[wp-trac] [WordPress Trac] #63338: Image distortion since WordPress 6.8, previously correct image now blurry

[WordPress Trac]

#63338: Image distortion since WordPress 6.8, previously correct image now blurry
-------------------------------+------------------------------
 Reporter:  doobmanager        |       Owner:  (none)
     Type:  defect (bug)       |      Status:  new
 Priority:  normal             |   Milestone:  Awaiting Review
Component:  Media              |     Version:  6.8
 Severity:  normal             |  Resolution:
 Keywords:  reporter-feedback  |     Focuses:
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Comment (by SirLouen):

 Replying to [comment:15 siliconforks]:
 > Replying to [comment:14 SirLouen]:
 > > 1. Go to this file: `wp-includes/class-wp-image-editor-imagick.php`
 > > 2. And simply comment the line 509 like this:
 > >
 > > {{{
 > > // $this->image->quantizeImage( $max_colors,
 $this->image->getColorspace(), 0, false, false );
 > > }}}
 > >
 > > 3. And test again uploading the images
 >
 > Actually, I think that the steps above might not work because I suspect
 this particular issue is elsewhere in the code.
 >
 > However, your patch https://github.com/WordPress/wordpress-
 develop/pull/8813.diff will probably fix the issue.

 Yes, its true
 I seem to be an special use-case of not-Indexed a GrayScale image

 The current script is filtering out Grayscale images and indexing them by
 default. This image will trigger both depht (8bit) + Grayscale comparisons
 (Colorspace: Gray). Ultimately the Quantization part will be executed
 twice, ending with a blurry Quantized image.

 And as you say, only commenting the line I proposed is not enough, I have
 updated my message to also comment another line for testing purposes,
 although my patch solves all use-cases (but I'm not sure if they know how
 to apply the patch, so I filtered down to a simpler version just for
 testing purposes)

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Ticket URL: <https://core.trac.wordpress.org/ticket/63338#comment:17>
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