The development of this product and features is complete. We are completing QA and then it will be released. It will likely still be a month or so before it is publicly available, but it will accomplish the described result if you aren't too pressed for time.
There is a hand-coded example of this in the power store as well.. basiclly you can use the gd2 library to manipulate the images after they are uploaded, but you would have to do it by hand to integrate into DFP v1.