JPEG / Jpegli

rotbus19 · Post by **rotbus19** » Thu Nov 14, 2024 5:47 pm

This mainly relates to the Export dialog for Jpegli but may apply to other places, e.g. Save As and information in the Properties dialog.

1. XNView refers to 'JPEG-li' but it should be 'Jpegli' - see https://opensource.googleblog.com/2024/ ... brary.html

2. 'Optimize Huffman' doesn't appear to do anything when used with Jpegli. CLI help says disable Huffman must be used with Progressive level = 0 - could that be the issue?

3. DCT Method does nothing - disable this for Jpegli?

4. Smoothing factor does nothing - disable this for Jpegli?

5. Subsampling factor - the labelling for this is non-standard and inconsistent. Should be 444, 422, 420 (https://en.wikipedia.org/wiki/Chroma_subsampling + https://kraken.io/docs/chroma-subsampling).

However, better to make this human-friendly? I.E.

High compression (420)
Medium compression (422)
Low compression (440)
No compression (444)

Note: Jpegli allows for these 4 settings even though XNView only exposes 3 (omits 440)