Re: ISO 21496‐1:20XX Gain Maps

> On Nov 15, 2023, at 20:12, Chris Lilley <chris@w3.org> wrote:
> 
> Thanks for that data, although it mainly covers JPEG-compressed images.
> 
> I would be interested to see a comparison between, for example:
> 
> 8 bit PNG compressed SDR image plus 10 bit PNG compressed HDR image
> 8 bit PNG compressed baseline SDR image containing un-resampled 16-bit gain map
> both in terms of file sizes and also in terms of per-pixel error visualization in the reconstructed alternate image.
> 
Right. I have no idea how this behaves for PNG. The work has mainly been intended for photographic content.
It's very hard to predict how it will behave for a deflate-based compression scheme.

Cheers,
//Leo

> On 2023-11-15 14:03, Leo Barnes wrote:
>>> The claim of storage efficiency has not been backed up by any measurements that I have seen.
>> 
>> It's in the white-paper <https://helpx.adobe.com/camera-raw/using/gain-map.html> published by Adobe:
> -- 
> Chris Lilley
> @svgeesus
> Technical Director @ W3C
> W3C Strategy Team, Core Web Design
> W3C Architecture & Technology Team, Core Web & Media