摘要：Healthcare providers employ Quick Response (QR) codes for patient identification and tracking. Earlier, we have implemented a zero watermarking system in the composite Contourlet Transform (CT), Singular Value Decomposition (SVD) domain to embed a QR code of a Health Level 7 (HL7) PID segment, for patient authentication. The work proposed in this study is an extension of the above which presents a study on the behavior of the system exclusively under intense noise attacks. The purpose of this study is to evaluate the robustness of the systems under noise attacks in the composite CT-SVD and SVD domains. The methodology employed for this study implements watermarking systems employing SVD and Hus image invariants and extracts the QR code watermark from the host images subjected to AWGN, poisson, salt and pepper and speckle noise attacks. The findings of this investigation show that the system exhibits better robustness in the CT-SVD domain compared to the SVD domain. Further, it is also demonstrated that, lower order Hus moments are adequate to impart robustness against noise in zero watermarking systems. This research also advocates the need to identify noise invariants for medical images with small regions of interest. Extreme robustness demonstrated by the systems also calls for further investigations on ambiguity attacks on zero watermarking systems.
