Abstract:
As a protection against unauthorized
copying of digital multimedia objects, digital
watermarking technology is now attracting
substantial attention. In this paper, an image
watermarking algorithm is presented by utilizing
a cascade of two powerful mathematical
transforms; the Lifting Wavelet Transform
(LWT) and the Discrete Cosine Transform
(DCT). The lifting wavelet transform is applied
to decompose the original image into four subband
images. Then the discrete cosine transform
is computed on the selected sub-band of the LWT
coefficients. The watermark is embedded in the
DCT transformed the selected LWT sub-band of
the cover image. The proposed system focuses on
an invisible watermark embedding and quality
factors such as imperceptibility to degradation of
watermarked image and performance evaluation
metrics. This presented algorithm is realized in
MATLAB.
