A stereo image processing apparatus comprising: an image matching section that performs image matching on a target image and a reference image so as to obtain a corresponding point in the reference image corresponding to a target point in the target image; an image clipping section that extracts, from the target image, first two-dimensional pixel data having a plurality of pixel rows and a plurality of pixel columns and including the target point, and extracts, from the reference image, second two-dimensional pixel data having a plurality of pixel rows and a plurality of pixel columns and including the corresponding point; an image reconstructing section that reconstructs columnwise, based on a predetermined reconstruction rule, the first two-dimensional pixel data and the second two-dimensional pixel data to first one-dimensional pixel data and second one-dimensional pixel data, respectively; an anti-aliasing section that removes a folding noise, generated due to the reconstruction, from the first one-dimensional pixel data and the second one-dimensional pixel data; and a filter generating section that calculates an inverted phase filtering coefficient by inverting, in a direction in which pixels are arranged, a position of each pixel value in the first one-dimensional pixel data with the noise removed, and filters the second one-dimensional pixel data with the noise removed using the inverted phase filtering coefficient; and a peak position detecting section that calculates a disparity based on a correlation between the first one-dimensional pixel data with the noise removed and the filtered second one-dimensional pixel data with the noise removed. an image matching section that performs image matching on a target image and a reference image so as to obtain a corresponding point in the reference image corresponding to a target point in the target image; an image clipping section that extracts, from the target image, first two-dimensional pixel data having a plurality of pixel rows and a plurality of pixel columns and including the target point, and extracts, from the reference image, second two-dimensional pixel data having a plurality of pixel rows and a plurality of pixel columns and including the corresponding point; an image reconstructing section that reconstructs columnwise, based on a predetermined reconstruction rule, the first two-dimensional pixel data and the second two-dimensional pixel data to first one-dimensional pixel data and second one-dimensional pixel data, respectively; an anti-aliasing section that removes a folding noise, generated due to the reconstruction, from the first one-dimensional pixel data and the second one-dimensional pixel data; and a filter generating section that calculates an inverted phase filtering coefficient by inverting, in a direction in which pixels are arranged, a position of each pixel value in the first one-dimensional pixel data with the noise removed, and filters the second one-dimensional pixel data with the noise removed using the inverted phase filtering coefficient; and a peak position detecting section that calculates a disparity based on a correlation between the first one-dimensional pixel data with the noise removed and the filtered second one-dimensional pixel data with the noise removed.