sips

Apple Scriptable Image Processing System. Raster/Query images and ColorSync ICC Profiles. More information: https://keith.github.io/xcode-man-pages/sips.1.html.

• Specify an output directory so that originals do not get modified:

sips --out path/to/out_dir

• Resample image at specified size, Image aspect ratio may be altered:

sips --resampleHeightWidth 1920 300 image_file.ext

• Resample image so height and width aren't greater than specified size (notice the capital Z):

sips --resampleHeightWidthMax 1920 300 image_file.ext

• Resample all images in a directory to fit a width of 960px (honoring aspect ratio):

sips --resampleWidth 960 path/to/images

• Convert an image from CMYK to RGB:

sips --matchTo "/System/Library/ColorSync/Profiles/Generic RGB Profile.icc" path/to/image.ext path/to/out_dir

• Remove ColorSync ICC profile from an image:

sips --deleteProperty profile --deleteColorManagementProperties path/to/image_file.ext