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src/Drivers/Gd/Modifiers/TrimModifier.php

@@ -20,6 +20,8 @@ public function apply(ImageInterface $image): ImageInterface
             throw new NotSupportedException('Trim modifier cannot be applied to animated images.');
         }
 
+        // apply tolerance with a min. value of .5 because the default tolerance of '0' should
+        // already trim away similar colors which is not the case with imagecropauto.
         $trimmed = imagecropauto(
             $image->core()->native(),
             IMG_CROP_THRESHOLD,