Baseline information has been used for diverse purposes in handwriting research. The baseline represents a first orientation in a word and it is often a precondition for subsequent algorithms, including preprocessing ...
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ISBN:
(纸本)0769516920
Baseline information has been used for diverse purposes in handwriting research. The baseline represents a first orientation in a word and it is often a precondition for subsequent algorithms, including preprocessing tasks, segmentation and feature extraction for recognition systems. Approaches based on the horizontal projection histogram are used for Arabic printed text but they are ill-suited for Arabic handwritten words. In this paper we present a method that is completely based on polygonally approximated skeleton processing. The central algorithm is concerned with finding features in the skeleton and processing linear regression analysis. Our method performs very well as long as the model assumption of one straight line applies. We tested the method on 26459 isolated Tunisian town names written by 411 writers (IFNIENIT-database).
This paper deals with the issue of combining fuzzy results obtained from two individual systems in multimedia query processing. Consider a query such as retrieve images similar to I_1 by color AND with associated text...
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ISBN:
(纸本)0909925836
This paper deals with the issue of combining fuzzy results obtained from two individual systems in multimedia query processing. Consider a query such as retrieve images similar to I_1 by color AND with associated text flower. Suppose we have a color subsystem which can return a sorted list of images based on similarity with I_1 and a text subsystem which can return a sorted list of images based on similarity with flower. Our task is to combine these two results. In other words, we need to evaluate the fuzzy combining function AND, giving a sorted list of the images. Fagin has proved that the probabilistic complexity of the problem is almost linear (Fagin 1996), and our multi-step algorithm (Nepal & *** 1999) is an optimal uniform algorithm (Fagin, Lotem & Naor 2001). In view of this inherent limitation, we investigated a non-uniform heuristic approach. In this paper, we discuss the problems of processing such queries, also referred to as aggregation queires in multimedia databases. The experimental results presented show that our "minimum depth first search" heuristic approach outperforms other uniform algorithms in general and by over 90% when the distribution of similarity values is not uniform.
3D reconstruction on large aperture PET systems based on rotating LSO panel detectors is a challenge due to the large amount of data. When reconstruction time is critical, fast reconstruction methods are attractive de...
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3D reconstruction on large aperture PET systems based on rotating LSO panel detectors is a challenge due to the large amount of data. When reconstruction time is critical, fast reconstruction methods are attractive despite the potential image quality loss due to rebinning approximation and the large polar aperture angle. This work validates a new data processing suite aimed at processing 3D data for two new PET scanner prototypes using two and five rotating LSO panel detectors, respectively. The processing includes /spl mu/-map reconstruction, generation of a 3D attenuation correction, scatter correction and image reconstruction with FORE(J)+OSEM2D and weighted OSEM3D schemes. The validation is based on reconstructing images for simulated wholebody FDG data with realistic random and scatter fractions and given statistics. The same processing suite was applied on experimental data acquired at intermediate statistics on a contrast sphere phantom and on a low statistics FDG wholebody study. Despite the large polar aperture angle, the image quality obtained with FORE(J)+OSEM2D was in excellent agreement with those obtained with time consuming methods such as OSEM3D. The loss in axial resolution from FOREJ to FORE was assessed from noiseless data. We also observed that, on low statistics wholebody data, FOREJ as implemented, required sinogram rebinning and smoothing to control the noise which offsets the benefits of the exact rebinning. The best images in terms of resolution and contrast were obtained with OSEM3D but they required precise normalization and deadtime corrections to avoid ring and banding artifacts.
The principal constituents of computational intelligence are fuzzy logic, neural networks and evolutionary algorithms, with emphasis in their mutual enhancement. The present paper reviews some applications of these fo...
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The principal constituents of computational intelligence are fuzzy logic, neural networks and evolutionary algorithms, with emphasis in their mutual enhancement. The present paper reviews some applications of these formalisms in the area of medical imageprocessing, where advantage is taken from the ability of fuzzy logic to work with imprecise information, the ability of neural networks to learn a system's behavior from representative examples and the ability of evolutionary algorithms to optimize complex systems, particularly when no mathematical model is available. The paper focuses mainly on neural networks in medical imageprocessing. A special kind of cellular neural networks based on multiple valued threshold logic in the complex plane will be presented and its efficacy for medical imaging will be documented. (C) 2001 Elsevier Science B.v. All rights reserved.
In this paper we present a brief review and examples of image registration. When one wishes to fuse multiple images from disparate sources, the first step is image registration, finding the appropriate transform which...
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ISBN:
(纸本)0819441856
In this paper we present a brief review and examples of image registration. When one wishes to fuse multiple images from disparate sources, the first step is image registration, finding the appropriate transform which maps pixels in image 1 to the corresponding pixels in image 2. Only after this step one may begin to correctly fuse and process information from both images simultaneously.
One of the main challenges of any control (or imageprocessing) paradigm is being able to handle complex systems under unforeseen uncertainties. A system may be called complex here if its dimension (order) is too high...
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ISBN:
(纸本)0819441856
One of the main challenges of any control (or imageprocessing) paradigm is being able to handle complex systems under unforeseen uncertainties. A system may be called complex here if its dimension (order) is too high and its model (if available) is nonlinear, interconnected, and information on the system is uncertain such that classical techniques cannot easily handle the problem. Examples of complex systems are power networks, space robotic colonies, national air traffic control system, an integrated manufacturing plant the Hubble Telescope, the International Space Station, etc. Soft computing, a consortia of methodologies such as fuzzy logic, neuro-computing, genetic algorithms and genetic programming, has proven to be powerful tools for adding autonomy and semi-autonomy to many complex systems. For such systems the size of soft computing control architecture will be nearly infinite. In this paper new paradigms using soft computing approaches are utilized to design autonomous controllers and image enhancers for a number of application areas. These applications are satellite array formations for synthetic aperture radar interferometry (InSAR) and enhancement of analog and digital images.
Genetic algorithms (GAs) are known to be robust for search and optimization problems. image registration can take advantage of the robustness of GAs in finding best transformation between two images, of the same locat...
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Genetic algorithms (GAs) are known to be robust for search and optimization problems. image registration can take advantage of the robustness of GAs in finding best transformation between two images, of the same location with slightly different orientation, produced by moving spaceborne remote sensing instruments. In this paper, we present 2-phase sequential and coarse-grained parallel image registration algorithms using GAs as optimization mechanism. In its first phase, the algorithm finds a small set of goad solutions using low-resolution versions of the images. Based on these candidate low-resolution solutions, the algorithm uses the full resolution image data to refine the final registration results in the second phase. Experimental results are presented and revealed that our algorithms yield very accurate registration results for LandSat Thematic Mapper images, and the parallel algorithm scales quite well on the Beowulf parallel cluster. (C) 2001 Elsevier Science B.v. All rights reserved.
In this paper, we focus on the total-system-energy minimization of a wireless image transmission system including both digital and analog components. Traditionally, digital power consumption has been ignored in system...
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In this paper, we focus on the total-system-energy minimization of a wireless image transmission system including both digital and analog components. Traditionally, digital power consumption has been ignored in system design, since transmit power has been the most significant component. However, as we move to an era of pico-cell environments and as more complex signal processingalgorithms are being used at higher data rates, the digital power consumption of these systems becomes an issue. We present an energy-optimized image transmission system for indoor wireless applications which exploits the variabilities in the image data and the wireless multipath channel by employing dynamic algorithm transformations and joint source-channel coding. The variability in the image data is characterized by the rate-distortion curve, and the variability in the channel characteristics is characterized by the path-loss and impulse response of the channel. The system hardware configuration space is characterized by the error-correction capability of the channel encoder/decoder, number of powered-up fingers in the RAKE receiver, and transmit power of the power amplifier. An optimization algorithm is utilized to obtain energy-optimal configurations subject to end-to-end performance constraints. The proposed design is tested over QCIF images, IMT-2000 channels and 0.18 mum, 2.5 v CMOS technology parameters. Simulation results over various images, various distances, two different channels, and two different rates show that the average energy savings in utilizing a total-system-energy minimization over a fixed system (designed for the worst image, the worst channel and the maximum distance) are 53.6% and 67.3%, respectively, for short-range (under 20 m) and long-range (over 20 m) systems.
We propose a method of synthesizing computer-generated holograms of real-life three-dimensional (3-D) objects. An ordinary digital camera illuminated by incoherent white light records several projections of the 3-D ob...
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ISBN:
(纸本)0819441856
We propose a method of synthesizing computer-generated holograms of real-life three-dimensional (3-D) objects. An ordinary digital camera illuminated by incoherent white light records several projections of the 3-D object from different points of view. The recorded data are numerically processed to yield a two-dimensional complex function, which is then encoded as a computer-generated hologram. When this hologram is illuminated by a plane wave, a 3-D real image of the object is reconstructed.
A new three-dimensional display system based on a volume-scanning method is demonstrated. To form a three-dimensional real image, an inclined two-dimensional image is rapidly moved with a mirror scanner while the cros...
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ISBN:
(纸本)0819441856
A new three-dimensional display system based on a volume-scanning method is demonstrated. To form a three-dimensional real image, an inclined two-dimensional image is rapidly moved with a mirror scanner while the cross-section patterns of a three-dimensional object are displayed sequentially. A vector-scan CRT display unit is used to obtain a high-resolution image. An optical scanning system is constructed with concave mirrors and a galvanometer mirror. It is confirmed that three-dimensional images, formed by the experimental system, satisfy all the criteria for human stereoscopic vision.
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