Image slicer software program

Looking for an application to take a large image file and split it up into many smaller images. Inputs: .jpg, .png, .gif files .csv file containing list of x-y coordinates indicating two diagonal corners of each image slice starting index of first output file name. (e.g., [login to view URL]) Outputs: .png files must retain transparency maximum color depth output file names in sequential order from starting index (e.g., [login to view URL], [login to view URL], ...) C# .NET app or PHP server app are preferred. Source code must be provided and well commented. This should be very simple for someone familiar with image manipulation. Will not accept any bids over $50 USD.