An image decoding apparatus is provided that decodes a coded image, the coded image being generated by coding an image segmented into a plurality of blocks on a block basis. The image decoding apparatus includes a quantization parameter obtaining unit that obtains a quantization parameter for each block of the plurality of blocks, a decoding unit that decodes the coded image to obtain a reconstructed image, and a pixel difference value obtaining unit that obtains a pixel difference value. The image decoding apparatus also includes a comparing unit that compares the pixel difference value with a threshold value, and a removing unit that removes a coding distortion in an area disposed on both sides of a block boundary between the first block and the second block, by applying a filter for coding distortion removal.