[wp-trac] [WordPress Trac] #63448: Image quality significantly degrades for resized PNGs with transparency in WordPress 6.8.1

[WordPress Trac]

#63448: Image quality significantly degrades for resized PNGs with transparency in
WordPress 6.8.1
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 Reporter:  elvismdev     |       Owner:  (none)
     Type:  defect (bug)  |      Status:  new
 Priority:  normal        |   Milestone:  6.8.2
Component:  Media         |     Version:  6.8
 Severity:  major         |  Resolution:
 Keywords:                |     Focuses:
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Comment (by wildworks):

 I found that [https://github.com/t-hamano/wordpress-
 develop/blob/33a612053d5db243ac928a99ccec41d6e2f8a80e/src/wp-includes
 /class-wp-image-editor-imagick.php#L509 this line] causes the image
 degradation. If I comment out this line, the image degradation is not
 observed. This might be a problem with older versions of Imagick.

 The following steps should allow you to reproduce the problem.

 - Launch `wordpress-develop`repo. In my environment, Imagick version is:
   - ImageMagick version string: ImageMagick 6.9.11-60 Q16 x86_64
 2021-01-25 https://imagemagick.org
   - Imagick  version: 3.8.0
 - Upload [https://core.trac.wordpress.org/attachment/ticket/63448/vivid-
 green-bird-sample-original.pngthis this  image].
 - Access the resized image. Example: http://localhost:8889/wp-
 content/uploads/2025/05/vivid-green-bird-sample-original-1024x1024.png
 - When you compare it to the original image, you will see significant
 image degradation.

 @adamsilverstein Do you no anything about this problem?

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Ticket URL: <https://core.trac.wordpress.org/ticket/63448#comment:7>
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