Patent ID: 6674910
Filing Date: 2004-01-06
Classification: H04N

Abstract:
An image compression-encoding apparatus for performing an orthogonal transform for blocks of an input image signal in accordance with an adaptive transform method, thereby compressing the input image signal blocks, comprising:transform mode control means for generating a transform direction control signal to perform an orthogonal transform after said transform mode control means selectively receives transform coefficients, obtained after an orthogonal transform for blocks of an input image signal, and an image signal block to be currently encoded, determining correlations of the input values in horizontal and vertical directions, and generating a transform direction control signal based on the determined correlations, the transform direction control signal being adapted to control an orthogonal transform for the current image signal block in such a fashion that the current image signal block is orthogonal-transformed in a direction involving a higher correlation, and then in a inverse direction; and orthogonal transform means for receiving the transform direction control signal from the transform mode control means, and performing an orthogonal transform based on the received transform direction control signal.