sips

Apple Scriptable Image Processing System. Raster/Query images and ColorSync ICC Profiles. More information: https://ss64.com/osx/sips.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}}