convert .xpm images (used in gtk 2 theme) from the base directory of the theme: magick mogrify -path converstion/png -format png xfwm4/*.xpm relevant links: ImageMagick – Command-line Tools: Convert File Handling -- IM v6 Examples Basic Usage -- IM v6 Examples ImageMagick (legacy) – Search ImageMagick – Image Formats XPM: Summary from the Encyclopedia of Graphics File Formats