tTh/FloatImg
2
2
Fork 1
Code Issues 2 Pull Requests Releases Wiki Activity

new func: fimg_halfsize_1

Browse Source
This commit is contained in:
tth
2021-04-09 19:04:59 +02:00
parent b8a4514773
commit 27af6d5282
5 changed files with 73 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

50
funcs/geometry.c
View File

@@ -26,7 +26,7 @@ fprintf(stderr, ">>> %s ( %p %p %d )\n", __func__,
/* no magic check here ? */
if (dst->width || dst->height) {
fprintf(stderr, "*** %s: image at %p not empty\n", __func__, dst);
fimg_describe(dst, "destination halfsize");
fimg_describe(dst, "destination halfsize 0");
return -2;
}
@@ -55,3 +55,51 @@ for (y=0; y<hd; y++) {
return 0;
}
/* --------------------------------------------------------------------- */
int fimg_halfsize_1(FloatImg *src, FloatImg *dst, int notused)
{
int wd, hd;
int foo, x, y, x2, y2;
float ac;
if (dst->width || dst->height) {
fprintf(stderr, "*** %s: image at %p not empty\n", __func__, dst);
fimg_describe(dst, "destination halfsize 1");
return -2;
}
wd = src->width / 2; hd = src->height / 2;
if ( (foo = fimg_create(dst, wd, hd, FIMG_TYPE_RGB)) ) {
fprintf(stderr, "%s: err create %d\n", __func__, foo);
return -3;
}
#define WS (src->width)
#define WD (dst->width)
for (y=0; y<hd; y++) {
y2 = y * 2;
for (x=0; x<wd; x++) {
x2 = x * 2;
ac = src->R[(y2*WS)+x2] + src->R[(y2*WS)+x2+1] +
src->R[((1+y2)*WS)+x2] + src->R[((1+y2)*WS)+x2+1];
dst->R[y*WD +x] = ac / 4.0;
ac = src->G[(y2*WS)+x2] + src->G[(y2*WS)+x2+1] +
src->G[((1+y2)*WS)+x2] + src->G[((1+y2)*WS)+x2+1];
dst->G[y*WD +x] = ac / 4.0;
ac = src->B[(y2*WS)+x2] + src->B[(y2*WS)+x2+1] +
src->B[((1+y2)*WS)+x2] + src->B[((1+y2)*WS)+x2+1];
dst->B[y*WD +x] = ac / 4.0;
}
}
#undef WS
#undef WD
return 0;
}
/* --------------------------------------------------------------------- */