An image processing apparatus includes: an acceptance section; an edge detection section; and a screen processing section, wherein the edge detection section includes: a first edge determination section that subjects a pixel of interest to edge determination by reference to information about a density of the pixel of interest and information about densities of pixels around the pixel of interest determined by an edge detection window; and a second edge determination section that compares minimum density information among the information about densities of pixels determined by the edge detection window with a predetermined background threshold value, and that redetermines the pixel of interest, which is determined to belong to an edge portion by the first edge determination section, as belonging to anon-edge portion in cases where the minimum density is equal to or greater than the background threshold value.