An image processing method includes: calculating a rotation matrix to eliminate vertical parallax by converting stereo image captured by stereo camera as if it is image captured by camera rotated about an origin of camera coordinate system, wherein the stereo image includes left image obtained by left camera and right image obtained by right camera; calculating a rotation matrix to adjust the horizontal parallax of the left image and a rotation matrix to adjust the horizontal parallax of the right image; calculating a geometric transformation matrix for the stereo image based on each camera characteristic matrix representing lens characteristics, the rotation matrix for eliminating vertical parallax, and the rotation matrices for adjusting horizontal parallax; and generating new stereo image in which vertical parallax is eliminated and horizontal parallax is adjusted by performing image warping for the stereo image captured by the stereo camera based on the calculated geometric transformation matrix.