static int iwopt_palette_is_valid_gray(struct iw_context *ctx, struct iw_opt_ctx *optctx, int bpp,
int *pbinary_trns, unsigned int *ptrns_shade)
{
int factor;
int i;
int max_entries;
iw_byte clr_used[256];
iw_byte key_clr=0;
*pbinary_trns = 0;
*ptrns_shade = 0;
if(optctx->has_color) return 0;
if(optctx->has_partial_transparency) return 0;
if(optctx->has_transparency && !ctx->opt_binary_trns) return 0;
if(optctx->has_transparency && !(ctx->output_profile&IW_PROFILE_BINARYTRNS)) return 0;
switch(bpp) {
case 1: factor=255; max_entries=2; break;
case 2: factor=85; max_entries=4; break;
case 4: factor=17; max_entries=16; break;
case 8: factor=1; max_entries=256; break;
default: return 0;
}
if(optctx->palette->num_entries > max_entries)
return 0;
// If there is a background color label, it must be one of the available gray shades.
if(optctx->has_bkgdlabel && bpp<8) {
// We already know the bkgd label is gray (because has_color is false), so we
// only have to look at one of the components.
if(optctx->bkgdlabel[0] % factor != 0) {
return 0;
}
}
iw_zeromem(clr_used,256);
for(i=0;i<optctx->palette->num_entries;i++) {
if(optctx->palette->entry[i].a>0) { // Look at all the nontransparent entries.
if(optctx->palette->entry[i].r % factor) return 0;
// Keep track of which shades were used.
clr_used[optctx->palette->entry[i].r / factor] = 1;
}
}
// In order for binary transparency to be usable, there must be at least
// one unused gray shade.
if(optctx->has_transparency) {
if(!iwopt_find_unused(clr_used,max_entries,&key_clr))
return 0;
*pbinary_trns = 1;
*ptrns_shade = (unsigned int)key_clr;
}
return 1;
}
static void iwopt_try_gray8_binary_trns(struct iw_context *ctx, struct iw_opt_ctx *optctx)
{
int i,j;
const unsigned char *ptr;
unsigned char *ptr2;
unsigned char clr_used[256];
unsigned char key_clr;
unsigned char *trns_mask = NULL;
if(!(ctx->output_profile&IW_PROFILE_BINARYTRNS)) return;
if(!ctx->opt_binary_trns) return;
memset(&clr_used,0,256*sizeof(unsigned char));
trns_mask = iw_malloc_large(ctx, optctx->width, optctx->height);
if(!trns_mask) goto done;
for(j=0;j<optctx->height;j++) {
for(i=0;i<optctx->width;i++) {
ptr = &optctx->pixelsptr[j*optctx->bpr+i*2];
if(ptr[1]==0) {
// Transparent pixel
trns_mask[j*optctx->width+i] = 0;
continue;
}
else {
// Nontransparent pixel
trns_mask[j*optctx->width+i] = 1;
}
clr_used[(int)ptr[0]] = 1;
}
}
if(!iwopt_find_unused(clr_used,256,&key_clr)) {
goto done;
}
// Strip the alpha channel:
iw_opt_copychannels_8(ctx,optctx,IW_IMGTYPE_GRAY,0,0,0);
if(!optctx->tmp_pixels) goto done;
// Change the color of all transparent pixels to the key color
for(j=0;j<optctx->height;j++) {
for(i=0;i<optctx->width;i++) {
ptr2 = &optctx->tmp_pixels[j*optctx->bpr+i];
if(trns_mask[j*optctx->width+i]==0) {
ptr2[0] = key_clr;
}
}
}
optctx->has_colorkey_trns = 1;
optctx->colorkey_r = key_clr;
optctx->colorkey_g = key_clr;
optctx->colorkey_b = key_clr;
done:
if(trns_mask) iw_free(trns_mask);
}
static int iwopt_palette_is_valid_gray(struct iw_context *ctx, struct iw_opt_ctx *optctx, int bpp,
int *pbinary_trns, unsigned int *ptrns_shade)
{
int factor;
int i;
int max_entries;
unsigned char clr_used[256];
unsigned char key_clr=0;
*pbinary_trns = 0;
*ptrns_shade = 0;
if(optctx->has_color) return 0;
if(optctx->has_partial_transparency) return 0;
if(optctx->has_transparency && !ctx->opt_binary_trns) return 0;
if(optctx->has_transparency && !(ctx->output_profile&IW_PROFILE_BINARYTRNS)) return 0;
switch(bpp) {
case 1: factor=255; max_entries=2; break;
case 2: factor=85; max_entries=4; break;
case 4: factor=17; max_entries=16; break;
case 8: factor=1; max_entries=256; break;
default: return 0;
}
if(optctx->palette->num_entries > max_entries)
return 0;
memset(&clr_used,0,256*sizeof(unsigned char));
for(i=0;i<optctx->palette->num_entries;i++) {
if(optctx->palette->entry[i].a>0) { // Look at all the nontransparent entries.
if(optctx->palette->entry[i].r % factor) return 0;
// Keep track of which shades were used.
clr_used[optctx->palette->entry[i].r / factor] = 1;
}
}
// In order for binary transparency to be usable, there must be at least
// one unused gray shade.
if(optctx->has_transparency) {
if(!iwopt_find_unused(clr_used,max_entries,&key_clr))
return 0;
*pbinary_trns = 1;
*ptrns_shade = (unsigned int)key_clr;
}
return 1;
}
static void iwopt_try_rgb16_binary_trns(struct iw_context *ctx, struct iw_opt_ctx *optctx)
{
int i,j;
const unsigned char *ptr;
unsigned char *ptr2;
unsigned char clr_used[256];
unsigned char key_clr; // low 8-bits of red component of the key color
unsigned char *trns_mask = NULL;
if(!(ctx->output_profile&IW_PROFILE_BINARYTRNS)) return;
if(!ctx->opt_binary_trns) return;
memset(&clr_used,0,256*sizeof(unsigned char));
trns_mask = iw_malloc_large(ctx, optctx->width, optctx->height);
if(!trns_mask) goto done;
for(j=0;j<optctx->height;j++) {
for(i=0;i<optctx->width;i++) {
ptr = &optctx->pixelsptr[j*optctx->bpr+(i*2)*4];
if(ptr[6]==0 && ptr[7]==0) {
// Transparent pixel
trns_mask[j*optctx->width+i] = 0;
continue;
}
else {
// Nontransparent pixel
trns_mask[j*optctx->width+i] = 1;
}
// For the colors we look for, all bytes are 192 except possibly the low-red byte.
if(ptr[0]!=192 || ptr[2]!=192 || ptr[3]!=192 || ptr[4]!=192 || ptr[5]!=192)
continue;
clr_used[(int)ptr[1]] = 1;
}
}
if(!iwopt_find_unused(clr_used,256,&key_clr)) {
goto done;
}
// Strip the alpha channel:
iw_opt_copychannels_16(ctx,optctx,IW_IMGTYPE_RGB,0,1,2);
if(!optctx->tmp_pixels) goto done;
// Change the color of all transparent pixels to the key color
for(j=0;j<optctx->height;j++) {
for(i=0;i<optctx->width;i++) {
ptr2 = &optctx->tmp_pixels[j*optctx->bpr+(i*2)*3];
if(trns_mask[j*optctx->width+i]==0) {
ptr2[0] = 192;
ptr2[1] = key_clr;
ptr2[2] = 192;
ptr2[3] = 192;
ptr2[4] = 192;
ptr2[5] = 192;
}
}
}
optctx->has_colorkey_trns = 1;
optctx->colorkey_r = 192*256+key_clr;
optctx->colorkey_g = 192*256+192;
optctx->colorkey_b = 192*256+192;
done:
if(trns_mask) iw_free(trns_mask);
}
// Try to convert from RGBA to RGB+binary trns.
// Assumes we already know there is transparency, but no partial transparency.
static void iwopt_try_rgb8_binary_trns(struct iw_context *ctx, struct iw_opt_ctx *optctx)
{
int i,j;
const unsigned char *ptr;
unsigned char *ptr2;
unsigned char clr_used[256];
unsigned char key_clr; // Red component of the key color
unsigned char *trns_mask = NULL;
if(!(ctx->output_profile&IW_PROFILE_BINARYTRNS)) return;
if(!ctx->opt_binary_trns) return;
// Try to find a color that's not used in the image.
// Looking for all 2^24 possible colors is too much work.
// We will just look for 256 predefined colors: R={0-255},G=192,B=192
memset(&clr_used,0,256*sizeof(unsigned char));
// Hard to decide how to do this. I don't want the optimization phase
// to modify img2.pixels, though that would be the easiest method.
// Another option would be to make a version of iw_opt_copychannels_8()
// that sets the transparent pixels to a certain value, but that would
// get messy.
// Instead, I'll make a transparency mask, then strip the alpha
// channel, then use the mask to patch up the new image.
trns_mask = iw_malloc_large(ctx, optctx->width, optctx->height);
if(!trns_mask) goto done;
for(j=0;j<optctx->height;j++) {
for(i=0;i<optctx->width;i++) {
ptr = &optctx->pixelsptr[j*optctx->bpr+i*4];
if(ptr[3]==0) {
// transparent pixel
trns_mask[j*optctx->width+i] = 0; // Remember which pixels are transparent.
continue;
}
else {
trns_mask[j*optctx->width+i] = 1;
}
if(ptr[1]!=192 || ptr[2]!=192) continue;
clr_used[(int)ptr[0]] = 1;
}
}
if(!iwopt_find_unused(clr_used,256,&key_clr)) {
goto done;
}
// Strip the alpha channel:
iw_opt_copychannels_8(ctx,optctx,IW_IMGTYPE_RGB,0,1,2);
if(!optctx->tmp_pixels) goto done;
// Change the color of all transparent pixels to the key color
for(j=0;j<optctx->height;j++) {
for(i=0;i<optctx->width;i++) {
ptr2 = &optctx->tmp_pixels[j*optctx->bpr+i*3];
if(trns_mask[j*optctx->width+i]==0) {
ptr2[0] = key_clr;
ptr2[1] = 192;
ptr2[2] = 192;
}
}
}
optctx->has_colorkey_trns = 1;
optctx->colorkey_r = key_clr;
optctx->colorkey_g = 192;
optctx->colorkey_b = 192;
done:
if(trns_mask) iw_free(trns_mask);
}
static void iwopt_try_gray16_binary_trns(struct iw_context *ctx, struct iw_opt_ctx *optctx)
{
int i,j;
const iw_byte *ptr;
iw_byte *ptr2;
iw_byte clr_used[256];
iw_byte key_clr=0; // low 8-bits of the key color
iw_byte *trns_mask = NULL;
if(!(ctx->output_profile&IW_PROFILE_BINARYTRNS)) return;
if(!ctx->opt_binary_trns) return;
iw_zeromem(clr_used,256);
trns_mask = iw_malloc_large(ctx, optctx->width, optctx->height);
if(!trns_mask) goto done;
for(j=0;j<optctx->height;j++) {
for(i=0;i<optctx->width;i++) {
ptr = &optctx->pixelsptr[j*optctx->bpr+(i*2)*2];
if(ptr[2]==0 && ptr[3]==0) {
// Transparent pixel
trns_mask[j*optctx->width+i] = 0;
continue;
}
else {
// Nontransparent pixel
trns_mask[j*optctx->width+i] = 1;
}
// For the colors we look for, the high byte is always 192.
if(ptr[0]!=192)
continue;
clr_used[(int)ptr[1]] = 1;
}
}
if(!iwopt_find_unused(clr_used,256,&key_clr)) {
goto done;
}
// Strip the alpha channel:
iw_opt_copychannels_16(ctx,optctx,IW_IMGTYPE_GRAY,0,0,0);
if(!optctx->tmp_pixels) goto done;
// Change the color of all transparent pixels to the key color
for(j=0;j<optctx->height;j++) {
for(i=0;i<optctx->width;i++) {
ptr2 = &optctx->tmp_pixels[j*optctx->bpr+(i*2)];
if(trns_mask[j*optctx->width+i]==0) {
ptr2[0] = 192;
ptr2[1] = key_clr;
}
}
}
optctx->has_colorkey_trns = 1;
optctx->colorkey[IW_CHANNELTYPE_RED] = 192*256+key_clr;
optctx->colorkey[IW_CHANNELTYPE_GREEN] = 192*256+key_clr;
optctx->colorkey[IW_CHANNELTYPE_BLUE] = 192*256+key_clr;
done:
if(trns_mask) iw_free(ctx,trns_mask);
}