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rename filters, document them

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master
Sean Barrett ago%!(EXTRA string=11 years)
parent da2aa8f6b7
commit 29b36b3dea
2 changed files with 28 additions and 28 deletions
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  1. 20
      stb_image_resize.h
  2. 36
      tests/resample_test.cpp

20
stb_image_resize.h
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@ -135,7 +135,7 @@
and modify this file as you see fit.
TODO
Don't decode all of the image data when only processing a subtile
Don't decode all of the image data when only processing a partial tile
Installable filters?
Resize that respects alpha test coverage
(Reference code: FloatImage::alphaTestCoverage and FloatImage::scaleAlphaToCoverage:
@ -247,11 +247,11 @@ STBIRDEF int stbir_resize_uint8_srgb_edgemode(const unsigned char *input_pixels
typedef enum
{
STBIR_FILTER_DEFAULT = 0, // use same filter type that easy-to-use API chooses
STBIR_FILTER_BOX = 1, // Is actually a trapezoid. See https://developer.nvidia.com/content/non-power-two-mipmapping
STBIR_FILTER_BILINEAR = 2,
STBIR_FILTER_BICUBIC = 3, // A cubic b spline
STBIR_FILTER_CATMULLROM = 4,
STBIR_FILTER_MITCHELL = 5,
STBIR_FILTER_BOX = 1, // Actually a trapezoid. See https://developer.nvidia.com/content/non-power-two-mipmapping
STBIR_FILTER_TRIANGLE = 2, // On upsampling, produces same results as bilinear texture filtering
STBIR_FILTER_CUBIC = 3, // A cubic b-spline: why this one ????????????
STBIR_FILTER_CATMULLROM = 4, // interpolating cubic spline
STBIR_FILTER_MITCHELL = 5, // Mitchell-Netrevalli filter with B=1/3, C=1/3
} stbir_filter;
typedef enum
@ -651,7 +651,7 @@ static float stbir__support_trapezoid(float scale)
return 0.5f + scale / 2;
}
static float stbir__filter_bilinear(float x, float s)
static float stbir__filter_triangle(float x, float s)
{
STBIR__UNUSED_PARAM(s);
@ -663,7 +663,7 @@ static float stbir__filter_bilinear(float x, float s)
return 0;
}
static float stbir__filter_bicubic(float x, float s)
static float stbir__filter_cubic(float x, float s)
{
STBIR__UNUSED_PARAM(s);
@ -726,8 +726,8 @@ static float stbir__support_two(float s)
static stbir__filter_info stbir__filter_info_table[] = {
{ NULL, stbir__support_zero },
{ stbir__filter_trapezoid, stbir__support_trapezoid },
{ stbir__filter_bilinear, stbir__support_one },
{ stbir__filter_bicubic, stbir__support_two },
{ stbir__filter_triangle, stbir__support_one },
{ stbir__filter_cubic, stbir__support_two },
{ stbir__filter_catmullrom, stbir__support_two },
{ stbir__filter_mitchell, stbir__support_two },
};

36
tests/resample_test.cpp
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@ -584,7 +584,7 @@ void test_subpixel_4()
unsigned char output[8 * 8];
stbir_resize_region(image, 8, 8, 0, output, 8, 8, 0, STBIR_TYPE_UINT8, 1, STBIR_ALPHA_CHANNEL_NONE, 0, STBIR_EDGE_CLAMP, STBIR_EDGE_CLAMP, STBIR_FILTER_BILINEAR, STBIR_FILTER_BILINEAR, STBIR_COLORSPACE_LINEAR, &g_context, 0, 0, 1, 1);
stbir_resize_region(image, 8, 8, 0, output, 8, 8, 0, STBIR_TYPE_UINT8, 1, STBIR_ALPHA_CHANNEL_NONE, 0, STBIR_EDGE_CLAMP, STBIR_EDGE_CLAMP, STBIR_FILTER_TRIANGLE, STBIR_FILTER_TRIANGLE, STBIR_COLORSPACE_LINEAR, &g_context, 0, 0, 1, 1);
STBIR_ASSERT(memcmp(image, output, 8 * 8) == 0);
}
@ -672,26 +672,26 @@ void test_filters(void)
image88_int[j][i] = value;
verify_filter_normalized(STBIR_FILTER_BOX, 8, value);
verify_filter_normalized(STBIR_FILTER_BILINEAR, 8, value);
verify_filter_normalized(STBIR_FILTER_BICUBIC, 8, value);
verify_filter_normalized(STBIR_FILTER_TRIANGLE, 8, value);
verify_filter_normalized(STBIR_FILTER_CUBIC, 8, value);
verify_filter_normalized(STBIR_FILTER_CATMULLROM, 8, value);
verify_filter_normalized(STBIR_FILTER_MITCHELL, 8, value);
verify_filter_normalized(STBIR_FILTER_BOX, 4, value);
verify_filter_normalized(STBIR_FILTER_BILINEAR, 4, value);
verify_filter_normalized(STBIR_FILTER_BICUBIC, 4, value);
verify_filter_normalized(STBIR_FILTER_TRIANGLE, 4, value);
verify_filter_normalized(STBIR_FILTER_CUBIC, 4, value);
verify_filter_normalized(STBIR_FILTER_CATMULLROM, 4, value);
verify_filter_normalized(STBIR_FILTER_MITCHELL, 4, value);
verify_filter_normalized(STBIR_FILTER_BOX, 2, value);
verify_filter_normalized(STBIR_FILTER_BILINEAR, 2, value);
verify_filter_normalized(STBIR_FILTER_BICUBIC, 2, value);
verify_filter_normalized(STBIR_FILTER_TRIANGLE, 2, value);
verify_filter_normalized(STBIR_FILTER_CUBIC, 2, value);
verify_filter_normalized(STBIR_FILTER_CATMULLROM, 2, value);
verify_filter_normalized(STBIR_FILTER_MITCHELL, 2, value);
verify_filter_normalized(STBIR_FILTER_BOX, 1, value);
verify_filter_normalized(STBIR_FILTER_BILINEAR, 1, value);
verify_filter_normalized(STBIR_FILTER_BICUBIC, 1, value);
verify_filter_normalized(STBIR_FILTER_TRIANGLE, 1, value);
verify_filter_normalized(STBIR_FILTER_CUBIC, 1, value);
verify_filter_normalized(STBIR_FILTER_CATMULLROM, 1, value);
verify_filter_normalized(STBIR_FILTER_MITCHELL, 1, value);
@ -705,7 +705,7 @@ void test_filters(void)
for (j = 0; j < 100 * 100; ++j)
input[j] = v;
stbir_resize(input, 100, 100, 0, output, 11, 11, 0, STBIR_TYPE_UINT32, 1, STBIR_ALPHA_CHANNEL_NONE, 0, STBIR_EDGE_CLAMP, STBIR_EDGE_CLAMP, STBIR_FILTER_BILINEAR, STBIR_FILTER_BILINEAR, STBIR_COLORSPACE_LINEAR, NULL);
stbir_resize(input, 100, 100, 0, output, 11, 11, 0, STBIR_TYPE_UINT32, 1, STBIR_ALPHA_CHANNEL_NONE, 0, STBIR_EDGE_CLAMP, STBIR_EDGE_CLAMP, STBIR_FILTER_TRIANGLE, STBIR_FILTER_TRIANGLE, STBIR_COLORSPACE_LINEAR, NULL);
for (j = 0; j < 11 * 11; ++j)
STBIR_ASSERT(v == output[j]);
@ -821,8 +821,8 @@ void test_suite(int argc, char **argv)
for (o = -5; o <= 5; ++o) {
sums[0] += stbir__filter_mitchell(x + o, 1);
sums[1] += stbir__filter_catmullrom(x + o, 1);
sums[2] += stbir__filter_bicubic(x + o, 1);
sums[3] += stbir__filter_bilinear(x + o, 1);
sums[2] += stbir__filter_cubic(x + o, 1);
sums[3] += stbir__filter_triangle(x + o, 1);
sums[4] += stbir__filter_trapezoid(x + o, 0.5f);
}
for (i = 0; i < 5; ++i)
@ -837,9 +837,9 @@ void test_suite(int argc, char **argv)
for (o = -5; o <= 5; o += y) {
sums[0] += y * stbir__filter_mitchell(x + o, 1);
sums[1] += y * stbir__filter_catmullrom(x + o, 1);
sums[2] += y * stbir__filter_bicubic(x + o, 1);
sums[2] += y * stbir__filter_cubic(x + o, 1);
sums[4] += y * stbir__filter_trapezoid(x + o, 0.5f);
sums[3] += y * stbir__filter_bilinear(x + o, 1);
sums[3] += y * stbir__filter_triangle(x + o, 1);
}
for (i = 0; i < 3; ++i)
STBIR_ASSERT(sums[i] >= 1.0 - 0.0170 && sums[i] <= 1.0 + 0.0170);
@ -916,14 +916,14 @@ void test_suite(int argc, char **argv)
// filter tests
resize_image(barbara, 2, 2, STBIR_FILTER_BOX , STBIR_EDGE_CLAMP, STBIR_COLORSPACE_SRGB, "test-output/barbara-upsample-nearest.png");
resize_image(barbara, 2, 2, STBIR_FILTER_BILINEAR , STBIR_EDGE_CLAMP, STBIR_COLORSPACE_SRGB, "test-output/barbara-upsample-bilinear.png");
resize_image(barbara, 2, 2, STBIR_FILTER_BICUBIC , STBIR_EDGE_CLAMP, STBIR_COLORSPACE_SRGB, "test-output/barbara-upsample-bicubic.png");
resize_image(barbara, 2, 2, STBIR_FILTER_TRIANGLE , STBIR_EDGE_CLAMP, STBIR_COLORSPACE_SRGB, "test-output/barbara-upsample-bilinear.png");
resize_image(barbara, 2, 2, STBIR_FILTER_CUBIC , STBIR_EDGE_CLAMP, STBIR_COLORSPACE_SRGB, "test-output/barbara-upsample-bicubic.png");
resize_image(barbara, 2, 2, STBIR_FILTER_CATMULLROM, STBIR_EDGE_CLAMP, STBIR_COLORSPACE_SRGB, "test-output/barbara-upsample-catmullrom.png");
resize_image(barbara, 2, 2, STBIR_FILTER_MITCHELL , STBIR_EDGE_CLAMP, STBIR_COLORSPACE_SRGB, "test-output/barbara-upsample-mitchell.png");
resize_image(barbara, 0.5f, 0.5f, STBIR_FILTER_BOX , STBIR_EDGE_CLAMP, STBIR_COLORSPACE_SRGB, "test-output/barbara-downsample-nearest.png");
resize_image(barbara, 0.5f, 0.5f, STBIR_FILTER_BILINEAR , STBIR_EDGE_CLAMP, STBIR_COLORSPACE_SRGB, "test-output/barbara-downsample-bilinear.png");
resize_image(barbara, 0.5f, 0.5f, STBIR_FILTER_BICUBIC , STBIR_EDGE_CLAMP, STBIR_COLORSPACE_SRGB, "test-output/barbara-downsample-bicubic.png");
resize_image(barbara, 0.5f, 0.5f, STBIR_FILTER_TRIANGLE , STBIR_EDGE_CLAMP, STBIR_COLORSPACE_SRGB, "test-output/barbara-downsample-bilinear.png");
resize_image(barbara, 0.5f, 0.5f, STBIR_FILTER_CUBIC , STBIR_EDGE_CLAMP, STBIR_COLORSPACE_SRGB, "test-output/barbara-downsample-bicubic.png");
resize_image(barbara, 0.5f, 0.5f, STBIR_FILTER_CATMULLROM, STBIR_EDGE_CLAMP, STBIR_COLORSPACE_SRGB, "test-output/barbara-downsample-catmullrom.png");
resize_image(barbara, 0.5f, 0.5f, STBIR_FILTER_MITCHELL , STBIR_EDGE_CLAMP, STBIR_COLORSPACE_SRGB, "test-output/barbara-downsample-mitchell.png");

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