Source : Free On-Line Dictionary of Computing

image recognition
     
         The identification of
        objects in an {image}.  This process would probably start with
        {image processing} techniques such as {noise removal},
        followed by (low-level) {feature extraction} to locate lines,
        regions and possibly areas with certain textures.
     
        The clever bit is to interpret collections of these shapes as
        single objects, e.g. cars on a road, boxes on a conveyor belt
        or cancerous cells on a microscope slide.  One reason this is
        an {AI} problem is that an object can appear very different
        when viewed from different angles or under different lighting.
        Another problem is deciding what features belong to what
        object and which are background or shadows etc.  The human
        visual system performs these tasks mostly unconsciously but a
        computer requires skillful programming and lots of processing
        power to approach human performance.
     
        (1997-07-20)