FloatImg4PythonBinding/lib/fimg-2gray.c

59 lines
1.2 KiB
C

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