In this paper the watermarking programs based on the discrete cosine transform (DCT) domain DC component (DC) is adopted. Through adjusting the block DCT coefficient of the image the watermarks are hidden. And blocking the selected image according to 8×8 pixel, then dividing the selected image into four non-overlapped sub image blocks according to 4×4 pixel, and thus the watermarks are embedded through adjusting their DCT coefficient. The experimental results show that the method has strong robust. Keywords—Digital Watermark, DCT, Direct Current Component, JPEG.

Watermarking Algorithm Research and Implementation Based on DCT Block

Technology that combines a 2D BarCode with a digital watermark is a topic of great interest in current research related to the security field. This paper presents a new digital watermark method for the QR Code(Quick Response Code). An invisible watermark is embedded in the QR Code image using watermark technology, and while this is being done, the DCT intermediate frequency coefficients are compared. To prevent the overflow of the QR Code in the DCT domain of the image, QR image need fuzzy processing and be added noise to. In order to resist image distortion after print and scan operations, the watermark is embedded repeatedly. The watermark is extracted by using the two maximum membership degree of fuzzy pattern recognition, without the original image. Experimental results have demonstrated the feasibility of the algorithm.

http://www.aicit.org/ijiip/ppl/04_IJIIP1-027025.pdf

A Digital Watermark Algorithm for QR Code

This paper proposes a color image digital watermarking method based on Singular Value Decomposition. Aiming at the binary text image's characteristics of simple pixel, complex texture and bad immunity of information concealment, a digital watermarking embedment location choosing method based upon Singular Value Decomposition has been put forward. This method divides binary text images into different DCT classes. Equivalence classes are further divided into different DCT subclasses according to each pixel's degree and texture changes between blocks. The method has strong resistance to attacks like filtering and zooming. Experimental results indicate that detection in the LL band is robust for one group of attacks, and detection in the HH band is robust for another group of attacks.

Color Image Digital Watermarking Algorithm Based on Singular Value Decomposition

In this paper, we proposed an Binary Image Watermarking Algorithm Based on SVD and used AES algorithm with KEY, because this type of watermark has stronger impact during the copyright reclamation moment, compared with the use of a pseudo random pattern generated by a secret key as watermark code. The proposed algorithm is evaluated from the transparency point of view and the robustness against some common attacks, such as a JPEG compression, filtering, noise corruption and cropping.

Binary Image Watermarking Algorithm Based on SVD

Wide and even distribution of pixels is the main parameter to evaluate the scrambling degree of the binary image. An evaluation method for the scrambling degree of the binary image is put forward by quoting the concepts of the bipartite graph and its degree along with applying the characteristic which the variance and mean square deviation can measure the discrete degree of nodes according to the pixels characteristic of the binary image. This method consists of dividing the image into the same size blocks, constructing the bipartite graph of every block, calculating its degree, building up a real sequence, analyzing the discrete degree of the sequence by applying the variance and mean square deviation, and, finally, deciding the scrambling degree of the binary image.

Binary image scrambling evaluation method based on the mean square deviation and the bipartite graph

In the era of computer network, it is essential to take measures for copyright protection and data authentication of binary images, whose transmission is a major activity during everyday communication Digital watermarking techniques have been proposed to address the issue This paper reviews various watermarking algorithms for binary images, and analyzes their advantages and disadvantages The paper also proposes several research topics at next stage

Zhang Jing

Papers

Overview of Digital Watermarking Techniques for Binary Images