The image processing apparatus of the present invention includes: an edge determination unit configured to detect an edge pixel to which a white pixel and a black pixel are adjacent in a first direction in an image in which each pixel is represented as a white pixel or a black pixel; a first detection unit configured to detect a number of consecutive pixels up to the edge pixel in the first direction in the image; a second detection unit configured to detect a number of consecutive pixels whose number of consecutive pixels in the first direction is larger than a first threshold in a second direction perpendicular to the first direction in the image; and a type determination unit configured to determine a type of the edge pixel based on detection results by the first detection unit and detection results by the second detection unit.