An image processing apparatus, including: an averaging processing section to periodically carry out an averaging processing on image data of an averaging target, the averaging processing calculating an average value of pixel values of pixels which correspond to a position of a one-dimensional or two-dimensional averaging pattern designating averaging target pixels and replacing each pixel value of the pixels which correspond to the position of the averaging pattern with the average value; and a screen processing section to, by using a screen pattern, periodically carry out a screen processing on the image data on which the averaging processing has been carried out, a periodicity of the screen processing is same as that of the averaging processing.