Video encoding and decoding apparatus

摘要

A video encoding apparatus characterized by comprising:
an orthogonal transform circuit for dividing an input video signal into a plurality of blocks each containing N x N pixels and orthogonally transforming an arbitrary-shape picture in units of blocks to obtain a plurality of transform coefficients;
means for encoding and outputting an alpha-map signal for discriminating a background of a picture from an object thereof;
means for calculating an average value of pixel values of an object portion using the alpha-map signal in units of blocks;
means for assigning the average value to a background portion of the block;
means for deciding using the alpha-map signal whether a pixel in the object is close to the background;
means for compressing the amplitude of the object picture 2007 around the average value (2012) to obtain a compressed picture (2014); and
means for orthogonally transforming each block to output an orthogonal transform coefficient.