Improvement of perceptual watermarking based on the multiresolution analysis of still images

Abstract

SUMMARYElectronic watermarking has drawn attention as a way to prevent or limit unauthorized copying of digital contents and has been studied and improved extensively. In this paper, as an improved version of the electronic watermarking method proposed by Cox, a method is proposed in which a pseudorandom number sequence is embedded as watermarking information into the wavelet coefficients of the image. In this method, two conventional schemes known as improvements of Cox's method are included. With regard to this electronic watermarking scheme, the detection accuracy of the watermarking information and the quality of the image with watermarking are analyzed. It is shown that the detection accuracy of the watermarking information is better than in the conventional scheme. This conclusion is verified by numerical experiments.

Improvement of Detection Performance in DWT-Based Image Watermarking under Specified False Positive Probability

“…For example, in [11], the threshold is calculated by setting the false positive probability to be 10 −8 . Also, the detection results with 1000 different pseudo random number sequences are shown in [6] and it implies that the false positive probability is smaller than 10 −3 . From above facts, we think (41) is an appropriate condition in the watermark detection.…”

“…Barni et al [11] have proposed the DWT-based image watermarking method in which the watermark signal is de-tected based on the false positive probability which can be calculated by the watermarked DWT coefficients. Though there are many other methods for the DWT-based image watermarking have proposed [6]- [10], the study [11] is especially significant and important because consideration of the false positive rate is useful for judgment of watermark presence. The purpose of this work is to develop a new watermarking method under specified false positive probability and we call the work studied by Barni et al the conventional method.…”

Improved Data Embedding Method for Digital Image with Human Visual Systems

“…Digital watermarking was developed for copyright protection of digital content, including voice, music, and images, and numerous reports have been published in the field . Watermarks are embedded into digital content in order to prevent unauthorized copying and distribution.…”

“…A number of watermarking schemes have been proposed, including embedding in the discrete cosine transform (DCT) domain and in the discrete wavelet transform (DWT) domain . Such embedding in frequency space offers greater robustness than direct embedding in the luminance components of the image.…”

“…Such embedding in frequency space offers greater robustness than direct embedding in the luminance components of the image. The embedded data can be single‐bit data or multiple bits (bit patterns) . The methods supporting the embedding of bit patterns not only provide copyright protection but also allow the addition of diverse information to images, which can be helpful in many applications.…”