Design and implementation of FPGA based invisible image watermarking encoder using wavelet transformation

A watermarking system can be implemented with either in software or hardware. There are numerous software based watermarking schemes available in literature. There is a gap between image capture and transmission in the way watermarking is used presently. Once the images are acquired watermarks are inserted in them offline and then images are made available. The objective of this work is to implement hardware based invisible watermarking scheme so as to bridge that gap, so that watermarking is done in real time while capturing the image. In this paper, VLSI architecture for implementing invisible watermarking scheme based upon Haar [1]wavelet transformation is proposed. This technique uses a 2D DWT to decompose an image into various frequency channels. A scaled image is used as the watermark and inserted into mid frequency wavelet channel. Taking 2D IDWT of the altered wavelet decomposition produces the watermark embedded image. In order to reduce the complexities of the design, linear algebra view of DWT and IDWT has been use in this paper.