can we convert PNG with specified sampling format？ about cavif-rs

[kornelski]

This crate always uses 444 (highest resolution) color sampling, so it isn't supposed to cause any distortions like this.

Do I understand correctly that you've encoded this image using a different tool and still saw the incorrect line? That would suggest it's a bug in the decoder, not the encoder.

I would prefer to kill chroma subsampling for good. AV1 handles color quite well, and doesn't need to continue the tradition of using a mathematically-dubious hack invented for an analog TV signal from more than a half century ago.

[woshilaiba]

This crate always uses 444 (highest resolution) color sampling, so it isn't supposed to cause any distortions like this.

Do I understand correctly that you've encoded this image using a different tool and still saw the incorrect line? That would suggest it's a bug in the decoder, not the encoder.

I've encoded this image using "avifenc"， the cli is "avifenc -y 444 tray.png tray_avifenc.avif", and using "cavif" with "cavif -Q 50 tray.png" .
They both get the incorrect line at the right edge, but It is correct when I encode it with "avifenc -y 422 xxxx.png xxx.avif".
I'm not familiar with "Chroma Subsampling", just a guess!

operating system: Windows 10 subsystem for linux

[eugenesvk]

I've read in this blog that the vertical bar is an issue with Microsoft Photos, so might indeed be a decoder issue

Additionally, for avif images created by libavif, Microsoft Photos will have a strange vertical color bar on the right side of the images when the format is set to YUV444

[kornelski]

Yup, I think it's a decoder issue.