Blind Image Watermarking Based on Adaptive Data Spreading in n-Level DWT Subbands

Figure 7

Examples of the extracted watermark from subband; 3×3 Gaussian blur filtering attack to 512×512 F16 image: (a) 3-level subbands (LL, HL, LH, and HH), (b) final watermark (NCC value: 0.973); 3% Gaussian noise addition attack to 1,920×1,080 black bear image: (c) 3-level subbands (LL, HL, LH, and HH), and (d) final watermark (NCC value: 0.975).

(a)

(b)

(c)

(d)