Open hiding for truncating hackers - a block truncation and wavelet approach

Abstract

Authentication of images with a focus on tamper proofing requires a critical attention. While most of the watermarking schemes look to assist authentication through data concealing in specific section, reversibility of the cover images remains a challenge to be addressed. Post tampering retrieval of the cover associated with the watermarking is the prime objective of this work. The key elements involved in this work are Integer Wavelet Transform (IWT) and Block Truncation Code (BTC). After application of IWT on the chosen cover image, the BTC generated from the HH sub band will be embedded in select regions of the LL sub band of the transformed image. BTC has been employed in this approach and tested for various pixel block sizes namely 2 × 2, 4 × 4 and 8 × 8 in the preferred HH sub band which carry the edge information. While the imperceptibility of recovered cover image was commendable through this reversible scheme, the suggested approach also withstands noticeably against a variety of image processing attacks.