88 lines
2.4 KiB
C
88 lines
2.4 KiB
C
/*
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* SpanDSP - a series of DSP components for telephony
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*
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* make_cielab_luts.c - Create the look up tables for CIELab colour management
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*
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* Written by Steve Underwood <steveu@coppice.org>
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*
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* Copyright (C) 2011 Steve Underwood
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*
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* All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2, as
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* published by the Free Software Foundation.
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*
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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 General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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/*! \file */
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#include <inttypes.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include <memory.h>
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#include <math.h>
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typedef struct
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{
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float L;
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float a;
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float b;
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} cielab_t;
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int main(int argc, char *argv[])
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{
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float r;
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uint8_t srgb;
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int i;
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printf("/* THIS FILE WAS AUTOMATICALLY GENERATED - ANY MODIFICATIONS MADE TO THIS");
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printf(" FILE MAY BE OVERWRITTEN DURING FUTURE BUILDS OF THE SOFTWARE */\n");
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printf("\n");
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printf("static const float srgb_to_linear[256] =\n");
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printf("{\n");
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for (i = 0; i < 256; i++)
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{
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/* Start with "i" as the sRGB value */
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r = i/256.0f;
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/* sRGB to Linear RGB */
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r = (r > 0.04045f) ? powf((r + 0.055f)/1.055f, 2.4f) : r/12.92f;
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printf((i < 255) ? " %f,\n" : " %f\n", r);
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}
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printf("};\n");
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printf("static const uint8_t linear_to_srgb[4096] =\n");
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printf("{\n");
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for (i = 0; i < 4096; i++)
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{
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/* Start with "i" as the linear RGB value */
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/* Linear RGB to sRGB */
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r = i/4096.0f;
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r = (r > 0.0031308f) ? (1.055f*powf(r, 1.0f/2.4f) - 0.055f) : r*12.92f;
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r = floorf(r*256.0f);
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srgb = (uint8_t) ((r < 0) ? 0 : (r <= 255) ? r : 255);
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printf((i < 4095) ? " %d,\n" : " %d\n", srgb);
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}
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printf("};\n");
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return 0;
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}
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/*- End of function --------------------------------------------------------*/
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/*- End of file ------------------------------------------------------------*/
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