An Improved Algorithm for Data Hiding Using HH-subband Haar Wavelet Coefficients

This paper presents an improved adaptive algorithm for enhanced data hiding under HH-subband Haar Wavelet coefficients of a gray scale host image. The algorithm uses an optimal set of the Wavelet coefficients selected through frequency distribution analysis of the host image to determine the lower and upper bounds of the Haar wavelet coefficients for achieving higher data hiding capacity. Simulation results using JPEG2000 lossless compression on nine standard images indicate that our algorithm provides 17% to 62% increase in hiding capacity with full extraction of hidden data along with stable behavior of impacting stego-image PSNR. Therefore the proposed algorithm can be attractive for enhanced data hiding of radiological images / forensic patterns for secure telemedicine applications.