Three-dimensional reversible watermarking with tamper detection and localization capability for volumetric DICOM images

• Main Author: Dou, Wenbo
• Other Authors: Guan Yong Liang
• Format: Final Year Project
• Language: English
• Published: 2011
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Wireless communication systems
• Online Access: http://hdl.handle.net/10356/46189
• Institution: Nanyang Technological University

Teleradiology brings the convenience of global medical record access along with the concerns over the security of medical images transmitted over the open network. With the prevailing adoption of 3-D imaging modalities, it is vital to develop a security mechanism to provide large volumes of medical images with privacy and reliability. This Final Year Project aims to develop a 3-D fully reversible dual layer digital watermarking scheme with tamper localization capability for volumetric DICOM images. Firstly, a new and improved method of implementing tamper localization, which involves utilizing the 3-D property of volumetric data and developing an improved adaptive data insertion algorithm, was developed to achieve much faster processing time at both transmitter and detector sides without compromising tamper localization accuracy. The performance of the scheme based on the proposed method was evaluated by using sample volumetric DICOM images. Results show that the scheme achieved on average about 65% and 72% reduction in watermarking and de-watermarking processing time, respectively, and was able to ensure confidentiality, authenticity and integrity. For cases where the images had been tampered, the scheme can detect and localize the tampered areas in the images accurately. A second method was developed to achieve the full recovery of tamper-free regions in tampered image slices, which allows re-watermarking of tampered image slices. Performance evaluations show that the scheme implemented by the second method achieves the complete restoration capability and retains the desirable features and functionalities achieved by the first method. The new property allows tampered images to be re-watermarked and circulated among radiologists for medical practice as long as the tamper is located inside the regions of non interest, which substantially avoids unnecessary retransmission that is time consuming and costly.