Papers by Sanjiv K. Bhatia
The current times have witnessed an exponential increase in the popularity of the Internet as wel... more The current times have witnessed an exponential increase in the popularity of the Internet as well as advanced data collection tools across a wide variety of application domains. This has led to an explosive growth of data accumulation from terabytes to petabytes at a dramatic pace, and is already trending towards exabytes. The data flows from various sources including business (Web, e-commerce, transactions, stocks, and business intelligence), science (remote sensing, bioinformatics, Large Hedron Collider, and scientific simulations), and society (news, blogs, forums, and social networks). The heterogeneous nature of such voluminous data dictates the requirement to extract and reveal the summary of knowledge that can be used in tasks such as decision making, event prediction, and pattern extraction. More recently, data mining techniques have also been applied to predict vulnerabilities of Web applications, involving scripts running on multiple sites, for computer security (Shar & T...
• Extensive experience in design and implementation of algorithms for image processing, target tr... more • Extensive experience in design and implementation of algorithms for image processing, target tracking, computer graphics, image databases, data clustering, and information retrieval. • Over 16 years' experience in real-time software development projects. • In-depth experience in Unix (Solaris and Linux) and C/C++ development (both Gnu and Visual Studio); some experience with Linux kernel programming • Experienced in programming Linux cluster using MPI; familiar with grid computing and cloud computing • Over 24 years' experience in teaching various Computer Science courses at both graduate and undergraduate levels, at universities as well as in corporate training environment. • Extensive project management experience for research, academic, and industrial projects. • Knowledge of Windows and network programming.
Image database indexing is used for e'cient retrieval of images in response to a query expres... more Image database indexing is used for e'cient retrieval of images in response to a query expressed as an example image. The query image is processed to extract information that is matched against the index to provide pointers to similar images. We present a technique that facilitates content similarity-based retrieval of JPEG-compressed images without 8rst having to uncompress them. The technique is based on an index developed from a subset of JPEG coe'cients and a similarity measure to determine the di9erence between the query image and the images in the database. This method o9ers substantial e'ciency as images are processed in compressed format, information that was derived during the original compression of the images is reused, and extensive early pruning is possible. Initial experiments with the index have provided encouraging results. The system outputs a set of ranked images in the database with respect to the query using the similarity measure, and can be limited ...
Proceedings of the 1990 Symposium on Applied Computing, 2000
An approach to cluster characterization is developed. The clusters are constructed by using one o... more An approach to cluster characterization is developed. The clusters are constructed by using one of the user-oriented techniques. If the clusters have been characterized on the basis of user preferences, the representations of documents contained within the clusters need not be scanned to determine the relevance of a cluster of documents to a query. Since the cluster representations are decided
Pattern Recognition Letters, Oct 1, 2003
ABSTRACT This paper introduces LocalLines––a robust, high-resolution line detector that operates ... more ABSTRACT This paper introduces LocalLines––a robust, high-resolution line detector that operates in linear time. LocalLines tolerates noisy images well and can be optimized for various specialized applications by adjusting the values of configurable parameters, such as mask values and mask size. As described in this paper, the resolution of LocalLines is the maximum that can be justified for pixelized data. Despite this high resolution, LocalLines is of linear asymptotic complexity in terms of number of pixels in an image. This paper also provides a comparison of LocalLines with the prevalent Hough Transform Line Detector.
Proceedings of the 7th International Conference on Industrial and Engineering Applications of Artificial Intelligence and Expert Systems, 1994
ABSTRACT Image database indexing is used for efficient retrieval of images in response to a query... more ABSTRACT Image database indexing is used for efficient retrieval of images in response to a query expressed as an example image. The query image is processed to extract information that is matched against the index to provide pointers to similar images. We present a technique that facilitates content similarity-based retrieval of jpeg-compressed images without first having to uncompress them. The technique is based on an index developed from a subset of jpeg coefficients and a similarity measure to determine the difference between the query image and the images in the database. This method offers substantial efficiency as images are processed in compressed format, information that was derived during the original compression of the images is reused, and extensive early pruning is possible. Initial experiments with the index have provided encouraging results. The system outputs a set of ranked images in the database with respect to the query using the similarity measure, and can be limited to output a specified number of matched images by changing the threshold match.
Proceedings of the 1993 Acm Sigapp Symposium on Applied Computing States of the Art and Practice, Mar 1, 1993
Clustering is employed in information retrieval systems to enhance the efficiency and effect iven... more Clustering is employed in information retrieval systems to enhance the efficiency and effect iveneas of the retrieval process. Clustering is achieved by partitioning the documents in a collection into classes such that documents that are jointly relevant to some topics are sssigned to the same cluster. This relevance can be determined by examining the index term representation of documents or
Pattern Recognition
Chang and S.-Y. Lee. Retrieval of similar pictures on pictorial databases.Patter Recogitio, 24(7)... more Chang and S.-Y. Lee. Retrieval of similar pictures on pictorial databases.Patter Recogitio, 24(7):675 680, 1991.S. K. Bhatia and C. L. Sabharwal. A fast implementation of a perfect hashfunction for picture objects. Patter lrlecogitio, 27(3):365 376, 1994.Z. J. Czech and B. S. Majewski. A linear time algorithm for finding minimalperfect hash functions. The Computer Joural, 36(6):579 587, 1993.M. Dietzfelbinger, A. Karlin, K. Mehlhorn, F. Heide, H. Rohnert, and R. E. Tar-jan. Dynamic...
The Journal of Visualization and Computer Animation
Regular expressions provide a powerful tool for textual search in computers. The language of regu... more Regular expressions provide a powerful tool for textual search in computers. The language of regular expressions forms the basis for many applications and languages in computers, including vi, sed, awk, and perl. In this article, I'll present the use of regular expressions to perform search and replace operations, using vi, sed, and awk as the applications.
Computer Animation and Virtual Worlds
This paper presents a generalized solution to modelling hydraulic erosion using ideas from fluid ... more This paper presents a generalized solution to modelling hydraulic erosion using ideas from fluid mechanics. The model is based on the Navier–Stokes equations, which provide the dynamics of velocity and pressure. These equations form the basis for the model to balance erosion and deposition that determine changes in the layers between water and erosion material. The eroded material is captured and relocated by water according to a material transport equation. The resulting model is fully 3D and is able to simulate a variety of phenomena including river meanders, low hill sediment wash, natural water springs and receding waterfalls. The simulations show the terrain morphogenesis and can be used for animations as well as for static scene generation. Copyright © 2006 John Wiley & Sons, Ltd.
Proceedings of the fourteenth international conference on Genetic and evolutionary computation conference - GECCO '12, 2012
ABSTRACT This paper proposes a hybrid genetic algorithm to perform image segmentation based on ap... more ABSTRACT This paper proposes a hybrid genetic algorithm to perform image segmentation based on applying the q-state Potts spin glass model to a grayscale image. First, the image is converted to a set of weights for a q-state spin glass and then a steady-state genetic algorithm is used to evolve candidate segmented images until a suitable candidate solution is found. To speed up the convergence to an adequate solution, hierarchical local search is used on each evaluated solution. The results show that the hybrid genetic algorithm with hierarchical local search is able to efficiently perform image segmentation. The necessity of hierarchical search for these types of problems is also clearly demonstrated.
Proceedings of the 1992 ACM/SIGAPP Symposium on Applied computing technological challenges of the 1990's - SAC '92, 1992
ABSTRACT An abstract is not available.
Documenta Ophthalmologica Proceedings Series, 1997
We report data from experiments measuring reaction times necessary to discriminate human faces fr... more We report data from experiments measuring reaction times necessary to discriminate human faces from non-faces. The study is a continuation of our previous work 1] to establish a benchmark in human face recognition using degraded images. A two-alternative forced-choice (2afc) experiment is used. Both stimulus images (face/non-face) are uniformly degraded in terms of the number of pixels (using a modi cation of the Haar wavelet) and the number of gray scales.
Proceedings of the second international conference on Information and knowledge management - CIKM '93, 1993
Personal construct theory is one of the important tools for knowledge acquisition. It provides an... more Personal construct theory is one of the important tools for knowledge acquisition. It provides an expert's opinion of the relationship between objects and their properties in the form of a repertory grid. The current techniques provide the repertory grid in the form of a matrix of integers. This paper describes the preliminary attempts for elicitation and analysis of repertory grid using a range of integers for each relationship. Such an elicitation leads to a more natural description of the expert's knowledge in addition to a better user interface.
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Papers by Sanjiv K. Bhatia