libvips/libvips/colour/sRGB2XYZ.c

201 lines
4.1 KiB
C

/* Turn displayable rgb files to XYZ.
*
* 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
*/
/*
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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 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 <vips/intl.h>
#include <stdio.h>
#include <math.h>
#include <vips/vips.h>
#include "colour.h"
typedef VipsColourCode VipssRGB2XYZ;
typedef VipsColourCodeClass VipssRGB2XYZClass;
G_DEFINE_TYPE( VipssRGB2XYZ, vips_sRGB2XYZ, VIPS_TYPE_COLOUR_CODE );
/* Convert a buffer of 8-bit pixels.
*/
static void
vips_sRGB2XYZ_line_8( float *q, VipsPel *p, int width )
{
int i;
for( i = 0; i < width; i++ ) {
int r = p[0];
int g = p[1];
int b = p[2];
float R, G, B;
float X, Y, Z;
p += 3;
vips_col_sRGB2scRGB_8( r, g, b, &R, &G, &B );
vips_col_scRGB2XYZ( R, G, B, &X, &Y, &Z );
q[0] = X;
q[1] = Y;
q[2] = Z;
q += 3;
}
}
/* Convert a buffer of 16-bit pixels.
*/
static void
vips_sRGB2XYZ_line_16( float *q, unsigned short *p, int width )
{
int i;
for( i = 0; i < width; i++ ) {
int r = p[0];
int g = p[1];
int b = p[2];
float R, G, B;
float X, Y, Z;
p += 3;
vips_col_sRGB2scRGB_16( r, g, b, &R, &G, &B );
vips_col_scRGB2XYZ( R, G, B, &X, &Y, &Z );
q[0] = X;
q[1] = Y;
q[2] = Z;
q += 3;
}
}
static void
vips_sRGB2XYZ_line( VipsColour *colour,
VipsPel *out, VipsPel **in, int width )
{
if( colour->in[0]->BandFmt == VIPS_FORMAT_UCHAR )
vips_sRGB2XYZ_line_8( (float *) out,
(VipsPel *) in[0], width );
else
vips_sRGB2XYZ_line_16( (float *) out,
(unsigned short *) in[0], width );
}
static int
vips_sRGB2XYZ_build( VipsObject *object )
{
VipsColourCode *code = (VipsColourCode *) object;
if( code->in )
code->input_format =
code->in->BandFmt == VIPS_FORMAT_USHORT ?
VIPS_FORMAT_USHORT : VIPS_FORMAT_UCHAR;
if( VIPS_OBJECT_CLASS( vips_sRGB2XYZ_parent_class )->
build( object ) )
return( -1 );
return( 0 );
}
static void
vips_sRGB2XYZ_class_init( VipssRGB2XYZClass *class )
{
VipsObjectClass *object_class = (VipsObjectClass *) class;
VipsColourClass *colour_class = VIPS_COLOUR_CLASS( class );
object_class->nickname = "sRGB2XYZ";
object_class->description = _( "convert an sRGB image to XYZ" );
object_class->build = vips_sRGB2XYZ_build;
colour_class->process_line = vips_sRGB2XYZ_line;
}
static void
vips_sRGB2XYZ_init( VipssRGB2XYZ *sRGB2XYZ )
{
VipsColour *colour = VIPS_COLOUR( sRGB2XYZ );
VipsColourCode *code = VIPS_COLOUR_CODE( sRGB2XYZ );
colour->coding = VIPS_CODING_NONE;
colour->interpretation = VIPS_INTERPRETATION_XYZ;
colour->format = VIPS_FORMAT_FLOAT;
colour->bands = 3;
code->input_coding = VIPS_CODING_NONE;
code->input_bands = 3;
/* The default. This can get changed above ^^ if we see a
* 16-bit input.
*/
code->input_format = VIPS_FORMAT_UCHAR;
}
/**
* vips_sRGB2XYZ:
* @in: input image
* @out: output image
*
* Convert an sRGB image to XYZ.
*
* See also: im_LabS2LabQ(), im_sRGB2XYZ(), im_rad2float().
*
* Returns: 0 on success, -1 on error.
*/
int
vips_sRGB2XYZ( VipsImage *in, VipsImage **out, ... )
{
va_list ap;
int result;
va_start( ap, out );
result = vips_call_split( "sRGB2XYZ", ap, in, out );
va_end( ap );
return( result );
}