An identification document is provided comprising a printable layer, a
computer readable data storage element, and a computer readable
calibration element. The computer readable data storage element is formed
on the printable layer and comprises a plurality of pixels, wherein each
pixel has one of a predetermined plurality of colors. The computer
readable calibration element is formed on the printable layer and
comprises a plurality of pixels and includes information enabling a
determination of the pixel size in the computer readable data storage
element and also a determination of at least a portion of the
predetermined plurality of colors.