This is a now mostly obsolete image reader and writer based on the ImageMagick library. It works but you should consider other options.
For reading images another source filter, for example BestSource is recommended. It's FFmpeg based and can handle most image formats as well.
Writing is a bit of a misfeature even and simply output using vspipe into FFmpeg or your favorite tool.
Note that the plugin still has a few niche uses and works. It just isn't being actively developed ever again.