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Better colorspace support for the jpeg loader (#61211):

Browse Source 
* io-jpeg.c (convert_cmyk_to_rgb): New function.
	(gdk_pixbuf__jpeg_image_load,
	gdk_pixbuf__jpeg_image_load_increment): Allocate a pixbuf with
	alpha for 4-channel jpegs and call convert_cmyk_to_rgb for these.
This commit is contained in:
Matthias Clasen 2002-07-01 22:20:20 +00:00
parent 3778b86c2e
commit 155aa55bed
2 changed files with 119 additions and 18 deletions
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9
gdk-pixbuf/ChangeLog
View File

@ -1,3 +1,12 @@
2002-07-02 Matthias Clasen <maclas@gmx.de>
Better colorspace support for the jpeg loader (#61211):
* io-jpeg.c (convert_cmyk_to_rgb): New function.
(gdk_pixbuf__jpeg_image_load,
gdk_pixbuf__jpeg_image_load_increment): Allocate a pixbuf with
alpha for 4-channel jpegs and call convert_cmyk_to_rgb for these.
2002-06-28 Sven Neumann <sven@gimp.org>
* gdk-pixbuf-csource.c (print_blurb): converted a Tab to spaces.

128
gdk-pixbuf/io-jpeg.c
View File

@ -135,6 +135,7 @@ explode_gray_into_buf (struct jpeg_decompress_struct *cinfo,
g_return_if_fail (cinfo != NULL);
g_return_if_fail (cinfo->output_components == 1);
g_return_if_fail (cinfo->out_color_space == JCS_GRAYSCALE);
/* Expand grey->colour. Expand from the end of the
* memory down, so we can use the same buffer.
@ -155,6 +156,43 @@ explode_gray_into_buf (struct jpeg_decompress_struct *cinfo,
}
}
static void
convert_cmyk_to_rgb (struct jpeg_decompress_struct *cinfo,
guchar **lines)
{
gint i, j;
g_return_if_fail (cinfo != NULL);
g_return_if_fail (cinfo->output_components == 4);
g_return_if_fail (cinfo->out_color_space == JCS_CMYK);
for (i = cinfo->rec_outbuf_height - 1; i >= 0; i--) {
guchar *p;
p = lines[i];
for (j = 0; j < cinfo->image_width; j++) {
int c, m, y, k;
c = p[0];
m = p[1];
y = p[2];
k = p[3];
if (cinfo->saw_Adobe_marker) {
p[0] = k*c / 255;
p[1] = k*m / 255;
p[2] = k*y / 255;
}
else {
p[0] = (255 - k)*(255 - c) / 255;
p[1] = (255 - k)*(255 - m) / 255;
p[2] = (255 - k)*(255 - y) / 255;
}
p[3] = 255;
p += 4;
}
}
}
typedef struct {
struct jpeg_source_mgr pub; /* public fields */
@ -219,6 +257,20 @@ stdio_term_source (j_decompress_ptr cinfo)
{
}
static gchar *
colorspace_name (const J_COLOR_SPACE jpeg_color_space)
{
switch (jpeg_color_space) {
case JCS_UNKNOWN: return "UNKNOWN";
case JCS_GRAYSCALE: return "GRAYSCALE";
case JCS_RGB: return "RGB";
case JCS_YCbCr: return "YCbCr";
case JCS_CMYK: return "CMYK";
case JCS_YCCK: return "YCCK";
default: return "invalid";
}
}
/* Shared library entry point */
static GdkPixbuf *
gdk_pixbuf__jpeg_image_load (FILE *f, GError **error)
@ -277,8 +329,10 @@ gdk_pixbuf__jpeg_image_load (FILE *f, GError **error)
cinfo.do_fancy_upsampling = FALSE;
cinfo.do_block_smoothing = FALSE;
pixbuf = gdk_pixbuf_new (GDK_COLORSPACE_RGB, FALSE, 8, cinfo.output_width, cinfo.output_height);
pixbuf = gdk_pixbuf_new (GDK_COLORSPACE_RGB,
cinfo.out_color_components == 4 ? TRUE : FALSE,
8, cinfo.output_width, cinfo.output_height);
if (!pixbuf) {
jpeg_destroy_decompress (&cinfo);
@ -298,7 +352,6 @@ gdk_pixbuf__jpeg_image_load (FILE *f, GError **error)
dptr = pixbuf->pixels;
/* decompress all the lines, a few at a time */
while (cinfo.output_scanline < cinfo.output_height) {
lptr = lines;
for (i = 0; i < cinfo.rec_outbuf_height; i++) {
@ -308,8 +361,28 @@ gdk_pixbuf__jpeg_image_load (FILE *f, GError **error)
jpeg_read_scanlines (&cinfo, lines, cinfo.rec_outbuf_height);
if (cinfo.output_components == 1)
explode_gray_into_buf (&cinfo, lines);
switch (cinfo.out_color_space) {
case JCS_GRAYSCALE:
explode_gray_into_buf (&cinfo, lines);
break;
case JCS_RGB:
/* do nothing */
break;
case JCS_CMYK:
convert_cmyk_to_rgb (&cinfo, lines);
break;
default:
if (error && *error == NULL) {
g_set_error (error,
GDK_PIXBUF_ERROR,
GDK_PIXBUF_ERROR_UNKNOWN_TYPE,
_("Unsupported JPEG color space (%s)"),
colorspace_name (cinfo.out_color_space));
}
jpeg_destroy_decompress (&cinfo);
return NULL;
}
}
jpeg_finish_decompress (&cinfo);
@ -572,8 +645,17 @@ gdk_pixbuf__jpeg_image_load_increment (gpointer data,
context->got_header = TRUE;
} else if (!context->did_prescan) {
int rc;
/* start decompression */
cinfo->buffered_image = TRUE;
rc = jpeg_start_decompress (cinfo);
cinfo->do_fancy_upsampling = FALSE;
cinfo->do_block_smoothing = FALSE;
context->pixbuf = gdk_pixbuf_new(GDK_COLORSPACE_RGB,
FALSE,
cinfo->output_components == 4 ? TRUE : FALSE,
8,
cinfo->image_width,
cinfo->image_height);
@ -594,14 +676,6 @@ gdk_pixbuf__jpeg_image_load_increment (gpointer data,
NULL,
context->user_data);
} else if (!context->did_prescan) {
int rc;
/* start decompression */
cinfo->buffered_image = TRUE;
rc = jpeg_start_decompress (cinfo);
cinfo->do_fancy_upsampling = FALSE;
cinfo->do_block_smoothing = FALSE;
if (rc == JPEG_SUSPENDED)
continue;
@ -638,10 +712,28 @@ gdk_pixbuf__jpeg_image_load_increment (gpointer data,
if (nlines == 0)
break;
/* handle gray */
if (cinfo->output_components == 1)
explode_gray_into_buf (cinfo, lines);
switch (cinfo->out_color_space) {
case JCS_GRAYSCALE:
explode_gray_into_buf (cinfo, lines);
break;
case JCS_RGB:
/* do nothing */
break;
case JCS_CMYK:
convert_cmyk_to_rgb (cinfo, lines);
break;
default:
if (error && *error == NULL) {
g_set_error (error,
GDK_PIXBUF_ERROR,
GDK_PIXBUF_ERROR_UNKNOWN_TYPE,
_("Unsupported JPEG color space (%s)"),
colorspace_name (cinfo->out_color_space));
}
return FALSE;
}
context->dptr += nlines * context->pixbuf->rowstride;
/* send updated signal */