60 lines
2.2 KiB
C
60 lines
2.2 KiB
C
/*
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* Copyright (c) 2011, Tom Distler (http://tdistler.com)
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* All rights reserved.
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*
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* The BSD License
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* - Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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*
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* - Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* - Neither the name of the tdistler.com nor the names of its contributors may
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* be used to endorse or promote products derived from this software without
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* specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "decimate.h"
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#include <stdlib.h>
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int _iqa_decimate(float *img, int w, int h, int factor, const struct _kernel *k, float *result, int *rw, int *rh)
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{
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int x,y;
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int sw = w/factor + (w&1);
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int sh = h/factor + (h&1);
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int dst_offset;
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float *dst=img;
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if (result)
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dst = result;
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/* Downsample */
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for (y=0; y<sh; ++y) {
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dst_offset = y*sw;
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for (x=0; x<sw; ++x,++dst_offset) {
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dst[dst_offset] = _iqa_filter_pixel(img, w, h, x*factor, y*factor, k, 1.0f);
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}
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}
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if (rw) *rw = sw;
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if (rh) *rh = sh;
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return 0;
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}
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