxg, minb, maxb, v;
|
|
|
|
minr = maxr = PPM_GETR( chv[indx].color );
|
|
ming = maxg = PPM_GETG( chv[indx].color );
|
|
minb = maxb = PPM_GETB( chv[indx].color );
|
|
for ( i = 1; i < clrs; ++i )
|
|
{
|
|
v = PPM_GETR( chv[indx + i].color );
|
|
minr = min( minr, v );
|
|
maxr = max( maxr, v );
|
|
v = PPM_GETG( chv[indx + i].color );
|
|
ming = min( ming, v );
|
|
maxg = max( maxg, v );
|
|
v = PPM_GETB( chv[indx + i].color );
|
|
minb = min( minb, v );
|
|
maxb = max( maxb, v );
|
|
}
|
|
PPM_ASSIGN(
|
|
colormap[bi].color, ( minr + maxr ) / 2, ( ming + maxg ) / 2,
|
|
( minb + maxb ) / 2 );
|
|
#endif /*REP_CENTER_BOX*/
|
|
#ifdef REP_AVERAGE_COLORS
|
|
register int16 indx = bv[bi].ind;
|
|
register int16 clrs = bv[bi].colors;
|
|
register int32 r = 0, g = 0, b = 0;
|
|
|
|
for ( i = 0; i < clrs; ++i )
|
|
{
|
|
r += PPM_GETR( chv[indx + i].color );
|
|
g += PPM_GETG( chv[indx + i].color );
|
|
b += PPM_GETB( chv[indx + i].color );
|
|
}
|
|
r = r / clrs;
|
|
g = g / clrs;
|
|
b = b / clrs;
|
|
PPM_ASSIGN( colormap[bi].color, (pixval)r, (pixval)g, (pixval)b );
|
|
#endif /*REP_AVERAGE_COLORS*/
|
|
#ifdef REP_AVERAGE_PIXELS
|
|
register int16 indx = bv[bi].ind;
|
|
register int16 clrs = bv[bi].colors;
|
|
register int32 r = 0, g = 0, b = 0, sum = 0;
|
|
|
|
for ( i = 0; i < clrs; ++i )
|
|
{
|
|
r += PPM_GETR( chv[indx + i].color ) * chv[indx + i].value;
|
|
g += PPM_GETG( chv[indx + i].color ) * chv[indx + i].value;
|
|
b += PPM_GETB( chv[indx + i].color ) * chv[indx + i].value;
|
|
sum += chv[indx + i].value;
|
|
}
|
|
r = r / sum;
|
|
if ( r > maxval ) r = maxval; /* avoid math errors */
|
|
g = g / sum;
|
|
if ( g > maxval ) g = maxval;
|
|
b = b / sum;
|
|
if ( b > maxval ) b = maxval;
|
|
PPM_ASSIGN( colormap[bi].color, r, g, b );
|
|
#endif /*REP_AVERAGE_PIXELS*/
|
|
}
|
|
|
|
/*
|
|
** All done.
|
|
*/
|
|
free (bv);
|
|
return colormap;
|
|
}
|
|
|
|
static int
|
|
redcompare( ch1, ch2 )
|
|
const colorhist_vector ch1, ch2;
|
|
{
|
|
return (int16) PPM_GETR( ch1->color ) - (int16) PPM_GETR( ch2->color );
|
|
}
|
|
|
|
static int
|
|
greencompare( ch1, ch2 )
|
|
const colorhist_vector ch1, ch2;
|
|
{
|
|
return (int16) PPM_GETG( ch1->color ) - (int16) PPM_GETG( ch2->color );
|
|
}
|
|
|
|
static int
|
|
bluecompare( ch1, ch2 )
|
|
const colorhist_vector ch1, ch2;
|
|
{
|
|
return (int16) PPM_GETB( ch1->color ) - (int16) PPM_GETB( ch2->color );
|
|
}
|
|
|
|
static int
|
|
sumcompare( b1, b2 )
|
|
const box_vector b1, b2;
|
|
{
|
|
return b2->sum - b1->sum;
|
|
}
|