High capacity lossless data hiding based on integer wavelet transform

Abstract

This paper proposes a novel approach to high capacity lossless data hiding based on integer wavelet transform, which embeds high capacity data into the most insensitive bit-planes of wavelet coefficients. Specifically, three high capacity lossless data hiding methods, namely A, B and C are proposed. Method A is the traditional lossless data hiding technique, which can losslessly recover the original image. The capacity can reach 1/10 of the data volume that the original image occupies and histogram modification is used to prevent over/underflow. Method B is not a traditional lossless data hiding technique. It can only losslessly recover the pre-processed image instead of the original image. However, the capacity can reach 1/2 of the data volume that the original image occupies. It has better visual quality than replacing the four least significant bit-planes in the spatial domain. Method C has not only the larger capacity but also better visual quality than Method B. However, it can only losslessly recover the hidden data. These three methods passed through the test on all 1096 images of CorelDraw database. These techniques can be applied to e-government, e-business, e-medical data system, e-law enforcement and military system.

Optimal capacity threshold for reversible watermarking using score function

“…We can solve this optimization problem with equality constraint using the method of Lagrange multipliers because both the distortion function and the capacity function have continuous first partial derivatives on (tp, tn)  (0, ∞) × (-∞, 0). From this we get the optimal threshold must be satisfied by (5).…”

“…We attempt to get the values which are as close as possible to boundary. Moreover, and Tn must be satisfied by (5).…”