Abstract:

In order to improve the performance of digital watermarking system, a watermarking algorithm was proposed for color images based on the combination of discrete wavelet transform, singular value decomposition and Turbo codes. Firstly, digital watermarking was pretreated by chaotic encrypting and Turbo coding; secondly, the blue component of color image was decomposed via discrete wavelet transform; finally, the pretreated watermarking information was embedded into the low frequency band of the blue component which had been DWT of the original image by modifying its singular value. It does not need the original image when the watermarking is extracted, so it can be applied in the practice easily. Simulation results show that the watermarking algorithm has good invisibility and robustness to common attacks and geometric attacks.

Key words: digital watermarking, discrete wavelet transform, singular value decomposition, Turbo codes, chaotic encryption