DNG files export - allow 8 or 16-bit encoding, lossy and unlossy compression

Rationale : Photolab export to linear DNG file lacks options for user to choose image quality and compression.

Feature requests:

  • allow 8 or 16-bit encoding ( 24-bit and 48-bit color )
  • lossy and unlossy compression

Why not just use TIFF. As seen in the other thread file size isn’t much different. And TIFF is a general accepted file.
I never understood the benefit of DNG.


1 Like

Why not ? Adobe software solutions allow exporting to DNG with user selected compression

I don’t know what you mean.


I must question the rationale. Why would you want a dng container for something that already exists in far more compatible containers, jpeg for 8-bit and Tiff for 16-bit if that is what you need for further processing or archive. DNG is based on Tiff anyway, and its just a container, trying to make into some flavor that would be less compatible with other apps, than current formats with no perceivable benefits. Its the same strange rational as expecting PhotoLab to be able to import and process anything with dng extension regardless of what the data actually is.

If DXO could find the way to get file size of current linear DNG they export to be smaller with no loss of quality or compatibility, that would make a lot more sense.


With lossy DNG compression, the user would get to choose different quality and thus file size. It would be great to have different quality levels thus different file sizes, rather than 8-bit and 16-bit bloated TIF or DNG files.

Follow the link below for an article about Lightroom’s dng feature
Adobe Lightroom’s Solution for Managing Large DNG RAW File Sizes - Storyteller (picturestoryteller.com)

It doesn’t say what is compressed: a RGB image or the RAW image. It doesn’t mention the used bit depth. The original RAW image may contain a full size JPG. Losing only that one will reduce file size alone. How will editing behave when it has to be done with less data and smaller bit depth?
We strive for greater quality but if the result is a larger file then we are going to undo that quality by deleting and compressing data.


1 Like

What Lightrroom does exactly is not relevant. However, it would be useful if DxO software including PL, Pure Raw, Nik collection could work with DNG files where the user could choose compression, lossy and unlossy, and quality level if lossy, and size of the embedded JPG.

Further to my initial request, saving the output image with in-between depths such as 12-bit depth would be useful.