Open and process compress dng


(Michael Gruteser) #1

Hello everyone, is there a way to open and process compressed dng files with rawtherapee?
I’ve created files because I was not concerned with failures from compressing pics but I wanted to take advantage of the color range instead.
Many thanks, Michael


(Ingo Weyrich) #2

Which version of rt do you use?


(Michael Gruteser) #3

Hi, it’s the current one. I can open uncompress dng, but not the compressed ones.


(Ingo Weyrich) #4

So it’s a 5.0 version? Can you upload a sample file to filebin.net and post the link here?


(Alberto) #5

fwiw, if you create a compressed dng with Adobe dng converter, then RT can’t open it. actually, it doesn’t even appear in the browser. last time I checked (a few months ago) the dcraw code was #ifdef’d out (though I might remember wrong)


(Ingo Weyrich) #6

@agriggio You are correct :slight_smile: Currently rt only supports compressed float dng files


(Michael Gruteser) #7

You’re right. Alberto, the file won’t appear in the browser. Do you know whether there are plans to get it back in?
I used the DNG converter. I have scanned lots of pictures and want to preserve the colors. Artefacts from compressing is not that much of concern for me.


(Michael Gruteser) #8

Hi, here are three pics: the CR2, the uncompressed DNG and the compressed one. But I guess we won’t need them any longer.
https://filebin.net/d3341s9rjr0cqlkd


(Alberto) #9

I don’t know of any plans, sorry. In fact, I’m not even sure why the code is commented out. I just tried a quick hack to put it back in, and it seems to work fine on my machine (warning: with only very limited testing). Here is the patch if someone is interested.
Maybe some of the RT developers know?
lossy-dng.patch (1.1 KB)


(Ingo Weyrich) #10

@agriggio Thanks for the patch. I tried it and it works fine. Don’t know why this was disabled and when. Must have been before my time :slight_smile: Can you make a pr for it to get more tests?


(Alberto) #11

@heckflosse sure, let me polish the code a bit and I’ll open a pr.


(Michael Gruteser) #12

You guys are incredible! Thx!


(Michael Gruteser) #13

Hi, one question please: what is the process for a pr? Is there something I would have to do?


(Mica) #14

A PR, or pull request, is a workflow feature in github/github-like source hosting systems. You can read about it here: https://help.github.com/articles/creating-a-pull-request/


(Ingo Weyrich) #15

@Michael2 You don’t have to make a pr. Alberto already did and also fixed the issue :slight_smile: It’s already in current rt code. You only have to wait for a new build.


(Michael Gruteser) #16

:slight_smile: