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darktable is an open source photography workflow application and raw developer
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DNG file has strange default wb values, wrong colors and error message #3555

Closed gadolf66 closed 4 years ago

gadolf66 commented 4 years ago

Describe the bug DNG files from a CHDK point-and-shoot Canon show strange default values in white balance module and very pale colors. Besides, everytime the file is opened or a module is activated, it shows a warning/error message stating that

Canon Canon Powershot A3100 IS color matrix not found Rawtherapee and Photoflow show "normal" values. By "normal" I mean a color temperature around 6, 7K, not 25K as show by darktable.

To Reproduce

  1. Open attached dng file
  2. See default white balance values
  3. Open the same file in Rawtherapee and/or Photoflow and compare.

Expected behavior 1) Color temperature is way too high (25K) 2) Colors are very faint

Screenshots After opening file in dt: Screenshot from 2019-11-24 23-59-45

After opening file in rt: Screenshot from 2019-11-24 23-27-12

After opening file in PhF: Screenshot from 2019-11-24 23-28-00

Platform (please complete the following information):

Additional context raw file:

IMG_5861.zip

jenshannoschwalm commented 4 years ago

dng file has a CalibrationIlluminant1=1 and dt has no conversion matrix for this atm. I will fix this and there will be a proper temperature.

About the image being dull --> you will have to use some module like base curve or filmic ...

gadolf66 commented 4 years ago

Thanks, As for the dullness, I was referring to the fact that it is much more dull than Rawtherapee or Photoflow. Please note that both rt and phf are showing the unedited raw and show more color than dt. EDIT: Even using modules like you've mentioned I can't recover the right colors. Only if I increase (a lot) some saturation module (for example, color balance), I can get closer to reality, but it then gives some color shift.

gadolf66 commented 4 years ago

Sorry, I forgot to mention, dt also shows black borders around the image (if you turn on the over/under exposed indicator, it becomes clear). Again, rt and phf don't.

jenshannoschwalm commented 4 years ago
  1. "Right color" will be fixed
  2. "Dullness" is not a bug but intended in dt as you should apply base curve or preferred rgb-filmic.
  3. I also saw the borders, another point that should be fixed. The cropping exif data in your image is somewhat strange.
jenshannoschwalm commented 4 years ago

The colour matrix problem has been fixed via #3565 so your colours will look much better!

About the black border; in fact this is by "intention". dt takes the size as suggested by "Default Crop Size" (which is normally smaller than "Active Area", in your image it's the same size, you can see these data by using exiftool. This behaviour is suggested by DNG standard. rt automatically crops borders in this case. If you want to get rid of these borders you could use the crop module and activate that automatically (the manual tells you how to do it) or define a style. Keep going!

jenshannoschwalm commented 4 years ago

Think of closing this issue please

gadolf66 commented 4 years ago

Thanks! I'm unable to test it now. Will I have to build it myself,or will this be merged to master, so that I can grab it via opensuse package?

jenshannoschwalm commented 4 years ago

You can watch the pr to find out when it's available in master.