Santanu Chaudhury

Bio: Santanu Chaudhury is an academic researcher from Indian Institute of Technology, Jodhpur. The author has contributed to research in topics: Ontology (information science) & Image segmentation. The author has an hindex of 28, co-authored 380 publications receiving 3691 citations. Previous affiliations of Santanu Chaudhury include Central Electronics Engineering Research Institute & Indian Institute of Technology Delhi.

Characterizing user-subgroups in Flickr Group: A block LDA based approach

Abstract: The last few years have seen an exponential increase in the amount of multimedia content that is available online thanks to collaborative-online communities such as Flickr, You Tube etc. As opposed to “pure” social networking services these collaborative-online communities not only allow users to create new social links (e.g. add people to one's friend list) but also allow users to contribute multimedia content and engage in content-driven interactions. A good example of this can be seen in Flickr, in general and Flickr Group in particular where users can comment on or “like” an image contributed by another user. This paper looks at utilizing this within group user-user interaction information, along with image meta-data to discover user communities (user-subgroups) that contribute content around specific topics (subgroup-themes) at specific points in time. A good example of this is a group of users (e.g sports fans) contributing content and interacting with each other only at specific times of the year (e.g close to their favorite sporting event). We demonstrate that our proposed generative model Temporal BlockLink LDA is able to successfully extract such user-subgroups, subgroup-themes and associated temporal patterns from data in an unsupervised manner.

Video Shot Characterization Using Principles of Perceptual Prominence and Perceptual Grouping in Spatio–Temporal Domain

Abstract: We present a novel approach for applying perceptual grouping principles to the spatio-temporal domain of video. Our perceptual grouping scheme, applied on blobs, makes use of a specified spatio-temporal coherence model. The grouping scheme identifies the blob cliques or perceptual clusters in the scene. We propose a computational model for analyzing a video shot based on a novel principle of perceptual prominence. The principle of perceptual prominence captures the key aspects of mise-en-scene required for characterizing a video scene.

Hierarchical System for Content Based Categorization and Orientation of Consumer Images

Abstract: A hierarchical framework to perform automatic categorization and reorientation of consumer images based on their content is presented. Sometimes the consumer rotates the camera while taking the photographs but the user has to later correct the orientation manually. The present system works in such cases; it first categorizes consumer images in a rotation invariant fashion and then detects their correct orientation. It is designed to be fast, using only low level color and edge features. A recently proposed information theoretic feature selection method is used to find most discriminant subset of features and also to reduce the dimension of feature space. Learning methods are used to categorize and detect the correct orientation of consumer images. Results are presented on a collection of about 7000 consumer images, collected by an independent testing team, from the internet and personal image collections.

Method and system for content based image categorization

Abstract: PURPOSE: A method, device and system are provided to classify an image based on content which improved accuracy of an image classification and reduce a processing time. CONSTITUTION: An electronic device(105) includes an identification unit(160), a extracting unit(165), a determining unit(170), a grouped unit(175), an index unit(180), and a classifying unit(185). The identification unit identifying unit identifies at least one interest area from a plurality of images which is related to a category. The extracting unit extracts a plurality of pixels from at least one identified interest areas. The determining unit determines color values about extracted pixels. The grouped unit groups the color values in a code book corresponding to a category.

A novel variety-based 3DTV content generation scheme for casually captured sparse photo collections

Abstract: This paper presents a novel parameterized variety-based 3D exploration model to comprehend the sparse unstructured collection of photographs, and automatically plan virtual 3D tours of the world's landmarks through interesting viewpoints without explicit 3D reconstruction. The proposed system analyzes the collection of unstructured but related image data containing the same location or environment to create a parameterized scene graph: a data structure that conveys spatial relations and enable smooth virtual navigation between photos. A novel statistical-heuristic criteria is evolved exploiting the scene spatial layout and appearance to automatically identify best available portals between photographs. Once well connected, the graph is parameterized and consistently rendered choosing visually compelling 3D transition paths, maintaining a pleasing essence of parallax. The system's ability is demonstrated on several casually captured personal photo collections of heritage sites and imagery gathered from “Flickr” data.

Data clustering: a review

Abstract: Clustering is the unsupervised classification of patterns (observations, data items, or feature vectors) into groups (clusters). The clustering problem has been addressed in many contexts and by researchers in many disciplines; this reflects its broad appeal and usefulness as one of the steps in exploratory data analysis. However, clustering is a difficult problem combinatorially, and differences in assumptions and contexts in different communities has made the transfer of useful generic concepts and methodologies slow to occur. This paper presents an overview of pattern clustering methods from a statistical pattern recognition perspective, with a goal of providing useful advice and references to fundamental concepts accessible to the broad community of clustering practitioners. We present a taxonomy of clustering techniques, and identify cross-cutting themes and recent advances. We also describe some important applications of clustering algorithms such as image segmentation, object recognition, and information retrieval.

Computer vision : a modern approach = 计算机视觉 : 一种现代的方法

Abstract: From the Publisher: The accessible presentation of this book gives both a general view of the entire computer vision enterprise and also offers sufficient detail to be able to build useful applications. Users learn techniques that have proven to be useful by first-hand experience and a wide range of mathematical methods. A CD-ROM with every copy of the text contains source code for programming practice, color images, and illustrative movies. Comprehensive and up-to-date, this book includes essential topics that either reflect practical significance or are of theoretical importance. Topics are discussed in substantial and increasing depth. Application surveys describe numerous important application areas such as image based rendering and digital libraries. Many important algorithms broken down and illustrated in pseudo code. Appropriate for use by engineers as a comprehensive reference to the computer vision enterprise.

Online and off-line handwriting recognition: a comprehensive survey

Abstract: Handwriting has continued to persist as a means of communication and recording information in day-to-day life even with the introduction of new technologies. Given its ubiquity in human transactions, machine recognition of handwriting has practical significance, as in reading handwritten notes in a PDA, in postal addresses on envelopes, in amounts in bank checks, in handwritten fields in forms, etc. This overview describes the nature of handwritten language, how it is transduced into electronic data, and the basic concepts behind written language recognition algorithms. Both the online case (which pertains to the availability of trajectory data during writing) and the off-line case (which pertains to scanned images) are considered. Algorithms for preprocessing, character and word recognition, and performance with practical systems are indicated. Other fields of application, like signature verification, writer authentification, handwriting learning tools are also considered.