Blind consecutive extraction of multi-carrier spread spectrum data from digital images

We address blind extraction of spread spectrum data embedded in a digital image. The multicarrier iterative generalized least-squares (M-IGLS) data extraction algorithm is the basis of our study and a new algorithm based on M-IGLS is introduced in which both computational complexity and data extraction accuracy are enhanced. In the new method named multicarrier consecutive iterative generalized least-squares (M-CIGLS) algorithm, neither the cover image nor the spread spectrum carriers are required for the hidden data extraction. Additionally, knowledge of the number of carriers is no more needed. Simulation results show the ability of this method to extract data with a superior performance with respect to M-IGLS. Moreover, the probability of bit error rate is comparable with those of obtained by informed algorithms in which both cover image and spread spectrum carriers are known.