8884680
Using Segmented Objects in Ostensive Video Shot Retrieval
This paper presents a system for video shot retrieval in which shots are retrieved based on matching video objects using a combination of colour, shape and texture. Rather than matching on individual objects, our system supports sets of query objects which in total reflect the user's object-based information need. Our work also adapts to a shifting user information need by initiating the partitioning of a user's search into two or more distinct search threads, which can be followed by the user in sequence. This is an automatic process which maps neatly to the ostensive model for information retrieval in that it allows a user to place a virtual checkpoint on their search, explore one thread or aspect of their information need and then return to that checkpoint to then explore an alternative thread. Our system is fully functional and operational and in this paper we illustrate several design decisions we have made in building it.
15989010
Interactive Object-Based Retrieval Using Relevance Feedback
In this paper we present an interactive, object-based video retrieval system which features a novel query formulation method that is used to iteratively refine an underlying model of the search object. As the user continues query composition and browsing of retrieval results, the system’s object modeling process, based on Gaussian probability distributions, becomes incrementally more accurate, leading to better search results. To make the interactive process understandable and easy to use, a custom user-interface has been designed and implemented that allows the user to interact with segmented objects in formulating a query, in browsing a search result, and in re-formulating a query by selecting an object in the search result.
5988668
Using text search for personal photo collections with the MediAssist system
The MediAssist system enables organisation and searching of personal digital photo collections based on contextual information, content-based analysis and semi-automatic annotation. One mode of user interaction uses automatically extracted features to create text surrogates for photos, which enables text search of photo collections without manual annotation. Our evaluation shows that this text search facility is effective for known-item search.
6879205
Mobile access to personal digital photograph archives
Handheld computing devices are becoming highly connected devices with high capacity storage. This has resulted in their being able to support storage of, and access to, personal photo archives. However the only means for mobile device users to browse such archives is typically a simple one-by-one scroll through image thumbnails in the order that they were taken, or by manually organising them based on folders. In this paper we describe a system for context-based browsing of personal digital photo archives. Photos are labeled with the GPS location and time they are taken and this is used to derive other context-based metadata such as weather conditions and daylight conditions. We present our prototype system for mobile digital photo retrieval, and an experimental evaluation illustrating the utility of location information for effective personal photo retrieval.
15518000
MediAssist: Using Content-Based Analysis and Context to Manage Personal Photo Collections
We present work which organises personal digital photo collections based on contextual information, such as time and location, combined with content-based analysis such as face detection and other feature detectors. The MediAssist demonstration system illustrates the results of our research into digital photo management, showing how a combination of automatically extracted context and content-based information, together with user annotation, facilitates efficient searching of personal photo collections.
586486
Object-Based Access to TV Rushes Video
Recent years have seen the development of different modalities for video retrieval. The most common of these are (1) to use text from speech recognition or closed captions, (2) to match keyframes using image retrieval techniques like colour and texture [6] and (3) to use semantic features like “indoor”, “outdoor” or “persons”. Of these, text-based retrieval is the most mature and useful, while image-based retrieval using low-level image features usually depends on matching keyframes rather than whole-shots. Automatic detection of video concepts is receiving much attention and as progress is made in this area we will see consequent impact on the quality of video retrieval. In practice it is the combination of these techniques which realises the most useful, and effective, video retrieval as shown by us repeatedly in TRECVid [5].
8279890
Location tracking using quorums in mobile ad hoc networks
Abstract We explore applications of quorum systems to the problem of tracking locations of mobile users in mobile ad hoc networks (MANETs). The location tracking system uses biquorum systems, a generalization of traditional quorum systems. We performed extensive simulations of the location tracking system. The simulation results show that our strict biquorum implementation has better performance than the traditional strict quorum implementations. Moreover, our results show that randomized dynamic quorum implementations have better overall performance than strict (bi)quorum implementations.
26056268
A Unified Hardware/Software Approach for Reducing Context Switching Time with Multiple Tasks
10735662
MAS platforms as an enabler of enterprise mobilisation: the state of the art
One of the main application areas for multi-agent systems technology is enterprise mobilization, wherein the main business process actors are nomadic workers. An agent's autonomy, sociality and intelligence are highly prized features when it comes to supporting those mobile workers who are geographically isolated from the main knowledge source (i.e. the corporate Intranet) and are frequently moving from one location to another. Based on experience gained from two field trials of applications (built using for multi-agent systems technology and running on lightweight handheld devices) that support mobile business processes for telecommunications service provisioning and maintenance, this paper proposes desirable metrics for any multi-agent systems platform intended for enterprise mobilisation use. These metrics are then used to compare a number of existing multi-agent systems platforms, and based on the results, this paper identifies some areas for improvement.
5620319
Extraction of digital elevation models from satellite stereo images through stereo matching based on epipolarity and scene geometry
This paper addresses the problem of generating digital elevation models from satellite images taken by linear pushbroom cameras. Since there exist unique geometric properties for linear pushbroom images, we argue that the conventional DEM generation schemes developed for perspective images are not suitable for satellite images. Using the geometric properties of linear pushbroom images, we design a new matching strategy optimized for linear pushbroom image in three aspects: conjugate search method, correlation patch design and match sequence determination. We will discuss in what aspect conventional approaches and our new approach differ and show how performance has improved by hiring proper techniques. A series of experiments using SPOT panchromatic stereo pairs showed that our approach outperformed conventional approaches in terms of accuracy and processing time. q 2003 Elsevier B.V. All rights reserved.
46208894
Evaluation of Feature Extraction Techniques for Robust Watermarking
This paper addresses feature extraction techniques for robust watermarking. Geometric distortion attacks desynchronize the location of the inserted watermark and hence prevent watermark detection. Watermark synchronization, which is a process of finding the location for watermark insertion and detection, is crucial to design robust watermarking. One solution is to use image features. This paper reviews feature extraction techniques that have been used in featurebased watermarking: the Harris corner detector and the Mexican Hat wavelet scale interaction method. We also evaluate the scale-invariant keypoint extractor in comparison with other techniques in aspect of watermarking. After feature extraction, the set of triangles is generated by Delaunay tessellation. These triangles are the location for watermark insertion and detection. Redetection ratio of triangles is evaluated against geometric distortion attacks as well as signal processing attacks. Experimental results show that the scale-invariant keypoint extractor is appropriate for robust watermarking.