Figure 14

(a)–(d) The watermarked Lena, Baboon, Peppers and Crowd images with 256 × 256 watermark image as shown in Figure 11(b) after JPEG compression with quality factor 40%, 30%, 20% and 10%, respectively. (e)–(h) The extracted watermarks (256 × 256) from (a)–(d), respectively. (i)–(l) The watermarked Lena, Baboon, Peppers and Crowd images with 256 × 256 watermark image as shown in Figure 11(d) after JPEG compression with quality factor 40%, 30%, 20% and 10%, respectively. (m)–(p) The extracted watermarks (256 × 256) from (i)–(l), respectively. (a)PSNR = 34.89 dB (b)PSNR = 31.71 dB (c)PSNR = 32.32 dB (d)PSNR = 27.72 dB (e)γ = 0.7689 (f)γ = 0.7120 (g)γ = 0.5794 (h)γ = 0.4493 (i)PSNR = 34.91 dB (j)PSNR = 31.73 dB (k)PSNR = 32.35 dB (l)PSNR = 27.72 dB (m)γ = 0.8319 (e)γ = 0.7029 (o)γ = 0.5629 (p)γ = 0.4065