Panorama created from denoise AI generated .dng files.

[Terese Kristi30483064v9s8]

Hi, I'm working with stitching panoramas in Lightroom Classic. Camera: Nikon Z8. If I do enhance the raw files by the new denoise AI, the files are converted to .dng files. When I do create panorama from 14 of the enhanced .dng files, the resulting panorama file size (73 Mb, and around 231 mega pixels) is less than any of the single .dng file (77 Mb, around 45 mega pixels). I do not understand how this is possible without loosing a lot of information. If I do stitch the same panorama from RAW files, it will create a .dng file of 341 Mb. Maybe a bad workflow to create panoramas from .dng files?

[Ian Lyons]

The Enhanced DNG files created by LrC, ACR and LrD are now compressed lossy files. The compression used is JPEG XL, which allows for much smaller files with minimal loss in quality.

[Terese Kristi30483064v9s8]

Thank you for the comment! Yes, I do understand that. But this also applies to the .dng files that the panarama is merged from. So how can the resulting panorama be less in size than the single photo it is merged from? It does look like the compression is performed on already compressed files. I do not understand how a single file of 45MP is greater than a 231MP file with the same file type/compression without loosing information.

[Ian Lyons]

If you reread my post you'll see that I made no claims regarding 'information', and neither did @JohanElzenga in his post.

Adobe claim that files compressed using JPEG XL are smaller than those compressed using JPEG and that they suffer from minimal loss in quality.

More information on JPEG XL can be found at https://jpegxl.info/  In particular, theyext relating to Key Features and Compression.

[JohanElzenga]

Thank you for the comment! Yes, I do understand that. But this also applies to the .dng files that the panarama is merged from. So how can the resulting panorama be less in size than the single photo it is merged from? It does look like the compression is performed on already compressed files. I do not understand how a single file of 45MP is greater than a 231MP file with the same file type/compression without loosing information.

By @Terese Kristi30483064v9s8

AFAIK, the denoised DNG contains a copy of the original raw data. I assume that when you merge these DNG's to panorama, that is no longer the case and that explains how the panorama can be smaller than one of the brackets, without losing quality.

[Terese Kristi30483064v9s8]

Hi Johan, thank you very much for your explanation. That was reassuring.

[JohanElzenga]

Look at the resulting panorama, not at the file size on disk. Do you see anything that makes you worried about the quality loss in the compression method that Lightroom uses?