A block noise removal device calculates a block boundary correction value which indicates a correction amount for a pixel sample value immediately before a block boundary position and a correction amount for a pixel sample value immediately after the block boundary position for each block boundary position in a pixel sample value sequence. The block noise removal device obtains the block boundary correction value based on at least two consecutive pixel sample values immediately before the block boundary position and at least two consecutive pixel sample values immediately after the block boundary position. The block noise removal device generates a block noise correction signal representing a correction amount for the pixel sample values corresponding to respective pixels in the pixel block by performing interpolation computations based on the block boundary correction value found for each two adjacent block boundary positions.