31557244
Isothetic polygon representation for contours
Abstract An isothetic polygon, which has all its edges oriented in two orthogonal directions, is one of the simplest representations for a contour of binary images. This paper introduces an efficient, onepass algorithm for generating the isothetic polygons for the contours in binary images.
38916969
A Generic System for Form Dropout
Recent advances in intelligent character recognition are enabling us to address many challenging problems in document image analysis. One of them is intelligent form analysis. This paper describes a generic system for form dropout when the filled-in characters or symbols are either touching or crossing the form frames. We propose a method to separate these characters from form frames whose locations are unknown. Since some of the character strokes are either touching or crossing the form frames, we need to address the following three issues: 1) localization of form frames; 2) separation of characters and form frames; and 3) reconstruction of broken strokes introduced during separation. The form frame is automatically located by finding long straight lines based on the block adjacency graph. Form frame separation and character reconstruction are implemented by means of this graph. The proposed system includes form structure learning and form dropout. First, a form structure-based template is automatically generated from a blank form which includes form frames, preprinted data areas and skew angle. With this form template, our system can then extract both handwritten and machine-typed filled-in data. Experimental results on three different types of forms show the performance of our system. Further, the proposed method is robust to noise and skew that is introduced during scanning.
34534588
Lane boundary detection using a multiresolution Hough transform
Lane boundary detection is the problem of estimating the geometric structure of the lane boundaries of a road based on the images grabbed by a camera on board a vehicle. We use the Hough transform to detect lane boundaries with a parabolic model under a variety of road pavement types, lane structures and weather conditions. In the three-dimensional Hough space, a parabolic curve is represented as a straight line. To simplify the computation, the parametric space can be divided into (i) a two-dimensional space measured by the parameters which are shared by all the lane edges, and (ii) a one-dimensional space of the parameter which makes a distinction among different edges in an image. A multiresolution strategy is used to improve both the speed and accuracy of the Hough transform. Experimental results show that the proposed method is relatively less prone to the image noise and is computationally tractable.
46138594
Document Representation and Its Application to Page Decomposition
Transforming a paper document to its electronic version in a form suitable for efficient storage, retrieval, and interpretation continues to be a challenging problem. An efficient representation scheme for document images is necessary to solve this problem. Document representation involves techniques of thresholding, skew detection, geometric layout analysis, and logical layout analysis. The derived representation can then be used in document storage and retrieval. Page segmentation is an important stage in representing document images obtained by scanning journal pages. The performance of a document understanding system greatly depends on the correctness of page segmentation and labeling of different regions such as text, tables, images, drawings, and rulers. We use the traditional bottom-up approach based on the connected component extraction to efficiently implement page segmentation and region identification. A new document model which preserves top-down generation information is proposed based on which a document is logically represented for interactive editing, storage, retrieval, transfer, and logical analysis. Our algorithm has a high accuracy and takes approximately 1.4 seconds on a SGI Indy workstation for model creation, including orientation estimation, segmentation, and labeling (text, table, image, drawing, and ruler) for a 2550/spl times/3300 image of a typical journal page scanned at 300 dpi. This method is applicable to documents from various technical journals and can accommodate moderate amounts of skew and noise.
39489918
An economical contour extraction algorithm for understanding large-size engineering drawings
An algorithm is described which produces the extraction of an object's contours in a binary image while storing only two raster lines at a time during processing. The major data structure used is a block adjacency graph which occupies much less space (typically one hundredth) than the original image. Because this algorithm has very low costs of memory space and processing time, it is a powerful tool for processing large-size engineering drawings. Applications of the method to the recognition of some loop-structure logical symbols are described.<<ETX>>
27633879
A more efficient branch and bound algorithm for feature selection
Abstract An algorithm is presented to be able to select the globally optimal subset of d features from a larger D -feature set. This is a fundamental problem in statistical pattern recognition and combinatorial optimization. Exhaustive enumeration is computationally unfeasible in most applications. This algorithm dynamically searches for the globally optimal solution on a minimum solution tree which is a subtree of the solution tree used in the traditional branch and bound algorithm. The new algorithm is compared theoretically with the branch and bound algorithm. The analysis and the experimental results show that it is more efficient than the traditional algorithm.
5803741
Incentive Mechanisms for Peer-to-Peer Systems
Most of the existing research in peer-to-peer systems focuses on protocol design and doesn’t consider the rationality of each peer. One phenomenon that should not be ignored is free riding. Some peers simply consume system resources but contribute nothing to the system. In this paper we present an agent-based peer-to-peer system, in which each peer is a software agent and the agents cooperate to search the whole system through referrals. We present a static and a dynamic pricing mechanism to motivate each agent to behave rationally while still achieving good overall system performance. We study the behavior of the agents under two pricing mechanisms and evaluate the impact of free riding using simulations.
15309050
Prediction of Transmembrane Helical Segments in Membrane Proteins Using Back Propagation Neural Network with Wavelet Analysis
Transmembrane proteins possess important physiological function. The increasing transmembrane protein sequences from genome projects raise the needs for theoretical methods to predict their structures, especially transmembrane helical segments (TMHs). wnnTM, a new method of BP neural network based on wavelet multiresolution analysis (MRA) is initially developed to predict the number and location of TMHs in membrane proteins. 80 proteins with known 3D-structure randomly selected from Mptopo database are used as test set to evaluate the prediction accuracy of the method. The final results indicate that the proposed method is more effective than BP neural network model only.
15046055
Transform from Models to Service Description Based on MDA
Within MDA framework, system models can be built up on an abstract level that is independent from the platform. Later on, this abstract model can be transmitted into service description, which is related to specific platform on the implementation level. In Web services applications, this transition has a great advantage. Because, while the model of implementation changes from one case to another to fit the different platforms, the model of whole system, on a higher abstract level, stays the same. Thus, the efficiency is promoted. This paper firstly discusses the extension of UML for Web services, and then it presents the modeling process of WSDL. Finally, it gives the rules and arithmetic of transition from models to WSDL documents in detail
10542337
A realtime software solution for resynchronizing filtered MPEG2 Transport stream
With the increasing demand and popularity of multimedia streaming applications over the current Internet, manipulating MPEG streams in a real-time software manner is gaining more and more importance. In this work, we studied the synchronization problem that arises when a gateway changes the data content carried in an MPEG2 Transport stream. In short, the distance between original time stamps will be changed non-uniformly when the video frames are resized, and decoders will fail to reconstruct the encoding clock from the resulting stream. We propose a cheap software real-time approach to solve this problem, which basically reuses the original time stamp packets and adapts their distance to accommodate the changes in bit rate. Experimental results from a real-time HDTV stream filter shows that our approach is correct and efficient.
17926099
Research and Design of One Key Agreement Scheme in Bluetooth
Since there is eavesdropping and MITM attack during establishing encryption key between two Bluetooth devices, a secure key agreement scheme is designed based on elliptic curves cryptography and interlock protocol. This scheme can defend two kinds of attacks mentioned above. It provides bidirectional authentication for two devices and key integrity verification by exchanging the keyspsila Hash-value. Then security of the scheme is theoretically analyzed and efficiency of it is compared with that of other schemes in relative papers. The results demonstrate the scheme proposed in this paper is secure and efficient.