A stereo image processing device comprising: a pair of imaging units (101a, 101b); a similarity calculation unit configured to receive a pair of images captured with the pair of imaging units (101a, 101b) and calculate similarity for each parallax of the pair of images; a parallax calculation unit configured to calculate parallax for an identical object on the basis of the similarity for each parallax; a parallax data buffer unit configured to store data on the parallax calculated with the parallax calculation unit; a speed detection unit configured to detect a moving speed of the pair of imaging units (101a, 101b); and a parallax prediction unit configured to calculate a predicted parallax value (dfo) on the basis of the moving speed and past data on parallax stored in the parallax data buffer unit and to calculate a predicted variation (ed) of the predicted parallax value (dfo), wherein the parallax calculation unit is configured to calculate parallax for an identical object on the basis of the similarity for each parallax and the predicted parallax value (dfo), wherein the pair of imaging units (101a, 101b) are mounted on a vehicle, and the speed detection unit is configured to detect a traveling speed of the vehicle as the moving speed, wherein the parallax calculation unit is configured to weight the similarity for each parallax on the basis of the predicted parallax value (dfo), and when an absolute value of a difference between the parallax calculated with the parallax calculation unit and the predicted parallax value (dfo) exceeds the predicted variation (ed), to perform correction by lowering a weight assigned to the similarity corresponding to the parallax having a deviation exceeding the predicted variation (ed) relative to the predicted parallax value (dfo), and wherein the parallax calculation unit is configured to determine parallax corresponding to the highest weighted similarity as parallax for an identical object contained in the images. a pair of imaging units (101a, 101b); a similarity calculation unit configured to receive a pair of images captured with the pair of imaging units (101a, 101b) and calculate similarity for each parallax of the pair of images; a parallax calculation unit configured to calculate parallax for an identical object on the basis of the similarity for each parallax; a parallax data buffer unit configured to store data on the parallax calculated with the parallax calculation unit; a speed detection unit configured to detect a moving speed of the pair of imaging units (101a, 101b); and a parallax prediction unit configured to calculate a predicted parallax value (dfo) on the basis of the moving speed and past data on parallax stored in the parallax data buffer unit and to calculate a predicted variation (ed) of the predicted parallax value (dfo), wherein the parallax calculation unit is configured to calculate parallax for an identical object on the basis of the similarity for each parallax and the predicted parallax value (dfo), wherein the pair of imaging units (101a, 101b) are mounted on a vehicle, and the speed detection unit is configured to detect a traveling speed of the vehicle as the moving speed, wherein the parallax calculation unit is configured to weight the similarity for each parallax on the basis of the predicted parallax value (dfo), and when an absolute value of a difference between the parallax calculated with the parallax calculation unit and the predicted parallax value (dfo) exceeds the predicted variation (ed), to perform correction by lowering a weight assigned to the similarity corresponding to the parallax having a deviation exceeding the predicted variation (ed) relative to the predicted parallax value (dfo), and wherein the parallax calculation unit is configured to determine parallax corresponding to the highest weighted similarity as parallax for an identical object contained in the images.