Resize node causes artifacts on Blue Channel of RGBA images

[Rockmih]

Information:

• Chainner version: 0.25.1
• OS: Windows 10

Description
Resize tool seems to have issues downsampling images adding noise/artifacts (i dont really know how to describe it) im not sure this is specific to the blue channel but on the images im trying to process (0GBA normal maps) it seems to be the case, i did tested all interpolation methods with multiple images (all of them down sized from 8192 to 4096) and got similar results

You can visualize the issue here

And you can see the node tree here, downsizing the channel individually doesnt return the same issue

[Velorexe]

I've tried different 4096 x 8192 images, but could not replicate the same issue you're facing. Is there a change I could see the normal map you're facing issues with?

[Rockmih]

Sure, this is the file https://workupload.com/file/JvPpdr3CKvE i the issue persist on other files but this is the one used in the report.

[Velorexe]

Can reproduce your issue with that image. Seems like all the interpolation methods except Nearest Neighbour have this issue. I'll see if I can find the issue that's causing this.

[Velorexe]

Ah, seems the fix was a bit easier than I first expected. @Rockmih you need to toggle Separate Alpha. If you've enabled that, then you won't have this issue anymore. With that enabled, the alpha channel will be resized separately from the RGB channels, which properly handles transparency and prevents the color bleeding artifacts!

[Rockmih]

Ill try that! it is weird to get this kind of color bleeding i guess it makes sense the issue was coming from the Alpha channel it just didn't clicked for me. Thanks for the help!