GIMP Canon G12 Invalid MyColors data

Started by mmuehler, May 24, 2019, 12:47:34 AM

Previous topic - Next topic

mmuehler

I do get some error message when using exiftool and can't really figure out how to fix it.

I use a Canon G12. After taking photos I do lens corrected them in GIMP for Linux using lensfun filter . After that I set back date using

$ls
'woods original Canon G12.jpg'
'woods saved with GIMP Canon G12.jpg'

$exiftool -r '-DateTimeOriginal>FileModifyDate' .

Warning: Invalid MyColors data - ./woods saved with GIMP Canon G12.jpg
    1 directories scanned
    2 image files updated

I can reproduce the error indepent of using lensfun or not. I can also change the saving parameters for the jpg like IPTC, compression etc. Doesn't change anything. Get still the error.

I tried to find a solution to fix this problem but I do reach my limit of understanding. Could someone help me?

Interstingly, I had once borrowed a Lumix G3 and I cannot reproduce the error with this camera. Although, To me iT seems that GIMP causes the error?

I did add the original photo and the one saved in GIMP (see file name)

Thanks

StarGeek

If you run
exiftool -g1 -a -s -U -Canon:all
on both the files, you'll see that the Original has a lot of unknown Canon MakerNotes tags (Canon_FaceDetect3_0xHHHH, Canon_MyColors_0xHHHH, Canon_CameraInfoPowerShot2_0xHHHH, where HHHH is a hex code) that have been stripped away from the GIMP version.

You don't have the same problem with the Lumix files because the Canon MakerNotes don't exist there in the first place.

I have no idea what the lost tags do, but they most likely would only be read properly by Canon software.  You can try copying the MakerNotes back into the GIMP version with (see FAQ 8)
exiftool -tagsfromfile src.jpg -makernotes -make -model dst.jpg
* Did you read FAQ #3 and use the command listed there?
* Please use the Code button for exiftool code/output.
 
* Please include your OS, Exiftool version, and type of file you're processing (MP4, JPG, etc).

mmuehler

Thank you very much for the straight forward answer. Could fix it with your instructions! :-) Do have to change a little my workflow.