Small Ridge Transform Domain-aware Watermarking Algorithm

In this paper, we establish a visual model in ridgelet transform domain, and a new perceptual watermarking algorithm in the ridgelet domain is proposed. The ridgelet transform (Candes and Donoho, 1999) was introduced as a new efficient multi-scale representation for functions that are smooth away from discontinuities along lines. Ridgelet transform decompose the spatial frequency domain into some subbands with different directions and frequencies. This hierarchy matchs the multi-channel model of HVS(Human Visual System) better than wavelet transform . In this paper, we build a visual model in the ridgelet domain by taking advantage of the current knowledge of visual perception, which is a pioneer work. Then we propose a new perceptual watermarking algorithm in the ridgelet domain. We adjust the strength of embedded watermark in according to the visual model in the ridgelet domain. Experimental results show that our algorithm is very effective. Performance improvement is obtained.