10843699
Efficient feature extraction for 2D/3D objects in mesh representation
Meshes are dominantly used to represent 3D models as they fit well with graphics rendering hardware. Features such as volume, moments, and Fourier transform coefficients need to be calculated from the mesh representation efficiently. We propose an algorithm to calculate these features without transforming the mesh into other representations such as the volumetric representation. To calculate a feature for a mesh, we show that we can first compute it for each elementary shape such as a triangle or a tetrahedron, and then add up all the values for the mesh. The algorithm is simple and efficient, with many potential applications.
11474786
A Self-Reconfigurable Camera Array
This paper presents a self-reconfigurable camera array system that captures video sequences from an array of mobile cameras, renders novel views on the fly and reconfigures the camera positions to achieve better rendering quality. The system is composed of 48 cameras mounted on mobile platforms. The contribution of this paper is twofold. First, we propose an efficient algorithm that is capable of rendering high-quality novel views from the captured images. The algorithm reconstructs a view-dependent multi-resolution 2D mesh model of the scene geometry on the fly and uses it for rendering. The algorithm combines region of interest (ROI) identification, JPEG image decompression, lens distortion correction, scene geometry reconstruction and novel view synthesis seamlessly on a single Intel Xeon 2.4 GHz processor, which is capable of generating novel views at 4-10 frames per second (fps). Second, we present a view-dependent adaptive capturing scheme that moves the cameras in order to show even better rendering results. Such camera reconfiguration naturally leads to a nonuniform arrangement of the cameras on the camera plane, which is both view-dependent and scene-dependent.
15778343
Smart rebinning for compression of concentric mosaics
Concentric mosaics offer a quick solution to construct a virtual copy of a real environment, and navigate in the virtual environment. However, the huge amount of data associated with concentric mosaics is a heavy burden for its application. A 3D wavelet transform-based compressor has been proposed in previous work to compress the concentric mosaics. In this paper, we greatly improve the performance of the 3D wavelet coder with a data rearrangement mechanism called “smart rebinning”. The proposed scheme first aligns the concentric mosaic image shots along the horizontal direction and then rebins the shots into multi-perspective panoramas. Smart rebinning greatly improves the cross shot correlation and enables the coder to better explore the redundancy among shots. Experimental results show that the performance of the 3D wavelet coder improves an average of 4.3dB with the use of smart rebinning. The proposed coder outperforms MPEG-2 coding of concentric mosaics by an average of 3.7dB.
12091703
Indexing and retrieval of 3D models aided by active learning
We demonstrate a system for indexing and retrieval of 3D models aided by active learning. We propose a new set of region-based features for 3D models. Each model is treated as a solid volume with a uniform density. Features such as the volume-surface ratio, the moment invariants and the Fourier transform coefficients are efficiently calculated from the mesh model directly. Comparable retrieval performance is achieved with other features such as the cord histogram, the 3D shape spectrum, etc. To further improve the performance, we incorporate hidden annotation into our system. We propose to use active learning to improve the annotation efficiency. We show that with active learning, the system can perform better than random annotation, and the retrieval result improves rapidly with the number of annotated samples. Moreover, relevance feedback is included in the system and combined with active learning, which provides better user-adoptive retrieval results.
10867502
Robust Visual Tracking via Pixel Classification and Integration
We propose a novel framework for tracking non-rigid objects via pixel classification and integration (PCI). Given a new input frame, the tracker first performs object classification on each pixel and then finds the region that has the highest integral of scores. There are several key advantages of the proposed approach: it is computationally very efficient; it finds a global, instead of local (e.g., mean-shift), optimal solution within a search range; and it is inherently robust to different object scales with minimum extra computation. Within this framework, a mixture of long-term and short-term appearance model is further introduced to perform PCI. As a result, the tracker is able to adapt to both slow and rapid appearance changes without drifting. Challenging video sequences are presented to illustrate how the proposed tracker handles large motion, dramatic shape changes, scale variations, illumination variations and partial occlusions
15005856
Security analysis for key generation systems using face images
In this paper, we analyze the security problem of user information associated key generation (UIAKG) systems. We consider three kinds of attacks from the hacker: the exhaustive search attack, the authentic key statistics attack and the device key statistics attack. Under each attack, we give the estimate of the number of guesses the hacker has to make in order to access the system. Such analysis provides useful guidelines in designing a UIAKG system. The analysis also suggests that a user-dependent UIAKG is more secure than a user-independent one. Two UIAKG systems using face images as inputs are designed and compared to support the above theoretical analysis.
11885669
A decision tree-based multimodal data mining framework for soccer goal detection
We propose a new multimedia data mining framework for the extraction of soccer goal events in soccer videos by using combined multimodal analysis and decision tree logic. The extracted events can be used to index the soccer videos. We first adopt an advanced video shot detection method to produce shot boundaries and some important visual features. Then, the visual/audio features are extracted for each shot at different granularities. This rich multimodal feature set is filtered by a pre-filtering step to clean the noise as well as to reduce the irrelevant data. A decision tree model is built upon the cleaned data set and is used to classify the goal shots. Finally, the experimental results demonstrate the effectiveness of our framework for soccer goal extraction.
14282862
Design and Deployment of Locality-Aware Overlay Multicast Protocol for Live Streaming Services
This paper presents the design and deployment of a locality-aware overlay multicast protocol called Anysee. The key idea of Anysee is to use the geometrical information of end hosts to construct the locality-aware overlay data delivery tree such that nearby users in the underlying network can be organized into nearby subtrees. The prototype of Anysee has been widely used in CERNET. Logging traces obtained from broadcasting 2004 Athens Olympic Games over 16 days have shown that the performance of Anysee, such as end-to-end delay and absolute data delivery delay, significantly outperforms that of randomly constructed overlay multicast.
40273501
Pattern Discovery in Probabilistic Databases
Modeling probabilistic data is one of important issues in databases due to the fact that data is often uncertainty in real-world applications. So, it is necessary to identify potentially useful patterns in probabilistic databases. Because probabilistic data in 1NF relations is redundant, previous mining techniques don't work well on probabilistic databases. For this reason, this paper proposes a new model for mining probabilistic databases. A partition is thus developed for preprocessing probabilistic data in a probabilistic databases. We evaluated the proposed technique, and the experimental results demonstrate that our approach is effective and efficient.
25611508
Regression Nearest Neighbor in Face Recognition
In this paper, we introduce a regression nearest neighbor framework for general classification tasks. To alleviate potential problems caused by nonlinearity, we propose a kernel regression nearest neighbor (KRNN) algorithm and its convex counterpart (CKRNN) as two specific extensions of nearest neighbor algorithm and present a fast and useful kernel selection method correspondingly. Comprehensive analysis and extensive experiments are used to demonstrate the effectiveness of our methods in real face datasets
17440979
Generic Middleware Substrate Through Modelware
Conventional middleware architectures suffer from insufficient module-level reusability and the ability to adapt in face of functionality evolution and diversification. To overcome these deficiencies, we propose the Modelware methodology adopting the Model Driven Architecture (MDA) approach and aspect oriented programming (AOP). We advocate the use of models and views to separate intrinsic functionalities of middleware from extrinsic ones. This separation effectively lowers the concern density per component and fosters the coherence and the reuse of the components of middleware architectures. Comparing to the conventionally designed version, Modelware improves the standard benchmark performance by as much as 40% through architectural optimizations. Our evaluation also shows that Modelware considerably reduces coding efforts in supporting the funcitonal evolution of middleware and dramatically different application domains.