libvips/libvips/colour/sRGB2scRGB.c

330 lines
7.2 KiB
C

/* Turn displayable rgb files to scRGB.
*
* Modified:
* 15/11/94 JC
* - memory leak fixed
* - error message added
* 16/11/94 JC
* - partialed
* 21/9/12
* - redone as a class
* - sRGB only, support for other RGBs is now via lcms
* 6/11/12
* - add 16-bit sRGB import
* 11/12/12
* - cut about to make sRGB2scRGB.c
* 12/2/15
* - add 16-bit alpha handling
* 26/2/16
* - look for RGB16 tag, not just ushort, for the 16-bit path
* 24/11/17 lovell
* - special path for 3 and 4 band images
*/
/*
This file is part of VIPS.
VIPS is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA
*/
/*
These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /*HAVE_CONFIG_H*/
#include <glib/gi18n-lib.h>
#include <stdio.h>
#include <math.h>
#include <vips/vips.h>
#include "pcolour.h"
/* We can't use VipsColourCode as our parent class. We want to handle
* alpha ourselves so we can get 16 -> 8 bit conversion right.
*/
typedef struct _VipssRGB2scRGB {
VipsOperation parent_instance;
VipsImage *in;
VipsImage *out;
} VipssRGB2scRGB;
typedef VipsOperationClass VipssRGB2scRGBClass;
G_DEFINE_TYPE( VipssRGB2scRGB, vips_sRGB2scRGB, VIPS_TYPE_OPERATION );
/* Convert a buffer of 8-bit pixels.
*/
static void
vips_sRGB2scRGB_line_8( float * restrict q, VipsPel * restrict p,
int extra_bands, int width )
{
int i, j;
if( extra_bands == 0 ) {
for( i = 0; i < width; i++ ) {
q[0] = vips_v2Y_8[p[0]];
q[1] = vips_v2Y_8[p[1]];
q[2] = vips_v2Y_8[p[2]];
p += 3;
q += 3;
}
}
else if( extra_bands == 1 ) {
for( i = 0; i < width; i++ ) {
q[0] = vips_v2Y_8[p[0]];
q[1] = vips_v2Y_8[p[1]];
q[2] = vips_v2Y_8[p[2]];
q[3] = p[3];
p += 4;
q += 4;
}
}
else {
for( i = 0; i < width; i++ ) {
q[0] = vips_v2Y_8[p[0]];
q[1] = vips_v2Y_8[p[1]];
q[2] = vips_v2Y_8[p[2]];
p += 3;
q += 3;
for( j = 0; j < extra_bands; j++ )
q[j] = p[j];
p += extra_bands;
q += extra_bands;
}
}
}
/* Convert a buffer of 16-bit pixels.
*/
static void
vips_sRGB2scRGB_line_16( float * restrict q, unsigned short * restrict p,
int extra_bands, int width )
{
int i, j;
if( extra_bands == 0 ) {
for( i = 0; i < width; i++ ) {
q[0] = vips_v2Y_16[p[0]];
q[1] = vips_v2Y_16[p[1]];
q[2] = vips_v2Y_16[p[2]];
p += 3;
q += 3;
}
}
else if( extra_bands == 1 ) {
for( i = 0; i < width; i++ ) {
q[0] = vips_v2Y_16[p[0]];
q[1] = vips_v2Y_16[p[1]];
q[2] = vips_v2Y_16[p[2]];
q[3] = p[3] / 256.0;
p += 4;
q += 4;
}
}
else {
for( i = 0; i < width; i++ ) {
q[0] = vips_v2Y_16[p[0]];
q[1] = vips_v2Y_16[p[1]];
q[2] = vips_v2Y_16[p[2]];
p += 3;
q += 3;
for( j = 0; j < extra_bands; j++ )
q[j] = p[j] / 256.0;
p += extra_bands;
q += extra_bands;
}
}
}
static int
vips_sRGB2scRGB_gen( VipsRegion *or,
void *seq, void *a, void *b, gboolean *stop )
{
VipsRegion *ir = (VipsRegion *) seq;
VipsRect *r = &or->valid;
VipsImage *in = ir->im;
int y;
if( vips_region_prepare( ir, r ) )
return( -1 );
VIPS_GATE_START( "vips_sRGB2scRGB_gen: work" );
if( in->BandFmt == VIPS_FORMAT_UCHAR ) {
vips_col_make_tables_RGB_8();
for( y = 0; y < r->height; y++ ) {
VipsPel *p = VIPS_REGION_ADDR( ir, r->left, r->top + y );
float *q = (float *)
VIPS_REGION_ADDR( or, r->left, r->top + y );
vips_sRGB2scRGB_line_8( q, p, in->Bands - 3, r->width );
}
}
else {
vips_col_make_tables_RGB_16();
for( y = 0; y < r->height; y++ ) {
VipsPel *p = VIPS_REGION_ADDR( ir, r->left, r->top + y );
float *q = (float *)
VIPS_REGION_ADDR( or, r->left, r->top + y );
vips_sRGB2scRGB_line_16( q, (unsigned short *) p,
in->Bands - 3, r->width );
}
}
VIPS_GATE_STOP( "vips_sRGB2scRGB_gen: work" );
return( 0 );
}
static int
vips_sRGB2scRGB_build( VipsObject *object )
{
VipsObjectClass *class = VIPS_OBJECT_GET_CLASS( object );
VipssRGB2scRGB *sRGB2scRGB = (VipssRGB2scRGB *) object;
VipsImage **t = (VipsImage **) vips_object_local_array( object, 2 );
VipsImage *in;
VipsImage *out;
VipsBandFormat format;
if( VIPS_OBJECT_CLASS( vips_sRGB2scRGB_parent_class )->
build( object ) )
return( -1 );
in = sRGB2scRGB->in;
if( vips_check_bands_atleast( class->nickname, in, 3 ) )
return( -1 );
format = in->Type == VIPS_INTERPRETATION_RGB16 ?
VIPS_FORMAT_USHORT : VIPS_FORMAT_UCHAR;
if( in->BandFmt != format ) {
if( vips_cast( in, &t[0], format, NULL ) )
return( -1 );
}
else {
t[0] = in;
g_object_ref( t[0] );
}
in = t[0];
out = vips_image_new();
if( vips_image_pipelinev( out,
VIPS_DEMAND_STYLE_THINSTRIP, in, NULL ) ) {
g_object_unref( out );
return( -1 );
}
out->Type = VIPS_INTERPRETATION_scRGB;
out->BandFmt = VIPS_FORMAT_FLOAT;
if( vips_image_generate( out,
vips_start_one, vips_sRGB2scRGB_gen, vips_stop_one,
in, sRGB2scRGB ) ) {
g_object_unref( out );
return( -1 );
}
g_object_set( object, "out", out, NULL );
return( 0 );
}
static void
vips_sRGB2scRGB_class_init( VipssRGB2scRGBClass *class )
{
GObjectClass *gobject_class = G_OBJECT_CLASS( class );
VipsObjectClass *object_class = (VipsObjectClass *) class;
VipsOperationClass *operation_class = VIPS_OPERATION_CLASS( class );
gobject_class->set_property = vips_object_set_property;
gobject_class->get_property = vips_object_get_property;
object_class->nickname = "sRGB2scRGB";
object_class->description = _( "convert an sRGB image to scRGB" );
object_class->build = vips_sRGB2scRGB_build;
operation_class->flags = VIPS_OPERATION_SEQUENTIAL;
VIPS_ARG_IMAGE( class, "in", 1,
_( "Input" ),
_( "Input image" ),
VIPS_ARGUMENT_REQUIRED_INPUT,
G_STRUCT_OFFSET( VipssRGB2scRGB, in ) );
VIPS_ARG_IMAGE( class, "out", 100,
_( "Output" ),
_( "Output image" ),
VIPS_ARGUMENT_REQUIRED_OUTPUT,
G_STRUCT_OFFSET( VipssRGB2scRGB, out ) );
}
static void
vips_sRGB2scRGB_init( VipssRGB2scRGB *sRGB2scRGB )
{
}
/**
* vips_sRGB2scRGB: (method)
* @in: input image
* @out: (out): output image
* @...: %NULL-terminated list of optional named arguments
*
* Convert an sRGB image to scRGB. The input image can be 8 or 16-bit.
*
* If the input image is tagged as #VIPS_INTERPRETATION_RGB16, any extra
* channels after RGB are divided by 256. Thus, scRGB alpha is
* always 0 - 255.99.
*
* See also: vips_scRGB2XYZ(), vips_scRGB2sRGB(), vips_rad2float().
*
* Returns: 0 on success, -1 on error.
*/
int
vips_sRGB2scRGB( VipsImage *in, VipsImage **out, ... )
{
va_list ap;
int result;
va_start( ap, out );
result = vips_call_split( "sRGB2scRGB", ap, in, out );
va_end( ap );
return( result );
}