static int
k_means(Pixel *pixelData,
uint32_t nPixels,
Pixel *paletteData,
uint32_t nPaletteEntries,
uint32_t *qp,
int threshold)
{
uint32_t *avg[3];
uint32_t *count;
uint32_t i;
uint32_t *avgDist;
uint32_t **avgDistSortKey;
int changes;
int built=0;
if (nPaletteEntries > UINT32_MAX / (sizeof(uint32_t))) {
return 0;
}
/* malloc check ok, using calloc */
if (!(count=calloc(nPaletteEntries, sizeof(uint32_t)))) {
return 0;
}
for(i=0;i<3;i++) {
avg[i]=NULL;
}
for(i=0;i<3;i++) {
/* malloc check ok, using calloc */
if (!(avg[i]=calloc(nPaletteEntries, sizeof(uint32_t)))) {
goto error_1;
}
}
/* this is enough of a check, since the multiplication n*size is done above */
if (nPaletteEntries > UINT32_MAX / nPaletteEntries) {
goto error_1;
}
/* malloc check ok, using calloc, checking n*n above */
avgDist=calloc(nPaletteEntries*nPaletteEntries, sizeof(uint32_t));
if (!avgDist) { goto error_1; }
/* malloc check ok, using calloc, checking n*n above */
avgDistSortKey=calloc(nPaletteEntries*nPaletteEntries, sizeof(uint32_t *));
if (!avgDistSortKey) { goto error_2; }
#ifndef NO_OUTPUT
printf("[");fflush(stdout);
#endif
while (1) {
if (!built) {
compute_palette_from_quantized_pixels(pixelData,nPixels,paletteData,nPaletteEntries,avg,count,qp);
build_distance_tables(avgDist,avgDistSortKey,paletteData,nPaletteEntries);
built=1;
} else {
recompute_palette_from_averages(paletteData,nPaletteEntries,avg,count);
resort_distance_tables(avgDist,avgDistSortKey,paletteData,nPaletteEntries);
}
changes=map_image_pixels_from_quantized_pixels(pixelData,
nPixels,
paletteData,
nPaletteEntries,
avgDist,
avgDistSortKey,
qp,
avg,
count);
if (changes<0) {
goto error_3;
}
#ifndef NO_OUTPUT
printf (".(%d)",changes);fflush(stdout);
#endif
if (changes<=threshold) break;
}
#ifndef NO_OUTPUT
printf("]\n");
#endif
if (avgDistSortKey) free(avgDistSortKey);
if (avgDist) free(avgDist);
for(i=0;i<3;i++) if (avg[i]) free (avg[i]);
if (count) free(count);
return 1;
error_3:
if (avgDistSortKey) free(avgDistSortKey);
error_2:
if (avgDist) free(avgDist);
error_1:
for(i=0;i<3;i++) if (avg[i]) free (avg[i]);
if (count) free(count);
return 0;
}
int
quantize(Pixel *pixelData,
uint32_t nPixels,
uint32_t nQuantPixels,
Pixel **palette,
uint32_t *paletteLength,
uint32_t **quantizedPixels,
int kmeans)
{
PixelList *hl[3];
HashTable *h;
BoxNode *root;
uint32_t i;
uint32_t *qp;
uint32_t nPaletteEntries;
uint32_t *avgDist;
uint32_t **avgDistSortKey;
Pixel *p;
#ifndef NO_OUTPUT
uint32_t timer,timer2;
#endif
#ifndef NO_OUTPUT
timer2=clock();
printf ("create hash table..."); fflush(stdout); timer=clock();
#endif
h=create_pixel_hash(pixelData,nPixels);
#ifndef NO_OUTPUT
printf ("done (%f)\n",(clock()-timer)/(double)CLOCKS_PER_SEC);
#endif
if (!h) {
goto error_0;
}
#ifndef NO_OUTPUT
printf ("create lists from hash table..."); fflush(stdout); timer=clock();
#endif
hl[0]=hl[1]=hl[2]=NULL;
hashtable_foreach(h,hash_to_list,hl);
#ifndef NO_OUTPUT
printf ("done (%f)\n",(clock()-timer)/(double)CLOCKS_PER_SEC);
#endif
if (!hl[0]) {
goto error_1;
}
#ifndef NO_OUTPUT
printf ("mergesort lists..."); fflush(stdout); timer=clock();
#endif
for(i=0;i<3;i++) {
hl[i]=mergesort_pixels(hl[i],i);
}
#ifdef TEST_MERGESORT
if (!test_sorted(hl)) {
printf ("bug in mergesort\n");
goto error_1;
}
#endif
#ifndef NO_OUTPUT
printf ("done (%f)\n",(clock()-timer)/(double)CLOCKS_PER_SEC);
#endif
#ifndef NO_OUTPUT
printf ("median cut..."); fflush(stdout); timer=clock();
#endif
root=median_cut(hl,nPixels,nQuantPixels);
#ifndef NO_OUTPUT
printf ("done (%f)\n",(clock()-timer)/(double)CLOCKS_PER_SEC);
#endif
if (!root) {
goto error_1;
}
nPaletteEntries=0;
#ifndef NO_OUTPUT
printf ("median cut tree to hash table..."); fflush(stdout); timer=clock();
#endif
annotate_hash_table(root,h,&nPaletteEntries);
#ifndef NO_OUTPUT
printf ("done (%f)\n",(clock()-timer)/(double)CLOCKS_PER_SEC);
#endif
#ifndef NO_OUTPUT
printf ("compute palette...\n"); fflush(stdout); timer=clock();
#endif
if (!compute_palette_from_median_cut(pixelData,nPixels,h,&p,nPaletteEntries)) {
goto error_3;
}
#ifndef NO_OUTPUT
printf ("done (%f)\n",(clock()-timer)/(double)CLOCKS_PER_SEC);
#endif
free_box_tree(root);
root=NULL;
/* malloc check ok, using calloc for overflow */
qp=calloc(nPixels, sizeof(uint32_t));
if (!qp) { goto error_4; }
if (nPaletteEntries > UINT32_MAX / nPaletteEntries ) {
goto error_5;
}
/* malloc check ok, using calloc for overflow, check of n*n above */
avgDist=calloc(nPaletteEntries*nPaletteEntries, sizeof(uint32_t));
if (!avgDist) { goto error_5; }
/* malloc check ok, using calloc for overflow, check of n*n above */
avgDistSortKey=calloc(nPaletteEntries*nPaletteEntries, sizeof(uint32_t *));
if (!avgDistSortKey) { goto error_6; }
if (!build_distance_tables(avgDist,avgDistSortKey,p,nPaletteEntries)) {
goto error_7;
}
if (!map_image_pixels_from_median_box(pixelData,nPixels,p,nPaletteEntries,h,avgDist,avgDistSortKey,qp)) {
goto error_7;
}
#ifdef TEST_NEAREST_NEIGHBOUR
#include <math.h>
{
uint32_t bestmatch,bestdist,dist;
HashTable *h2;
printf ("nearest neighbour search (full search)..."); fflush(stdout); timer=clock();
h2=hashtable_new(unshifted_pixel_hash,unshifted_pixel_cmp);
for (i=0;i<nPixels;i++) {
if (hashtable_lookup(h2,pixelData[i],&paletteEntry)) {
bestmatch=paletteEntry;
} else {
bestmatch=0;
bestdist=
_SQR(pixelData[i].c.r-p[0].c.r)+
_SQR(pixelData[i].c.g-p[0].c.g)+
_SQR(pixelData[i].c.b-p[0].c.b);
for (j=1;j<nPaletteEntries;j++) {
dist=
_SQR(pixelData[i].c.r-p[j].c.r)+
_SQR(pixelData[i].c.g-p[j].c.g)+
_SQR(pixelData[i].c.b-p[j].c.b);
if (dist==bestdist && j==qp[i]) {
bestmatch=j;
}
if (dist<bestdist) {
bestdist=dist;
bestmatch=j;
}
}
hashtable_insert(h2,pixelData[i],bestmatch);
}
if (qp[i]!=bestmatch ) {
printf ("discrepancy in matching algorithms pixel %d [%d %d] %f %f\n",
i,qp[i],bestmatch,
sqrt((double)(_SQR(pixelData[i].c.r-p[qp[i]].c.r)+
_SQR(pixelData[i].c.g-p[qp[i]].c.g)+
_SQR(pixelData[i].c.b-p[qp[i]].c.b))),
sqrt((double)(_SQR(pixelData[i].c.r-p[bestmatch].c.r)+
_SQR(pixelData[i].c.g-p[bestmatch].c.g)+
_SQR(pixelData[i].c.b-p[bestmatch].c.b)))
);
}
}
hashtable_free(h2);
}
#endif
#ifndef NO_OUTPUT
printf ("k means...\n"); fflush(stdout); timer=clock();
#endif
if (kmeans) k_means(pixelData,nPixels,p,nPaletteEntries,qp,kmeans-1);
#ifndef NO_OUTPUT
printf ("done (%f)\n",(clock()-timer)/(double)CLOCKS_PER_SEC);
#endif
*quantizedPixels=qp;
*palette=p;
*paletteLength=nPaletteEntries;
#ifndef NO_OUTPUT
printf ("cleanup..."); fflush(stdout); timer=clock();
#endif
if (avgDist) free(avgDist);
if (avgDistSortKey) free(avgDistSortKey);
destroy_pixel_hash(h);
#ifndef NO_OUTPUT
printf ("done (%f)\n",(clock()-timer)/(double)CLOCKS_PER_SEC);
printf ("-----\ntotal time %f\n",(clock()-timer2)/(double)CLOCKS_PER_SEC);
#endif
return 1;
error_7:
if (avgDistSortKey) free(avgDistSortKey);
error_6:
if (avgDist) free(avgDist);
error_5:
if (qp) free(qp);
error_4:
if (p) free(p);
error_3:
if (root) free_box_tree(root);
error_1:
destroy_pixel_hash(h);
error_0:
*quantizedPixels=NULL;
*paletteLength=0;
*palette=NULL;
return 0;
}
static int
k_means(Pixel *pixelData,
unsigned long nPixels,
Pixel *paletteData,
unsigned long nPaletteEntries,
unsigned long *qp,
int threshold)
{
unsigned long *avg[3];
unsigned long *count;
unsigned long i;
unsigned long *avgDist;
unsigned long **avgDistSortKey;
int changes;
int built=0;
if (!(count=malloc(sizeof(unsigned long)*nPaletteEntries))) {
return 0;
}
for(i=0;i<3;i++) {
avg[i]=NULL;
}
for(i=0;i<3;i++) {
if (!(avg[i]=malloc(sizeof(unsigned long)*nPaletteEntries))) {
goto error_1;
}
}
avgDist=malloc(sizeof(unsigned long)*nPaletteEntries*nPaletteEntries);
if (!avgDist) { goto error_1; }
avgDistSortKey=malloc(sizeof(unsigned long *)*nPaletteEntries*nPaletteEntries);
if (!avgDistSortKey) { goto error_2; }
#ifndef NO_OUTPUT
printf("[");fflush(stdout);
#endif
while (1) {
if (!built) {
compute_palette_from_quantized_pixels(pixelData,nPixels,paletteData,nPaletteEntries,avg,count,qp);
build_distance_tables(avgDist,avgDistSortKey,paletteData,nPaletteEntries);
built=1;
} else {
recompute_palette_from_averages(paletteData,nPaletteEntries,avg,count);
resort_distance_tables(avgDist,avgDistSortKey,paletteData,nPaletteEntries);
}
changes=map_image_pixels_from_quantized_pixels(pixelData,
nPixels,
paletteData,
nPaletteEntries,
avgDist,
avgDistSortKey,
qp,
avg,
count);
if (changes<0) {
goto error_3;
}
#ifndef NO_OUTPUT
printf (".(%d)",changes);fflush(stdout);
#endif
if (changes<=threshold) break;
}
#ifndef NO_OUTPUT
printf("]\n");
#endif
if (avgDistSortKey) free(avgDistSortKey);
if (avgDist) free(avgDist);
for(i=0;i<3;i++) if (avg[i]) free (avg[i]);
if (count) free(count);
return 1;
error_3:
if (avgDistSortKey) free(avgDistSortKey);
error_2:
if (avgDist) free(avgDist);
error_1:
for(i=0;i<3;i++) if (avg[i]) free (avg[i]);
if (count) free(count);
return 0;
}