XnViewMP 1.01 - browser window has problems with 32bit color depth files (AVIF/PNG)

[masterjp]

I have some 32bit color depth pictures in avif and png file format in one directory. I opened the folder in browser window and the thumbnails of these two files have graphic errors. I can rebuild the thumbnails of these pictures and the results are perfect. If I open the same folder in browser window again,
I will see the same graphic errors.
.
1. AVIF (32bit color depth) => errors
2. PNG (32bit color depth) => errors
3. AVIF (24bit color depth) => no errors
.
I can open all files in fullscreen mode and all pictures have no graphic errors.
.
My XnViewMP program use the webp file format for catalog caching.
If I use the jpeg quality (low or high), everything is fine.
.
Is it possible to modify the catalog system for webp quality setting?
If you use 16 or 24bit color depth for webp thumbnail cache file, we would'nt see any graphic errors.
.

gfx-errror.jpg

[xnview]

even after a thumbnail rebuild?

[masterjp]

I tried a thumbnail rebuild and they looked right.
After that I browsed to another folder and moved again into the directory with the 32bit avif/png files.
The thumbnails get the same graphic errors again.

[xnview]

i've tried with 1.02 & 32bits PNG, and no problem

[masterjp]

Here is a small video for you, which shows the problem.
It is a mp4 video file (HEVC encoded).

[xnview]

could you send me the 3 files?

[masterjp]

Here are my test files.

32bit sample files.zip

[xnview]

Thanks to your detailed description I can reproduce the problem.
It occurs when alpha is blank

[masterjp]

Fantastic! Thank you!

[xnview]

This problem is supposed to be fixed in XnView MP 1.3.0. Please check and confirm the bug fix here.