Efficient Interpolation-based Reversible Watermarking for Protecting Fingerprint Images

In this paper, an efficient interpolation-based reversible watermarking scheme for protecting fingerprint images is proposed. The interpolation approach, which generates additional pixels, is adopted to ensure perfect retrieval of the original image. The aim of this scheme is to guarantee both authenticity and integrity verification of fingerprint images, by embedding two multibit watermarks into interpolated pixels. A new robust watermarking technique is proposed to embed the authenticity watermark into the Lifting Wavelet Transform (LWT) coefficients, by using an adapted perceptual model. The insertion of the integrity watermark is achieved by adapting a semi-fragile technique, which is based on the Intermediate Significant Bit Substitution (ISBS) approach and operates in the spatial domain. The integrity watermark is generated from a block checksum procedure and serves for tamper detection and localization purposes. Experimental results showed that the proposed technique offers good performances in terms of imperceptibility and robustness, and is also capable of detecting and localizing tampers on watermarked images.