A method and apparatus for embedding information in an image during
relative movement between a print medium and an ink jet print head is
provided. A plurality of first lines are printed and a plurality of
second lines are printed. Each of the first lines includes a plurality of
first dots and a plurality of second dots offset from the first dots by a
first amount, and each of the second lines includes a plurality of third
dots and a plurality of fourth dots offset from the third dots by a
second amount different than the first amount. The information is encoded
in the image using an encoding scheme in which the first lines represent
a first value in the encoding scheme and the second lines represent a
second value in the encoding scheme.