Queries referring to content embedded within images are an essential component of content-based search, browse, or summarize operations in imagedatabases. Localization of such queries under changes in appearance, occ...
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Queries referring to content embedded within images are an essential component of content-based search, browse, or summarize operations in imagedatabases. Localization of such queries under changes in appearance, occlusions and background clutter, is a difficult problem, for which current spatial access structures in databases are not suitable. In this paper we present a new method of indexing imagedatabases called location hashing that uses a special data structure called the location hash tree (LHT) for organizing feature information from images of a database. Location hashing is based on the principle of geometric hashing and determines simultaneously, the relevant images in the database and the regions within them that are most likely to contain a 2d pattern query without incurring detailed search of either. the location hash tree being a red-black tree, allows for efficient search for candidate locations using pose-invariant feature information derived from the query.
Withthe abstraction of digital video as the corresponding binary video- a process which upon numerous subjective experimentation seems to preserve (most of the) intelligibility of video content- we can pursue a preci...
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Withthe abstraction of digital video as the corresponding binary video- a process which upon numerous subjective experimentation seems to preserve (most of the) intelligibility of video content- we can pursue a precise and analytic approach to (digital videostorage and retrieval) algorithm design that are based upon geometrical (morphological) intuition. the foremost and tangible general benefit of such abstraction, however, is the immediate reductions of both data and computational complexities involved in implementing various algorithms and databases. the general paradigm presented may be utilized to address all issues pertaining to video library construction including visualization, optimum feedback query generation, object recognition, e.t.c., but the primary focus of attention in this paper are the ones pertaining to detection of fast (including presence of flashlights) and gradual scene changes (such as dissolves, fades, and various special effects such as wipes). Upon simulation we observed that we can achieve performances comparable to those of others with drastic reductions in bothstorage and computational complexities. Furthermore, since the conversion from grayscale to binary videos can be performed directly (with minimal additional computation) in the compressed domain by thresholding on the DCT DC coefficients themselves (or by using the contour information attached to MPEG4 formats), the algorithms presented herein are ideally suited for performing fast (on-the-fly) determinations of scene change, object recognition and/or tracking, and other more intelligent tasks traditionally requiring heavy demand on computational and/or storage complexities. the fast determinations may then be used on their own merits or can be used in conjunction or complementation with other higher-layer information in the future.
the Fractal Transform (FT) was originally introduced as a methodology for compressing digital images and representing them at different scales. the process of calculating an FT generates a great deal of information ab...
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the Fractal Transform (FT) was originally introduced as a methodology for compressing digital images and representing them at different scales. the process of calculating an FT generates a great deal of information about the affine similarities and dissimilarities of an image, most of which is discarded in compression applications. In this paper we introduce the concept of Fractal Transform Analysis and use it to derive new image descriptors. We present results of experiments in which description schemes comprised of some of these FT-based descriptors are applied to the problems of finding objects in an image similar to a given object, of indexing images, and of querying an image database consisting of about 17,000 images. Complexity and timing data are also presented.
While current approaches for video segmentation and indexing are mostly focused on visual information, audio signals may actually play a primary role in video content parsing. In this paper, we present an approach for...
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While current approaches for video segmentation and indexing are mostly focused on visual information, audio signals may actually play a primary role in video content parsing. In this paper, we present an approach for automatic segmentation, indexing, and retrieval of audiovisual data based on audio content analysis. the accompanying audio signal of audiovisual data is first segmented and classified into basic types, i.e. speech, music, environmental sound, and silence. this coarse-level segmentation and indexing step is based on morphological and statistical analysis of several short-term features of the audio signals. then, environmental sounds are classified into finer classes such as applause, explosion, bird's sound, etc. this fine-level classification and indexing step is based on time-frequency analysis of audio signals and the use of hidden Markov model (HMM) as the classifier. On top of this archiving scheme, an audiovisual data retrieval system is proposed. Experimental results show that the proposed approach has an accuracy rate higher than 90% for the coarse-level classification, and higher than 85% for the fine-level classification. Examples of audiovisual data segmentation and retrieval are also provided.
Recent research on imagedatabases has been aimed at the development of content-based retrieval techniques for the management of visual information. Compared with such visual information as color, texture, and spatial...
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Recent research on imagedatabases has been aimed at the development of content-based retrieval techniques for the management of visual information. Compared with such visual information as color, texture, and spatial constraints, shape is so important a feature associated withthose image objects of interest that shape alone may be sufficient to identify and classify an object completely and accurately. this paper presents a novel method based on feature point histogram indexing for object shape representation in imagedatabases. In this scheme, the feature point histogram is obtained by discretizing the angles produced by the Delaunay triangulation of a set of unique feature points which characterize object shape in the context, and then counting the number of times each discrete angle occurs in the resulted triangulation. the proposed shape representation technique is translation, scale, and rotation independent. Our various experiments concluded that the Euclidean distance performs very well as the similarity measure function in combination withthe feature point histogram computed by counting the two largest angles of each individual Delaunay triangle. through the further experiment, we also found evidence that an image object representation using a feature point histogram provides an effective cue for image object discrimination.
this article describes the use of gesture recognition techniques in computer vision as a natural interface for video content navigation, and the design of a navigation and browsing system that caters to these natural ...
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this article describes the use of gesture recognition techniques in computer vision as a natural interface for video content navigation, and the design of a navigation and browsing system that caters to these natural means of computer-human interaction. For consumer applications, video content navigation presents two challenges: (1) how to parse and summarize multiple video streams in an intuitive and efficient manner, and (2) what type of interface will enhance the ease of use for video browsing and navigation in a living room setting or an interactive environment. In this paper, we address the issues and propose the techniques that combine video content navigation with gestures, seamlessly and intuitively, in an integrated system. the current framework can incorporate speech recognition technology. We present a new type of browser for browsing and navigating video content, as well as a gesture recognition interface for this browser.
In this paper we propose a method for tracking a video object in an ordered sequence of two-dimensional images, where the outcome is the trajectory of the video object throughout the time sequence of images. this meth...
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In this paper we propose a method for tracking a video object in an ordered sequence of two-dimensional images, where the outcome is the trajectory of the video object throughout the time sequence of images. this method is designed to run in real-time in a synchronous video collaboration environment, and used for producing dynamic object annotations for enhanced video content understanding. A dynamic object is an object whose location or size in the video frame constantly changes due to the camera motion, the motion of its own, or both. We suggest a novel method for finding the trajectory of the object in the intermediate frames given the locations and shapes of the object in two end frames. In addition to the shape and location information of the object, its texture information in the end frames is used to predict the location and search space of it in the intermediate frames.
For the last few years, shot boundary detection has been recognized as an important research issue on videoretrieval. Also as a preliminary step for the task, it is essential to extract salient features from videos. ...
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For the last few years, shot boundary detection has been recognized as an important research issue on videoretrieval. Also as a preliminary step for the task, it is essential to extract salient features from videos. Recently, it has become common to perform the two tasks in compressed domain to alleviate their computational costs. In this paper, we propose novel shot boundary detection technique, which uses two feature images, or DC and edge images, extracted directly from MPEG compressed video. While a DC image can be easily obtained, edge image extraction usually requires considerable computational burden. For fast edge image extraction, we suggest to utilize only a few AC coefficients of each DCT block in motion compensated P-frames and B-frames as well as I-frames. this drastically reduces the computational burden compared to edge extraction in the spatial domain. In order to further reduce the computational burden, another edge image extraction technique is also suggested on the basis of AC prediction using DC images. By using the edge energy diagram obtained from edge images and histograms from DC images, shot boundaries such as abrupt transitions, fades, and dissolves are detected automatically. Simulation results show that the proposed techniques are fast and effective.
Withthe currently existing shot change detection algorithms, abrupt changes are detected fairly well. It is thus more challenging to detect gradual changes including fades, dissolves, and wipes as these are often mis...
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Withthe currently existing shot change detection algorithms, abrupt changes are detected fairly well. It is thus more challenging to detect gradual changes including fades, dissolves, and wipes as these are often missed or falsely detected. In this paper, we focus on the detection of wipes. the proposed algorithm begins by processing the visual rhythm, a portion of the DC image sequence. It is a single image, a sub-sampled version of a full video in which the sampling is performed in a pre-determined and in a systematic fashion. the visual rhythm contains distinctive patterns or visual features for many different types of video effects. the different video effects manifest themselves differently on the visual rhythm. In particular, wipes appear as curves that run from the top to the bottom of the visual rhythm. thus, using the visual rhythm, it becomes possible to automatically detect wipes simply by determining various lines and curves on the visual rhythm.
A novel similarity measure based on the Choquet integral was introduced for retrieving images from a image database that "mostly" fit the query image. We showed that in certain conditions the measure is a no...
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ISBN:
(纸本)0819431273
A novel similarity measure based on the Choquet integral was introduced for retrieving images from a image database that "mostly" fit the query image. We showed that in certain conditions the measure is a norm, a fact that can be used to reduce the searching time using the triangle inequality. To test the new measure, a content based imageretrieval system was built. the system was benchmarked against the visual retrieval cartridge, Virage, built into Oracle 8 database system. the results suggested that the new measure is useful for imageretrieval.
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