PDF Compression (ie: Reduce File Size) Function

I need a function that will reduce the file size of a PDF while still keeping as much of the quality as possible. The deliverable will be a C# function and a sample .NET c# application that uses the function as a test platform.? The function should pass in the path and name? to the PDF file and the path and name of the output file. A sample 140MB PDF file can be downloaded? here: <[login to view URL]> Other samples are availble if needed. ? The goal would be to reduce the filesize by around 50% although I'm not entirely sure if that is fully possible or not while still keeping a decent quality so I'll be looking for some expertise on what is possible with the sample file. Ultimately these files will end up on a Kindle type device and as such the final output should look decent on a 150ppi screen with 16 shades of gray. Possibly just reducing the dimensions of the PDF might help with file size.? Other ideas include playing with the grayscale or ppi settings, etc. ## Deliverables Make sure any PDF library that is used is a freeware or something like iTextSharp.