Image Watermarking Algorithm Based on Multiobjective Ant Colony Optimization and Singular Value Decomposition in Wavelet Domain

Figure 7

Extracted watermarks under different attacks.

(a)  Salt and peppers noise

(b) Gaussian filter

(c) Cropping

(d) JPEG compression

(e) Sharpening

(f) Scaling

(g) Histogram equalization

(h) Gray-scale quantization

(i) Rewatermarked

(j) Gamma correction

(k) Dithering

(l) Motion blur