1. An image processing apparatus comprising: an image interface which acquires photographed images, with photography ranges thereof being gradually changed in at least one dimension; and a processor configured to: perform a raster scan of the photographed images, specify a commodity and a position of the commodity based on the raster scan of each of the photographed images, generate a commodity map from the photographed images, based on the specified commodity and commodity position, and generate a commodity inspection map representing differences between the commodity and commodity position shown in the commodity map and those shown in commodity layout plan information representing a commodity layout plan, wherein: the differences are indicated in the commodity inspection map by a message or a pattern, and the commodity inspection map indicates: that a first commodity not indicated by the commodity layout plan information is located in the commodity map, that a second commodity in the commodity map is located where the commodity layout plan information indicates no commodity should be located, and that a third commodity is located where the commodity layout plan information indicates a fourth commodity should be located.