A Blind Digital Watermarking Algorithm Based on Chaotic Systems

A blind digital watermarking algorithm based on chaotic is proposed. Logistic system is used to generate chaotic sequence, which is binarizated in the following step. Then one-dimensional binary Logistic sequences are changed into two-dimensional matrix through inverse Zigzag scanning, which is XOR encrypted with the original watermark. Turn the original color image to the YCbCr color spaces, and decompose Y component by 2-layer wavelet. Then the new relationship among the chosen wavelet coefficients can be built using the chaotic matrix. Consequently, the watermark is embedded into the low frequency wavelet coefficients based on this relationship. During watermark extraction, the relationship can be obtained by the same algorithm. Finally, the modified wavelet coefficients are applied to replace the original wavelet coefficients, and we can obtain the image component containing watermark, then with the other two color components, which are color-space changed into the RGB space. The image with watermark is gotten. Therefore, the original watermark can be extracted without original image. The experimental results indicate that, compared with other algorithms, the robustness is stronger while the computation complexity is lower, but the transparency is comparatively inferior.