From 9b55b2a84bf9ae8b712a883a00cb6c4ee462904b Mon Sep 17 00:00:00 2001
From: vadimr <futuramedium@yandex.ru>
Date: Sun, 23 Jan 2022 18:51:47 +0000
Subject: [PATCH] fix t_xyz2lab

---
 CHANGES                    | 2 ++
 lib/PDL/Transform/Color.pm | 4 +---
 t/color.t                  | 8 +++++++-
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/CHANGES b/CHANGES
index 0bdd542..98b24aa 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,5 @@
+- fix t_xyz2lab - thanks @vadim-160102
+
 1.005 2020-09-17
 - eliminate // to keep 5.006 compat
 
diff --git a/lib/PDL/Transform/Color.pm b/lib/PDL/Transform/Color.pm
index 9560a0a..a25c58b 100644
--- a/lib/PDL/Transform/Color.pm
+++ b/lib/PDL/Transform/Color.pm
@@ -1539,9 +1539,7 @@ sub t_xyz2lab {
     my $wp_xyy = xyy_from_illuminant($me->{params}->{white});
     $me->{params}->{wp_xyz} = $wp_xyy->copy;
     $me->{params}->{wp_xyz}->slice('2') .= 1 - $wp_xyy->slice('0') - $wp_xyy->slice('1');
-    $me->{params}->{wp_xyz} *= $wp_xyy->slice('2');
-    
-
+    $me->{params}->{wp_xyz} *= $wp_xyy->slice('2') / $wp_xyy->slice('1');
     # input is XYZ by the time it gets here
     $me->{func} = sub {
 	my($in,$opt) = @_;
diff --git a/t/color.t b/t/color.t
index fdfba5e..05a9ce7 100644
--- a/t/color.t
+++ b/t/color.t
@@ -167,11 +167,17 @@ ok(all( ($aa > $a -1e-10) & ($aa < $a + 1e-10) ),"decoding undoes coding");
 # (minimal testing)
 $a = xvals(101)/100;
 eval {$t = t_pc();};
-ok(($@ && $@=~m/^Usage\:/), "t_pc with no arguments died and threw out an info message");
+like $@, qr/^Usage\:/, "t_pc with no arguments died and threw out an info message";
 eval {$t = t_pc('sepia');};
 is $@, '', "t_pc('sepia') ran OK";
 eval {$b=$a->apply($t);};
 is $@, '', "t_pc applied OK";
 ok($b->ndims==2 && $b->dim(0)==3, "t_pc created an RGB output");
 
+eval {$t = t_xyz2lab();};
+is $@, '', "t_xyz2lab ran OK";
+eval {$b=pdl(1,1,1)->apply($t);};
+is $@, '', "t_xyz2lab applied OK";
+ok all(approx $b, pdl(100, 8.5841461, 5.5183538)), 't_xyz2lab right values' or diag "got=$b";
+
 done_testing;