Robust Signature-Based Copyright Protection Scheme Using the Most Significant Gray-Scale Bits of the Image

Table 8

MSB attacked images along with their corresponding retrieved logos using Elaine image and NUS logo by different approaches of the proposed MSB-based scheme and existing TROI-based [12] and VQ-based [13] schemes.

MSB Attacked Images^1,2→
Schemes^3↓	20.00, 31	25.00, 54	30.00, 70	35.00, 81	40.00, 88	45.00, 92	50.00, 95
UROI	6.41, 26	7.04, 46	8.52, 66	9.85, 78	11.51, 86	13.21, 91	14.93, 94
TBLK	7.59, 23	9.45, 44	11.59, 65	13.96, 79	15.77, 87	17.79, 91	19.49, 94
DCTMSB	8.04, 33	10.41, 56	12.81, 74	15.04, 85	17.81, 92	20.00, 95	21.51, 97
𝑡-DWT; (𝑡=4)	13.21, 79	16.31, 90	20.01, 96	24.26, 99	30.23, 100	37.98, 100	∞, 100
DCT	15.86, 91	20.43, 97	26.21, 99	34.59, 100	44.10, 100	69.20, 100	∞, 100
TROI [12]	16.25, 45	16.72, 49	17.10, 50	17.39, 51	17.46, 53	17.47, 53	17.47, 54
VQ [13]	19.20, 49	23.28, 61	24.83, 68	25.25, 68	25.33, 66	25.34, 66	25.34, 68

¹Images with PSNR <30 dB are unacceptable [13].
²With target PSNR (dB) and MSB similarity rate (%).
³Retrieved logos with PSNR (dB) and LRR (%).