Why astc and etc2 looks different from orginal png?

[kopaka1822]

Why astc and etc2 looks different from orginal png?

[kopaka1822]

I will try to take a look at this on the weekend

[powof2]

Here is what they look in imageviewer:

ps. I mean ImageViewer and not TextureViewer in the picture.

[kopaka1822]

Hello,

the etc2 version in ImageViewer, it will looks much greener

I fixed this. The red and blue channels were swapped, that's why this issue occurred. The problem is that I cannot really test non directx formats with my unit tests. So it looks like my compression tool (compressonator) swapped the channels when saving the image and then swapped them again when loading (that's why this issue didn't occur to me yet).

the astc version in ImageViewer, it will looks much lighter

I could not reproduce that. Can you tell me which exact format did not work? I used ASTC 4x4 srgb (vulkan) to test this but I had no issue (Are you sure that you did not use linear instead of srgb?).

I added the updated files as attachment, so that you can test if the issues were solved. (for version 3.5)
imageloader.zip

[powof2]

Hi,
I thinks the etc2 looks better because they both looks lighter:

what they look in PVRTexTool:

more info:
the astc encode format : ASTC_5x5, sRGB, unsigned normalized byte
the etc2 endode format : etc2_RGB, sRGB, unsgiend normalied byte

here is the images used for testing:
lena-test.zip

[kopaka1822]

Hello,
when i open your lena-astc5x5.ktx or etc file in my PVRTexTool (which I downloaded yesterday) I get exactly the same issue:

I think there might have been an issue in the older versions of the tool which they fixed by now.
If I use my PVRTexTool to create to create an ASTC file, it works in the TexTool and in the ImageViewer.

PS: I would also recommend you to use one of the supercompressed formats (BASISU ETC1S/UASTC), because they will compress the file on CPU and GPU, so you also save some disk space (this requires .ktx2 file formats)

[powof2]

yes, I use older version of PVRTexTool, because the new one has errors when running in command line (accept astc_4x4 and astc_8x8 only, older version has no this problem).

I guess it may be a problem of the software decoder, i'll check it out.
and as for ktx2, i'll check it out as well.

thank you for the great tool.