DWT Blind Detection Algorithm of Digital Watermarking on still Image Based on KFDA

Abstract

The algorithm of blind detection on DWT (Discrete Wavelet Transform) digital watermarking of still image is proposed to overcome the lower detection rate and higher false alarm rate problem. The algorithm utilizes KFDA (Kernel Fisher Discrimination Analysis) theory. With the help of research results of blind detection on DCT digital watermarking, the algorithm passes the test information by stochastic resonance system so as to amplify weak signals. Then the algorithm chooses suitable sample vector by computation. KFDA theory, a kind of learning machine with high precision is used to realize blind detection. Both theoretical analysis and simulation results show that the algorithm improves detection probability at low embedding strength. At the same time the algorithm also decreases false alarm rate.