1. An image processing apparatus comprising: a decimated image generator for generating a decimated image through pixel decimation from an input image; an edge pixel extractor for extracting edge pixels from said decimated image; an edge class extractor for extracting an isolated edge pixel from among said edge pixels; a histogram generator for generating an isolated histogram from only said isolated edge pixel; and a decision unit for making, based on said isolated histogram, a decision as to whether or not said input image contains a background element.