[Steven]

I use open-source software called ScanTailor to pre-process my jpegs. There is a learning curve to it, but it gives you full control, including skew and margins. It has an amazing equalization filter which levels the color on the sheet.  I typically output the jpegs to 140dpi color for sheet music. This will allow 250 pages to be rendered into a pdf smaller than 50MB. MobileSheets can be used for rendering the ScanTailor output jpegs into pdfs.