Image processing apparatus

An image processing apparatus, comprising:

• an edge detector configured to detect outlines extending from lower left toward upper right with respect to objects located on left side of a vehicle, and detects outlines extending from lower right toward upper left with respect to objects located on right side of the vehicle, on a basis of a luminance value of an image out of a pair of images, the pair of images being images in a traveling direction of a vehicle captured by a stereo camera;
• and
• a sidewall information calculator configured to recognize, on a basis of three-dimensional positional information of the objects having the outlines detected by the edge detector, whichever of the objects having the outlines detected by the edge detector is located at a predetermined height or greater from a road surface and has a predetermined length or greater in a front-rear direction of the vehicle, as a sidewall,
• wherein the pair of images include a reference image and a comparative image,
• wherein the edge detector detects the outlines extending from the lower left toward the upper right on a basis of an edge detection process based on a differential value of the luminance value along a horizontal line and a right-down line in a left half region of the reference image, the right-down line being a line that is (1) unparallel with the horizontal line and (2) inclined clockwise by an acute angle from the horizontal line, and
• wherein the edge detector detects the outlines extending from the lower right toward the upper left on a basis of an edge detection process based on the differential value of the luminance value along the horizontal line and a left-down line in a right half region of the reference image, the left-down line being a line that is (1) unparallel with the horizontal line and (2) inclined counter-clockwise by an acute angle from the horizontal line.