As a new research field on controlling science and engineering, fractional-order control gets more and more concerning. This article provides an overview of fractional-order control of background and basic knowledge o...
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In this paper, we evaluate and investigate two main types of relevance feedback algorithms;the Euclidean and the correlation-based approaches. In the first case, we examine heuristic and optimal techniques, which expl...
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ISBN:
(纸本)0780377508
In this paper, we evaluate and investigate two main types of relevance feedback algorithms;the Euclidean and the correlation-based approaches. In the first case, we examine heuristic and optimal techniques, which exploit either on the weighted or the generalized Euclidean distance. In the second type, two different ways for parametrizing the cross-correlation similarity metric are proposed. The first scales only the elements of the query feature vector, while the second scales both the query and the selected samples. All the examined algorithms are evaluated using objective criteria, such as the precision -recall curve and the average normalized modified retrieval rank (ANMRR). Discussions and comparisons of all the aforementioned relevance feedback algorithms are presented.
Aiming at the available edge detection algorithms can not effectively extract the edge information for low SNR image, a new edge detection algorithm for low SNR image based on mixed filter is proposed in this paper. W...
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Recently, a new class of image coding algorithms coupling standard scalar quantization of frequency coefficients with tree-structured quantization (related to spatial structures) has attracted wide attention because i...
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Recently, a new class of image coding algorithms coupling standard scalar quantization of frequency coefficients with tree-structured quantization (related to spatial structures) has attracted wide attention because its good performance appears to confirm the promised efficiencies of hierarchical representation [1], [2]. This paper addresses the problem of how spatial quantization modes and standard scalar quantization can be applied in a jointly optimal fashion in an image coder. We consider zerotree quantization (zeroing out tree-structured sets of wavelet coefficients) and the simplest form of scalar quantization (a single common uniform scalar quantizer applied to all nonzeroed coefficients), and we formalize the problem of optimizing their joint application. We develop an image coding algorithm for solving the resulting optimization problem, Despite the basic form of the two quantizers considered, the resulting algorithm demonstrates coding performance that is competitive, often outperforming the very best coding algorithms in the literature.
This paper presents an effort to define a method for evaluation of parallel architectures dedicated to vision. A definition of the benchmark concept, and a characterisation of a standard set of general-purpose vision ...
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This paper presents an effort to define a method for evaluation of parallel architectures dedicated to vision. A definition of the benchmark concept, and a characterisation of a standard set of general-purpose vision algorithms which could constitue a benchmark are proposed. These algorithms are independent of machine architecture, environments, programming models and parallelisation techniques supported. A detailed example illustrating the proposed approach is given.
We present a probabilistic complexity analysis of a class of multi-stage algorithms which incrementally refine DFT approximations. Each stage of any algorithm in this class improves the results of the previous stage b...
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We present a probabilistic complexity analysis of a class of multi-stage algorithms which incrementally refine DFT approximations. Each stage of any algorithm in this class improves the results of the previous stage by a fixed increment in one of three dimensions: SNR, frequency resolution, or frequency coverage. However, the complexity of each stage is probabilistically dependent upon certain characteristics of the input signal. Assuming that an algorithm has to be terminated before its arithmetic cost exceeds a given limit, we have formulated a method for predicting the probability of completion of each of the algorithm's stages. This analysis is useful for low-power and real-time applications where FFT algorithms cannot meet the specified limits on arithmetic cost.
Kalman filters are an important technique for building fault-tolerance into a wide range of systems, including real-time imaging. From a software engineering perspective, however, it is not easy to build Kalman filter...
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Kalman filters are an important technique for building fault-tolerance into a wide range of systems, including real-time imaging. From a software engineering perspective, however, it is not easy to build Kalman filters. Each has to be custom designed and most software engineers are not sufficiently grounded in the necessary systems theory to perform this design. The contributions of this paper, therefore, are a set of recipes for implementation of the Kalman filter to a variety of real-time imaging settings, the presentation of a set of object-oriented requirements, and a design for a class of Kalman filters suitable for real-time imageprocessing. First, we describe the Kalman filter and motivate its use as a mechanism for fault-tolerant computing and sensor fusion. Next, the details of using Kalman filters in imaging applications are discussed and several associated algorithms presented. Then, the advantages of using object-oriented specification, design and languages for the implementation of Kalman filters are explored. Finally, we present a specification and design for a class of Kalman filters, which is suitable for coding. This work extends significantly upon that first appearing in 2003 at an SPIE conference (Laplante and Neill, proceedings of the real-time imaging conference, SPIE, Santa Clara, January 2003, pp. 22-29). (C) 2003 Elsevier Ltd. All rights reserved.
In this study, an image coding algorithm based on directional lifting wavelet transform (DLWT) and universal trellis-coded quantisation (UTCQ) is presented, and the coding performance is evaluated with three objective...
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In this study, an image coding algorithm based on directional lifting wavelet transform (DLWT) and universal trellis-coded quantisation (UTCQ) is presented, and the coding performance is evaluated with three objective image quality metrics. Compared to the discrete wavelet transform, DLWT performing prediction and update along the direction of the local region can provide an efficient representation of edges in images, but shows a similar ability in representing the smooth region. To further improve the visual quality of the smooth background regions, UTCQ is adopted to quantising the wavelet coefficients. The proposed algorithm is measured with not only the dominant peak signal-to-noise ratio (PSNR), but also new metrics multi-scale structural similarity index measure (MSSIM) and visual information fidelity (VIF) which provide a better approximation to the perceived image quality than PSNR by taking the property of human visual system (HVS) into account. Experimental results show that the proposed algorithm has the best MSSIM and VIF performance among the compared algorithms (including JPEG2000) for the typical test images, and its decoded images at low bit-rate are visually more appealing in both edges and smooth background regions. For image Barbara, the proposed algorithm outperforms JPEG2000 up to 24.63% relatively in VIF and 1.93 dB in PSNR at 0.5 bpp, at most 3.62% relatively in MSSIM at 0.125 bpp. The experimental results also show that UTCQ does perform better than scalar quantisation (SQ) in MSSIM and VIF and improves the subjective visual quality, although UTCQ is not necessarily better than SQ in PSNR.
Many computer vision and imageprocessingalgorithms rely on the knowledge of the image noise variance as their input. parameter. However, in practice, the distinction between noise and image features is not easy to d...
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ISBN:
(纸本)0819452017
Many computer vision and imageprocessingalgorithms rely on the knowledge of the image noise variance as their input. parameter. However, in practice, the distinction between noise and image features is not easy to draw. In this paper, image noise variance is estimated by a novel method employing rigorously derived polynomial masks. The method is based on the assumption that the image can be locally represented as a polynomial of the given degree and constitutes a generalization of some of previously proposed approaches.
Large gains in the automation of human detection and tracking techniques have been made over the past several years. Several of these techniques have been implemented on larger robotic platforms, in order to increase ...
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ISBN:
(纸本)9780819475985
Large gains in the automation of human detection and tracking techniques have been made over the past several years. Several of these techniques have been implemented on larger robotic platforms, in order to increase the situational awareness provided by the platform. Further integration onto a smaller robotic platform that already has obstacle detection and avoidance capabilities would allow these algorithms to be utilized in scenarios that are not plausible for larger platforms, such as entering a building and surveying a room for human occupation with limited operator intervention. However, transitioning these algorithms to a man-portable robot imparts several unique constraints, including limited power availability, size and weight restrictions, and limited processor ability. Many imaging sensors, processing hardware, and algorithms fail to adequately address one or more of these constraints. In this paper, we describe the design of a payload suitable for our chosen man-portable robot, the iRobot Packbot. While the described payload was built for a Packbot, it was carefully designed in order to be platform agnostic, so that it can be used on any man-portable robot. Implementations of several existing motion and face detection algorithms that have been chosen for testing on this payload are also discussed in some detail.
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