Embedded interaction code recognition

A computer-readable medium containing computer-executable instructions for recognizing embedded interaction code (EIC) symbols by performing steps comprising:

• generating EIC dots based on effective EIC symbols, which have been generated by processing an image containing the EIC symbols, by obtaining graylevels of selected positions of the EIC-symbols;
• generating rotated EIC dots based on the EIC dots by determining which grid cells correspond to the EIC symbols and by determining which direction is a correct orientation of the EIC symbols;
• updating a homography matrix with orientation information based on the EIC dots;
• and
• extracting EIC bits from the rotated EIC dots based on graylevels of selected positions of the rotated EIC dots.

A system for recognizing embedded interaction code (EIC) symbols, the system comprising:

• means for generating EIC dots based on effective EIC symbols, which have been generated by processing an image containing the EIC symbols, by obtaining graylevels of selected positions of the EIC-symbols;
• means for generating rotated EIC dots by determining which grid cells correspond to the EIC symbols and by determining which direction is a correct orientation of the EIC symbols;
• means for updating a homography matrix with orientation information based on the EIC dots;
• and
• means for extracting EIC bits from the rotated EIC dots based on graylevels of selected positions of the rotated EIC dots.