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/*
* $Id: color.h,v 1.18 2010/02/05 23:50:22 simakov Exp $
*
* EPSILON - wavelet image compression library.
* Copyright (C) 2006,2007,2010 Alexander Simakov, <xander@entropyware.info>
*
* This file is part of EPSILON
*
* EPSILON 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 3 of the License, or
* (at your option) any later version.
*
* EPSILON 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 EPSILON. If not, see <http://www.gnu.org/licenses/>.
*
* http://epsilon-project.sourceforge.net
*/
/** \file
*
* \brief Color space convertion
*
* This file contains routines for color space conversion.
*
* \section References
*
* International Telecommunications Union, ITU-R BT.601 */
#ifndef __COLOR_H__
#define __COLOR_H__
#ifdef __cplusplus
extern "C" {
#endif
/** \addtogroup color Color space conversion */
/*@{*/
#include <common.h>
/** Round value to the nearest integer */
#define ROUND(_x) ((_x) < 0 ? (int) ((_x) - 0.5) : (int) ((_x) + 0.5))
/** Enclose value in the [0..255] interval */
#define CLIP(_x) ((_x) < 0 ? 0 : ((_x) > 255 ? 255 : ROUND((_x))))
/** RGB to YCbCr conversion
*
* This function converts image from RGB to YCbCr color space.
*
* \param R Red channel
* \param G Green channel
* \param B Blue channel
* \param Y Luma channel
* \param Cb Chroma-blue channel
* \param Cr Chroma-red channel
* \param width Image width
* \param height Image height
*
* \return \c VOID */
void convert_RGB_to_YCbCr(coeff_t **R, coeff_t **G, coeff_t **B,
coeff_t **Y, coeff_t **Cb, coeff_t **Cr,
int width, int height);
/** YCbCr to RGB conversion
*
* This function converts image from YCbCr to RGB color space.
*
* \param Y Luma channel
* \param Cb Chroma-blue channel
* \param Cr Chroma-red channel
* \param R Red channel
* \param G Green channel
* \param B Blue channel
* \param width Image width
* \param height Image height
*
* \return \c VOID
*
* \note On return, all values are enclosed within [0..255] interval. */
void convert_YCbCr_to_RGB(coeff_t **Y, coeff_t **Cb, coeff_t **Cr,
coeff_t **R, coeff_t **G, coeff_t **B,
int width, int height);
/** Channel clipping
*
* This function encloses (clips) each \a channel value within [0..255] interval
* with appropriative rounding.
*
* \param channel Channel to clip
* \param width Image width
* \param height Image height
*
* \return \c VOID */
void clip_channel(coeff_t **channel, int width, int height);
/*@}*/
#ifdef __cplusplus
}
#endif
#endif /* __COLOR_H__ */
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