A Novel Gray Digital Watermark Algorithm Based on the Multi-Approach Transform Domain

A novel Multi-Approach transform domain gray watermark embedding algorithm combining Arnold Transform is presented in this paper. Owing to the correlations between the coefficients, the low-frequency coefficients LL used by DWT of the original image are transformed to DCT coefficients. Before being embedded, watermark image by Arnold transform is then transformed to DCT coefficients to enhance robustness of the approach and its imperceptibility. The experiment results indicates that the method could resist some typical watermarking attacks such as JPEG compress- ing and so on.