[lifthrasiir]

I mean, JPEG XL is designed as an all-encompassing file format that also subsumes RAW and DNG. On the other hand, DNG 1.7.0.0 added JPEG XL as one of compression options back in 2022 (!), which might be what Samsung is actually using.

[112233]

Where can I read more about JPEG XL subsumming of raw? As far as I understand, you cannot specify differen colorspace for different subsets of pixels?

[lifthrasiir]

That is done by a custom ICC profile. JPEG XL's own colorspace support is more like a shorthand for frequent presets.

[112233]

how can custom ICC profile encode information about bayer filter layout, dark frame or dead/phase photosites?

[lonjil]

The parent commenter is incorrect. Yes, the JXL authors do want to try to use JXL as a raw format, but they are focusing on other priorities right now, so the specification for how JXL could be used as a raw format doesn't exist yet. But the format is flexible enough to allow for it, without backwards-incompatible changes.

[lifthrasiir]

Ah, yeah, the current JPEG XL is not enough for the full RAW coverage. (I was talking more about per-channel color spaces.) There is indeed a reserved extra channel type for specific filter layouts among others, but its specification doesn't exist yet.

[JyrkiAlakuijala]

For some, possibly most, needs of using raw having yuv444, 14+ (or 16+) bits of precision and lossless or near-lossless (with strong guarantees of maximum error on individual pixels) compression is supposedly acceptable. I base this interpretation mostly on digital photography discussions I have seen on the internet. I am not a photographer myself.

(12 bits of component already requires adapting to the current lighting and can supposedly slow down professional photography.)