Bulk Picture Merge Program

I am looking for a simple bulk picture merge program. Currently we use a program called "Picture Merge Genius" to do this manually. I need a program to do this in bulk. What we do is take an existing .jpg file of various sizes and merge it with a blank white background file of a fixed size such as 600 X 800. I do not need to do any sizing or editing on the existing .jpg file only select them from a folder in bulk preferably by selecting the files by highlihting. Output file would need to retain the same name as the existing .jpg file. We use Windows XP Thank you for looking Craig ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform Windows XP