Patent ID: 6604682
Filing Date: 2003-08-12
Classification: G06K

Abstract:
A method of reading a two-dimensional bar code symbol having orientation modules and a finder pattern with a center point, the method comprising a data module search step that calculates position and shape information for all modules constituting the bar code symbol by calculating an orientation axis passing through an orientation module and the finder pattern center point in a scanned image of the bar code symbol based on finder pattern position, orientation module position, and orientation module shape information in the scanned image, wherein the data module search step comprises the following steps:(a) an orientation axis module position calculating step that calculates, based on finder pattern position information and orientation module position information and shape information, position and shape information for a plurality of modules constituting a module group on said orientation axis; (b) an orientation axis data module bit pattern detecting step that detects a bit pattern of said plural data modules on the orientation axis calculated by the orientation axis module position calculating step; (c) a between-orientation axis module position calculating step that calculates, based on the position and shape information of the plural modules of the module group on the orientation axis calculated by the orientation axis module position calculating step, position information for a plurality of modules constituting a module group between adjacent orientation axes; and (d) a between-orientation axis data module bit pattern detecting step that detects the bit pattern of the plural data modules present between the orientation axes calculated by the between-orientation axis module position calculating step.