43122767
Independent Motion Detection in 3D Scenes
This paper presents an algorithmic approach to the problem of detecting independently moving objects in 3D scenes that are viewed under camera motion. There are two fundamental constraints that can be exploited for the problem: 1) two/multiview camera motion constraint (for instance, the epipolar/trilinear constraint) and 2) shape constancy constraint. Previous approaches to the problem either use only partial constraints, or rely on dense correspondences or flow. We employ both the fundamental constraints in an algorithm that does not demand a priori availability of correspondences or flow. Our approach uses the plane-plus-parallax decomposition to enforce the two constraints. It is also demonstrated that for a class of scenes, called sparse 3D scenes in which genuine parallax and independent motions may be confounded, how the plane-plus-parallax decomposition allows progressive introduction, and verification of the fundamental constraints. Results of the algorithm on some difficult sparse 3D scenes are promising.
6283962
Multi-view 3D analysis with applications for augmented reality and enhanced video visualization
The article presents methods for 3D scene geometry recovery/refinement and pose estimation from motion imagery in two representative scenarios. First, we present a method for pose estimation and scene geometry recovery from extended sequences without prior knowledge of the scheme. Second, we discuss how to recover camera poses when a rough scene model is provided. We show how to extend and refine the scene model using the recovered poses. Finally, we present applications of the above techniques for 3D imagery manipulation such as enhanced visualization for video and 3D insertion of synthetic objects in the imagery.
31836660
A Global Matching Framework for Stereo Computation
This paper presents a new global matching framework f o r stereo computation. In this framework, the second view is first predicted front the reference view using the depth information. A global match measure is then defined as the similarity function between the predicted image and the actual image. Stereo coniputcction is converted into a search problem where the goal is to find the depth rnup that maximizes the global match measure. The major advantage of this framework is that the global visibility constraint is inherently enforced in the computation. This paper explores several key components of this framework including ( I ) three color segmentation based depth representations, (2) an incremental warping algorithm that dramatically reduces the computational complexity, and (3) scene constraints such as the smoothness constraint and the color sinzilarity constraint. Experimental results using different types of depth representations are presented. The quality of the computed depth maps is demonstrated through image-based rendering from new viewpoints.
5884426
Validation of an optical flow method for tag displacement estimation
Presents a validation study of an optical-flow method for the rapid estimation of myocardial displacement in magnetic resonance tagged cardiac images. This registration and change visualization (RCV) software uses a hierarchical estimation technique to compute the flow field that describes the warping of an image of one cardiac phase into alignment with the next. This method overcomes the requirement of constant pixel intensity in standard optical-flow methods by preprocessing the input images to reduce any intensity bias which results from the reduction in stripe contrast throughout the cardiac cycle. To validate the method, SPAMM-tagged images were acquired of a silicon gel phantom with simulated rotational motion. The pixel displacement was estimated with the RCV method and the error in pixel tracking was <4% 1000 ms after application of the tags, and after 30/spl deg/ of rotation. An additional study was performed using a SPAMM-tagged multiphase slice of a canine left ventricle. The true displacement was determined using a previously validated active contour model (snakes). The error between methods was 6.7% at end systole. The RCV method has the advantage of tracking all pixels in the image in a substantially shorter period than the snakes method.
13996299
Action video retrieval based on atomic action vocabulary
We propose an efficient action retrieval system that is based on a novel action representation and an effective video matching method. We represent actions with a hierarchical encoding scheme that at low-level measures local body parts motions, which then evolves into encoding of instantaneous global body motions and finally high-level description of actions through atomic action vocabulary. Atomic action vocabulary extends the notion of keyframe-based indexing techniques, where a long action video is decomposed into a sequence of atomic sub-actions matched from the vocabulary. Efficient video matching is achieved by exploiting precomputed inter-vocabulary distances so that global video distance between video sequences can be computed in a very efficient manner that is equivalent to index lookup operations with minimal additional computational loads. Combined with atomic action vocabulary, this can provide flexible video matching schemes of finding compound action sequences of arbitrary lengths. The proposed approach is evaluated on surveillance video and a public video dataset.
9659860
True multi-image alignment and its application to mosaicing and lens distortion correction
Multiple images of a scene are related through 2D/3D view transformations and linear and non-linear camera transformations. In all the traditional techniques to compute these transformations, especially the ones relying on direct intensity gradients, one image and its coordinate system have been assumed to be ideal and distortion free. In this paper, we present a formulation and an algorithm for true multi-image alignment that does not rely on the measurements of a reference image being distortion free. For instance, in the presence of lens distortion, none of the images can be assumed to be ideal. In our formulation, all the images are modeled as intensity measurements represented in their respective coordinate systems, each of which is related to an ideal coordinate system through an interior camera transformation and an exterior view transformation. The goal of the accompanying algorithm is to compute an image in the ideal coordinate system while solving for the transformations that relate the ideal system with each of the data images. Key advantages of the technique presented in this paper are: (i) no reliance on one distortion free image, (ii) ability to register images and compute coordinate transformations even when the multiple images are of an extended scene with no overlap between the first and last frame of the sequence, and (iii) ability to handle linear and non-linear transformations within the same framework. The new algorithm is evaluated in the context of two applications: (i) correction of lens distortion, and (ii) creation of video mosaics.
18669485
A QoS routing protocol for delay-sensitive applications in mobile ad hoc networks
The Ad hoc On Demand Distance Vector (AODV) routing protocol is intended for use by mobile nodes in ad hoc networks. To provide quality of service, extensions can be added to the messages used during route discovery. These extensions specify the service requirements which must be met by nodes rebroadcasting a route request (RREQ) or returning a route reply (RREP) for a destination. In order to provide quality delivery to delay sensitive applications such as voice and video, it is extremely important that mobile ad hoc networks provide quality of service (QoS) support in terms of bandwidth and delay. Most existing routing protocols for mobile ad hoc networks are designed to search for the shortest path with minimum hop count. However, the shortest routes do not always provide the best performance, especially when there are congested nodes along these routes. In this paper we propose an on demand delay based quality of service (QoS) routing protocol (AODV-D) to ensure that delay does not exceed a maximum value for mobile ad hoc networks. This protocol will take into consideration MAC layer channel contention information and number of packets in the interface queue in addition to minimum hops. The protocol is implemented and simulated using GlomoSim simulator. Performance comparisons of the proposed AODV-D protocol against AODV, and QS-AODV is presented and shown that the proposed algorithm performs well.
752417
Single-ISA Heterogeneous Multi-Core Architectures: The Potential for Processor Power Reduction
This paper proposes and evaluates single-ISA heterogeneousmulti-core architectures as a mechanism to reduceprocessor power dissipation. Our design incorporatesheterogeneous cores representing different points inthe power/performance design space; during an application'sexecution, system software dynamically chooses themost appropriate core to meet specific performance andpower requirements.Our evaluation of this architecture shows significant energybenefits. For an objective function that optimizes forenergy efficiency with a tight performance threshold, for 14SPEC benchmarks, our results indicate a 39% average energyreduction while only sacrificing 3% in performance.An objective function that optimizes for energy-delay withlooser performance bounds achieves, on average, nearly afactor of three improvement in energy-delay product whilesacrificing only 22% in performance. Energy savings aresubstantially more than chip-wide voltage/frequency scaling.
15134584
Replication of Biomolecular Techniques for Implementing Intelligent Systems
In this paper, it has been shown that computational jobs, such as encoding of input data and AND, OR operation, can work on the computers (by using computer databases and algorithms for the purpose of speeding up and enhancing biological research). By combining more complex functions, more complex molecular programs for gene analysis can be constructed. It is expected an in vivo (i.e. inside cellular life forms) computer will be realized from this technology, which detects the cell state through gene expression patterns, and controls the cell conditions with output RNA (ribose nucleic acid). The replication of biomolecular techniques based upon DNA (deoxyribose nucleic acid) architecture has been proposed. It may provide a powerful tool for both research and clinical applications. To develop functional supra-molecular systems, where sequence-programmable and evolvable molecular systems have been constructed as cell-free chemical systems using biomolecules such as DNA and proteins based on the integration of electronics, computer science, IT (information technology), mathematical and statistical tools. This paper is organised into four parts: part I describes the functioning and encoding processes of DNA computers, which are implemented using a traveling salesman problem (as in artificial intelligent systems) and single shortest path routing approach (as in computer networks) using object-oriented approach of software development, part II presents database integration with DNA using client-server technologies of Web design, part III discusses the implications of DNA for computer and network security, and part IV investigates and shows the results with the use of above mentioned approaches.
65135986
Model dependent inference of three-dimensional information from a sequence of two-dimensional images
In order to autonomously navigate through a complex environment, a mobile robot requires sensory feedback. This feedback will typically include the 3D motion and location of the robot and the 3D structure and motion of obstacles and other environmental features. The general problem considered in this thesis is how this 3D information may be obtained from a sequence of images generated by a camera mounted on a mobile robot. 
The first set of algorithms developed in this thesis are for robust determination of the 3D pose of the mobile robot from a matched set of model and image landmark features. Least-squares techniques for point and line tokens, which minimize both rotation and translation simultaneously are developed and shown to be far superior to the earlier techniques which solved for rotation first and then translation. However, least-squares techniques fail catastrophically when outliers (or gross errors) are present in the match data. Outliers arise frequently due to incorrect correspondences or gross errors in the 3D model. Robust techniques for pose determination are developed to handle data contaminated by fewer than 50.0% outliers. 
To make the model based approach widely applicable, it is necessary to be able to automatically build the landmark models. The approach adopted in this thesis is one of model extension and refinement. A partial model of the environment is assumed to exist and this model is extended over a sequence of frames. As will be shown in the experiments, the prior knowledge of the small partial model greatly enhances the robustness of the 3D structure computations. The initial 3D model may have errors and these too are refined over the sequence of frames. 
Finally, the sensitivity of pose determination and model extension to incorrect estimates of camera parameters is analyzed. It is shown that for small field of view systems, offsets in the image center do not significantly affect the location of the camera and the location of new 3D points in a world coordinate system. Errors in the focal length significantly affect only the component of translation along the optical axis in the pose computation.
17431951
Analyzing Performance of Web-Based Metrics for Evaluating Reliability and Maintainability of Hypermedia Applications
This paper has been designed to identify the Web metrics for evaluating the reliability and maintainability of hypermedia applications. In the age of information and communication technology (ICT), Web and the Internet, have brought significant changes in information technology (IT) and their related scenarios. Therefore in this paper an attempt has been made to trace out the Web-based measurements towards the creation of efficient Web centric applications. The dramatic increase in Web site development and their relative usage has led to the need of Web-based metrics. These metrics will accurately assess the efforts in the Web-based applications. Here we promote the simple, but elegant approaches to estimate the efforts needed for designing Web-based applications with the help of user behavior model graph (UBMG), Web page replacement algorithms, and RS Web Application Effort Assessment (RSWAEA) method. Effort assessment of hyperdocuments is crucial for Web-based systems, where outages can result in loss of revenue and dissatisfied customers. Here we advocate a simple, but elegant approach for effort estimation for Web applications from an empirical point of view. The proposed methods and models have been designed after carrying out an empirical study with the students of an advanced university class and Web designers that used various client-server based Web technologies. Our first aim was to compare the relative importance of each Web-based metric and method. Second, we also implemented the quality of the designs obtained based by constructing the User Behavior Model Graphs (UBMGs) to capture the reliability of Web-based applications. Thirdly, we use Web page replacement algorithms for increasing the Web site usability index, maintainability, reliability, and ranking. The results obtained from the above Web-based metrics can help us to analytically identify the effort assessment and failure points in Web-based systems and makes the evaluation of reliability of these systems simple.