Add another interesting profile to the test corpus
This one has three different tables, and each table has a "shoulder" at
the high end. The blue table is much shallower than red or green (which
are both fairly close to gamma 2.2).
Our current approximation code produces a good curve for green, but red
and blue are quite bad (inverse curves top out at 0.83 and 0.87). The
"best" single curve ends up being the red curve, so we end up darkening
all colors substantially.
My upcoming change to iteration/fitting strategy should improve these
results, but this really points to a failure in our current testing:
We don't have enough information about the quality of the "best single
curve" against the other two tables in our .txt files, nor about
objective quality measures of the curves (abs(f(1) - 1)). Improving the
testing should be straightforward.
We also may want to revisit separate curves per channel?
Bug: chromium:1017960
Change-Id: I6e662612d2d7d9a8b1bae9cdcc0b38eb60e87a3f
Reviewed-on: https://skia-review.googlesource.com/c/skcms/+/255519
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
diff --git a/profiles/misc/crbug_1017960_19.icc b/profiles/misc/crbug_1017960_19.icc
new file mode 100644
index 0000000..b87eef8
--- /dev/null
+++ b/profiles/misc/crbug_1017960_19.icc
Binary files differ
diff --git a/profiles/misc/crbug_1017960_19.icc.txt b/profiles/misc/crbug_1017960_19.icc.txt
new file mode 100644
index 0000000..28f3f51
--- /dev/null
+++ b/profiles/misc/crbug_1017960_19.icc.txt
@@ -0,0 +1,60 @@
+ Size : 0x00000F3C : 3900
+ Data color space : 0x52474220 : 'RGB '
+ PCS : 0x58595A20 : 'XYZ '
+ Tag count : 0x0000000E : 14
+
+ Tag : Type : Size : Offset
+ ------ : ------ : ------ : --------
+ 'desc' : 'desc' : 111 : 300
+ 'dscm' : 'mluc' : 68 : 412
+ 'cprt' : 'text' : 35 : 480
+ 'wtpt' : 'XYZ ' : 20 : 516
+ 'rXYZ' : 'XYZ ' : 20 : 536
+ 'gXYZ' : 'XYZ ' : 20 : 556
+ 'bXYZ' : 'XYZ ' : 20 : 576
+ 'rTRC' : 'curv' : 524 : 596
+ 'bTRC' : 'curv' : 524 : 1120
+ 'gTRC' : 'curv' : 524 : 1644
+ 'vcgt' : 'vcgt' : 48 : 2168
+ 'ndin' : 'ndin' : 1598 : 2216
+ 'chad' : 'sf32' : 44 : 3816
+ 'mmod' : 'mmod' : 40 : 3860
+
+rTRC : 16-bit table with 256 entries
+ ~= : 4.841902, 0.719986, 0.3762827, 0.1407054, 0.2431373, -0.02175903, 0 (Max error: 0.127342) (D-gap: -2.65129e-05)
+gTRC : 16-bit table with 256 entries
+ ~= : 2.197707, 1.013412, -0.02046552, 0.09246967, 0.1333333, 0.003822327, 0 (Max error: 0.0139048) (D-gap: 5.78072e-05)
+bTRC : 16-bit table with 256 entries
+ ~= : 1.923471, 1.129272, 0.06547091, 0.0077821, 0.003921569, -0.005767822, 0 (Max error: 0.169685) (D-gap: 0.00018987)
+Best : 4.841902, 0.719986, 0.3762827, 0.1407054, 0.2431373, -0.02175903, 0 (D-gap: -2.65129e-05)
+Inv : 0.2065304, 4.906921, 0.1067699, 7.107047, 0.03421073, -0.5224304, -0 (D-gap: 0.000164136)
+ XYZ : | 0.3805542 0.434021 0.14962769 |
+ | 0.21951294 0.68196106 0.098526 |
+ | 0.04006958 0.088272095 0.6965637 |
+CHAD : | 1.0478821 0.022918701 -0.050201416 |
+ | 0.029571533 0.9904938 -0.017059326 |
+ | -0.009231567 0.015075684 0.75164795 |
+WTPT : | 0.95047 1 1.0890961 |
+252 random bytes transformed to linear XYZD50 bytes:
+ 3f564a a3cb20 4b5e1b 1b124c 23186f 52430d 578330
+ 68404e 191519 68493e 9e9c1a 4a580d 364642 442fad
+ a894bd 5867b0 7b8273 425221 2e1d7b 867614 8857b8
+ 6d4335 150e5c def08f 7f4db3 8baf37 291b9d 557066
+ 4a4c49 392f60 23176a 888a79 9ecb94 83539c 476e0e
+ 7d8eab 3a4a21 472a0a 649244 08090a 22198c 303275
+ 2619a0 242606 556896 0e0d27 25350d 402c1c 9073b5
+ b8ae81 a17dc0 513631 496840 5f8457 150e17 70ad1d
+ 55792c 716312 21193e 2e2a11 151051 0a072a 372a2d
+ 6a6493 523c88 3b580d 4c2f84 2c1a3f 343774 656baf
+ 2d401a 372da5 150f4f 4b2d0c 5f8d13 040311 5760b7
+ 6ba01b 3d2948 404858 513a37 638b59 412d26 5a65a9
+81 edge-case pixels transformed to sRGB 8888 (unpremul):
+ 00000000 0012186c 00333fe9 0000783c 00127b7b 003386ef 0000f27f 0010f3a3 0033f8ff
+ 009f2a00 00a03368 00a64ce8 009f7f34 00a08277 00a58cee 009ff47c 00a0f6a0 00a5faff
+ 00fb4800 00fc4d61 00ff5fe5 00fb8a1f 00fc8c71 00ff96eb 00fbf976 00fcfa9c 00ffffff
+ 7f000000 7f12186c 7f333fe9 7f00783c 7f127b7b 7f3386ef 7f00f27f 7f10f3a3 7f33f8ff
+ 7f9f2a00 7fa03368 7fa64ce8 7f9f7f34 7fa08277 7fa58cee 7f9ff47c 7fa0f6a0 7fa5faff
+ 7ffb4800 7ffc4d61 7fff5fe5 7ffb8a1f 7ffc8c71 7fff96eb 7ffbf976 7ffcfa9c 7fffffff
+ ff000000 ff12186c ff333fe9 ff00783c ff127b7b ff3386ef ff00f27f ff10f3a3 ff33f8ff
+ ff9f2a00 ffa03368 ffa64ce8 ff9f7f34 ffa08277 ffa58cee ff9ff47c ffa0f6a0 ffa5faff
+ fffb4800 fffc4d61 ffff5fe5 fffb8a1f fffc8c71 ffff96eb fffbf976 fffcfa9c ffffffff
diff --git a/tests.c b/tests.c
index 80663d2..7a69a31 100644
--- a/tests.c
+++ b/tests.c
@@ -694,6 +694,9 @@
// Reasonable table, bad approximation (converges very slowly)
"profiles/misc/MR2416GSDF.icc", // chromium:869115
+
+ // Three different tables w/shoulders, bad approximation (slow convergence)
+ "profiles/misc/crbug_1017960_19.icc", // chromium:1017960
};
static void test_Parse(bool regen) {
