Silver halide (AgCl:AgBr) and chalcogenide(Arsenic Trisulfide) fibers are two major mid-IR fibers that are used in gas sensing and light transmission. For both purposes, especially for power transmission, it is import...
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ISBN:
(纸本)0819428701
Silver halide (AgCl:AgBr) and chalcogenide(Arsenic Trisulfide) fibers are two major mid-IR fibers that are used in gas sensing and light transmission. For both purposes, especially for power transmission, it is important to increase the launching efficiency from the mid-IR source (Globar) to fiber so that the signal-to-noise ratio of the whole system will be improved. However, due to the shape of the Globar (4 mm x 4 mm with central hollow), it is often difficult to gel a uniform and small spot image with ordinary lens or mirror. In this paper, a "mid-IR cavity" has been designed to increase the collecting ratio of infrared radiation from a Globar. Comparing with direct forward collection method (one lens or mirror is used to couple the light from source to fiber), the cavity offers not only higher power, more important, but also the uniform Gaussian and smaller spot. As a result, higher signal to noise ratio has been obtained in the fiber ends. This can be used to improve the spectral resolution, signalprocessing time for FT-IR based real-time Chemical Vapor Deposition (CVD) processing and other type of applications.
We introduce novel robust filtering algorithms applicable to image and signalprocessing in the remote sensing applications. They were derived using RM-type point estimators and the restriction technique of the well-k...
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We introduce novel robust filtering algorithms applicable to image and signalprocessing in the remote sensing applications. They were derived using RM-type point estimators and the restriction technique of the well-known specific for imageprocessing KNN filter. Novel RM-KNN filters effectively remove impulsive noise while edge and fine details are preserved. The proposed filters were tested on simulated images and radar data and were provided excellent visual quality of the processed images and good quantitative quality in the MSE sense over standard median filter. Recommendations to obtain best processing results by proper selection of derived filter parameters are given in this paper. Two derived filters are suitable for impulsive noise reduction in the remote sensing imageprocessingapplications. RM-KNN filters can be used as the first stage of image enhancement following by any non-robust techniques such as Sigma-filter on the second stage.
A wavelet-based image matching method was developed for removal of normal anatomic structures in chest radiographs for reduction of false positives reported by our computer-aided diagnosis (CAD) scheme for detection o...
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ISBN:
(纸本)0819429139
A wavelet-based image matching method was developed for removal of normal anatomic structures in chest radiographs for reduction of false positives reported by our computer-aided diagnosis (CAD) scheme for detection of lung nodules. In our approach, two regions of interest (ROIs) are extracted, one from the position where a candidate of a nodule is located, and the other from the position located at a point symmetric to the first position relative to the spine. The second ROI contains normal anatomic structures similar to those of the first ROI. A non-linear functional representing the squared differences between the two images is formulated, and is minimized by a coarse-to-fine approach to yield a planar mapping that matches the two similar images. A smoothing term is added to the non-linear functional, which penalizes discontinuous and irregular mappings. If no structure remains in the difference between these matched images, then the first ROI is identified to be a false detection (i.e., it contains only normal structures);otherwise, it is regarded as a nodule (i.e., it contains an abnormal structure). A preliminary result shows that our method is effective in removing normal anatomic structures and thus is useful for substantially reducing the number of false detections in our CAD scheme.
Tn this paper, we propose an integration of two techniques: catastrophe-based image compression/coding, and hyperspectral video, based on acousto-optic technology. As a result, we obtain a joint tool for sensing and t...
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ISBN:
(纸本)0819429104
Tn this paper, we propose an integration of two techniques: catastrophe-based image compression/coding, and hyperspectral video, based on acousto-optic technology. As a result, we obtain a joint tool for sensing and transmission of hyperspectral data, with minimized bandwidth and latency.
In this paper a method for noise reduction in ocular fundus image sequences is described. The eye is the only part of the human body where the capillary network can be observed along with the arterial and venous circu...
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ISBN:
(纸本)0819429155
In this paper a method for noise reduction in ocular fundus image sequences is described. The eye is the only part of the human body where the capillary network can be observed along with the arterial and venous circulation using a non invasive technique. The study of the retinal vessels is very important both for the study of the local pathology (retinal disease) and for the large amount of information it offers on systemic haemodynamics, such as hypertension, arteriosclerosis, and diabetes. In this paper a method for image integration of ocular fundus image sequences is described. The procedure can be divided in two step: registration and fusion. First we describe an automatic alignment algorithm for registration of ocular fundus images. In order to enhance vessel structures, we used a spatially oriented bank of filters designed to match the properties of the objects of interest. To evaluate interframe misalignment we adopted a fast cross-correlation algorithm. The performances of the alignment method have been estimated by simulating shifts between image pairs and by using a cross-validation approach. Then we propose a temporal integration technique of image sequences so as to compute enhanced pictures of the overall capillary network. image registration is combined with image enhancement by fusing subsequent frames of a same region. To evaluate the attainable results, the signal-to-noise ratio was estimated before and after integration. Experimental results on synthetic images of vessel-like structures with different kind of Gaussian additive noise as well as on real fundus images are reported.
During the last ten years, the impact of infrared and laser devices on surveillance and weapon systems has rapidly increased. Compared to the technology used in the first generation of devices and systems, today's...
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During the last ten years, the impact of infrared and laser devices on surveillance and weapon systems has rapidly increased. Compared to the technology used in the first generation of devices and systems, today's technology has reached a higher level of maturity, allowing such advanced infrared and laser devices to be integrated in a variety of military applications. In Germany, the definition of infrared and laser sensors has changed in the last 10 years, and is almost used synonymously with the complete integration of sensor hardware and sophisticated signal and imageprocessing instead of just considering `pure' device technologies. This new understanding shows the challenge for future applications and defines the basic methodology for planning the research efforts to improve the use of infrared and laser devices in military systems. This determines the basic elements for future research and development support by the German government: Next generation of infrared detectors (quantum well and superlattices);Thermal imagers;Windows for IR and radar sensors;Multifunction laser sensors;imageprocessing and pattern recognition;and Demonstrators for sensors.
The proliferation of digital imaging techniques has permeated in the Experimental Mechanics arena as well. More so the fact that since digital imaging records information in discrete and periodic intervals, this syste...
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ISBN:
(纸本)0819428590
The proliferation of digital imaging techniques has permeated in the Experimental Mechanics arena as well. More so the fact that since digital imaging records information in discrete and periodic intervals, this system lends itself nicely as a moire reference grating in the various moire techniques. The aliasing feature, which is generally avoided in traditional digital image and signalprocessing, now can be used to analyze the deformed specimen grating for deformation studies. This paper will discuss the use of digital moire technique and demonstrate their application for the range of moire methods. Furthermore the use of phase shifting, one of the most powerful fringe processing technique will also be discussed in conjunction with this.
The Defense Research Establishment, Valcartier has an ongoing project on a multi-sensors system, called CAMUS (Common Aperture MUlti-Sensors). The main objective of this project is to demonstrate the concept of fusing...
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ISBN:
(纸本)0819428914
The Defense Research Establishment, Valcartier has an ongoing project on a multi-sensors system, called CAMUS (Common Aperture MUlti-Sensors). The main objective of this project is to demonstrate the concept of fusing three sensors on a single chassis. The project covers the development of the sensors' head and the processing sub-systems required for fusing the acquired data and information. The three sensors identified for this project are: a visible camera, a 3-5 mu m infrared camera and a 94 GHz millimeter-wave radar. This paper describes the approach used to combine the three sensors along with the various processing schemes to merge the visible and infrared images with the radar information. The CAMUS system will present all the information gathered by the three sensors an a single display to the operator. The main application of this project is to demonstrate an advanced sight for a direct fire control system.
In this paper, we address the problem of lossless and nearly-lossless multispectral compression of remote-sensing data acquired using SPOT satellites. Lossless compression algorithms classically have two stages: Trans...
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ISBN:
(纸本)0819427446
In this paper, we address the problem of lossless and nearly-lossless multispectral compression of remote-sensing data acquired using SPOT satellites. Lossless compression algorithms classically have two stages: Transformation of the available data, and coding. The purpose of the first stage is to express the data as uncorrelated data in an optimal way. In the second stage, coding is performed by means of an arithmetic coder. In this paper, we discuss two well-known approaches for spatial as well as multispectral compression of SPOT images: 1) The efficiency of several predictive techniques (MAP, CALIC, 3D predictors), are compared, and the advantages of 2D versus 3D error feedback and context modeling are examinated;2) The use of wavelet transforms for lossless multispectral compression are discussed. Then, applications of the above mentionned methods for quincunx sampling are evaluated. Lastly, some results, on how predictive and wavelet techniques behave when nearly-lossless compression is needed, are given.
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