This invention proposes to transcode the compressed image, that may be in the JPEG format for example, to an intermediate format that allows pseudo-random access. Such a pseudo-random access would that allow efficient image transformation. By using this format, in most cases a pixel is decoded only once...http://www.google.de/patents/US20020118390?utm_source=gb-gplus-sharePatent US20020118390 - Transcoding scheme for assistance in image transformations
