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check whether filter kernels are normalized

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This commit is contained in:
Sean Barrett 2014-09-07 05:29:43 -07:00
parent 7da729bfce
commit 7f8ac35e42
1 changed files with 35 additions and 0 deletions
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35
tests/resample_test.cpp
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@ -601,6 +601,41 @@ void test_suite(int argc, char **argv)
else
barbara = "barbara.png";
#if 1
{
float x,y;
for (x = -1; x < 1; x += 0.05f) {
float sums[4] = {0};
float o;
for (o=-5; o <= 5; ++o) {
sums[0] += stbir__filter_mitchell(x+o);
sums[1] += stbir__filter_catmullrom(x+o);
sums[2] += stbir__filter_bicubic(x+o);
sums[3] += stbir__filter_bilinear(x+o);
}
for (i=0; i < 4; ++i)
STBIR_ASSERT(sums[i] >= 1.0 - 0.01 && sums[i] <= 1.0 + 0.01);
}
#if 1
for (y = 0.11f; y < 1; y += 0.01f) {
for (x = -1; x < 1; x += 0.05f) {
float sums[4] = {0};
float o;
for (o=-5; o <= 5; o += y) {
sums[0] += y * stbir__filter_mitchell(x+o);
sums[1] += y * stbir__filter_catmullrom(x+o);
sums[2] += y * stbir__filter_bicubic(x+o);
sums[3] += y * stbir__filter_bilinear(x+o);
}
for (i=0; i < 3; ++i)
STBIR_ASSERT(sums[i] >= 1.0 - 0.02 && sums[i] <= 1.0 + 0.02);
}
}
#endif
}
#endif
#if 0 // linear_to_srgb_uchar table
for (i=0; i < 256; ++i) {
float f = stbir__srgb_to_linear((i+0.5f)/256.0f);