How to I batch convert .CR2 (raw) photos to JPEG?

Asklemmy@lemmy.ml – 23 points – 1 years ago

Issue - I have 282 .CR2(raw) photos that need to be converted in batch/mass to same time but don't know how. OS - Vanilla OS 22.10 (Ubuntu)

Can this be done with darktable? If so how?
Any software recommendations for this? I rather not use online tools for privacy and compression reasons.

With GNU Parallel and Imagemagick installed, this command should do it:

parallel convert {} {.}.jpg ::: *.cr2

As always, backup your files before you run things some internet rando gave you.

Check out mogrify. I think it's installed standard with ImageMagick, and it does wildcard conversions.

Can mogrify do format conversion? I thought it was for editing images. It doesn't even seem to have a way to specify input and output filenames.

Yes. I've used it to batch convert PNG and jpg to webp.

Thank you for this! I will test it out

Do you have an example?

I'm not sure what you're asking for. That's the command. Unless you meant an explanation?

The basic command is convert filename.cr2 filename.jpg.

That parallel command runs the convert command on all of the .cr2 files in the current directory, running a bunch of them simultaneously. {} is replaced with the name of a file, and {.} is replaced with the filename without the extension.

https://www.gnu.org/software/parallel/parallel_examples.html

If you didn't want to use parallel and are okay with it slowly converting one file at a time, you can just use a for loop:

for file in *.cr2 ; do
  convert $file ${file%.cr2}.jpg
done

That one uses some Bash variable magic to remove the .cr2 and add .jpg to the file name of the output file.

convert is smart enough that you can just give it an output name ending in .jpg and it knows it should convert the input file to JPEG.

Example? They gave you the exact thing to run.

Your best bet would be imagemagick in command-line

https://blog.nathantsoi.com/article/Batch_Convert_CR2_to_JPG/

Since you mentioned darktable I assume you already know this, but depending on the camera's raws and the presets that imagemagick has for converting these photos the results might be undesirable if not inspected or tweaked. Not disparaging any advice given here, just mentioning that generally raws are edited on a case by case basis to fix camera artifacts and color issues. Hope the solutions others have posted work out for you!