APPARATUS AND METHOD FOR ENCODING AND DECODING COMPRESSED DIGITAL IMAGE USING SHAPE ADAPTIVE SELECTION

摘要

PURPOSE: An apparatus and method for encoding and decoding a compressed digital image using a shape adaptive selection are provided to increase the compression efficiency for an image signal. CONSTITUTION: The apparatus for encoding and decoding a compressed digital image using a shape adaptive selection comprises a mode controller(100,100') for receiving a shape information of an image signal block to be encoded and analyzing a number of pixels in a longitudinal and lateral direction and outputting a mode control signal to firstly perform a transformation process in a direction having more pixels, and an orthogonal transformation portion(200,200') for receiving the mode control signal from the mode controller and performing the transformation process. A method for encoding and decoding the compressed digital image using the shape adaptive selection comprises steps of receiving the shape information of the image signal block to be encoded and comparing the number of pixels at four edges of the image signal block to determine an inverse transformation method and then outputting the mode control signal responding to the inverse transformation method.