How to use ImageMagick through Omeka

Hi,

I was wondering how to use ImageMagick through Omeka so that each time an image is uploaded, it will be automatically compressed to a certain file size. I'm also trying to figure out how to even access ImageMagick on Omeka.

Thanks,
QCDA

Omeka automatically uses ImageMagick to create thumbnails when images are uploaded, but Omeka does not have a setting for specifying "a certain file size" for compression.