The low-level imageprocessing that takes place in the retina is intended to compress the relevant visual information to a manageable size. The behavior of the external layers of the biological retina has been success...
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ISBN:
(纸本)0819449792
The low-level imageprocessing that takes place in the retina is intended to compress the relevant visual information to a manageable size. The behavior of the external layers of the biological retina has been successfully modelled by a Cellular Neural Network, whose evolution can be described by a set of coupled nonlinear differential equations. A mixed-signal vLSI implementation of the focal-plane low-level imageprocessing based upon this biological model constitutes a feasible and cost effective alternative to conventional digital processing in real-time applications. For these reasons, a programmable array processor prototype chip has been designed and fabricated in a standard 0.5mum CMOS technology. The integrated system consists of a network of two coupled layers, containing 32 x 32 elementary processors, running at different time constants. Involved imageprocessingalgorithms can be programmed on this chip by tuning the appropriate interconnections weights. Propagative, active wave phenomena and retina-like effects can be observed in this chip. Design challenges, trade-offs, the buildings blocks and some test results are presented in this paper.
Biometric authentication systems require a fast and accurate method of matching biometric data for identification purposes. This paper introduces a data reduction technique based, on imageprocessing to better embed b...
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ISBN:
(纸本)0819448206
Biometric authentication systems require a fast and accurate method of matching biometric data for identification purposes. This paper introduces a data reduction technique based, on imageprocessing to better embed biometric data in small images. For the most part, biometric. data cannot be directly embedded in small images, because of limited embedding capacities and a large amount of data in biometric images. An imageprocessing technique to extract features from biometric data, like fingerprints and retinal scans, has been developed and tested. This new technique developed to extract features is based on the Hough transform and has been tested on a large volume of real image data. The-data reduction technique was applied to these images and the data reduced to a size, which could be easily embedded in small pictures, like those on identity cards. Existing embedding algorithms were utilized.
From a system level perspective, this paper presents a 128 x 128 flexible and reconfigurable Focal-Plane Analog Programmable Array Processor, which has been designed as a single chip in a 0.35mum standard digital 1P-5...
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ISBN:
(纸本)0819449776
From a system level perspective, this paper presents a 128 x 128 flexible and reconfigurable Focal-Plane Analog Programmable Array Processor, which has been designed as a single chip in a 0.35mum standard digital 1P-5M CMOS technology. The core processing array has been designed to achieve high-speed of operation and large-enough accuracy (similar to7bit) with low power consumption. The chip includes on-chip program memory to allow for the execution of complex, sequential and/or bifurcation flow imageprocessingalgorithms. It also includes the structures and circuits needed to guarantee its embedding into conventional digital hosting systems: external data interchange and control are completely digital. The chip contains close to four million transistors, 90% of them working in analog mode. The chip features up to 330GOPs (Giga Operations per second), and uses the power supply (180GOP/Joule) and the silicon area (3.8 GOPS/mm(2)) efficiently, as it is able to maintain vGA processing throughputs of 100Frames/s with about 15 basic imageprocessing tasks on each frame.
This paper presents single-chip FPGA Rijndael algorithm implementations of the Advanced Encryption Standard (AES) algorithm, Rijndael. In particular, the designs utilise look-up tables to implement the entire Rijndael...
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This paper presents single-chip FPGA Rijndael algorithm implementations of the Advanced Encryption Standard (AES) algorithm, Rijndael. In particular, the designs utilise look-up tables to implement the entire Rijndael Round function. A comparison is provided between these designs and similar existing implementations. Hardware implementations of encryption algorithms prove much faster than equivalent software implementations and since there is a need to perform encryption on data in real time, speed is very important. In particular, Field Programmable Gate Arrays (FPGAs) are well suited to encryption implementations due to their flexibility and an architecture, which can be exploited to accommodate typical encryption transformations. In this paper, a Look-Up Table (LUT) methodology is introduced where complex and slow operations are replaced by simple LUTs. A LUT-based fully pipelined Rijndael implementation is described which has a pre-placement performance of 12 Gbits/sec, which is a factor 1.2 times faster than an alternative design in which look-up tables are utilised to implement only one of the Round function transformations, and 6 times faster than other previous single-chip implementations. Iterative Rijndael implementations based on the Look-Up-Table design approach are also discussed and prove faster than typical iterative implementations.
Spectral (color) and spatial (shape) features available in pictures are sources of information that need to be incorporated for advance content-based image database retrieval. The adaptive shape transform approach dev...
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ISBN:
(纸本)0819448141
Spectral (color) and spatial (shape) features available in pictures are sources of information that need to be incorporated for advance content-based image database retrieval. The adaptive shape transform approach developed in this research is originated from the premise that a two-dimensional (213) shape can be recovered completely from a set of the orthogonal Radon transform-based projections. For search consistency, it is necessary to identify the region(s) of interest (ROI) before applying the Radon transform to shape query. ROI's are detected automatically by means of saliency map-based segmentation. The Radon transform packs the shape information of a 2D mess along the projection axis of known orientation, and generates a series of one-dimensional (1D) functions from color channels for projection angles ranging from 1degrees to 180degrees. The optimal number of projections for a particular shape is determined by imposing the Kullback-Leibler distance (KLD) histogram comparison as the similarity metric between the query and database images. The Radon transforms with the shortest and longest lengths yield the most distinctive shape attributes for the object classes being queried. For translation- and rotation-invariant retrieval, the principal component analysis is utilized as the preprocessing tool in the spatial plane. Size invariance is achieved by normalizing the Radon transforms in the (R, G, B) color channels independently. The proposed algorithm was tested on a wide range of complex shaped objects imaged in 24-bit color with different spatial resolutions. The KLDs between two images are calculated in the longest and shortest directions of the Radon transform, and then are added together to find the similarity measure corresponding to the query and database pictures. Higher measures indicate two dissimilar shapes, while smaller values represent two similar ones. Experimental results show that the method is robust and accounts for high noise immunity.
Transmission of digital video signals over wireless networks demands efficient compression algorithms as well as reliable coding strategies. In this project, we provide a thorough evaluation of the joint source-channe...
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ISBN:
(纸本)0780376633
Transmission of digital video signals over wireless networks demands efficient compression algorithms as well as reliable coding strategies. In this project, we provide a thorough evaluation of the joint source-channel video coding methodology from two points of view: source coding design for error resilience and channel coding for error detection and recovery. We investigate the current ITU video compression standard, H.263+, for 3G wireless transmission. In particular, we concentrate on error resilient features provided within the standard and forward error correction (FEC) to find the optimal combination of various system parameters under different lossy channel conditions.
Signal-level image fusion has in recent years established itself as a useful tool for dealing with vast amounts of image data obtained by disparate sensors. In many modem multisensor systems, fusion algorithms signifi...
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ISBN:
(纸本)0819449598
Signal-level image fusion has in recent years established itself as a useful tool for dealing with vast amounts of image data obtained by disparate sensors. In many modem multisensor systems, fusion algorithms significantly reduce the amount of raw data that needs to be presented or processed without loss of information content as well as provide an effective way of information integration. One of the most useful and widespread applications of signal-level image fusion is for display purposes. Fused images provide the observer with a more reliable and more complete representation of the scene than would be obtained through single sensor display configurations. In recent years, a plethora of algorithms that deal with the problem of fusion for display has been proposed. However, almost all are based on relatively basic processing techniques and do not consider information from higher levels of abstraction. As some recent studies have shown this does not always satisfy the complex demands of a human observer and a more subjectively meaningful approach is required. This paper presents a fusion framework based on the idea that subjectively relevant fusion could be achieved if information at higher levels of abstraction such as image edges and image segment boundaries are used to guide the basic signal-level fusion process. Fusion of processed, higher level information to form a blueprint for fusion at signal level and fusion of information from multiple levels of extraction into a single fusion engine are both considered. When tested on two conventional signal-level fusion methodologies, such multi-level fusion structures eliminated undesirable effects such as fusion artefacts and loss of visually vital information that compromise their usefulness. images produced by inclusion of multi-level information in the fusion process are clearer and of generally better quality than those obtained through conventional low-level fusion. This is verified through subjective evaluatio
Independent component analysis (ICA) for separating complex-valued sources is needed for convolutive source-separation in the frequency domain, or for performing source separation on complex-valued data, such as funct...
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ISBN:
(纸本)0780376633
Independent component analysis (ICA) for separating complex-valued sources is needed for convolutive source-separation in the frequency domain, or for performing source separation on complex-valued data, such as functional magnetic resonance imaging data. Functional magnetic resonance imaging (fMRI) is a technique that produces complex-valued data;however the vast majority of fMRI analyses utilize only magnitude images. We compare the performance of the complex infomax algorithm that uses an analytic (and hence unbounded) nonlinearity with the traditional complex infomax approaches that employ bounded (and hence non-analytic) nonlinearities as well as with a cumulant-based approach. We compare the performances of these algorithms for processing both simulated and real fMRI data and show that the complex infomax using analytic nonlinearity has the ability to separate both sub- and super-Gaussian sources with a hyperbolic tangent nonlinearity. The complex infomax algorithm that uses analytic nonlinearity thus provides a potentially powerful method for exploratory analysis of fMRI data.
Design of automated imageprocessingsystems to determine migration characteristics of individual cells is not trivial. Every test sample requires separate recording and the analysis of individual cell tracks in two- ...
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Design of automated imageprocessingsystems to determine migration characteristics of individual cells is not trivial. Every test sample requires separate recording and the analysis of individual cell tracks in two- or three-dimensional migration systems by time-lapse microscopy is extremely laborious. Here, we describe a new Automated Cell Track System (ACTS). In addition to contrast differences, which are used by existing analysis systems, the ACTS algorithms recognize cells on the basis of morphological similarities in successive images and adapt to the continuous shape changes of individual cells during migration. The system facilitates simultaneous analysis of multiple cells and the measurement of multiple wells in one single experiment. We validated the system studying HSB-2 T cell migration in standard 96-well microtiter plates coated with ICAM-1-Fc protein or control CD14-Fc protein. Migration of HSB-2 T cells on ICAM-1-Fc is Leukocyte Function-associated Antigen-1 (LFA-1)-mediated and both the number and the speed of migrating cells depend on the ICAM-1-Fc concentration. We show that automated analysis of the migration data yields similar results as manual analysis, but in a fraction of the time. We conclude that this system is extremely well suited to precisely monitor the migratory behavior of individual cells. The analysis of multiple wells in parallel makes this set-up appropriate in high throughput screening in which multiple components are simultaneously tested for their effect on cell migration. (C) 2003 Elsevier B.v. All rights reserved.
Most commercial ultrasound machines do not allow the researcher to acquire internal data, modify the signal processingalgorithms or test a new clinical application. A software-based ultrasound machine could offer the...
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ISBN:
(纸本)0780377893
Most commercial ultrasound machines do not allow the researcher to acquire internal data, modify the signal processingalgorithms or test a new clinical application. A software-based ultrasound machine could offer the needed flexibility to modify the ultrasound processingalgorithms and evaluate new ultrasound applications for clinical efficacy. We have designed an ultrasound machine in which all of the back-end processing is performed in software rather than in hardware. This programmable machine supports all the conventional ultrasound modes (e.g., B mode, color flow, M mode and spectral Doppler) without any performance degradation. The frame rates and image quality of this programmable machine were evaluated and found to be comparable to commercial ultrasound machines. Due to its programmability, we were able to improve the accuracy of flow velocity estimation by integrating a new clutter rejection filtering method into the system. The machine also supports advanced features such as 3D volume rendering in software. Our results demonstrate that a software-based ultrasound machine can provide the same functionality for clinical use as conventional ultrasound systems while offering increased flexibility at low cost.
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