Digital image processing, such as compression, transmission, browsing and communications is common in the art. Typically early methods of digital image transmission and storage used so-called Pulse Code Modulation (PCM). More recent systems use more complicated digital compression techniques.
Digital compression techniques according to the state of the art are based on transform coding. One such compression technique is the JPEG format as standardized by the Joint Photographic Experts Group according to the standards ITU-T T.81, ISO/IEC IS 10918-land ITU-T T.84, see inter alia “The JPEG Handbook”, by W. Pennebaker, J. Mitchell, Van Nostrand Reinhold, 1993.
It is also common to post-process compressed images. Post-processing may involve applying filters, changing the image format, etc. Post-processing may also involve scaling the compressed image to fit a small screen, and then zooming and panning the scaled image. One product for post-processing compressed images is the PhotoShop software suite provided by Adobe Systems Incorporated of USA.