ImageMagick is a free and open-source software suite for displaying, converting, and editing raster image and vector image files. It can read and write over 200 image file formats.

docker run --rm -v `pwd`:/app -w /app minidocks/imagemagick \
    https://www.ece.rice.edu/~wakin/images/lena512color.tiff -resize 256x256\> -colorspace Gray lenna.png

Tag	Size
latest, 7