Apart from their great image features the people at Magic Toolbox also offer an image serving utility which I've had the chance to test out.

I used it on the premium css layouts from our demo store, like here http://www.ectdemostore.com/blue-jeans-straight.asp - the speed / quality results are pretty impressive but all I've done there is pull the images from their server with no effects added. Have a look here for the full list of options https://sirv.com/help/resources/dynamic-imaging/ including a very interesting section on text overlays https://sirv.com/help/resources/dynamic-imaging/#Text_overlays

I have written a summary and added it along with a video to our Magic Toolbox page https://www.ecommercetemplates.com/help/magictoolbox.asp#sirv

Andy

Please feel free to review / rate our software

Very interesting features.
Pricing is reasonable too.

David
ECT Power User