164 lines
3.6 KiB
C
164 lines
3.6 KiB
C
/* to HSV ... useful for compatibility with other packages
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*
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* 9/6/15
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* - from LabS2Lab.c
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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 <vips/vips.h>
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#include "pcolour.h"
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typedef VipsColourCode VipssRGB2HSV;
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typedef VipsColourCodeClass VipssRGB2HSVClass;
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G_DEFINE_TYPE( VipssRGB2HSV, vips_sRGB2HSV, VIPS_TYPE_COLOUR_CODE );
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static void
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vips_sRGB2HSV_line( VipsColour *colour, VipsPel *out, VipsPel **in, int width )
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{
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unsigned char *p = (unsigned char *) in[0];
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unsigned char *q = (unsigned char *) out;
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int i;
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unsigned char c_max,c_min,delta;
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float wrap_around_hue = 0, secondary_diff = 0;
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for( i = 0; i < width; i++ ) {
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if (p[1] < p[2]) {
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if (p[2] < p[0]) {
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c_max = p[0];
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c_min = p[1];
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secondary_diff = p[1] - p[2];
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wrap_around_hue = 256.0f;
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} else {
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c_max = p[2];
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c_min = VIPS_MIN(p[1], p[0]);
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secondary_diff = p[0] - p[1];
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wrap_around_hue = 170.666f;
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}
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} else {
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if (p[1] < p[0]) {
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c_max = p[0];
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c_min = p[2];
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secondary_diff = p[1] - p[2];
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//wrap_around_hue = 0f;
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} else {
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c_max = p[1];
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c_min = VIPS_MIN(p[2], p[0]);
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secondary_diff = p[2] - p[0];
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wrap_around_hue = 85.333f;
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}
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}
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q[2] = c_max;
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if (c_max == 0) {
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q[0] = q[1] = 0;
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} else {
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delta = c_max - c_min;
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if (delta == 0) {
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q[0] = 0;
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} else {
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q[0] = (unsigned char) ((secondary_diff / (float) delta) + wrap_around_hue);
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}
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q[1] = (((float) delta / (float) c_max)*256.0f);
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}
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p += 3;
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q += 3;
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}
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}
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static void
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vips_sRGB2HSV_class_init( VipssRGB2HSVClass *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 = "sRGB2HSV";
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object_class->description = _( "transform sRGB to HSV" );
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colour_class->process_line = vips_sRGB2HSV_line;
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}
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static void
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vips_sRGB2HSV_init( VipssRGB2HSV *sRGB2HSV )
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{
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VipsColour *colour = VIPS_COLOUR( sRGB2HSV );
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VipsColourCode *code = VIPS_COLOUR_CODE( sRGB2HSV );
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colour->interpretation = VIPS_INTERPRETATION_HSV;
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colour->format = VIPS_FORMAT_UCHAR;
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colour->bands = 3;
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colour->input_bands = 3;
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code->input_coding = VIPS_CODING_NONE;
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code->input_format = VIPS_FORMAT_UCHAR;
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code->input_interpretation = VIPS_INTERPRETATION_sRGB;
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}
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/**
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* vips_sRGB2HSV:
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* @in: input image
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* @out: output image
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* @...: %NULL-terminated list of optional named arguments
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*
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* Convert to HSV.
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*
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* See also: vips_HSV2sRGB().
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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_sRGB2HSV( 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( "sRGB2HSV", ap, in, out );
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va_end( ap );
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return( result );
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}
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