Blind Image Data Hiding in the Wavelet Domain

In this paper, we propose a methodology for hiding a gray scale guest image of low resolution into another gray scale host image of higher resolution. The embedding scheme can be used for secure or economic transmission of the low resolution image through the established communication channel for the high resolution image. We encode the guest image by a two-description subband coder. The information of one description is embedded in one frequency subband of the host image, and the other description in the other frequency subbands. We embed the information in those areas of the host image that contains high texture to reduce visibility of the embedded information in the host image. At the receiver, a multiple description decoder combines the information of each description to reconstruct the original guest image. We experiment the proposed scheme by embedding a gray scale guest image of 128*128 pixels in the gray-scale host image of 512*512 pixels, and evaluate the system robustness to various signal processing operations.