A Semiblind Reversible Watermarking Scheme for Authentication and Fusion of Facial Thermograms

Thermography is a noninvasive procedure for acquiring the thermal profile of a subject in the diagnosis and surgical procedures. The superimposition of thermograms with corresponding visual image of the subjects is a technique followed by clinicians to relate the thermal image with the surface anatomy to localize the diseased parts. Authentication is an essential security aspect in healthcare systems to avoid medical errors. This study focuses on the fusion and authentication of thermograms. The semiblind reversible watermarking system proposed in this study presents a watermarking scheme that embeds the visual facial image of the patient within the facial thermogram in an invisible manner to both authenticate and protect the privacy of the patient. The watermark is extracted later to identify the patient and to generate a composite image for cross reference. The experimental results illustrated for different pathologies demonstrate the efficacy of the proposed technique.