A wavelet packet and fuzzy based digital image watermarking

In this paper, a new image watermarking technique has been adopted that can embed a specified watermark image in the cover image without affecting the imperceptibility and increase the security of watermarks. Watermarking techniques based on wavelet transform are reported in many literatures but robustness and security using wavelet packets are better when compared to wavelet transform. An attempt is made to develop a watermarking scheme based on wavelet packet transform and extraction using same. The image has been divided into several bands using wavelet packet transform and the watermark is embedded in a particular wavelet packet sub-band. Subband selection is based on the energy level that is calculated and the band which is having minimum energy is used for embedding the watermark into the cover image. The extraction is done by taking the inverse wavelet packet transform to the watermarked image and with the help of cover image the watermark has been extracted and also the fuzzy filtering concept has been adopted to remove the noise occurred during transmission. The quality of the image has been analyzed with the help of Pseudo Signal Noise Ratio (PSNR) value. From the simulation results, it is revealed that wavelet packet transform produces good PSNR value. Simulations are carried out using MatLab Software.