An image processing apparatus includes a contour pixel extraction unit configured to extract a contour pixel component from a bit plane. The bit plane is a set of bits, the number of which is equal to the number of pixels, and each of which is 1 bit of a plurality of bits representing an intensity of each of pixels. Also provided is a connectedness detection unit configured to detect equivalent bits adjacent to each other in a window including a bit corresponding to a target pixel on the bit plane. Also provided is a filter unit configured to reduce an intensity of the target pixel by a reduction amount determined in accordance with the contour pixel component extracted by the contour pixel extraction unit and the equivalent bits adjacent to each other detected by the connectedness detection unit.