Bian Yang

Bio: Bian Yang is an academic researcher from Gjøvik University College. The author has contributed to research in topics: Fingerprint recognition & Minutiae. The author has an hindex of 23, co-authored 79 publications receiving 1699 citations. Previous affiliations of Bian Yang include Harbin Institute of Technology.

Integer DCT-based reversible watermarking for images using companding technique

Abstract: We present a high capacity reversible watermarking scheme using companding technique over integer DCT coefficients of image blocks. This scheme takes advantage of integer DCT coefficients' Laplacian-shape-like distribution, which permits low distortion between the watermarked image and the original one caused by the bit-shift operations of the companding technique in the embedding process. In our scheme, we choose AC coefficients in the integer DCT domain for the bit-shift operation, and therefore the capacity and the quality of the watermarked image can be adjusted by selecting different numbers of coefficients of different frequencies. To prevent overflows and underflows in the spatial domain caused by modification of the DCT coefficients, we design a block discrimination structure to find suitable blocks that can be used for embedding without overflow or underflow problems. We can also use this block discrimination structure to embed an overhead of location information of all blocks suitable for embedding. With this scheme, watermark bits can be embedded in the saved LSBs of coefficient blocks, and retrieved correctly during extraction, while the original image can be restored perfectly.

A Secure Steganography Method based on Genetic Algorithm

Abstract: With the extensive application of steganography, it is challenged by ste- ganalysis. The most notable steganalysis algorithm is the RS attack which detects the steg-message by the statistic analysis of pixel values. To ensure the security against the RS analysis, we presents a new steganography based on genetic algorithm in this paper. After embedding the secret message in LSB (least signicant bit) of the cover image, the pixel values of the steg-image are modied by the genetic algorithm to keep their statistic characters. Thus, the existence of the secret message is hard to be detected by the RS analysis. Meanwhile, better visual quality can be achieved by the proposed algorithm. The experimental results demonstrate the proposed algorithm's eectiveness in resistance to steganalysis with better visual quality. Keywords: steganography; steganalysis; genetic algorithm; RS algorithm

Dynamic random projection for biometric template protection

Abstract: Random projection provides a good diversification effect for biometric template protection but is drawing increasing security concerns under the token-stolen (or public parameter) case. We propose a dynamic random projection method to alleviate these security concerns due to the stolen token by increasing the computational complexity to search for the unprotected biometric features. This is achieved by a projection process which dynamically assembles a random projection matrix from a set of candidate projection vectors. The selection of projection vectors is decided by the biometric feature vector itself and thus forms a nonlinear projection process. The proposed method permits the public and secure storage of all the candidate random vectors without the need for external secret keys. Experiments on the 800 samples in the database FVC2002DB2_A demonstrate the well-kept biometrie performance of the proposed method.

Reversible watermarking of 2D-vector data

Abstract: This paper presents a reversible watermarking scheme for the 2D-vector data (point coordinates) which are popularly used in geographical information related applications. This reversible watermarking scheme exploits the high correlation among points in the same polygon in a map and achieves the reversibility of the whole scheme by an 8-point integer DCT, which ensures that the original 2D-vector data can be watermarked during the watermark embedding process and then perfectly restored during the watermark extraction process, with the watermark accurately extracted at the same time.In our scheme, we use an efficient highest frequency coefficient modification technique in the integer DCT domain to modulate the watermark bit "0" or "1", which can be determined during extraction without any additional information to indicate.To alleviate the visual distortion in the watermarked map caused by the coefficient modification, we propose an improved reversible watermarking scheme based on the original coefficient modification technique. Combined with this improved scheme, the embedding capacity can be greatly increased while the watermarking distortion is otherwise deduced compared to the original coefficient modification scheme.To control the distortion between the watermarked 2D-vector data and its original version, we design an error estimation method to prevent those data which are able to cause large distortions in the coefficient modification process from being watermarked. This distortion limitation scheme can fine adjust the watermarking distortion and capacity for the proposed coefficient modification based reversible watermarking scheme according to different practical requirements.

Block Mean Value Based Image Perceptual Hashing

Abstract: Image perceptual hashing has been proposed to identify or authenticate image contents in a robust way against distortions caused by compression, noise, common signal processing and geometrical modifications, while still holding a good discriminability for different ones in sense of human perception. We propose and compare four normalized block mean value based image perceptual hashing algorithms which demonstrate higher performances than other existing algorithms in robustness-anddiscriminalibility and simplicity for implementation. Overlapped blocking and rotation operations are employed to enhance the robustness to geometrical distortions. To evaluate the proposed algorithms? robustness and discriminability, given fixed modifications, identification ratio is used; and given fixed content classification, receiver operating curves is obtained.

Reversible data hiding

Abstract: A novel reversible data hiding algorithm, which can recover the original image without any distortion from the marked image after the hidden data have been extracted, is presented in this paper. This algorithm utilizes the zero or the minimum points of the histogram of an image and slightly modifies the pixel grayscale values to embed data into the image. It can embed more data than many of the existing reversible data hiding algorithms. It is proved analytically and shown experimentally that the peak signal-to-noise ratio (PSNR) of the marked image generated by this method versus the original image is guaranteed to be above 48 dB. This lower bound of PSNR is much higher than that of all reversible data hiding techniques reported in the literature. The computational complexity of our proposed technique is low and the execution time is short. The algorithm has been successfully applied to a wide range of images, including commonly used images, medical images, texture images, aerial images and all of the 1096 images in CorelDraw database. Experimental results and performance comparison with other reversible data hiding schemes are presented to demonstrate the validity of the proposed algorithm.

Biometric template security

Abstract: Biometric recognition offers a reliable solution to the problem of user authentication in identity management systems. With the widespread deployment of biometric systems in various applications, there are increasing concerns about the security and privacy of biometric technology. Public acceptance of biometrics technology will depend on the ability of system designers to demonstrate that these systems are robust, have low error rates, and are tamper proof. We present a high-level categorization of the various vulnerabilities of a biometric system and discuss countermeasures that have been proposed to address these vulnerabilities. In particular, we focus on biometric template security which is an important issue because, unlike passwords and tokens, compromised biometric templates cannot be revoked and reissued. Protecting the template is a challenging task due to intrauser variability in the acquired biometric traits. We present an overview of various biometric template protection schemes and discuss their advantages and limitations in terms of security, revocability, and impact on matching accuracy. A template protection scheme with provable security and acceptable recognition performance has thus far remained elusive. Development of such a scheme is crucial as biometric systems are beginning to proliferate into the core physical and information infrastructure of our society.

Reversible Watermarking Algorithm Using Sorting and Prediction

Abstract: This paper presents a reversible or lossless watermarking algorithm for images without using a location map in most cases. This algorithm employs prediction errors to embed data into an image. A sorting technique is used to record the prediction errors based on magnitude of its local variance. Using sorted prediction errors and, if needed, though rarely, a reduced size location map allows us to embed more data into the image with less distortion. The performance of the proposed reversible watermarking scheme is evaluated using different images and compared with four methods: those of Kamstra and Heijmans, Thodi and Rodriguez, and Lee et al. The results clearly indicate that the proposed scheme can embed more data with less distortion.

Reversible data hiding

Abstract: This paper presents a novel reversible data hiding algorithm, which can recover the original image without distortion from the marked image after the hidden data have been extracted. This algorithm utilizes the zero or the minimum point of the histogram and slightly modifies the pixel values to embed data. It can embed more data as compared to most of the existing reversible data hiding algorithms. A theoretical proof and numerous experiments show that the PSNR of the marked image generated by this method is always above 48 dB, which is much higher than other reversible data hiding algorithms. The algorithm has been applied to a wide range of different images successfully. Some experimental results are presented to demonstrate the validity of the algorithm.

A survey on biometric cryptosystems and cancelable biometrics

Abstract: Form a privacy perspective most concerns against the common use of biometrics arise from the storage and misuse of biometric data. Biometric cryptosystems and cancelable biometrics represent emerging technologies of biometric template protection addressing these concerns and improving public confidence and acceptance of biometrics. In addition, biometric cryptosystems provide mechanisms for biometric-dependent key-release. In the last years a significant amount of approaches to both technologies have been published. A comprehensive survey of biometric cryptosystems and cancelable biometrics is presented. State-of-the-art approaches are reviewed based on which an in-depth discussion and an outlook to future prospects are given.