Save performance and standardise rendering by converting files on upload to a single format #30
Description
The plugin currently allows JPG and PNG (in the past also GIF) for backgroundimages. They have to be handled differently at some points. Unifying the internally used format by converting new uploads to a single format the spot (and maybe converting existing images during an update routine) makes the code simpler and increases performance. Also more formats might be supported as upload, as long as they can be converted fo the internally used format.