Media autoscale threshold change picture's colors

[fernandot]

When uploading a picture, the automatic autoscale threshold (2560) changes the picture's colors to a different color profile (fewer colors, less vivid)

I've deactivated the automatic autoscale with

add_filter('big_image_size_threshold', '__return_false');

and the issue disappears

This is a big problem for photography-related blogs or websites, where photo quality makes the difference.

It's ok to scale the images for better performance, but we should be able to avoid it without loss of quality.

Note: I've tried to remove the jpg quality loss applied by WordPress and that's not the problem, the problem comes with the autoscale.

(Attached: image file without autoscale, image file with autoscale)

[fernandot]

Image file without WP auto scale

[fernandot]

Image file after WP auto scale

[fanvid]

Im having a similar issue, new image uploads, every 2 or 3 images in 10 will come out corrupted after going through wordpress...

[nickchomey]

I cant really replicate this. I just uploaded the same file and, yes, it does lose some *detail* - as you'd expect - but the colour/tone doesn't seem all that different. Certainly not like yours shows.

I uploaded 2 versions - the 2nd one is after I applied a change to the Imagick editor that I've been working on - it might be barely-perceptibly better.

Can you share info about your server environment? Perhaps you're using GD rather than Imagick?

There's info in ​https://[YOURSITE.COM]/wp-admin/site-health.php

[nickchomey]

That last one was done with GD. So, yeah, that seems to be the issue. Honestly, GD doesn't really get a lot of love because Imagick is generally superior in terms of image quality, and is available when using most webhosts.

So, I'm going to close this and suggest you contact your host about Imagick support, or find a new one (they don't deserve your business if they don't have Imagick...).

Also WordPress 7.1 will be introducing a new image processing mechanism that runs in the browser, and uses the best-in-class libvips tool to do it. It'll almost certainly be faster, and probably higher quality as well.

They're currently looking for testers, so i encourage you to check that out: ​https://make.wordpress.org/core/2026/06/04/call-for-testing-client-side-media-processing/