Decoder having adaptive function of eliminating block effect

摘要

A decoder having an adaptive function of eliminating block effect in consideration of the contents of an image includes a buffer for storing a compressed signal coming at a fixed bit rate; a variable length decoder (VLD) for variable length decoding an output signal of the buffer to thereby output a motion vector signal and a quantized signal of spatial frequency; an 8*8 reverse quantizer for reversely quantizing the quantized signal of spatial frequency; a block effect deciding portion for determining whether there is a need for spatial frequency presumption or not; a border detector for deciding the border of object in a spatial frequency area; an adaptive low spatial frequency predictor for adaptively presuming the spatial frequency component, whether the current block is present at the border of object; an 8*8 reverse DCT transformer for converting a spatial frequency signal into a signal of pixel area; a motion compensator for compensating for motion using a motion vector signal; and a frame memory for storing the signal of pixel area output from the reverse DCT transformer.