region may include a consistent rule herein the reference pattern is configured of fractional regions each having the same consistent rule in order to facilitate the symmetry repetition and correction furthermore the size of the reference pattern may be defines as pixels and this may be decided based upon the size of the data image and the accuracy of the correction referring to fig2 to fig5 the illustrated reference pattern may be configured of 4 fractional regions when creating one of the 4 fractional regions 210 220 230 240 shown in fig2 the created fractional region is used to create the remaining 3 fractional regions this may be applied to other fractional regions other than a 4 fractional region configuration also the reference pattern may be generated so as to have the same number of on 39 s and off 39 s this is required for the stabilization of a center frequency when reproducing the data when one fractional region is decided in the reference pattern 200 configured of 4 fractional regions the remaining 3 fractional regions may be generated through inversion rotation and symmetry by using the created fractional region herein inversion corresponds to changing the contrast for example on may be changed to off and off may be changed to on rotation corresponds to rotating the generated fractional region by a constant degree for example the fractional region may be rotated by 90 u00b0 180 u00b0 and 270 u00b0 and symmetry corresponds to left right horizontal symmetry or up down vertical symmetry herein inversion.