Patent ID: 6122318
Filing Date: 2000-09-19
Classification: H04N

Abstract:
An alpha-map encoding apparatus comprising:a first down-sampling circuit configured to down sample an alpha-map signal, which represents a shape of an object and a position in a frame of the object, at a down-sampling ratio based on size conversion ratio information;an up-sampling circuit configured to up sample the alpha-map signal at an up-sampling ratio based on size conversion ratio information given to restore the alpha-map signal down-sampled by said first down-sampling circuit to an original size, and outputting a local decoded alpha-map signal;a motion compensation circuit configured to generate a motion compensation signal on the basis of a previous decoded video signal and a motion vector signal;a second down-sampling circuit configured to down sample the motion compensation signal at the down-sampling ratio;a binary image encoder configured to encode the alpha-map signal down-sampled by said first down-sampling circuit to a binary image in accordance with the motion compensation signal down-sampled by said second down-sampling circuit, and outputting an encoded binary image signal; anda multiplexer configured to multiplex and output the encoded binary image signal and the size conversion ratio information.