Source : WordNet®

bitmap
     n : an image represented as a two dimensional array of
         brightness values for pixels [syn: {electronic image}]

Source : Free On-Line Dictionary of Computing

bitmap
     
         A data file or structure which
        corresponds {bit} for bit with an {image} displayed on a
        screen, probably in the same format as it would be stored in
        the display's {video memory} or maybe as a {device independent
        bitmap}.  A bitmap is characterised by the width and height of
        the image in {pixels} and the number of bits per pixel which
        determines the number of shades of grey or colours it can
        represent.  A bitmap representing a coloured image (a
        "{pixmap}") will usually have pixels with between one and
        eight bits for each of the red, green, and blue components,
        though other colour encodings are also used.  The green
        component sometimes has more bits that the other two to cater
        for the human eye's greater discrimination in this component.
     
        See also {vector graphics}, {image formats}.
     
        (1996-09-21)