Digital image watermarking based on DWT DCT

The authenticity of content or matter is crucial factors for solving the problem of copying, modifying, and distributing the intellectual properties in an illegal way. Watermarking can resolve the stealing problem of intellectual properties. This paper considers a robust image watermarkingtechnique based on discrete wavelet transform (WDT) and discrete cosine transform (DCT) called hybrid watermarking. The hybridwatermarking is performed by two level, three level, and four level DWT followed by respective DCT on the host image. A new embedding algorithm (NEA) of digital watermarking is proposed in this paper. The simulation results are compared with Cox’s additive embedding algorithm and the NEA for additive white Gaussian noise (AWGN) attack and without attack.

Both algorithms use the hybrid watermarking.The NEA gives 3.04dB and 9.33dB better pick signal to noise ratio (PSNR) compared to Cox’s additive algorithm for the 4 level DWT for AWGN attack and without attack, respectively. Moreover, the NEA extracts the marked image 46 times better of Cox’s additive algorithm in 2 level DWT with AWGN attack. That means, the NEA can embed larger marks and high quality marks extract from the embedded watermarking even attacking condition. Though the NEA is evaluated in this paper by comparing performances with Cox’s algorithm, the performances of NEA will compare among other algorithms like Gaussian sequence, image fusion, nonlinear quantization embedding with various attacking conditions in near future.