If you use convert
, you can specify the parameter >
to only shrink bigger images, leaving the other untouched (the \ is required, or the magic char > is not escaped):
convert large_image.png -resize 1248x1024\> large_image.png convert not_large_image.png -resize 1248x1024\> not_large_image.png
It will only change the bigger images.
[ETA] convert
is part of ImageMagick.