Watermark Applications

In this book, three novel methods for color image watermarking were suggested, they don¿t require the original image for watermark extraction.These methods exploit the discrete wavelet transforms features. Different schemes of wavelet decompositions with various transform combinations were tested.The first suggested method can be used for owner identification, proof of ownership, and transactional watermarks (fingerprinting).The second was oriented to embed the watermark such that it is capable to survive against the high degree of compression produced by JPEG2000, the watermark was fully extracted under high degree of compression ratio.The third suggested method of watermark can be used for covert communication (a method of sending secret messages). Here, a general method is developed for embedding and extraction hidden message without need to know the key, as well as with the absence of source image. Finally, the perceptual impact of watermark is studied, to find the most suitable color model for the application of image watermarking.The considered color transforms are those commonly used in digital image processing applications these color models are RGB, YUV, YIQ, YCbCr and RCT