STORAGE AND RETRIEVAL OF LARGE DIGITAL IMAGES

摘要

Image compression and viewing are implemented. A DWT-based compression method uses a two-level memory computer. The viewing method selects image areas in compressed form at multiple resolutions. For compression, a plurality of discrete tile image subsets (118) is defined which form the complete image. Seamless wavelet-based image compression occurs by inputting the tiles in a selected sequence to a DWT (120) routine. The resulting DWT coefficients are stored in a first primary memory and periodically are compressed (128) and stored in a secondary memory (124). The sequence of DWT operations on the tiles effectively calculates a seamless DWT of the image. Data retrieval occurs by specifying a resolution and a region of the image for display (146). The subset of stored DWT coefficients corresponding to each requested scene is determined and then decompressed for input to an inverse DWT (164) to form the display (166). Interaction (168) may occur with a pointing device on previous retrieved displays.