A GitHub action to edit your images with ImageMagick. With ImageMagick

Use ImageMagick® to create, edit, compose, or convert bitmap images. It can read and write images in a variety of formats (over 200) including PNG, JPEG, GIF, HEIC, TIFF, DPX, EXR, WebP, Postscript, PDF, and SVG. ImageMagick can resize, flip, mirror, rotate, distort, shear and transform images, adjust image colors, apply various special effects, or draw text, lines, polygons, ellipses and Bézier curves.

- name: ImageMagick Action
  uses: routsi/ImageMagick-action@v1
  with:
    # ImageMagick command to be executed
    command: mogrify -path /my-path -auto-orient -resize 800x450 /my-path/*.* # default is mogrify -path src/assets/images -auto-orient -resize x500 src/assets/images*.*

PS: The action may fail if you have "non image" files inside files when you don't specify the file format (i.e. /my-path/*.jpg)

This action uses mogrify at its core. To understand more about the tool and how to define dimensions read this guide on mogrify

Check out a sample of how to use this action