How to batch resize all images in a folder (including subfolders)?

Question

I have huge, 12GB, gallery on the server, full of images in various subfolders. Those files are too big and not used in full resolution. I need to resize all the images down to 820px wide (keeping proportions). So my question is - how can I create some kind of crawling script which would resize all images bigger then 820px and save them back overwriting original file?

Hope you can help me :-) Thank you in advance.

find . -name "*.jpg" -exec mogrify -resize 820x {} + will do them all; if you don't want to process the "less than 820px" ones, there are some options here. — don_crissti, Apr 15 '15 at 14:00

score 24 · Answer 1 · edited Dec 27 '20 at 19:26

24

ImageMagick tools convert or mogrify will do the job.

You can get them via your package manager or the source/rpms here.

Basic usage (will overwrite the original file):

$ mogrify -resize 820x ./*.jpg

If you need recursion:

find . -name '*.jpg' -execdir mogrify -resize 820x {} +

edited Dec 27 '20 at 19:26

Stéphane Chazelas

544,893

answered Apr 15 '15 at 14:06

1

I don't think that "820px wide (keeping proportions)" means "resizing to 820x820". It's rather more like "820px wide and whatever-the-proportion-is high" ;) Plus this does not handle recursiveness. – Erathiel Apr 15 '15 at 15:42
1

Good point. Edited! – Apr 15 '15 at 19:22
2

If you want to make it so that it only resizes if they are larger than set dimensions and still keep the ratios, you can change it to this:
find . -name '*.jpg' -execdir mogrify -resize '820x620>' {} \;
– OpensaurusRex Dec 08 '18 at 22:30
5

Caution: This will overwrite your existing images. – kleo Aug 09 '19 at 21:31
Related: How do I control the compression rate of mogrify? (Super User) – Marc.2377 Nov 29 '19 at 19:37
Where's the convert example? – chovy May 16 '22 at 05:38
To only resize larger files, you can do find . -size +200k -execdir ... (only resize bigger than 200 kb+) – SurpriseDog Mar 10 '23 at 21:36

How to batch resize all images in a folder (including subfolders)?

1 Answers1