ASTC encoder output is resulting in a flipped image. about astc-encoder

[solidpixel]

Also more that origin is API dependent - DX/Vulkan is top left, GL/GLES is bottom left, so YMMV ...

[solidpixel]

Ask Apple. How to interpret and present the decompressed image is up to the viewing application.

The compressor doesn't flip the image, and by convention the origin is top left corner. Looks like the thumbnail preview is using a bottom left corner origin.

[SudarshanShetty1796]

I don't think it is a thumbnail preview issue. If I decode it back with the ASTC decoder, the image gets rotated back to the original orientation. Additionally, I'm seeing the same flipping issue when importing it into the Unity game engine.

[solidpixel]

ASTC doesn't flip the image unless you tell it to. PNG has a top-left origin. ASTC, by convention, has a top-left origin. We don't flip the data.

If the viewing application decides to interpret the data as a bottom left origin it's nothing to do with the texture format.

If you want to use textures in a system with a bottom left origin you will need to use -yflip.

[SudarshanShetty1796]

Cool, got it.

-yflip

was the solution, thanks.