DISCRETE WAVELET TRANSFORM APPARATUS AND METHOD CAPABLE OF ADAPTIVELY ENCODING A STILL IMAGE BASED ON ENERGY BY EACH BLOCK TO REDUCE CALCULATION QUANTITY AND PROCESS TIME

摘要

PURPOSE: Discrete wavelet transform apparatus and method capable of adaptively encoding a still image based on energy by each block are provided to reduce calculation quantity and process time in encoding and decoding all image coefficients that form a tile of an image. CONSTITUTION: An energy calculation part(200) calculates energy by each block comprised of predetermined pixels of an inputted image. An image decomposition part(300) decomposes an area of the block in which low-frequency components are distributed by three times so as to process three-level decomposition. A coefficient substitution part(400) substitutes zero for one of decomposed areas in which high-frequency components are distributed and thereby reconstructs the image.