Figure 15

(a)–(d) The watermarked Lena, Baboon, Peppers and Crowd images with 128 × 128 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 (128 × 128) from (a)–(d), respectively. (i)–(l) The watermarked Lena, Baboon, Peppers and Crowd image with 128 × 128 watermark images as shown in Figure 11(d) after JPEG compression with quality factor 40%, 30%, 20% and 10%, respectively. (m)–(p) The extracted watermarks (128 × 128) from (i)–(l), respectively. (a)PSNR = 35.04 dB (b)PSNR = 31.78 dB (c)PSNR = 32.41 dB (d)PSNR = 27.74 dB (e)γ = 0.9974 (f)γ = 0.8090 (g)γ = 0.7755 (h)γ = 0.6239 (i)PSNR = 35.05 dB (j)PSNR = 31.79 dB (k)PSNR = 32.42 dB (l)PSNR = 27.75 dB (m)γ = 0.8673 (n)γ = 0.7774 (o)γ = 0.7275 (p)γ = 0.5601