void
input_png_file(struct Options opts, struct PNGImage *img)
{
FILE *f;
int i, y, num_trans;
bool has_palette = false;
png_byte *trans_alpha;
png_color_16 *trans_values;
bool *full_alpha;
png_color *palette;
f = fopen(opts.infile, "rb");
if (!f) {
err(1, "Opening input png file '%s' failed", opts.infile);
}
img->png = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (!img->png) {
errx(1, "Creating png structure failed");
}
img->info = png_create_info_struct(img->png);
if (!img->info) {
errx(1, "Creating png info structure failed");
}
/* Better error handling here? */
if (setjmp(png_jmpbuf(img->png))) {
exit(1);
}
png_init_io(img->png, f);
png_read_info(img->png, img->info);
img->width = png_get_image_width(img->png, img->info);
img->height = png_get_image_height(img->png, img->info);
img->depth = png_get_bit_depth(img->png, img->info);
img->type = png_get_color_type(img->png, img->info);
if (img->type & PNG_COLOR_MASK_ALPHA) {
png_set_strip_alpha(img->png);
}
if (img->depth != depth) {
if (opts.verbose) {
warnx("Image bit depth is not %i (is %i).", depth,
img->depth);
}
}
if (img->type == PNG_COLOR_TYPE_GRAY) {
if (img->depth < 8) {
png_set_expand_gray_1_2_4_to_8(img->png);
}
png_set_gray_to_rgb(img->png);
} else {
if (img->depth < 8) {
png_set_expand_gray_1_2_4_to_8(img->png);
}
has_palette = png_get_PLTE(img->png, img->info, &palette,
&colors);
}
if (png_get_tRNS(img->png, img->info, &trans_alpha, &num_trans,
&trans_values)) {
if (img->type == PNG_COLOR_TYPE_PALETTE) {
full_alpha = malloc(sizeof(bool) * num_trans);
for (i = 0; i < num_trans; i++) {
if (trans_alpha[i] > 0) {
full_alpha[i] = false;
} else {
full_alpha[i] = true;
}
}
for (i = 0; i < num_trans; i++) {
if (full_alpha[i]) {
palette[i].red = 0xFF;
palette[i].green = 0x00;
palette[i].blue = 0xFF;
/*
* Set to the lightest color in the
* palette.
*/
}
}
free(full_alpha);
} else {
/* Set to the lightest color in the image. */
}
png_free_data(img->png, img->info, PNG_FREE_TRNS, -1);
}
if (has_palette) {
/* Make sure palette only has the amount of colors you want. */
} else {
/*
* Eventually when this copies colors from the image itself,
* make sure order is lightest to darkest.
*/
palette = malloc(sizeof(png_color) * colors);
if (strcmp(opts.infile, "rgb.png") == 0) {
palette[0].red = 0xFF;
palette[0].green = 0xEF;
palette[0].blue = 0xFF;
palette[1].red = 0xF7;
palette[1].green = 0xF7;
palette[1].blue = 0x8C;
palette[2].red = 0x94;
palette[2].green = 0x94;
palette[2].blue = 0xC6;
palette[3].red = 0x39;
palette[3].green = 0x39;
palette[3].blue = 0x84;
} else {
palette[0].red = 0xFF;
palette[0].green = 0xFF;
palette[0].blue = 0xFF;
palette[1].red = 0xA9;
palette[1].green = 0xA9;
palette[1].blue = 0xA9;
palette[2].red = 0x55;
palette[2].green = 0x55;
palette[2].blue = 0x55;
palette[3].red = 0x00;
palette[3].green = 0x00;
palette[3].blue = 0x00;
}
}
/*
* Also unfortunately, this sets it at 8 bit, and I can't find any
* option to reduce to 2 or 1 bit.
*/
#if PNG_LIBPNG_VER < 10402
png_set_dither(img->png, palette, colors, colors, NULL, 1);
#else
png_set_quantize(img->png, palette, colors, colors, NULL, 1);
#endif
if (!has_palette) {
png_set_PLTE(img->png, img->info, palette, colors);
free(palette);
}
/*
* If other useless chunks exist (sRGB, bKGD, pHYs, gAMA, cHRM, iCCP,
* etc.) offer to remove?
*/
png_read_update_info(img->png, img->info);
img->data = malloc(sizeof(png_byte *) * img->height);
for (y = 0; y < img->height; y++) {
img->data[y] = malloc(png_get_rowbytes(img->png, img->info));
}
png_read_image(img->png, img->data);
png_read_end(img->png, img->info);
fclose(f);
}
unsigned char *
ReadPNG(FILE *infile,int *width, int *height, XColor *colrs)
{
unsigned char *pixmap;
unsigned char *p;
png_byte *q;
png_struct *png_ptr;
png_info *info_ptr;
double screen_gamma;
png_byte *png_pixels=NULL, **row_pointers=NULL;
int i, j;
unsigned int packets;
png_color std_color_cube[216];
/* first check to see if its a valid PNG file. If not, return. */
/* we assume that infile is a valid filepointer */
{
int ret;
png_byte buf[8];
ret = fread(buf, 1, 8, infile);
if(ret != 8)
return 0;
ret = png_check_sig(buf, 8);
if(!ret)
return(0);
}
/* OK, it is a valid PNG file, so let's rewind it, and start
decoding it */
rewind(infile);
/* allocate the structures */
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if(!png_ptr)
return 0;
info_ptr = png_create_info_struct(png_ptr);
if(!info_ptr) {
png_destroy_read_struct(&png_ptr, NULL, NULL);
return 0;
}
/* Establish the setjmp return context for png_error to use. */
if (setjmp(png_jmpbuf(png_ptr))) {
#ifndef DISABLE_TRACE
if (srcTrace) {
fprintf(stderr, "\n!!!libpng read error!!!\n");
}
#endif
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
if(png_pixels != NULL)
free((char *)png_pixels);
if(row_pointers != NULL)
free((png_byte **)row_pointers);
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
return 0;
}
/* set up the input control */
png_init_io(png_ptr, infile);
/* read the file information */
png_read_info(png_ptr, info_ptr);
/* setup other stuff using the fields of png_info. */
*width = (int)png_get_image_width(png_ptr, info_ptr);
*height = (int)png_get_image_height(png_ptr, info_ptr);
#ifndef DISABLE_TRACE
if (srcTrace) {
fprintf(stderr,"\n\nBEFORE\nheight = %d\n", (int)png_get_image_width(png_ptr, info_ptr));
fprintf(stderr,"width = %d\n", (int)png_get_image_height(png_ptr, info_ptr));
fprintf(stderr,"bit depth = %d\n", png_get_bit_depth(png_ptr, info_ptr));
fprintf(stderr,"color type = %d\n", png_get_color_type(png_ptr, info_ptr));
fprintf(stderr,"compression type = %d\n", png_get_compression_type(png_ptr, info_ptr));
fprintf(stderr,"filter type = %d\n", png_get_filter_type(png_ptr, info_ptr));
fprintf(stderr,"interlace type = %d\n", png_get_interlace_type(png_ptr, info_ptr));
fprintf(stderr,"num colors = %d\n", png_get_palette_max(png_ptr, info_ptr));
fprintf(stderr,"rowbytes = %d\n", png_get_rowbytes(png_ptr, info_ptr));
}
#endif
#if 0
/* This handles alpha and transparency by replacing it with
a background value. */
/* its #if'ed out for now cause I don't have anything to
test it with */
{
png_color_16 my_background;
if (png_get_valid(png_ptr, info_ptr) & PNG_INFO_bKGD)
png_set_background(png_ptr, &(info_ptr->background),
PNG_GAMMA_FILE, 1, 1.0);
else
png_set_background(png_ptr, &my_background,
PNG_GAMMA_SCREEN, 0, 1.0);
}
#endif
/* strip pixels in 16-bit images down to 8 bits */
if (png_get_bit_depth(png_ptr, info_ptr) == 16)
png_set_strip_16(png_ptr);
/* If it is a color image then check if it has a palette. If not
then dither the image to 256 colors, and make up a palette */
if (png_get_color_type(png_ptr, info_ptr)==PNG_COLOR_TYPE_RGB ||
png_get_color_type(png_ptr, info_ptr)==PNG_COLOR_TYPE_RGB_ALPHA) {
if(! (png_get_valid(png_ptr, info_ptr, PNG_INFO_PLTE)) ) {
#ifndef DISABLE_TRACE
if (srcTrace) {
fprintf(stderr,"dithering (RGB->palette)...\n");
}
#endif
/* if there is is no valid palette, then we need to make
one up */
for(i=0;i<216;i++) {
/* 255.0/5 = 51 */
std_color_cube[i].red=(i%6)*51;
std_color_cube[i].green=((i/6)%6)*51;
std_color_cube[i].blue=(i/36)*51;
}
/* this should probably be dithering to
Rdata.colors_per_inlined_image colors */
png_set_quantize(png_ptr, std_color_cube,
216,
216, NULL, 1);
} else {
#ifndef DISABLE_TRACE
if (srcTrace) {
fprintf(stderr,"dithering (RGB->file supplied palette)...\n");
}
#endif
png_colorp palette;
int num_palette;
png_get_PLTE(png_ptr, info_ptr, palette, &num_palette);
png_uint_16p hist;
png_get_hIST(png_ptr, info_ptr, &hist);
png_set_quantize(png_ptr, palette,
num_palette,
get_pref_int(eCOLORS_PER_INLINED_IMAGE),
hist, 1);
}
}
/* PNG files pack pixels of bit depths 1, 2, and 4 into bytes as
small as they can. This expands pixels to 1 pixel per byte, and
if a transparency value is supplied, an alpha channel is
built.*/
if (png_get_bit_depth(png_ptr, info_ptr) < 8)
png_set_packing(png_ptr);
/* have libpng handle the gamma conversion */
if (get_pref_boolean(eUSE_SCREEN_GAMMA)) { /*SWP*/
if (png_get_bit_depth(png_ptr, info_ptr) != 16) { /* temporary .. glennrp */
screen_gamma=(double)(get_pref_float(eSCREEN_GAMMA));
#ifndef DISABLE_TRACE
if (srcTrace) {
fprintf(stderr,"screen gamma=%f\n",screen_gamma);
}
#endif
if (png_get_valid(png_ptr, info_ptr, PNG_INFO_gAMA)) {
double gamma;
png_get_gAMA(png_ptr, info_ptr, &gamma);
#ifndef DISABLE_TRACE
if (srcTrace) {
printf("setting gamma=%f\n",gamma);
}
#endif
png_set_gamma(png_ptr, screen_gamma, gamma);
}
else {
#ifndef DISABLE_TRACE
if (srcTrace) {
fprintf(stderr,"setting gamma=%f\n",0.45);
}
#endif
png_set_gamma(png_ptr, screen_gamma, (double)0.45);
}
}
}
if (png_get_interlace_type(png_ptr, info_ptr))
png_set_interlace_handling(png_ptr);
png_read_update_info(png_ptr, info_ptr);
#ifndef DISABLE_TRACE
if (srcTrace) {
fprintf(stderr,"\n\nAFTER\nheight = %d\n", (int)png_get_image_width(png_ptr, info_ptr));
fprintf(stderr,"width = %d\n", (int)png_get_image_height(png_ptr, info_ptr));
fprintf(stderr,"bit depth = %d\n", png_get_bit_depth(png_ptr, info_ptr));
fprintf(stderr,"color type = %d\n", png_get_color_type(png_ptr, info_ptr));
fprintf(stderr,"compression type = %d\n", png_get_compression_type(png_ptr, info_ptr));
fprintf(stderr,"filter type = %d\n", png_get_filter_type(png_ptr, info_ptr));
fprintf(stderr,"interlace type = %d\n", png_get_interlace_type(png_ptr, info_ptr));
fprintf(stderr,"num colors = %d\n", png_get_palette_max(png_ptr, info_ptr));
fprintf(stderr,"rowbytes = %d\n", png_get_rowbytes(png_ptr, info_ptr));
}
#endif
/* allocate the pixel grid which we will need to send to
png_read_image(). */
png_pixels = (png_byte *)malloc(png_get_rowbytes(png_ptr, info_ptr) *
(*height) * sizeof(png_byte));
row_pointers = (png_byte **) malloc((*height) * sizeof(png_byte *));
for (i=0; i < *height; i++)
row_pointers[i]=png_pixels+(png_get_rowbytes(png_ptr, info_ptr)*i);
/* FINALLY - read the darn thing. */
png_read_image(png_ptr, row_pointers);
/* now that we have the (transformed to 8-bit RGB) image, we have
to copy the resulting palette to our colormap. */
if (png_get_color_type(png_ptr, info_ptr) & PNG_COLOR_MASK_COLOR) {
if (png_get_valid(png_ptr, info_ptr, PNG_INFO_PLTE)) {
png_colorp palette;
int num_palette = png_get_palette_max(png_ptr, info_ptr);
for (i=0; i < num_palette; i++) {
png_get_PLTE(png_ptr, info_ptr, &palette, i);
colrs[i].red = palette->red << 8;
colrs[i].green = palette->green << 8;
colrs[i].blue = palette->blue << 8;
colrs[i].pixel = i;
colrs[i].flags = DoRed|DoGreen|DoBlue;
}
}
else {
for (i=0; i < 216; i++) {
colrs[i].red = std_color_cube[i].red << 8;
colrs[i].green = std_color_cube[i].green << 8;
colrs[i].blue = std_color_cube[i].blue << 8;
colrs[i].pixel = i;
colrs[i].flags = DoRed|DoGreen|DoBlue;
}
}
} else {
/* grayscale image */
for(i=0; i < 256; i++ ) {
colrs[i].red = i << 8;
colrs[i].green = i << 8;
colrs[i].blue = i << 8;
colrs[i].pixel = i;
colrs[i].flags = DoRed|DoGreen|DoBlue;
}
}
/* Now copy the pixel data from png_pixels to pixmap */
pixmap = (png_byte *)malloc((*width) * (*height) * sizeof(png_byte));
p = pixmap; q = png_pixels;
/* if there is an alpha channel, we have to get rid of it in the
pixmap, since I don't do anything with it yet */
if (png_get_color_type(png_ptr, info_ptr) & PNG_COLOR_MASK_ALPHA) {
#ifndef DISABLE_TRACE
if (srcTrace) {
fprintf(stderr,"Getting rid of alpha channel\n");
}
#endif
for(i=0; i<*height; i++) {
q = row_pointers[i];
for(j=0; j<*width; j++) {
*p++ = *q++; /*palette index*/
q++; /* skip the alpha pixel */
}
}
free((char *)png_pixels);
}
else {
#ifndef DISABLE_TRACE
if (srcTrace) {
fprintf(stderr,"No alpha channel\n");
}
#endif
for(i=0; i<*height; i++) {
q = row_pointers[i];
for(j=0; j<*width; j++) {
*p++ = *q++; /*palette index*/
}
}
free((char *)png_pixels);
}
free((png_byte **)row_pointers);
/* clean up after the read, and free any memory allocated */
/* free the structure */
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
return pixmap;
}
