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authorThibG <thib@sitedethib.com>2020-08-02 22:46:25 +0200
committerGitHub <noreply@github.com>2020-08-02 22:46:25 +0200
commitb988bc75649425266e848a25290a86a9fc53625e (patch)
tree0ca60f5d88936a2d768e29fe248f8d78eabd2581 /lib/paperclip/color_extractor.rb
parent141ac8db8b98230188b13f1da801611bcdc6a9f1 (diff)
parent8f0e6122a9cf85216d7e73bda5fa8338458b2b77 (diff)
Merge pull request #1393 from ThibG/glitch-soc/merge-upstream
Merge upstream changes
Diffstat (limited to 'lib/paperclip/color_extractor.rb')
-rw-r--r--lib/paperclip/color_extractor.rb8
1 files changed, 5 insertions, 3 deletions
diff --git a/lib/paperclip/color_extractor.rb b/lib/paperclip/color_extractor.rb
index 44fe5ff1d..c8bb771a0 100644
--- a/lib/paperclip/color_extractor.rb
+++ b/lib/paperclip/color_extractor.rb
@@ -5,6 +5,7 @@ require 'mime/types/columnar'
 module Paperclip
   class ColorExtractor < Paperclip::Processor
     MIN_CONTRAST        = 3.0
+    ACCENT_MIN_CONTRAST = 2.0
     FREQUENCY_THRESHOLD = 0.01
 
     def make
@@ -26,8 +27,9 @@ module Paperclip
 
       foreground_palette.each do |color|
         distance = ColorDiff.between(background_color, color)
+        contrast = w3c_contrast(background_color, color)
 
-        if distance > max_distance
+        if distance > max_distance && contrast >= ACCENT_MIN_CONTRAST
           max_distance = distance
           max_distance_color = color
         end
@@ -77,8 +79,8 @@ module Paperclip
     private
 
     def w3c_contrast(color1, color2)
-      luminance1 = (0.2126 * color1.r + 0.7152 * color1.g + 0.0722 * color1.b) + 0.05
-      luminance2 = (0.2126 * color2.r + 0.7152 * color2.g + 0.0722 * color2.b) + 0.05
+      luminance1 = color1.to_xyz.y * 0.01 + 0.05
+      luminance2 = color2.to_xyz.y * 0.01 + 0.05
 
       if luminance1 > luminance2
         luminance1 / luminance2