The magick utility can process, join, and convert images from one format to another. For a list of options, type magick convert -h in a shell window.
In previous versions of Maya, this was the imconvert utility. The name of the utility changed when the supported version updated to 7.0.10 on Linux and Windows.
See https://imagemagick.org/script/convert.php for conversion documentation
This utility is only available for Windows and Linux platforms.