Semi-OT: How to thumbnails

Software darktable
1

I need to make thumbnails for a couple of hundred images. They must end being 200x200 and PNG.

My problem is that the images are not square, but mostly either 5x7 or 6x7.

  1. I’m sure that I’m not the only person that has to that, what’s your strategy?
  2. In DT is there a way to automatically crop an already output as 1:1 from the center?
  3. Or what about imagemagick?

Thanks

2

I’d use imagemagick “mogriphy” tool
It can do bulk resize or crop in a one liner
https://codeyarns.com/tech/2014-11-15-how-to-crop-image-using-imagemagick.html#gsc.tab=0
for the crop or the mogriphy -thumbnail xxx ./* for the resize

If I understood your expectations correctly, I think it will be faster and more efficient than using darktable (like calling Michelangelo to apply corrosion protection on the golden gate bridge or the reverse, calling an building painter to copy a master work… )

3

I think (?) XnView MP can did this as a batch operation. Not at my computer at the moment to check, but it seems likely.

4

One of the 2 I think is fine
https://imagemagick.org/Usage/thumbnails/
https://patdavid.net/2013/04/using-imagemagick-to-create-contact/

5

Thanks, I’ll go though imagemagick.