A machine readable code, a code encoding method and device and a code decoding
method and device are provided. This machine readable code includes a data area
made up of at least one data cell, in which different colors or shades are encoded
and expressed depending on the content of the information, and a parity area made
up of at least one parity cell, the parity area provided to determine whether colors
or shades expressed in the data cells have been properly expressed depending on
the content of the information. Since this code image includes a parity area for
parity inspection, mal-recognition of colors due to differences between input devices
such as cameras or between the environments such as light can be easily detected
and corrected.