How to batch resize and compress images in linux
Table of Contents
‘Convert’ command is a very powerful image manipulation utility which comes preinstalled in almost all Linux distributions (ubuntu,debian,arch and fedora) and it is a part of ImageMagick software suite.
Check if convert command is available on your Linux distro #
convert -version
output:
Version: ImageMagick 6.9.7-4 Q16 x86_64 20170114 http://www.imagemagick.org Copyright: © 1999-2017 ImageMagick Studio LLC
If the above command is not found on your Linux distro you can install it by typing the below command.
Install convert tool on Ubuntu / Debian #
sudo apt-get install imagemagick
Install convert tool on fedora #
sudo dnf install imagemagick
Install convert tool on arch #
sudo pacman -S imagemagick
Note: It’s always good idea take backup of your images before running convert command.
Batch resize and compress images with convert command #
Below command will resize and compress all images ending with .jpg extension in a ‘for loop’ and save the compressed/resized image as ‘filename-Optimized.jpg’.
–quality : this option is used to set the image compression level in percentage
-resize : this option is used to resize the image to a given resolution , You can use -resize option with width ( -resize 1600x ) only or both width and height ( -resize 1600×900), In both cases convert command will automatically adjust the given resolution to get optimum aspect ratio so you don’t have to worry about stretched images.
Note: some jpeg image extensions may end with .JPG (in capital letters) ,Since Linux is case-sensitive you may need to adjust the bash script accordingly.
Open terminal and cd into the directory containing your photos and execute below command
mkdir photos-Optimized;for photos in *.JPG;do convert -verbose "$photos" -quality 85% -resize 1600x900 ./photos-Optimized/"$photos-Optimized.jpg"; done
Voilà! Now you have successfully resized/compressed images, You can see the optimized images in the photos-Optimized directory.