Embeded Exif Cropping Info - way to ignore/turn-off? DT4.2.0

Software darktable
1

New to Darktable and have spent hours trying to find a solution.

Some Canon cameras R6/R6mk2/R5 and probably others? have a menu feature “Add Cropping Information” which allows various aspect ratio limits to be shown on the EVF with the cropping box data added to the file’s Exif data; but without cropping the actual RAW data. This is a different feature to Canon’s “Cropping/Aspect Ratio” which does crop the actual RAW data.

Example embedded Exif Cropping Info:
Crop Left Margin : 0
Crop Right Margin : 0
Crop Top Margin : 0
Crop Bottom Margin : 0
Cropped Image Width : 5000
Cropped Image Height : 4000
Cropped Image Left : 500
Cropped Image Top : 0

Cannon exports the associated JPEG as the full uncropped image and the embedded RAW preview JPEG is also the full uncropped image.

Darktable seems to always honor this embedded Exif cropping info when processing. However, in other RAW developing software you can configure whether they honor the embedded Exif cropping information or not when processing the image.

Is there a hidden setting or module parameter that I have missed that would allow the Exif cropping info to be ignored for some photos?

2

Welcome! Unfortunately not, but we do have a similar GitHub issue about it AFAIR… I guess it should be looked at in more detail.

1 Like
3

Thanks for the reply and the link.

Yes - that seems to be the exact same situation for what appears to be for the exact same series of camera.

I’ll create a github user and add a @me-too to the github thread.

At least now - I know that I have not missed a config/parameter somewhere and the issue and the fix I found (rewriting Exif to remove the Crop info) is what others also have to do.

4

You can bypass it. Black/white point module pass through or in the config file for darktable.

5

Sure you can. But that leaves out correct white & black points

6

And double click on black 1-3 and white to reset them.
But easiest to enable the border tool in Black/White point module. The same topic was discussed here at pixls.us

Edit: Found it How to learn image dimensions in Darktable?

And the right post How to learn image dimensions in Darktable? - #27 by apostel338

7

Sure, not comfortable at all.

I think we should to do the same as we have for dng crop information. Keep sensor size intact for rawprepare but add a cropping hint for the crop module.

Don’t know how this can be done via libraw though atm.

1 Like
8

Exactly, it looks like we crop too early in LibRaw and this cannot be bypassed. Someone needs to try out other API options in debug, I won’t be able to do it for a while…

9

A short look, the current code looks ok but we might want to take iwidth and use the crops as a hint.

THAT would be a nice thing to do for someone wanting to enter the darktable’s dev world.

Would certainly assist…