Batch resize images into new folder using ImageMagick

image bash imagemagick filesize
tekknolagi picture tekknolagi · Jan 3, 2012 · Viewed 33.1k times · Source

I have a folder of images over 4MB - let's call this folder dsc_big/. I'd like to use convert -define jpeg:extent=2MB to convert them to under 2MB and copy dsc_big/* to a folder dsc_small/ that already exists.

I tried convert dsc_big/* -define jpeg:extent=2MB dsc_small/ but that produces images called -0, -1, and so on.

What do I do?

Answer

Eduardo Ivanec picture Eduardo Ivanec · Jan 3, 2012

convert is designed to handle a single input file as far as I can tell, although I have to admit I don't understand the output you're getting. mogrify is better suited for batch processing in the following style:

mogrify -path ../dsc_small -define jpeg:extent=2MB dsc_big/*

But honestly I consider it dangerous for general usage (it'll overwrite the original images if you forget that -path) so I always use convert coupled with a for loop for this:

for file in dsc_big/*; do convert $file -define jpeg:extent=2MB dsc_small/`basename $file`; done

The basename call isn't necessary if you're processing files in the current directory.

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