When it is estimated that first average brightness of image information of a projection image is under second average brightness of image information of a source image having a single spatial frequency on which a normal compensation is performed, an area having brightness above the second average brightness...http://www.google.co.uk/patents/US7872217?utm_source=gb-gplus-sharePatent US7872217 - Apparatus and method for projection image having an image processing device with a replica image information generating unit
