Processes and apparatuses analyze an image of maze pattern in order to extract bits encoded in the maze pattern. Grid lines of a maze pattern are determined. Directions for effective pixels of associated bars are estimated and are grouped into clusters. Lines are estimated for selected effective pixels of a selected cluster that is associated with a first principal direction. Grid lines of another cluster are determined, where the other cluster is associated with a second principal direction that is perpendicular with the first principal direction. Estimated lines are pruned based on slope variation analysis, grouped based on a distance analysis, and a best fit line is selected from each group. Affine parameters are determined from best fit lines. The correct orientation of a maze pattern is obtained by determining a type of missing corner of the maze pattern. Bits are extracted from the image of maze pattern by processing gray level values of the associated maze pattern cells.