Patent ID: 6546138
Filing Date: 2003-04-08
Classification: G06T,H04N

Abstract:
A computer system for encoding pictures, comprising:a first resolution converter configured to reduce an alpha-map signal to control an amount of generated codes of the alpha-map signal by changing a resolution conversion according to a reduction ratio setting information signal, the alpha map signal indicating information for discriminating a picture between an object region and a background region; an alpha-map encoder configured to encode a reduced alpha-map signal output from said first resolution converter and the reduction ratio setting information signal to output coded alpha-map data and coded reduction ratio setting information data; a second resolution converter configured to enlarge the reduced alpha-map signal at an enlargement ratio to return the reduced alpha-map signal to an original size and output an enlarged alpha-map signal; a multiplexer which multiplexes the coded alpha-map data and the coded reduction ratio setting information data; and a video encoder configured to encode, in accordance with the enlarged alpha-map signal, a picture corresponding to the enlarged alpha-map signal.