An image processing apparatus according to an embodiment includes a disparity-specific cost value calculation circuit configured to calculate the cost value of a disparity calculation target pixel in a source image and the cost value of cost value calculation target pixels at respective positions, in the horizontal direction, of pixels arranged from a position of the disparity calculation target pixel in a reference image up to a position by a maximum disparity apart from the disparity calculation target pixel at respective positions in the horizontal direction, an inter-line minimum cost value extraction circuit configured to extract a minimum cost value from a plurality of pixels which have the same positions in the horizontal direction as the positions of the cost value calculation target pixels, and a cost optimization operation circuit configured to perform a cost optimization operation through global optimization using the cost value corresponding to one line.