Preprocessing and authentication of 2D barcodes

Two dimensional (2D) barcode can carry much more information than the traditional 1D barcode. Nowadays, mobile phones come with camera which can be used as a barcode scanner with software embedded in the mobile phone for decoding. However, due to the uncontrolled capturing environments and unsteady hands of users, the captured barcode images are of various qualities. In this thesis, we investigate the detection step of a barcode by modeling its finder pattern as a 2D signal with finite rate of innovations and reconstructing it through block by block operation. Then, a quality checking step of the barcode images is added to reject those poor quality images for saving the time in processing the undecodable images and avoiding wrongly decoded information. In additional, due to the authenticity of a 2D barcode can be easily compromised by replacing it with another barcode generated by a standard encoder, we develop a 2D barcode authentication scheme with embedded data using the redundancy of the error correction codewords.Doctor of Philosoph