libvips/libvips/colour/XYZ2Yxy.c

127 lines
2.6 KiB
C

/* Turn XYZ to Yxy colourspace.
*
* Modified:
* 29/5/02 JC
* - from lab2xyz
* 2/11/09
* - gtkdoc
* - cleanups
* 20/9/12
* redo as a class
*/
/*
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 <vips/intl.h>
#include <stdio.h>
#include <math.h>
#include <vips/vips.h>
#include "pcolour.h"
typedef VipsColourTransform VipsXYZ2Yxy;
typedef VipsColourTransformClass VipsXYZ2YxyClass;
G_DEFINE_TYPE( VipsXYZ2Yxy, vips_XYZ2Yxy, VIPS_TYPE_COLOUR_TRANSFORM );
static void
vips_XYZ2Yxy_line( VipsColour *colour, VipsPel *out, VipsPel **in, int width )
{
float * restrict p = (float *) in[0];
float * restrict q = (float *) out;
int i;
for( i = 0; i < width; i++ ) {
float X = p[0];
float Y = p[1];
float Z = p[2];
double total = X + Y + Z;
float x, y;
p += 3;
x = X / total;
y = Y / total;
q[0] = Y;
q[1] = x;
q[2] = y;
q += 3;
}
}
static void
vips_XYZ2Yxy_class_init( VipsXYZ2YxyClass *class )
{
VipsObjectClass *object_class = (VipsObjectClass *) class;
VipsColourClass *colour_class = VIPS_COLOUR_CLASS( class );
object_class->nickname = "XYZ2Yxy";
object_class->description = _( "transform XYZ to Yxy" );
colour_class->process_line = vips_XYZ2Yxy_line;
}
static void
vips_XYZ2Yxy_init( VipsXYZ2Yxy *XYZ2Yxy )
{
VipsColour *colour = VIPS_COLOUR( XYZ2Yxy );
colour->interpretation = VIPS_INTERPRETATION_YXY;
}
/**
* vips_XYZ2Yxy: (method)
* @in: input image
* @out: (out): output image
* @...: %NULL-terminated list of optional named arguments
*
* Turn XYZ to Yxy.
*
* Returns: 0 on success, -1 on error
*/
int
vips_XYZ2Yxy( VipsImage *in, VipsImage **out, ... )
{
va_list ap;
int result;
va_start( ap, out );
result = vips_call_split( "XYZ2Yxy", ap, in, out );
va_end( ap );
return( result );
}