AVIF and HEIF NOT LOSSLESS Format ?

[Xn User]

Hi )
I very angry, very very very angry!
Why in XnConvert AVIF named as with lossless method if I select 100% quality ?
I do make test , compress from BMP to AVIF image and decompressing AVIF to BMP image and both BMP file do not match difference if do compare files in Total Commander , why ? Why so ? What for need this false ?

[Xn User]

This proves my post

[xnview]

you're right...
Thanks to your detailed description I can reproduce the problem.

[Xn User]

For avif if see syntax to lossless encoding It looks so :
avifenc -q 100 -l -s 0 original.png lossless.avif
or
avifenc -l -s 0 original.png toosamelossless.avif
if use syntax as :
avifenc -q 100 -s 0 original.png nolossless.avif
file will be lossy

In examples use (L not I)

from https://github.com/AOMediaCodec/libavif/releases

[Xn User]

In HIEF also lossy , but I not known syntax for lossless compression in HEIF )

[xnview]

This problem is supposed to be fixed in XnView MP 1.8.4. Please check and confirm the bug fix here.

[Xn User]

This problem fiexd , thank you )