An analog VLSI implementation of a smart microsensor that mimics the early visual processing stage in insects is described with an emphasis on the overall concept and the front-end detection. the system employs the &#...
详细信息
two triband imaging Infrared Radiometers (tI2R) were designed and fabricated for the U.S. Army Strategic Defense Command by Automated Sciences Group, Inc. the firsttI2R system was designed to perform hardware-in-the-...
详细信息
ISBN:
(纸本)0819412058
two triband imaging Infrared Radiometers (tI2R) were designed and fabricated for the U.S. Army Strategic Defense Command by Automated Sciences Group, Inc. the firsttI2R system was designed to perform hardware-in-the-loop (HWIL) simulations using a laser scene projector and electronic signal injection. the second tI2R system was designed for field testing to provide validation data for the HWIL simulation. this paper describes the design and operation of these two systems and the HWIL testing that was performed.
For several years the Night Vision and electronic Sensors Directorate (NVESD) has been using an internally developed forward looking infrared (FLIR) simulation program. In response to interest in the simulation part o...
详细信息
ISBN:
(纸本)0819412058
For several years the Night Vision and electronic Sensors Directorate (NVESD) has been using an internally developed forward looking infrared (FLIR) simulation program. In response to interest in the simulation part of these projects by other organizations, NVESD has been working on a new version of the simulation, NVSIM, that will be made generally available to the FLIR using community. NVSIM uses basic FLIR specification data, high resolution thermal inputimagery and spatial domain imageprocessingtechniques to produce simulated image outputs from a broad variety of FLIRs. It is being built around modular programming techniques to allow simpler addition of more sensor effects. the modularity also allows selective inclusion and exclusion of individual sensor effects at run time. the simulation has been written in the industry standard ANSI C programming language under the widely used UNIX operating system to make it easily portable to a wide variety of computer platforms.
Many times in electronicimagingsystems it is necessary to reduce the precision of the digital data for the display, storage, manipulation, or transformation of an image. For example, it may be necessary to reduce 12...
详细信息
ISBN:
(纸本)0819411469
Many times in electronicimagingsystems it is necessary to reduce the precision of the digital data for the display, storage, manipulation, or transformation of an image. For example, it may be necessary to reduce 12 bits/channel RGB data to 8 bits/channel due to storage requirements. to accomplish this reduction in the number of digital levels, a series of input levels must be grouped together for each output level. Since this process involves the quantization of previously quantized data, it is sometimes referred to as secondary quantization. the secondary quantization process necessarily results in artifacts, such as contouring in the image, where many colors have been mapped to a single color. Conventional methods, such as linear or power-law resampling, are suboptimal and do not consider intercolor effects. this paper describes a method for determining the quantization functions that will minimize the observable image artifacts generated by the secondary quantization process. the basic approach involves the use of nonlinear optimization techniques to minimize a cost function that provides a measure of the visible color error. Examples are presented that compare the optimized quantization process to conventional techniques.
We are developing an automatic `image quality meter' for assessing the degree of impairment of broadcasttV images. the meter incorporates a model of the human visual system derived from psychophysical and neuroph...
详细信息
ISBN:
(纸本)0819411469
We are developing an automatic `image quality meter' for assessing the degree of impairment of broadcasttV images. the meter incorporates a model of the human visual system derived from psychophysical and neurophysiological studies. Early visual processing is assumed to consist of a set of spatially parallel, largely independent functional modules; but later stages are more heavily resource limited and constrained by limitations on attention and memory capacity. In line with CCIR recommendations, image evaluation can focus either on detection of the impairment itself (typically, superimposed lines or noise, or color dropout) or on assessment of the perceptible quality of the depicted scene. the observer may choose to attend to either aspect. Experimental studies of human subjects suggestthatthese two processes are largely independent of each other and subjectto voluntary control. the meter captures images directly from tV via a CCD camera and digital sampling hardware. Early visual processes are emulated in software as a bank of spatial and temporal filters and higher level processes by a 3-layer neural network. Preliminary trials of the meter verify that it can produce quantitative CCIR gradings that match those made by an `expert' human assessor and it does so better than other electronicsystemsthat do not incorporate the model of early human vision.
Statistical Morphology is concerned with the statistical characterization of the four morphological operations — dilation, erosion, opening and closing. By statistical characterization of a morphological operator we ...
详细信息
ISBN:
(纸本)0819412791
Statistical Morphology is concerned with the statistical characterization of the four morphological operations — dilation, erosion, opening and closing. By statistical characterization of a morphological operator we mean the statistical characterization of the output in terms of the statistical characteristics of the input. Characterization of operators allows us to predictthe characteristics of the output of an algorithm composed of a sequence of morphological operations in terms of the statistical characteristics of the input and the sequence of morphological operators used. Furthermore, such statistical analyses of morphological algorithms is necessary for evaluating the algorithm's performance. In this paper we describe what we have learned about one way to characterize the dilation and opening morphological operators in a one dimensional setting. that is, the inputto each of these operators is assumed to be binary one-dimensional. the input is modeled as a union of randomly translated discrete lines of a fixed length. the line segments can overlap and result in line segments of various lengths. thus the final output appears as an unordered pattern of lines and gaps of various lengths. this input is characterized by giving its line and gap length distribution and the distribution of the number of line and gap segments of various lengths. the characterization of a morphological operator, therefore, entails a similar characterization of the output. there has been a recent interest in the area of statistical morphology and some results have been published in the literature. Morales and Acharya {MA92} analyzed the statistical characteristics of a morphological opening on grayscale signals perturbed by Gaussian noise. Stevenson and Arce {SA92] studied the effects of opening for a class of structuring elements. Atola, Koskinen and Neuvo [ALN93] studied the output distributions of one dimensional grayscale filtering. Costa and Haralick {CH92} came up with an empirica
the recent proliferation of digital binary output devices, such as laser printers and facsimile machines, has brought increased attention to high quality halftone reproduction. A question that often arises in halftone...
详细信息
ISBN:
(纸本)0819411469
the recent proliferation of digital binary output devices, such as laser printers and facsimile machines, has brought increased attention to high quality halftone reproduction. A question that often arises in halftone research is how to evaluate the quality of halftone images using a quantitative quality metric. Such metrics would allow objective evaluation, could be incorporated in halftoning algorithms, in addition to being independently reproducible. Given that halftoning introduces unique types of distortions and the display medium (a hardcopy device) is differentthan that of conventional imageprocessing applications (a CRt display), it becomes necessary to develop visual models specifically for halftoning applications. In this paper, frequency-domain visual models are investigated as to their suitability for the formulation of quantitative quality metrics specifically for halftoning applications. two types of frequency-domain models are investigated: models that utilize a simple contrast-sensitivity function and models that utilize multiple independent narrowband channels. the quantitative quality metric for both types of models is formulated as a weighted frequency domain error. Since the ultimate judges of image quality are human viewers, the success of the quantitative measures is assessed by comparing their results with the results of a psychovisual test performed on halftone images.
Dissemination of imagery has become an essential capability for successful military operations. As such, the use of commercial imageprocessingtechnology to achieve improvement in satellite communications channel res...
详细信息
ISBN:
(纸本)0780309537
Dissemination of imagery has become an essential capability for successful military operations. As such, the use of commercial imageprocessingtechnology to achieve improvement in satellite communications channel resource utilization was investigated. Aggressive application of the compression technology was found to result in lower capacity demands placed on defense satellite communications systems. Uniform and powerful compression algorithms are being developed and incorporated. the marriage of electronic, PC-based imagingsystems with portable/airborne satellite terminals showed considerable potential for a wide range of Air Force applications.
Various techniques are currently used to project video images. One of these, described in a previous paper by the author, operates by mechanical scanning of a laser beam with acousto- optic modulation, and has been pr...
详细信息
ISBN:
(纸本)0819412368
Various techniques are currently used to project video images. One of these, described in a previous paper by the author, operates by mechanical scanning of a laser beam with acousto- optic modulation, and has been proven suitable for high definition television and computer display scan rates by use of novel electronic and optical compensation methods. the requirement for improved image intensity with greater efficiency has led to a re-appraisal of the selection of the light source and the relationship between the light source, the form of the modulator, and the method of scanning. the electrical inputto visible radiation output ratio of the Argon-ion lasers currently used in the projector shows efficiency to be as low as 0.001%, a factor limiting the commercial exploitation of the projector. Recent developments in acousto- optics can be applied to the projector's optical system allowing alternative light sources to be used. these help to reduce the complexity of both the optical and signal processing stages as well as improve efficiency.
the proceedings contains 50 papers. the topics discussed are: color imagery;imageprocessing and filtering techniques;image/image-sequence restoration and reconstruction;image analysis and pattern recognition;image co...
详细信息
the proceedings contains 50 papers. the topics discussed are: color imagery;imageprocessing and filtering techniques;image/image-sequence restoration and reconstruction;image analysis and pattern recognition;image coding;and parallel architectures for imageprocessing.
暂无评论