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tests/color-icc-output: use two-norm tolerance

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Switch from per-channel max error tolerance to max two-norm (Euclidean
distance) error. Geometrically this means that previously the accepted
volume was a +/- tolerance cube around the reference point, and now it
is a sphere with tolerance radius.

The real benefit is simplifying the code.

The error tolerance are also changed to float. Integers cannot represent
values between 1 and 2, and the jump from 1 to 2 would have been too
much. AdobeRGB tolerance gets relaxed a bit, while BT2020 tolerance
becomes stricter. The new tolerance values are the reported achieved
two-norm max errors plus a bit of margin.

Surprisingly the sRGB case tolerances remain strictly at zero, and
that's no bug in the test.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>
This commit is contained in:
Pekka Paalanen
2022-06-17 17:22:55 +03:00
committed by Pekka Paalanen
parent 3acb1c4793
commit b5467ba258
1 changed files with 14 additions and 18 deletions
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tests/color-icc-output-test.c
+14 -18
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@@ -137,8 +137,10 @@ struct setup_args {
struct fixture_metadata meta;
int ref_image_index;
const struct lcms_pipeline *pipeline;
/**
* 2/255 or 3/255 maximum possible error, where 255 is 8 bit max value
* Two-norm color error tolerance in units of 1.0/255, computed in
* output electrical space.
*
* Tolerance depends more on the 1D LUT used for the
* inv EOTF than the tested 3D LUT size:
@@ -148,7 +150,8 @@ struct setup_args {
* in GL-renderer, then we should fix the tolerance
* as the error should reduce a lot.
*/
int tolerance;
float tolerance;
/**
* 3DLUT dimension size
*/
@@ -160,12 +163,12 @@ struct setup_args {
};
static const struct setup_args my_setup_args[] = {
/* name, ref img, pipeline, tolerance, dim, profile type, clut tolerance */
{ { "sRGB->sRGB" }, 0, &pipeline_sRGB, 0, 0, PTYPE_MATRIX_SHAPER },
{ { "sRGB->adobeRGB" }, 1, &pipeline_adobeRGB, 1, 0, PTYPE_MATRIX_SHAPER },
{ { "sRGB->BT2020" }, 2, &pipeline_BT2020, 5, 0, PTYPE_MATRIX_SHAPER },
{ { "sRGB->sRGB" }, 0, &pipeline_sRGB, 0, 17, PTYPE_CLUT, 0.0005 },
{ { "sRGB->adobeRGB" }, 1, &pipeline_adobeRGB, 1, 17, PTYPE_CLUT, 0.0065 },
/* name, ref img, pipeline, tolerance, dim, profile type, clut tolerance */
{ { "sRGB->sRGB" }, 0, &pipeline_sRGB, 0.0, 0, PTYPE_MATRIX_SHAPER },
{ { "sRGB->adobeRGB" }, 1, &pipeline_adobeRGB, 1.4, 0, PTYPE_MATRIX_SHAPER },
{ { "sRGB->BT2020" }, 2, &pipeline_BT2020, 4.5, 0, PTYPE_MATRIX_SHAPER },
{ { "sRGB->sRGB" }, 0, &pipeline_sRGB, 0.0, 17, PTYPE_CLUT, 0.0005 },
{ { "sRGB->adobeRGB" }, 1, &pipeline_adobeRGB, 1.8, 17, PTYPE_CLUT, 0.0065 },
};
static void
@@ -529,17 +532,14 @@ process_pipeline_comparison(const struct buffer *src_buf,
dump = fopen_dump_file("dump");
#endif
const float max_pixel_value = 255.0;
float max_allow_diff = arg->tolerance / max_pixel_value;
bool ok = true;
struct image_header ih_src = image_header_from(src_buf->image);
struct image_header ih_shot = image_header_from(shot_buf->image);
int y, x;
unsigned i;
struct color_float pix_src;
struct color_float pix_src_pipeline;
struct color_float pix_shot;
struct rgb_diff_stat diffstat = { .dump = dump };
bool ok;
/* no point to compare different images */
assert(ih_src.width == ih_shot.width);
@@ -564,13 +564,9 @@ process_pipeline_comparison(const struct buffer *src_buf,
}
}
for (i = 0; i < COLOR_CHAN_NUM; i++) {
if (diffstat.rgb[i].min < -max_allow_diff ||
diffstat.rgb[i].max > max_allow_diff)
ok = false;
}
ok = diffstat.two_norm.max <= arg->tolerance / 255.0f;
testlog("%s %s %s tol_req %d %s\n", __func__,
testlog("%s %s %s tolerance %f %s\n", __func__,
ok ? "SUCCESS" : "FAILURE",
arg->meta.name, arg->tolerance,
arg->type == PTYPE_MATRIX_SHAPER ? "matrix-shaper" : "cLUT");