Problem with DNG files from latest Samsung Expert Raw

Software RawTherapee
1

Hello, after updating to latest Expert Raw 3.0.05.12 I can not view or edit linear DNG files captured with my Samsung S23+ in RawTherapee 5.10 (5.9) anymore.
Here is a link to those files: https://ufile.io/f/l7c8i
12 MP file is LOSSLESS (new option in Expert Raw app)
50 MP file is LOSSY

Thank you

2

Welcome! There is a possibility they started using the latest DNG 1.7 spec w/ JPEG XL embedded compression. Might take a while to get that supported…

3

that means that LOSSLESS image is not LOSSLESS (standard RAW file) as expected

4

JPEG XL compression can be lossless as well. What Samsung actually implemented is not clear yet.

In any case, you are most likely not getting the raw sensor data anyway (even before this change), but some intermediate result of their computational photography pipeline. “No such thing as a real picture.”

5

I’m currently testing TinyDNG. It uses JPEG XL compression to reduce file size. I found that it isn’t recognized by RawTherapee and another open source software I tried. Are there any plans to implement the latest version of DNG? I used these settings:
tinydng-cli --input InputFile.dng -l -n -o output_jxl_same_preview.dng
I asked ChatGPT to write a batch script for me to compress a folder. But it is pretty useless as it stands now without support.

6

Welcome to the forum, @Archall

I joined the forum a couple of months ago with similar questions. I’m not qualified to give you a technical explanation, but (as a darktable user) here are a few things I’ve learned.

  1. DNG format serves as a wrapper for a few different types of content. This can include JXL and even raw data, plus metadata and (I suspect) HDR extensions for HDR-capable devices. Data can be compressed or not.
  2. DarkTable and RawTherapee can open some DNG’s but not all. So it’s a little complicated. There is some variation between these two excellent FOSS applications, as you might expect.
  3. As an iPhone and darktable user, I’ve found that I can change the file extension of Apple ProRAW files* from .DNG to .jxl, and that I can open these files in darktable. It’s been suggested that what I see is just a “jpeg preview” but these are labeled as “JPEG XL HDR” in the light table (of darktable). To be honest, I don’t even understand what could possibly be “raw” about iPhone ProRAW since the phone makes a composite from multiple exposures for resolution, noise reduction, and increased dynamic range.

*I am using JPEG XL lossy as the ProRAW format.

Good luck with your photographic journey. :blush: