[digiKam-users] How to keep my Color space info throughout my workflow

[Gerhard Hoogterp]

Hi,

Some time ago I noticed that at the end of my photoprocessing workflow I lost 
my color space and I'm trying to find out how I can avoid this.

First, my Sony A65 is set to AdobeRBG, the rawfile has this reflected in its 
exif as: Color space: uncalibrated, Interoperability: R03. According to the 
Exif specs this is correct. 

My general workflow is: Gimp which loads Darktable for the RAW conversion, 
then save and export to jpg. Digikam then handles the tags/metadata and using 
the batch too the resizing for the web.

First Darktable, which sees raw pixels and as such doesn't really know about 
colorspaces. I have set it up in such a way that all the RAW images from the 
SLT-A65 get an output profile AdobeRGB. 

When I export from Darktable to TIFF, this is also what I see in the Digikam 
metadata panel (Color space: uncalibrated, Interoperability: R03). All's ok 
till here.

When I use the digikam batch tool to resize the image using one of the two 
workflows I created which are 100% the same besides one of the explicitly 
converts the image to adobeRBG, the result is Color space: Unavailable, 
Interoperability: R03. This is not ok. Afaik as I understand the 
interoperability is only used when the color space is uncalibrated. So this is 
not ok.

To be complete, gimp, loading the image after delegating the raw conversion 
just says the image is a normal sRGB. Explicitly converting it back to 
AdobeRBG and exporting it to JPG leaves me with a color space uncalibrated and 
the Interoperability: unavailable. This can be very well due to the lack of 
this info in the exr file used between darktable and gimp. Saving the same 
image from Darktable to an exr file and trying to extract exifinfo with the 
exiftool does show a lot, but no color space info afaik.

So, basically whatever I use, I end up with an jpeg with an incomplete 
colorspace setting. 

Anybody who can shine a light on this or has ideas on how to massage the big 
three (Darktable, gimp and digikam) in leaving my exif as it is?


Gerhard




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