Google Ultra HDR support

[fredgolightly]

I see this has been mentioned at viewtopic.php?f=60&t=46421&p=193679&hilit=ultra#p193679 for XnView MP but the thread seems to have died.

I'd love to compress my Pixel 9 50mp images with this but really want to keep the Ultra HDR gran map of these photos. Can this be supported? I can provide some sample images for with and without the ultra hdr setting, and an ultra hdr photo which has been compressed and lost the grain map also if this helps. Edit: uploaded here https://gofile.io/d/etoUSo (original and XnConvert compressed which has lost the ultra hdr map I wish to keep)

I've tried Riot compressor on Windows, and Compress Image on Android - the former loses the Ultra HDR effect, the latter keeps it fine but I much prefer the XnConvert's compresion as it's noticeably sharper at similar file sizes and compression quality.

[fredgolightly]

Hi,
Is this something XnConvert would be able to support (keeping the uhdr grain map) or not something which can be done, please?

There's a few Android apps (Compress Image mb to kb) which can retain the uhdr metadata and I'm able to provide more sample files if needed.

Thank you

[xnview]

yes i need to check how to support them...

[fredgolightly]

So glad this has been picked up, espeically considering how huge 50mp uhdr photos are. If you need any/more samples at different settings/focal lengths I'd be happy to help & test the uhdr support on compressed images on supported hardware (P9P and P9 here).

Thank you so much for looking in to this!