A Strong Robust Zero-Watermarking Scheme Based on Shearlets’ High Ability for Capturing Directional Features

Figure 2

An illustration of NSST. (a) Original image (b) low-pass coefficients. Image of the detail shear coefficients are shown in (c) and (d) with 4 and 8 directions, respectively, corresponding to the different directional bands illustrated in Figure 1(a).

(a)

(b)

(c)

(d)