Information Hiding Algorithm for PDF417 Barcode

An improved information hiding method based on the spectrum spreading was proposed in this paper. Spreading the spectrum and mapping the information before hiding, then embedding them as errors at the adjacent of the bar and the space according to the allowance errors between the bars and spaces by fine tuning the width. Theoretical analysis and experimental results showed that this algorithm have better robustness to the attacks of copy and stain, high capacity of hiding information as well as the high security.