Patent US 6,487,315

Apparatus for decoding, block by block, image block of N×N pixels, in coded image signal form obtained by successfully coding pixel values of plural peripheral pixels in the vicinity of a coding target pixel, the apparatus including a device for replacing a pixel value of an undecoded pixel among three lines of nearby peripheral pixels with a pseudo pixel value obtained from a decoded peripheral pixel located closest to and on the same line as the uncoded pixel; a prediction value generator for generating a prediction pixel value for the target pixel from the value of the decoded pixel and the replacement pixel value of the undecoded pixel; a decoder for (a) receiving the coded image signal, (b) performing a decoding process using the pixel values of at least one decoded pixel in each of a previously decoded block, the decoding target block, and a pseudo pixel value of an undecoded pixel, and (c) outputting a decoded image signal for each block; and an inverse blocking unit for combining decoded image signals corresponding to the blocks.