4916415
Power efficient H.263 video transmission over wireless channels
We introduce an approach for adaptive minimization of the total power consumption of wireless video communications subject to a given level of quality of service. Our approach exploits tradeoffs between the power consumption of the H.263 encoder, the Reed-Solomon channel encoder and the transmitter. Simulation results show that source and channel coding parameters and transmit energy per bit should vary based on channel conditions. Optimized settings can reduce the total power consumption by a significant factor compared to fixed parameter settings which do not match with the channel conditions.
12221705
Fast mode decision and motion estimation for H.264 with a focus on MPEG-2/H.264 transcoding
The H.264 standard achieves much higher coding efficiency than previous video coding standards, due to its improved inter and intra prediction modes which come with a cost of higher computational complexity. When transcoding to H.264 from MPEG-2, motion information from MPEG-2 can be used to speed up the motion search. Fast mode decision algorithms are proposed for B and P frames, and a fast intra prediction algorithm is developed for intra coding. In addition, fast motion estimation is developed by reusing the motion information from MPEG-2. Simulation results demonstrate that we can achieve significant complexity reduction while maintaining the coding efficiency.
19393995
Skilled Forgery Detection in On-Line Signatures: A Multimodal Approach
Signature recognition has a long history of usage in authentication of transactions and legal contracts and hence is easily accepted by users in a variety of applications. However, the problem of skilled forgeries is an important challenge that needs to be overcome before signature recognition systems will become viable in unsupervised authentication systems. In this paper, we present a multimodal approach to forgery detection, where a physiological trait, the face of the signing person, is used to validate the signature. Methods of normalizing and combining the matching scores from the individual modalities are investigated. Test results of the system on a database of 100 users is presented. The system achieves an equal error rate of 2.2% in the presence of high quality skilled forgeries and could detect all the skilled forgeries at a genuine acceptance rate of 75%.
41811385
Orientation analysis for rotated human face detection
Abstract In this paper, we present a framework of orientation analysis for rotated human face detection. A novel orientation histogram is constructed for statistical analysis of face images, which can show a proper symmetry with respect to the orientation of the principal axis and a local peak at its orthogonal orientation. By analyzing the orientation histogram, we can easily find the principal axis' orientation of the rotated face. Then an upright frontal face detector based on orientation analysis and other knowledge is designed to verify the given face. The experimental results illustrate the effectiveness of our framework.
121253028
Three-dimensional model based face recognition
The performance of face recognition systems that use two-dimensional (2D) images is dependent on consistent conditions such as lighting, pose and facial expression. We are developing a multi-view face recognition system that utilizes three-dimensional (3D) information about the face to make the system more robust to these variations. This work describes a procedure for constructing a database of 3D face models and matching this database to 2.5D face scans which are captured from different views, using coordinate system invariant properties of the facial surface. 2.5D is a simplified 3D (x, y, z) surface representation that contains at most one depth value (z direction) for every point in the (x, y) plane. A robust similarity metric is defined for matching, based on an iterative closest point (ICP) registration process. Results are given for matching a database of 18 3D face models with 113 2.5D face scans.
11665105
Agent-based autonomous information services integration and allocation to achieve high response and low cost in distributed information service system
The goal of autonomous information service integration is to enable information utilization opportunities far beyond those possible in a disconnected environment. We have proposed an agent-based distributed information service system architecture, called Faded Information Field (FIF) to cope with the rapidly evolving situations of providers' and users' heterogeneous requirements. In the case of a mono-service request, the system is designed to reduce the time needed for users to access the information and to preserve the consistency of the replicas. However, when the user requests joint selection of multiple services, synchronization of atomic actions and timeliness have to be assured by the system. The service-oriented autonomous integration and allocation for heterogeneous FIFs to provide one-stop service for users' multiservice requirements are proposed. Through the comparison simulation to conventional systems, the effectiveness of the proposed technology is proved.
20901797
Decentralized workload management for assurance according to heterogeneous service levels
Due to the advent of electronic commerce, the service provider can offer the customer a Service Level Agreement (SLA) to distinguish itself in today's competitive market. Different users require different levels of service in terms of information consumption or response time, appearing a need of a system able to assure the heterogeneous service levels of the users in such a mission-critical environment. In this paper, we propose an information service infrastructure based on the Faded Information Field (FIF), a distributed service replica network founded on push/pull mobile agent technology. The cooperation between the autonomous agents and the nodes allows the online maintenance and auto-reconstruction of the FIF system in order to satisfy the different timely requirements of each user even in an ever-changing environment. Moreover, the system is able to provide different maximum information volume according to the user's service level, a double-sided feature that benefits to both the provider's business strategy and the differentiated timeliness access technology presented on this paper. The effectiveness of the proposed technology has been proved through evaluation and the simulation results show that the system is able to adapt and satisfy the different requirements of timeliness and the different levels of information volume required by each user under changing workloads, compared with conventional systems.