US Patent 7123385 Image processing apparatus

The image processing apparatus comprises a reading unit which simultaneously reads image data from two, an obverse and a reverse, surfaces of a document, and a compressing unit which compresses received image data. The apparatus further comprises a controlling unit which orchestrates a flow of image data from the reading unit to the compressing unit in such a manner that the image data corresponding to the obverse surface and the reverse surface is input into the compressing unit at different timing.