Cai Anni

Cracking Cancelable Fingerprint Template of Ratha

Cancelable biometrics may be a good approach to address the security and privacy concerns on biometric authentication. It uses some parameterized transforms to convert an original biometric template into a new version for authentication. The security of cancelable biometrics lies on noninvertibility of the transformed template, that is, the transforms should be noninvertible so that the original template can not be recovered. One way to achieve the noninvertibilty is through the use of many-to-one transforms. The idea of Ratha¿s scheme of generating fingerprint templates just depends on this. However, it is revealed in this paper that the form of the transforms and the parameters chosen in his implementation weaken the many-to-one property. This results in the possible recovery of original minutiae from one transformed template.

Automatic face segmentation in YCrCb images

This paper presents a novel technique to automatically detect the human face in videophone images with YCrCb format. By using the Cr-Cb histogram to eliminate the background, and applying region growing in the remaining areas, we can, with the aid of the proposed criteria, accurately detect the face from a complex background.

Hierarchical storage design using queueing model in VOD system

In this paper, we discuss the relationship between the blocking probability and the configuration of storage hierarchy in a VOD server using the proposed queueing model. With this model, the optimal configuration of the storage systems can be obtained.. It will be of benefit to the design of massive multimedia on demand systems.

Low-complexity rate-distortion optimal transcoding from MPEG-2 to MPEG-1 in DCT-domain

Transcoding is now widely used in many multimedia applications. This paper proposes a low-complexity rate-distortion optimal transcoding algorithm from MPEG-2 to MPEG-I in DCT-domain where spatial resolution reduction is involved. We jointly optimize transcoding parameters to select independently a across type, reused motion vector and quantization parameter for each individual MB in a frame by exploiting correlations between the input and output video and making use of try-and-error search method. The experimental results show that our method achieves improvement of average 1.4 dB peak signal-to-noise ratio (PNSR) over TM5 slightly increase in computational complexity.

Fractal based texture analysis for retrieval of image data

In this paper, directional fractal dimensions are computed for a special class of images with lines and curves. Then the texture variation coefficient is defined and a simple algorithm for detecting singularity fields of an image is proposed. Experiments show that 92% singularity fields are correctly recognized by the proposed algorithm, and this will greatly help with content-based retrieval of texture images from a large database.

Encrypted Fuzzy Vault Based on Fingerprint

Biometrics is the only factor that is directly linked with the distinguishing characteristic of an individual and has been widely applied to identity authentication, biometrics-based key management system may be expected to be a powerful competitor in the future. A popular technique of such a system is the fuzzy vault scheme. In this paper, a new scheme is proposed, which referred to as encrypted fuzzy vault scheme. The fingerprint-based implementation also is presented. In locking phase, a secret key is encrypted by the key derived from a set of random data. Then these data are encoded on the fingerprint minutiae. At last, the minutiae are encrypted by the private list. By these ways, the construction of the encoding polynomial is decoupled from the size of the secret key and less storage is required, but the higher level of security is achieved.