I worked on something for a client who had large JPEG images (well 1200x1600 pixels anyway.) The client wanted thumbnail images generated from the large images. He also wanted "drop shadows" added.

I was using PHP at the time and tried using the GD image libraries . This did work but the client was not happy with the quality of the thumbnails.

Next I tried the ImageMagik command line tools. Still the client was not happy with the thumbnails.

In the end he scripted PhotoShop. I'm not sure what is involved but I think it can record button clicks, etc. I can't tell you how to call a PhotoShop script from Perl but it might be useful to look into it.