An image decoding apparatus includes an entropy decoder, an inverse quantization module, an estimation module, an estimated coefficient value limiting module, and an inverse discrete cosine transformation module. The estimation module performs linear estimation of a correction value of a discrete cosine transformation coefficient to be processed, for an inverse quantization result, based on discrete cosine transformation coefficients in a rectangular area which includes a pixel to be processed and discrete cosine transformation coefficients in an area adjacent to the rectangular area including the pixel to be processed. The estimation coefficient value limiting module limits the correction value such that the correction value estimated by the estimation module falls within a predetermined range based on a quantization step.