Filter by metadata in image store plugin

It is possible to make a filter to display photos based on a filter for metadata in the front-end?

Example: see all the photos that have metadata Credit = 000?

The plugin is: http://ww.wp.xz.cn/plugins/image-store/

I’m not a real expert in php .. does anyone know how and where I can agigungere the code to do the filter?

Thank you,
Gianni

[ No bumping please. ]