Bug #10545

'Create HDR' leads to broken DNG files

Added by Christian Stussak almost 5 years ago. Updated almost 5 years ago.

Target version:
Start date:
Due date:
% Done:


Estimated time:
Affected Version:
git development version
hardware architecture:


The HDR DNG files created by darktable seem to be incompatible with the DNG standard. They open fine in darktable, but not in
  • Windows photo viewer using Adobe DNG Codec 2.0
  • RawTherapee v4.2.210 (image display as pink/magenta noise)
  • dcraw v9.22 and ufraw v0.22 ("Cannot decode file ...")

Here is a HDR DNG file created by darktable for testing:

I also asked a friend to develop this file in Adobe Lightroom, but he hasn't answered yet. I will add the information ASAP.

Related issues

Related to darktable - Bug #10177: HDRMerge DNG-formatFixed10/27/2014


#1 Updated by Pedro Côrte-Real almost 5 years ago

  • System changed from Mac OS X to all
  • Affected Version changed from 1.6.7 to git development version
  • % Done changed from 0 to 10
  • Status changed from New to Confirmed

Yeah, our hdr merge dng generation code is a mess and strictly for internal darktable use right now. The whitebalance is not being properly saved for example. We should definitely fix it.

#2 Updated by Christian Stussak almost 5 years ago

Maybe the cleanup of the DNG export code can go along with the DNG import code (#10177).

Is the current export using integer or float values? The HDR DNGs created by darktable are pretty huge compared to those generated by HDRMerge. Maybe you can just get inspiration (i.e. code) from HDRMerge. It allows to select either a 16, 24 or 32 bit float DNG 1.4 format for export and 32 bits are certainly almost never needed (they result in huge DNGs).

#3 Updated by Tobias Ellinghaus almost 5 years ago

  • Related to Bug #10177: HDRMerge DNG-format added

#4 Updated by Christian Stussak almost 5 years ago

I said above, that I will provide the info on darktable-exported DNG imported into Lightroom ASAP. Well, I am a little late. My fried said they don't open in Lightroom, but he hasn't provided any error message (which is no surprise to me).

In order to fix this bug, you may re-use some of the code provided in (DNGFloatWriter.*).

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