56 lines
1.1 KiB
C
56 lines
1.1 KiB
C
/*
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* fimg-2gray.c
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include "string.h"
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#include "../floatimg.h"
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extern int verbosity; /* must be declared around main() */
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/* --------------------------------------------------------------------- */
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/*
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* floating imgs MUST be allocated before calling this func.
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*/
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int fimg_mk_gray_from(FloatImg *src, FloatImg*dst, int k)
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{
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float kr, kg, kb, kdiv;
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int nbb, foo;
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kr = kg = kb = 1.0; /* canonic random values */
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kdiv = kr + kg + kb;
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/* we must check the validity of our parameters */
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if (FIMG_TYPE_RGB != src->type) {
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fprintf(stderr, "%s : bad src type %d on %p\n", __func__,
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src->type, src);
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return -8;
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}
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if (FIMG_TYPE_GRAY != dst->type) {
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fprintf(stderr, "%s : bad dst type %d on %p\n", __func__,
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dst->type, dst);
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return -9;
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}
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/* entering the main processing loop */
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nbb = src->width * src->height;
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for (foo=0; foo<nbb; foo++) {
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dst->R[foo] = ( (src->R[foo] * kr) +
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(src->G[foo] * kg) +
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(src->B[foo] * kb) ) /
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kdiv;
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}
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return 0;
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}
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/* --------------------------------------------------------------------- */
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