sergiotarxz/libvips
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do argb -> rgba for openslide read associated

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This commit is contained in:
John Cupitt 2014-08-09 22:21:10 +01:00
parent 296eb8b54e
commit 385b2ea5fa
2 changed files with 48 additions and 35 deletions
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1
ChangeLog
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@ -10,6 +10,7 @@
- vipsthumbnail defaults to bicubic + nosharpen
- better rounding behaviour for fixed-point bicubic reduces noise
- fix pngload with libpng >=1.6.11
- fix colour for openslide read associated
4/7/14 started 7.40.4
- fix vips_rawsave_fd(), thanks aferrero2707

82
libvips/foreign/openslide2vips.c
View File

@ -43,6 +43,8 @@
* - use openslide_detect_vendor() on >= 3.4.0
* 30/7/14
* - add autocrop toggle
* 9/8/14
* - do argb -> rgba for associated as well
*/
/*
@ -390,6 +392,45 @@ vips__openslide_read_header( const char *filename, VipsImage *out,
return( 0 );
}
/* Convert from ARGB to RGBA and undo premultiplication.
*
* We throw away transparency. Formats like Mirax use transparent + bg
* colour for areas with no useful pixels. But if we output
* transparent pixels and then convert to RGB for jpeg write later, we
* would have to pass the bg colour down the pipe somehow. The
* structure of dzsave makes this tricky.
*
* We could output plain RGB instead, but that would break
* compatibility with older vipses.
*/
static void
argb2rgba( uint32_t *buf, int n, uint32_t bg )
{
int i;
for( i = 0; i < n; i++ ) {
uint32_t *p = buf + i;
uint32_t x = *p;
uint8_t a = x >> 24;
VipsPel *out = (VipsPel *) p;
if( a != 0 ) {
out[0] = 255 * ((x >> 16) & 255) / a;
out[1] = 255 * ((x >> 8) & 255) / a;
out[2] = 255 * (x & 255) / a;
out[3] = 255;
}
else {
/* Use background color.
*/
out[0] = (bg >> 16) & 255;
out[1] = (bg >> 8) & 255;
out[2] = bg & 255;
out[3] = 255;
}
}
}
static int
vips__openslide_generate( VipsRegion *out,
void *_seq, void *_rslide, void *unused, gboolean *stop )
@ -401,7 +442,6 @@ vips__openslide_generate( VipsRegion *out,
uint32_t *buf = (uint32_t *) VIPS_REGION_ADDR( out, r->left, r->top );
const char *error;
int i;
VIPS_DEBUG_MSG( "vips__openslide_generate: %dx%d @ %dx%d\n",
r->width, r->height, r->left, r->top );
@ -434,39 +474,9 @@ vips__openslide_generate( VipsRegion *out,
return( -1 );
}
/* Convert from ARGB to RGBA and undo premultiplication. Since we are
* inside a cache, we know buf must be continuous.
*
* We throw away transparency. Formats like Mirax use transparent + bg
* colour for areas with no useful pixels. But if we output
* transparent pixels and then convert to RGB for jpeg write later, we
* would have to pass the bg colour down the pipe somehow. The
* structure of dzsave makes this tricky.
*
* We could output plain RGB instead, but that would break
* compatibility with older vipses.
/* Since we are inside a cache, we know buf must be continuous.
*/
for( i = 0; i < n; i++ ) {
uint32_t *p = buf + i;
uint32_t x = *p;
uint8_t a = x >> 24;
VipsPel *out = (VipsPel *) p;
if( a != 0 ) {
out[0] = 255 * ((x >> 16) & 255) / a;
out[1] = 255 * ((x >> 8) & 255) / a;
out[2] = 255 * (x & 255) / a;
out[3] = 255;
}
else {
/* Use background color.
*/
out[0] = (bg >> 16) & 255;
out[1] = (bg >> 8) & 255;
out[2] = bg & 255;
out[3] = 255;
}
}
argb2rgba( buf, n, bg );
return( 0 );
}
@ -519,6 +529,7 @@ vips__openslide_read_associated( const char *filename, VipsImage *out,
{
ReadSlide *rslide;
VipsImage *raw;
uint32_t *buf;
const char *error;
VIPS_DEBUG_MSG( "vips__openslide_read_associated: %s %s\n",
@ -532,14 +543,15 @@ vips__openslide_read_associated( const char *filename, VipsImage *out,
if( !(rslide = readslide_new( filename, raw, 0, FALSE, associated )) ||
vips_image_write_prepare( raw ) )
return( -1 );
openslide_read_associated_image( rslide->osr, rslide->associated,
(uint32_t *) VIPS_IMAGE_ADDR( raw, 0, 0 ) );
buf = (uint32_t *) VIPS_IMAGE_ADDR( raw, 0, 0 );
openslide_read_associated_image( rslide->osr, rslide->associated, buf );
error = openslide_get_error( rslide->osr );
if( error ) {
vips_error( "openslide2vips",
_( "reading associated image: %s" ), error );
return( -1 );
}
argb2rgba( buf, raw->Xsize * raw->Ysize, rslide->bg );
if( vips_image_write( raw, out ) )
return( -1 );