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Pillow/src/libImaging/Quant.c
Andrew Murray 65cdc21105 Changed quantize and quantize2 to static
2021-04-11 12:40:59 +10:00

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/*
* The Python Imaging Library
* $Id$
*
* image quantizer
*
* history:
* 1998-09-10 tjs Contributed
* 1998-12-29 fl Added to PIL 1.0b1
* 2004-02-21 fl Fixed bogus free() on quantization error
* 2005-02-07 fl Limit number of colors to 256
*
* Written by Toby J Sargeant <tjs@longford.cs.monash.edu.au>.
*
* Copyright (c) 1998 by Toby J Sargeant
* Copyright (c) 1998-2004 by Secret Labs AB. All rights reserved.
*
* See the README file for information on usage and redistribution.
*/
#include "Imaging.h"
#include <stdio.h>
#include <stdlib.h>
#include <memory.h>
#include <time.h>
#include "QuantTypes.h"
#include "QuantOctree.h"
#include "QuantPngQuant.h"
#include "QuantHash.h"
#include "QuantHeap.h"
/* MSVC9.0 */
#ifndef UINT32_MAX
#define UINT32_MAX 0xffffffff
#endif
#define NO_OUTPUT
typedef struct {
uint32_t scale;
} PixelHashData;
typedef struct _PixelList {
struct _PixelList *next[3], *prev[3];
Pixel p;
unsigned int flag : 1;
int count;
} PixelList;
typedef struct _BoxNode {
struct _BoxNode *l, *r;
PixelList *head[3], *tail[3];
int axis;
int volume;
uint32_t pixelCount;
} BoxNode;
#define _SQR(x) ((x) * (x))
#define _DISTSQR(p1, p2) \
_SQR((int)((p1)->c.r) - (int)((p2)->c.r)) + \
_SQR((int)((p1)->c.g) - (int)((p2)->c.g)) + \
_SQR((int)((p1)->c.b) - (int)((p2)->c.b))
#define MAX_HASH_ENTRIES 65536
#define PIXEL_HASH(r, g, b) \
(((unsigned int)(r)) * 463 ^ ((unsigned int)(g) << 8) * 10069 ^ \
((unsigned int)(b) << 16) * 64997)
#define PIXEL_UNSCALE(p, q, s) \
((q)->c.r = (p)->c.r << (s)), ((q)->c.g = (p)->c.g << (s)), \
((q)->c.b = (p)->c.b << (s))
#define PIXEL_SCALE(p, q, s) \
((q)->c.r = (p)->c.r >> (s)), ((q)->c.g = (p)->c.g >> (s)), \
((q)->c.b = (p)->c.b >> (s))
static uint32_t
unshifted_pixel_hash(const HashTable *h, const Pixel pixel) {
return PIXEL_HASH(pixel.c.r, pixel.c.g, pixel.c.b);
}
static int
unshifted_pixel_cmp(const HashTable *h, const Pixel pixel1, const Pixel pixel2) {
if (pixel1.c.r == pixel2.c.r) {
if (pixel1.c.g == pixel2.c.g) {
if (pixel1.c.b == pixel2.c.b) {
return 0;
} else {
return (int)(pixel1.c.b) - (int)(pixel2.c.b);
}
} else {
return (int)(pixel1.c.g) - (int)(pixel2.c.g);
}
} else {
return (int)(pixel1.c.r) - (int)(pixel2.c.r);
}
}
static uint32_t
pixel_hash(const HashTable *h, const Pixel pixel) {
PixelHashData *d = (PixelHashData *)hashtable_get_user_data(h);
return PIXEL_HASH(
pixel.c.r >> d->scale, pixel.c.g >> d->scale, pixel.c.b >> d->scale);
}
static int
pixel_cmp(const HashTable *h, const Pixel pixel1, const Pixel pixel2) {
PixelHashData *d = (PixelHashData *)hashtable_get_user_data(h);
uint32_t A, B;
A = PIXEL_HASH(
pixel1.c.r >> d->scale, pixel1.c.g >> d->scale, pixel1.c.b >> d->scale);
B = PIXEL_HASH(
pixel2.c.r >> d->scale, pixel2.c.g >> d->scale, pixel2.c.b >> d->scale);
return (A == B) ? 0 : ((A < B) ? -1 : 1);
}
static void
exists_count_func(const HashTable *h, const Pixel key, uint32_t *val) {
*val += 1;
}
static void
new_count_func(const HashTable *h, const Pixel key, uint32_t *val) {
*val = 1;
}
static void
rehash_collide(
const HashTable *h, Pixel *keyp, uint32_t *valp, Pixel newkey, uint32_t newval) {
*valp += newval;
}
/* %% */
static HashTable *
create_pixel_hash(Pixel *pixelData, uint32_t nPixels) {
PixelHashData *d;
HashTable *hash;
uint32_t i;
#ifndef NO_OUTPUT
uint32_t timer, timer2, timer3;
#endif
/* malloc check ok, small constant allocation */
d = malloc(sizeof(PixelHashData));
if (!d) {
return NULL;
}
hash = hashtable_new(pixel_hash, pixel_cmp);
hashtable_set_user_data(hash, d);
d->scale = 0;
#ifndef NO_OUTPUT
timer = timer3 = clock();
#endif
for (i = 0; i < nPixels; i++) {
if (!hashtable_insert_or_update_computed(
hash, pixelData[i], new_count_func, exists_count_func)) {
;
}
while (hashtable_get_count(hash) > MAX_HASH_ENTRIES) {
d->scale++;
#ifndef NO_OUTPUT
printf("rehashing - new scale: %d\n", (int)d->scale);
timer2 = clock();
#endif
hashtable_rehash_compute(hash, rehash_collide);
#ifndef NO_OUTPUT
timer2 = clock() - timer2;
printf("rehash took %f sec\n", timer2 / (double)CLOCKS_PER_SEC);
timer += timer2;
#endif
}
}
#ifndef NO_OUTPUT
printf("inserts took %f sec\n", (clock() - timer) / (double)CLOCKS_PER_SEC);
#endif
#ifndef NO_OUTPUT
printf("total %f sec\n", (clock() - timer3) / (double)CLOCKS_PER_SEC);
#endif
return hash;
}
static void
destroy_pixel_hash(HashTable *hash) {
PixelHashData *d = (PixelHashData *)hashtable_get_user_data(hash);
if (d) {
free(d);
}
hashtable_free(hash);
}
/* 1. hash quantized pixels. */
/* 2. create R,G,B lists of sorted quantized pixels. */
/* 3. median cut. */
/* 4. build hash table from median cut boxes. */
/* 5. for each pixel, compute entry in hash table, and hence median cut box. */
/* 6. compute median cut box pixel averages. */
/* 7. map each pixel to nearest average. */
static int
compute_box_volume(BoxNode *b) {
unsigned char rl, rh, gl, gh, bl, bh;
if (b->volume >= 0) {
return b->volume;
}
if (!b->head[0]) {
b->volume = 0;
} else {
rh = b->head[0]->p.c.r;
rl = b->tail[0]->p.c.r;
gh = b->head[1]->p.c.g;
gl = b->tail[1]->p.c.g;
bh = b->head[2]->p.c.b;
bl = b->tail[2]->p.c.b;
b->volume = (rh - rl + 1) * (gh - gl + 1) * (bh - bl + 1);
}
return b->volume;
}
static void
hash_to_list(const HashTable *h, const Pixel pixel, const uint32_t count, void *u) {
PixelHashData *d = (PixelHashData *)hashtable_get_user_data(h);
PixelList **pl = (PixelList **)u;
PixelList *p;
int i;
Pixel q;
PIXEL_SCALE(&pixel, &q, d->scale);
/* malloc check ok, small constant allocation */
p = malloc(sizeof(PixelList));
if (!p) {
return;
}
p->flag = 0;
p->p = q;
p->count = count;
for (i = 0; i < 3; i++) {
p->next[i] = pl[i];
p->prev[i] = NULL;
if (pl[i]) {
pl[i]->prev[i] = p;
}
pl[i] = p;
}
}
static PixelList *
mergesort_pixels(PixelList *head, int i) {
PixelList *c, *t, *a, *b, *p;
if (!head || !head->next[i]) {
if (head) {
head->next[i] = NULL;
head->prev[i] = NULL;
}
return head;
}
for (c = t = head; c && t;
c = c->next[i], t = (t->next[i]) ? t->next[i]->next[i] : NULL)
;
if (c) {
if (c->prev[i]) {
c->prev[i]->next[i] = NULL;
}
c->prev[i] = NULL;
}
a = mergesort_pixels(head, i);
b = mergesort_pixels(c, i);
head = NULL;
p = NULL;
while (a && b) {
if (a->p.a.v[i] > b->p.a.v[i]) {
c = a;
a = a->next[i];
} else {
c = b;
b = b->next[i];
}
c->prev[i] = p;
c->next[i] = NULL;
if (p) {
p->next[i] = c;
}
p = c;
if (!head) {
head = c;
}
}
if (a) {
c->next[i] = a;
a->prev[i] = c;
} else if (b) {
c->next[i] = b;
b->prev[i] = c;
}
return head;
}
#if defined(TEST_MERGESORT) || defined(TEST_SORTED)
static int
test_sorted(PixelList *pl[3]) {
int i, n, l;
PixelList *t;
for (i = 0; i < 3; i++) {
n = 0;
l = 256;
for (t = pl[i]; t; t = t->next[i]) {
if (l < t->p.a.v[i])
return 0;
l = t->p.a.v[i];
}
}
return 1;
}
#endif
static int
box_heap_cmp(const Heap *h, const void *A, const void *B) {
BoxNode *a = (BoxNode *)A;
BoxNode *b = (BoxNode *)B;
return (int)a->pixelCount - (int)b->pixelCount;
}
#define LUMINANCE(p) (77 * (p)->c.r + 150 * (p)->c.g + 29 * (p)->c.b)
static int
splitlists(
PixelList *h[3],
PixelList *t[3],
PixelList *nh[2][3],
PixelList *nt[2][3],
uint32_t nCount[2],
int axis,
uint32_t pixelCount) {
uint32_t left;
PixelList *l, *r, *c, *n;
int i;
int nRight, nLeft;
int splitColourVal;
#ifdef TEST_SPLIT
{
PixelList *_prevTest, *_nextTest;
int _i, _nextCount[3], _prevCount[3];
for (_i = 0; _i < 3; _i++) {
for (_nextCount[_i] = 0, _nextTest = h[_i];
_nextTest && _nextTest->next[_i];
_nextTest = _nextTest->next[_i], _nextCount[_i]++)
;
for (_prevCount[_i] = 0, _prevTest = t[_i];
_prevTest && _prevTest->prev[_i];
_prevTest = _prevTest->prev[_i], _prevCount[_i]++)
;
if (_nextTest != t[_i]) {
printf("next-list of axis %d does not end at tail\n", _i);
exit(1);
}
if (_prevTest != h[_i]) {
printf("prev-list of axis %d does not end at head\n", _i);
exit(1);
}
for (; _nextTest && _nextTest->prev[_i]; _nextTest = _nextTest->prev[_i])
;
for (; _prevTest && _prevTest->next[_i]; _prevTest = _prevTest->next[_i])
;
if (_nextTest != h[_i]) {
printf("next-list of axis %d does not loop back to head\n", _i);
exit(1);
}
if (_prevTest != t[_i]) {
printf("prev-list of axis %d does not loop back to tail\n", _i);
exit(1);
}
}
for (_i = 1; _i < 3; _i++) {
if (_prevCount[_i] != _prevCount[_i - 1] ||
_nextCount[_i] != _nextCount[_i - 1] ||
_prevCount[_i] != _nextCount[_i]) {
printf(
"{%d %d %d} {%d %d %d}\n",
_prevCount[0],
_prevCount[1],
_prevCount[2],
_nextCount[0],
_nextCount[1],
_nextCount[2]);
exit(1);
}
}
}
#endif
nCount[0] = nCount[1] = 0;
nLeft = nRight = 0;
for (left = 0, c = h[axis]; c;) {
left = left + c->count;
nCount[0] += c->count;
c->flag = 0;
nLeft++;
c = c->next[axis];
if (left * 2 > pixelCount) {
break;
}
}
if (c) {
splitColourVal = c->prev[axis]->p.a.v[axis];
for (; c; c = c->next[axis]) {
if (splitColourVal != c->p.a.v[axis]) {
break;
}
c->flag = 0;
nLeft++;
nCount[0] += c->count;
}
}
for (; c; c = c->next[axis]) {
c->flag = 1;
nRight++;
nCount[1] += c->count;
}
if (!nRight) {
for (c = t[axis], splitColourVal = t[axis]->p.a.v[axis]; c; c = c->prev[axis]) {
if (splitColourVal != c->p.a.v[axis]) {
break;
}
c->flag = 1;
nRight++;
nLeft--;
nCount[0] -= c->count;
nCount[1] += c->count;
}
}
#ifndef NO_OUTPUT
if (!nLeft) {
for (c = h[axis]; c; c = c->next[axis]) {
printf("[%d %d %d]\n", c->p.c.r, c->p.c.g, c->p.c.b);
}
printf("warning... trivial split\n");
}
#endif
for (i = 0; i < 3; i++) {
l = r = NULL;
nh[0][i] = nt[0][i] = NULL;
nh[1][i] = nt[1][i] = NULL;
for (c = h[i]; c; c = n) {
n = c->next[i];
if (c->flag) { /* move pixel to right list*/
if (r) {
r->next[i] = c;
} else {
nh[1][i] = c;
}
c->prev[i] = r;
r = c;
} else { /* move pixel to left list */
if (l) {
l->next[i] = c;
} else {
nh[0][i] = c;
}
c->prev[i] = l;
l = c;
}
}
if (l) {
l->next[i] = NULL;
}
if (r) {
r->next[i] = NULL;
}
nt[0][i] = l;
nt[1][i] = r;
}
return 1;
}
static int
split(BoxNode *node) {
unsigned char rl, rh, gl, gh, bl, bh;
int f[3];
int best, axis;
int i;
PixelList *heads[2][3];
PixelList *tails[2][3];
uint32_t newCounts[2];
BoxNode *left, *right;
rh = node->head[0]->p.c.r;
rl = node->tail[0]->p.c.r;
gh = node->head[1]->p.c.g;
gl = node->tail[1]->p.c.g;
bh = node->head[2]->p.c.b;
bl = node->tail[2]->p.c.b;
#ifdef TEST_SPLIT
printf("splitting node [%d %d %d] [%d %d %d] ", rl, gl, bl, rh, gh, bh);
#endif
f[0] = (rh - rl) * 77;
f[1] = (gh - gl) * 150;
f[2] = (bh - bl) * 29;
best = f[0];
axis = 0;
for (i = 1; i < 3; i++) {
if (best < f[i]) {
best = f[i];
axis = i;
}
}
#ifdef TEST_SPLIT
printf("along axis %d\n", axis + 1);
#endif
#ifdef TEST_SPLIT
{
PixelList *_prevTest, *_nextTest;
int _i, _nextCount[3], _prevCount[3];
for (_i = 0; _i < 3; _i++) {
if (node->tail[_i]->next[_i]) {
printf("tail is not tail\n");
printf(
"node->tail[%d]->next[%d]=%p\n", _i, _i, node->tail[_i]->next[_i]);
}
if (node->head[_i]->prev[_i]) {
printf("head is not head\n");
printf(
"node->head[%d]->prev[%d]=%p\n", _i, _i, node->head[_i]->prev[_i]);
}
}
for (_i = 0; _i < 3; _i++) {
for (_nextCount[_i] = 0, _nextTest = node->head[_i];
_nextTest && _nextTest->next[_i];
_nextTest = _nextTest->next[_i], _nextCount[_i]++)
;
for (_prevCount[_i] = 0, _prevTest = node->tail[_i];
_prevTest && _prevTest->prev[_i];
_prevTest = _prevTest->prev[_i], _prevCount[_i]++)
;
if (_nextTest != node->tail[_i]) {
printf("next-list of axis %d does not end at tail\n", _i);
}
if (_prevTest != node->head[_i]) {
printf("prev-list of axis %d does not end at head\n", _i);
}
for (; _nextTest && _nextTest->prev[_i]; _nextTest = _nextTest->prev[_i])
;
for (; _prevTest && _prevTest->next[_i]; _prevTest = _prevTest->next[_i])
;
if (_nextTest != node->head[_i]) {
printf("next-list of axis %d does not loop back to head\n", _i);
}
if (_prevTest != node->tail[_i]) {
printf("prev-list of axis %d does not loop back to tail\n", _i);
}
}
for (_i = 1; _i < 3; _i++) {
if (_prevCount[_i] != _prevCount[_i - 1] ||
_nextCount[_i] != _nextCount[_i - 1] ||
_prevCount[_i] != _nextCount[_i]) {
printf(
"{%d %d %d} {%d %d %d}\n",
_prevCount[0],
_prevCount[1],
_prevCount[2],
_nextCount[0],
_nextCount[1],
_nextCount[2]);
}
}
}
#endif
node->axis = axis;
if (!splitlists(
node->head, node->tail, heads, tails, newCounts, axis, node->pixelCount)) {
#ifndef NO_OUTPUT
printf("list split failed.\n");
#endif
return 0;
}
#ifdef TEST_SPLIT
if (!test_sorted(heads[0])) {
printf("bug in split");
exit(1);
}
if (!test_sorted(heads[1])) {
printf("bug in split");
exit(1);
}
#endif
/* malloc check ok, small constant allocation */
left = malloc(sizeof(BoxNode));
right = malloc(sizeof(BoxNode));
if (!left || !right) {
free(left);
free(right);
return 0;
}
for (i = 0; i < 3; i++) {
left->head[i] = heads[0][i];
left->tail[i] = tails[0][i];
right->head[i] = heads[1][i];
right->tail[i] = tails[1][i];
node->head[i] = NULL;
node->tail[i] = NULL;
}
#ifdef TEST_SPLIT
if (left->head[0]) {
rh = left->head[0]->p.c.r;
rl = left->tail[0]->p.c.r;
gh = left->head[1]->p.c.g;
gl = left->tail[1]->p.c.g;
bh = left->head[2]->p.c.b;
bl = left->tail[2]->p.c.b;
printf(" left node [%3d %3d %3d] [%3d %3d %3d]\n", rl, gl, bl, rh, gh, bh);
}
if (right->head[0]) {
rh = right->head[0]->p.c.r;
rl = right->tail[0]->p.c.r;
gh = right->head[1]->p.c.g;
gl = right->tail[1]->p.c.g;
bh = right->head[2]->p.c.b;
bl = right->tail[2]->p.c.b;
printf(" right node [%3d %3d %3d] [%3d %3d %3d]\n", rl, gl, bl, rh, gh, bh);
}
#endif
left->l = left->r = NULL;
right->l = right->r = NULL;
left->axis = right->axis = -1;
left->volume = right->volume = -1;
left->pixelCount = newCounts[0];
right->pixelCount = newCounts[1];
node->l = left;
node->r = right;
return 1;
}
static BoxNode *
median_cut(PixelList *hl[3], uint32_t imPixelCount, int nPixels) {
PixelList *tl[3];
int i;
BoxNode *root;
Heap *h;
BoxNode *thisNode;
h = ImagingQuantHeapNew(box_heap_cmp);
/* malloc check ok, small constant allocation */
root = malloc(sizeof(BoxNode));
if (!root) {
ImagingQuantHeapFree(h);
return NULL;
}
for (i = 0; i < 3; i++) {
for (tl[i] = hl[i]; tl[i] && tl[i]->next[i]; tl[i] = tl[i]->next[i])
;
root->head[i] = hl[i];
root->tail[i] = tl[i];
}
root->l = root->r = NULL;
root->axis = -1;
root->volume = -1;
root->pixelCount = imPixelCount;
ImagingQuantHeapAdd(h, (void *)root);
while (--nPixels) {
do {
if (!ImagingQuantHeapRemove(h, (void **)&thisNode)) {
goto done;
}
} while (compute_box_volume(thisNode) == 1);
if (!split(thisNode)) {
#ifndef NO_OUTPUT
printf("Oops, split failed...\n");
#endif
exit(1);
}
ImagingQuantHeapAdd(h, (void *)(thisNode->l));
ImagingQuantHeapAdd(h, (void *)(thisNode->r));
}
done:
ImagingQuantHeapFree(h);
return root;
}
static void
free_box_tree(BoxNode *n) {
PixelList *p, *pp;
if (n->l) {
free_box_tree(n->l);
}
if (n->r) {
free_box_tree(n->r);
}
for (p = n->head[0]; p; p = pp) {
pp = p->next[0];
free(p);
}
free(n);
}
#ifdef TEST_SPLIT_INTEGRITY
static int
checkContained(BoxNode *n, Pixel *pp) {
if (n->l && n->r) {
return checkContained(n->l, pp) + checkContained(n->r, pp);
}
if (n->l || n->r) {
#ifndef NO_OUTPUT
printf("box tree is dead\n");
#endif
return 0;
}
if (pp->c.r <= n->head[0]->p.c.r && pp->c.r >= n->tail[0]->p.c.r &&
pp->c.g <= n->head[1]->p.c.g && pp->c.g >= n->tail[1]->p.c.g &&
pp->c.b <= n->head[2]->p.c.b && pp->c.b >= n->tail[2]->p.c.b) {
return 1;
}
return 0;
}
#endif
static int
annotate_hash_table(BoxNode *n, HashTable *h, uint32_t *box) {
PixelList *p;
PixelHashData *d = (PixelHashData *)hashtable_get_user_data(h);
Pixel q;
if (n->l && n->r) {
return annotate_hash_table(n->l, h, box) && annotate_hash_table(n->r, h, box);
}
if (n->l || n->r) {
#ifndef NO_OUTPUT
printf("box tree is dead\n");
#endif
return 0;
}
for (p = n->head[0]; p; p = p->next[0]) {
PIXEL_UNSCALE(&(p->p), &q, d->scale);
if (!hashtable_insert(h, q, *box)) {
#ifndef NO_OUTPUT
printf("hashtable insert failed\n");
#endif
return 0;
}
}
if (n->head[0]) {
(*box)++;
}
return 1;
}
static int
_sort_ulong_ptr_keys(const void *a, const void *b) {
uint32_t A = **(uint32_t **)a;
uint32_t B = **(uint32_t **)b;
return (A == B) ? 0 : ((A < B) ? -1 : +1);
}
static int
resort_distance_tables(
uint32_t *avgDist, uint32_t **avgDistSortKey, Pixel *p, uint32_t nEntries) {
uint32_t i, j, k;
uint32_t **skRow;
uint32_t *skElt;
for (i = 0; i < nEntries; i++) {
avgDist[i * nEntries + i] = 0;
for (j = 0; j < i; j++) {
avgDist[j * nEntries + i] = avgDist[i * nEntries + j] =
_DISTSQR(p + i, p + j);
}
}
for (i = 0; i < nEntries; i++) {
skRow = avgDistSortKey + i * nEntries;
for (j = 1; j < nEntries; j++) {
skElt = skRow[j];
for (k = j; k && (*(skRow[k - 1]) > *(skRow[k])); k--) {
skRow[k] = skRow[k - 1];
}
if (k != j) {
skRow[k] = skElt;
}
}
}
return 1;
}
static void
build_distance_tables(
uint32_t *avgDist, uint32_t **avgDistSortKey, Pixel *p, uint32_t nEntries) {
uint32_t i, j;
for (i = 0; i < nEntries; i++) {
avgDist[i * nEntries + i] = 0;
avgDistSortKey[i * nEntries + i] = &(avgDist[i * nEntries + i]);
for (j = 0; j < i; j++) {
avgDist[j * nEntries + i] = avgDist[i * nEntries + j] =
_DISTSQR(p + i, p + j);
avgDistSortKey[j * nEntries + i] = &(avgDist[j * nEntries + i]);
avgDistSortKey[i * nEntries + j] = &(avgDist[i * nEntries + j]);
}
}
for (i = 0; i < nEntries; i++) {
qsort(
avgDistSortKey + i * nEntries,
nEntries,
sizeof(uint32_t *),
_sort_ulong_ptr_keys);
}
}
static int
map_image_pixels(
Pixel *pixelData,
uint32_t nPixels,
Pixel *paletteData,
uint32_t nPaletteEntries,
uint32_t *avgDist,
uint32_t **avgDistSortKey,
uint32_t *pixelArray) {
uint32_t *aD, **aDSK;
uint32_t idx;
uint32_t i, j;
uint32_t bestdist, bestmatch, dist;
uint32_t initialdist;
HashTable *h2;
h2 = hashtable_new(unshifted_pixel_hash, unshifted_pixel_cmp);
for (i = 0; i < nPixels; i++) {
if (!hashtable_lookup(h2, pixelData[i], &bestmatch)) {
bestmatch = 0;
initialdist = _DISTSQR(paletteData + bestmatch, pixelData + i);
bestdist = initialdist;
initialdist <<= 2;
aDSK = avgDistSortKey + bestmatch * nPaletteEntries;
aD = avgDist + bestmatch * nPaletteEntries;
for (j = 0; j < nPaletteEntries; j++) {
idx = aDSK[j] - aD;
if (*(aDSK[j]) <= initialdist) {
dist = _DISTSQR(paletteData + idx, pixelData + i);
if (dist < bestdist) {
bestdist = dist;
bestmatch = idx;
}
} else {
break;
}
}
hashtable_insert(h2, pixelData[i], bestmatch);
}
pixelArray[i] = bestmatch;
}
hashtable_free(h2);
return 1;
}
static int
map_image_pixels_from_quantized_pixels(
Pixel *pixelData,
uint32_t nPixels,
Pixel *paletteData,
uint32_t nPaletteEntries,
uint32_t *avgDist,
uint32_t **avgDistSortKey,
uint32_t *pixelArray,
uint32_t *avg[3],
uint32_t *count) {
uint32_t *aD, **aDSK;
uint32_t idx;
uint32_t i, j;
uint32_t bestdist, bestmatch, dist;
uint32_t initialdist;
HashTable *h2;
int changes = 0;
h2 = hashtable_new(unshifted_pixel_hash, unshifted_pixel_cmp);
for (i = 0; i < nPixels; i++) {
if (!hashtable_lookup(h2, pixelData[i], &bestmatch)) {
bestmatch = pixelArray[i];
initialdist = _DISTSQR(paletteData + bestmatch, pixelData + i);
bestdist = initialdist;
initialdist <<= 2;
aDSK = avgDistSortKey + bestmatch * nPaletteEntries;
aD = avgDist + bestmatch * nPaletteEntries;
for (j = 0; j < nPaletteEntries; j++) {
idx = aDSK[j] - aD;
if (*(aDSK[j]) <= initialdist) {
dist = _DISTSQR(paletteData + idx, pixelData + i);
if (dist < bestdist) {
bestdist = dist;
bestmatch = idx;
}
} else {
break;
}
}
hashtable_insert(h2, pixelData[i], bestmatch);
}
if (pixelArray[i] != bestmatch) {
changes++;
avg[0][bestmatch] += pixelData[i].c.r;
avg[1][bestmatch] += pixelData[i].c.g;
avg[2][bestmatch] += pixelData[i].c.b;
avg[0][pixelArray[i]] -= pixelData[i].c.r;
avg[1][pixelArray[i]] -= pixelData[i].c.g;
avg[2][pixelArray[i]] -= pixelData[i].c.b;
count[bestmatch]++;
count[pixelArray[i]]--;
pixelArray[i] = bestmatch;
}
}
hashtable_free(h2);
return changes;
}
static int
map_image_pixels_from_median_box(
Pixel *pixelData,
uint32_t nPixels,
Pixel *paletteData,
uint32_t nPaletteEntries,
HashTable *medianBoxHash,
uint32_t *avgDist,
uint32_t **avgDistSortKey,
uint32_t *pixelArray) {
uint32_t *aD, **aDSK;
uint32_t idx;
uint32_t i, j;
uint32_t bestdist, bestmatch, dist;
uint32_t initialdist;
HashTable *h2;
uint32_t pixelVal;
h2 = hashtable_new(unshifted_pixel_hash, unshifted_pixel_cmp);
for (i = 0; i < nPixels; i++) {
if (hashtable_lookup(h2, pixelData[i], &pixelVal)) {
pixelArray[i] = pixelVal;
continue;
}
if (!hashtable_lookup(medianBoxHash, pixelData[i], &pixelVal)) {
#ifndef NO_OUTPUT
printf("pixel lookup failed\n");
#endif
return 0;
}
initialdist = _DISTSQR(paletteData + pixelVal, pixelData + i);
bestdist = initialdist;
bestmatch = pixelVal;
initialdist <<= 2;
aDSK = avgDistSortKey + pixelVal * nPaletteEntries;
aD = avgDist + pixelVal * nPaletteEntries;
for (j = 0; j < nPaletteEntries; j++) {
idx = aDSK[j] - aD;
if (*(aDSK[j]) <= initialdist) {
dist = _DISTSQR(paletteData + idx, pixelData + i);
if (dist < bestdist) {
bestdist = dist;
bestmatch = idx;
}
} else {
break;
}
}
pixelArray[i] = bestmatch;
hashtable_insert(h2, pixelData[i], bestmatch);
}
hashtable_free(h2);
return 1;
}
static int
compute_palette_from_median_cut(
Pixel *pixelData,
uint32_t nPixels,
HashTable *medianBoxHash,
Pixel **palette,
uint32_t nPaletteEntries) {
uint32_t i;
uint32_t paletteEntry;
Pixel *p;
uint32_t *avg[3];
uint32_t *count;
*palette = NULL;
/* 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)))) {
for (i = 0; i < 3; i++) {
if (avg[i]) {
free(avg[i]);
}
}
free(count);
return 0;
}
}
for (i = 0; i < nPixels; i++) {
#ifdef TEST_SPLIT_INTEGRITY
if (!(i % 100)) {
printf("%05d\r", i);
fflush(stdout);
}
if (checkContained(root, pixelData + i) > 1) {
printf("pixel in two boxes\n");
for (i = 0; i < 3; i++) {
free(avg[i]);
}
free(count);
return 0;
}
#endif
if (!hashtable_lookup(medianBoxHash, pixelData[i], &paletteEntry)) {
#ifndef NO_OUTPUT
printf("pixel lookup failed\n");
#endif
for (i = 0; i < 3; i++) {
free(avg[i]);
}
free(count);
return 0;
}
if (paletteEntry >= nPaletteEntries) {
#ifndef NO_OUTPUT
printf(
"panic - paletteEntry>=nPaletteEntries (%d>=%d)\n",
(int)paletteEntry,
(int)nPaletteEntries);
#endif
for (i = 0; i < 3; i++) {
free(avg[i]);
}
free(count);
return 0;
}
avg[0][paletteEntry] += pixelData[i].c.r;
avg[1][paletteEntry] += pixelData[i].c.g;
avg[2][paletteEntry] += pixelData[i].c.b;
count[paletteEntry]++;
}
/* malloc check ok, using calloc */
p = calloc(nPaletteEntries, sizeof(Pixel));
if (!p) {
for (i = 0; i < 3; i++) {
free(avg[i]);
}
free(count);
return 0;
}
for (i = 0; i < nPaletteEntries; i++) {
p[i].c.r = (int)(.5 + (double)avg[0][i] / (double)count[i]);
p[i].c.g = (int)(.5 + (double)avg[1][i] / (double)count[i]);
p[i].c.b = (int)(.5 + (double)avg[2][i] / (double)count[i]);
}
*palette = p;
for (i = 0; i < 3; i++) {
free(avg[i]);
}
free(count);
return 1;
}
static int
recompute_palette_from_averages(
Pixel *palette, uint32_t nPaletteEntries, uint32_t *avg[3], uint32_t *count) {
uint32_t i;
for (i = 0; i < nPaletteEntries; i++) {
palette[i].c.r = (int)(.5 + (double)avg[0][i] / (double)count[i]);
palette[i].c.g = (int)(.5 + (double)avg[1][i] / (double)count[i]);
palette[i].c.b = (int)(.5 + (double)avg[2][i] / (double)count[i]);
}
return 1;
}
static int
compute_palette_from_quantized_pixels(
Pixel *pixelData,
uint32_t nPixels,
Pixel *palette,
uint32_t nPaletteEntries,
uint32_t *avg[3],
uint32_t *count,
uint32_t *qp) {
uint32_t i;
memset(count, 0, sizeof(uint32_t) * nPaletteEntries);
for (i = 0; i < 3; i++) {
memset(avg[i], 0, sizeof(uint32_t) * nPaletteEntries);
}
for (i = 0; i < nPixels; i++) {
if (qp[i] >= nPaletteEntries) {
#ifndef NO_OUTPUT
printf("scream\n");
#endif
return 0;
}
avg[0][qp[i]] += pixelData[i].c.r;
avg[1][qp[i]] += pixelData[i].c.g;
avg[2][qp[i]] += pixelData[i].c.b;
count[qp[i]]++;
}
for (i = 0; i < nPaletteEntries; i++) {
palette[i].c.r = (int)(.5 + (double)avg[0][i] / (double)count[i]);
palette[i].c.g = (int)(.5 + (double)avg[1][i] / (double)count[i]);
palette[i].c.b = (int)(.5 + (double)avg[2][i] / (double)count[i]);
}
return 1;
}
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;
}
static 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;
}
build_distance_tables(avgDist, avgDistSortKey, p, nPaletteEntries);
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;
}
typedef struct {
Pixel new;
Pixel furthest;
uint32_t furthestDistance;
int secondPixel;
} DistanceData;
static void
compute_distances(const HashTable *h, const Pixel pixel, uint32_t *dist, void *u) {
DistanceData *data = (DistanceData *)u;
uint32_t oldDist = *dist;
uint32_t newDist;
newDist = _DISTSQR(&(data->new), &pixel);
if (data->secondPixel || newDist < oldDist) {
*dist = newDist;
oldDist = newDist;
}
if (oldDist > data->furthestDistance) {
data->furthestDistance = oldDist;
data->furthest.v = pixel.v;
}
}
static int
quantize2(
Pixel *pixelData,
uint32_t nPixels,
uint32_t nQuantPixels,
Pixel **palette,
uint32_t *paletteLength,
uint32_t **quantizedPixels,
int kmeans) {
HashTable *h;
uint32_t i;
uint32_t mean[3];
Pixel *p;
DistanceData data;
uint32_t *qp;
uint32_t *avgDist;
uint32_t **avgDistSortKey;
/* malloc check ok, using calloc */
p = calloc(nQuantPixels, sizeof(Pixel));
if (!p) {
return 0;
}
mean[0] = mean[1] = mean[2] = 0;
h = hashtable_new(unshifted_pixel_hash, unshifted_pixel_cmp);
for (i = 0; i < nPixels; i++) {
hashtable_insert(h, pixelData[i], 0xffffffff);
mean[0] += pixelData[i].c.r;
mean[1] += pixelData[i].c.g;
mean[2] += pixelData[i].c.b;
}
data.new.c.r = (int)(.5 + (double)mean[0] / (double)nPixels);
data.new.c.g = (int)(.5 + (double)mean[1] / (double)nPixels);
data.new.c.b = (int)(.5 + (double)mean[2] / (double)nPixels);
for (i = 0; i < nQuantPixels; i++) {
data.furthestDistance = 0;
data.secondPixel = (i == 1) ? 1 : 0;
hashtable_foreach_update(h, compute_distances, &data);
p[i].v = data.furthest.v;
data.new.v = data.furthest.v;
}
hashtable_free(h);
/* malloc check ok, using calloc */
qp = calloc(nPixels, sizeof(uint32_t));
if (!qp) {
goto error_1;
}
if (nQuantPixels > UINT32_MAX / nQuantPixels) {
goto error_2;
}
/* malloc check ok, using calloc for overflow, check of n*n above */
avgDist = calloc(nQuantPixels * nQuantPixels, sizeof(uint32_t));
if (!avgDist) {
goto error_2;
}
/* malloc check ok, using calloc for overflow, check of n*n above */
avgDistSortKey = calloc(nQuantPixels * nQuantPixels, sizeof(uint32_t *));
if (!avgDistSortKey) {
goto error_3;
}
build_distance_tables(avgDist, avgDistSortKey, p, nQuantPixels);
if (!map_image_pixels(
pixelData, nPixels, p, nQuantPixels, avgDist, avgDistSortKey, qp)) {
goto error_4;
}
if (kmeans) {
k_means(pixelData, nPixels, p, nQuantPixels, qp, kmeans - 1);
}
*paletteLength = nQuantPixels;
*palette = p;
*quantizedPixels = qp;
free(avgDistSortKey);
free(avgDist);
return 1;
error_4:
free(avgDistSortKey);
error_3:
free(avgDist);
error_2:
free(qp);
error_1:
free(p);
return 0;
}
Imaging
ImagingQuantize(Imaging im, int colors, int mode, int kmeans) {
int i, j;
int x, y, v;
UINT8 *pp;
Pixel *p;
Pixel *palette;
uint32_t paletteLength;
int result;
uint32_t *newData;
Imaging imOut;
int withAlpha = 0;
ImagingSectionCookie cookie;
if (!im) {
return ImagingError_ModeError();
}
if (colors < 1 || colors > 256) {
/* FIXME: for colors > 256, consider returning an RGB image
instead (see @PIL205) */
return (Imaging)ImagingError_ValueError("bad number of colors");
}
if (strcmp(im->mode, "L") != 0 && strcmp(im->mode, "P") != 0 &&
strcmp(im->mode, "RGB") != 0 && strcmp(im->mode, "RGBA") != 0) {
return ImagingError_ModeError();
}
/* only octree and imagequant supports RGBA */
if (!strcmp(im->mode, "RGBA") && mode != 2 && mode != 3) {
return ImagingError_ModeError();
}
if (im->xsize > INT_MAX / im->ysize) {
return ImagingError_MemoryError();
}
/* malloc check ok, using calloc for final overflow, x*y above */
p = calloc(im->xsize * im->ysize, sizeof(Pixel));
if (!p) {
return ImagingError_MemoryError();
}
/* collect statistics */
/* FIXME: maybe we could load the hash tables directly from the
image data? */
if (!strcmp(im->mode, "L")) {
/* greyscale */
/* FIXME: converting a "L" image to "P" with 256 colors
should be done by a simple copy... */
for (i = y = 0; y < im->ysize; y++) {
for (x = 0; x < im->xsize; x++, i++) {
p[i].c.r = p[i].c.g = p[i].c.b = im->image8[y][x];
p[i].c.a = 255;
}
}
} else if (!strcmp(im->mode, "P")) {
/* palette */
pp = im->palette->palette;
for (i = y = 0; y < im->ysize; y++) {
for (x = 0; x < im->xsize; x++, i++) {
v = im->image8[y][x];
p[i].c.r = pp[v * 4 + 0];
p[i].c.g = pp[v * 4 + 1];
p[i].c.b = pp[v * 4 + 2];
p[i].c.a = pp[v * 4 + 3];
}
}
} else if (!strcmp(im->mode, "RGB") || !strcmp(im->mode, "RGBA")) {
/* true colour */
withAlpha = !strcmp(im->mode, "RGBA");
int transparency = 0;
unsigned char r, g, b;
for (i = y = 0; y < im->ysize; y++) {
for (x = 0; x < im->xsize; x++, i++) {
p[i].v = im->image32[y][x];
if (withAlpha && p[i].c.a == 0) {
if (transparency == 0) {
transparency = 1;
r = p[i].c.r;
g = p[i].c.g;
b = p[i].c.b;
} else {
/* Set all subsequent transparent pixels
to the same colour as the first */
p[i].c.r = r;
p[i].c.g = g;
p[i].c.b = b;
}
}
}
}
} else {
free(p);
return (Imaging)ImagingError_ValueError("internal error");
}
ImagingSectionEnter(&cookie);
switch (mode) {
case 0:
/* median cut */
result = quantize(
p,
im->xsize * im->ysize,
colors,
&palette,
&paletteLength,
&newData,
kmeans);
break;
case 1:
/* maximum coverage */
result = quantize2(
p,
im->xsize * im->ysize,
colors,
&palette,
&paletteLength,
&newData,
kmeans);
break;
case 2:
result = quantize_octree(
p,
im->xsize * im->ysize,
colors,
&palette,
&paletteLength,
&newData,
withAlpha);
break;
case 3:
#ifdef HAVE_LIBIMAGEQUANT
result = quantize_pngquant(
p,
im->xsize,
im->ysize,
colors,
&palette,
&paletteLength,
&newData,
withAlpha);
#else
result = -1;
#endif
break;
default:
result = 0;
break;
}
free(p);
ImagingSectionLeave(&cookie);
if (result > 0) {
imOut = ImagingNewDirty("P", im->xsize, im->ysize);
ImagingSectionEnter(&cookie);
for (i = y = 0; y < im->ysize; y++) {
for (x = 0; x < im->xsize; x++) {
imOut->image8[y][x] = (unsigned char)newData[i++];
}
}
free(newData);
pp = imOut->palette->palette;
for (i = j = 0; i < (int)paletteLength; i++) {
*pp++ = palette[i].c.r;
*pp++ = palette[i].c.g;
*pp++ = palette[i].c.b;
if (withAlpha) {
*pp++ = palette[i].c.a;
} else {
*pp++ = 255;
}
}
for (; i < 256; i++) {
*pp++ = 0;
*pp++ = 0;
*pp++ = 0;
*pp++ = 255;
}
if (withAlpha) {
strcpy(imOut->palette->mode, "RGBA");
}
free(palette);
ImagingSectionLeave(&cookie);
return imOut;
} else {
if (result == -1) {
return (Imaging)ImagingError_ValueError(
"dependency required by this method was not "
"enabled at compile time");
}
return (Imaging)ImagingError_ValueError("quantization error");
}
}
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