160 lines
3.2 KiB
C
160 lines
3.2 KiB
C
/* im_LCh2Lab
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*
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* 15/11/94 JC
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* - error messages added
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* - memory leak fixed
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* 16/11/94 JC
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* - uses im_wrap_oneonebuf() now
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* 8/2/95 JC
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* - im_wrap v2
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* 2/11/09
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* - gtkdoc
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* 19/9/12
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* - redone as a class
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*/
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/*
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This file is part of VIPS.
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VIPS is free software; you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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02110-1301 USA
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*/
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/*
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These files are distributed with VIPS - http://www.vips.ecs.soton.ac.uk
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*/
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#ifdef HAVE_CONFIG_H
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#include <config.h>
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#endif /*HAVE_CONFIG_H*/
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#include <vips/intl.h>
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#include <stdio.h>
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#include <math.h>
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#include <vips/vips.h>
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#include "pcolour.h"
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typedef VipsColourTransform VipsLCh2Lab;
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typedef VipsColourTransformClass VipsLCh2LabClass;
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G_DEFINE_TYPE( VipsLCh2Lab, vips_LCh2Lab, VIPS_TYPE_COLOUR_TRANSFORM );
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/* Process a buffer of data.
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*/
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static void
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vips_LCh2Lab_line( VipsColour *colour, VipsPel *out, VipsPel **in, int width )
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{
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float * restrict p = (float *) in[0];
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float * restrict q = (float *) out;
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int x;
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for( x = 0; x < width; x++ ) {
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float L = p[0];
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float C = p[1];
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float h = p[2];
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float a, b;
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p += 3;
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a = C * cos( VIPS_RAD( h ) );
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b = C * sin( VIPS_RAD( h ) );
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q[0] = L;
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q[1] = a;
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q[2] = b;
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q += 3;
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}
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}
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/**
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* vips_col_Ch2ab:
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* @C: Chroma
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* @h: Hue angle (degrees)
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* @a: return CIE a* value
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* @b: return CIE b* value
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*
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* Calculate ab from Ch, h in degrees.
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*/
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void
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vips_col_Ch2ab( float C, float h, float *a, float *b )
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{
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float in[3];
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float out[3];
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float *x;
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/* could be anything, we don't use this value, but we must supply one
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* or static analyzers will complain.
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*/
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in[0] = 50.0;
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in[1] = C;
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in[2] = h;
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x = &in[0];
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vips_LCh2Lab_line( NULL, (VipsPel *) out, (VipsPel **) &x, 1 );
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*a = out[1];
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*b = out[2];
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}
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static void
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vips_LCh2Lab_class_init( VipsLCh2LabClass *class )
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{
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VipsObjectClass *object_class = (VipsObjectClass *) class;
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VipsColourClass *colour_class = VIPS_COLOUR_CLASS( class );
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object_class->nickname = "LCh2Lab";
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object_class->description = _( "transform LCh to Lab" );
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colour_class->process_line = vips_LCh2Lab_line;
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}
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static void
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vips_LCh2Lab_init( VipsLCh2Lab *LCh2Lab )
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{
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VipsColour *colour = VIPS_COLOUR( LCh2Lab );
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colour->interpretation = VIPS_INTERPRETATION_LAB;
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}
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/**
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* vips_LCh2Lab: (method)
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* @in: input image
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* @out: (out): output image
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* @...: %NULL-terminated list of optional named arguments
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*
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* Turn LCh to Lab.
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*
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* Returns: 0 on success, -1 on error
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*/
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int
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vips_LCh2Lab( VipsImage *in, VipsImage **out, ... )
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{
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va_list ap;
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int result;
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va_start( ap, out );
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result = vips_call_split( "LCh2Lab", ap, in, out );
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va_end( ap );
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return( result );
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}
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