Robust Binary Image Watermarking Using DCT

This paper examine the workability of watermark embedding in the discrete cosine transform (DCT) domain for binary images. Watermark embedding is quite difficult for binary images due to its prevalence and compactness. This presents a watermarking algorithm for binary images. A post-embedding binarization is a necessary step to ensure that the watermarked image is still a binary image for frequency domain approach to binary image watermarking. This algorithm involves a blurring preprocessing and a biased binarization. After blurring the binary image, embeds a watermark by modifying the DC components of discrete cosine transform (DCT), followed by a biased binariztion. Experiments show that the embedding algorithm provide some degree of robustness against common signal processing and imperceptibility.