2,090 research outputs found

    Sensors for Desert Surveillance

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    Various types of sensors-visible, passive night vision, infrared, synthetic aperture radar, etc can be used for desert surveillance. The surveillance capability of these sensors depends to a large extent, on various atmospheric effects, viz., absorption, scattering, aerosol, turbulence, and optical mirage. In this paper, effects of various atmospheric phenomena on the transmission of signals, merits and demerits of different means of surveillance under desert environmental conditions are discussed. Advanced surveillance techniques, ie, multisensor fusion, multi and hyperspectral imaging, having special significance for desert surveillance, have also been discussed

    3D Holographic Millimeter-Wave Imaging for Concealed Metallic Forging Objects Detection

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    This chapter investigates the feasibility of using 3D holographic millimeter-wave (HMMW) imaging for diagnosis of concealed metallic forging objects (MFOs) in inhomogeneous medium. A 3D numerical system, including radio frequency (RF) transmitters and detectors, various realistic MFOs models and signal and imaging processing, is developed to analyze the measured data and reconstruct images of target MFOs. Simulation and experimental validations are performed to evaluate the HMMW approach for diagnosis of concealed MFOs. Results show that various concealed objects can be clearly represented in the reconstructed images with accurate sizes, locations and shapes. The proposed system has the potential for further investigation of concealed MFOs under clothing in the future, which has the potential applications in on body concealed weapon detection at security sites or MFOs detection in children

    Combine Target Extraction and Enhancement Methods to Fuse Infrared and LLL Images

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    For getting the useful object information from infrared image and mining more detail of low light level (LLL) image, we propose a new fusion method based on segmentation and enhancement methods in the paper. First, using 2D maximum entropy method to segment the original infrared image for extracting infrared target, enhancing original LLL image by Zadeh transform for mining more detail information, on the basis of the segmented map to fuse the enhanced LLL image and original infrared image. Then, original infrared image, the enhanced LLL image and the first fused image are used to realize fusion in non-subsampled contourlet transform (NSCT) domain, we get the second fused image. By contrast of experiments, the fused image of the second fused method’s visual effect is better than other methods’ from the literature. Finally, Objective evaluation is used to evaluate the fused images’ quality, its results also show that the proposed method can pop target information, improve fused image’s resolution and contrast

    A comparison of image fusion quality metrics

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    Measuring the fitness of the fused image plays a key role in image fusion applications. For a learning process performed in a machine learning algorithm, the result of the fusion should be evaluated numerically. In the literature, there are well-known quality metrics developed for this purpose. Each metric evaluates the quality of the image using a different method. However, to be used in the learning process, the quality metrics must be able to provide results compatible with the change in the image's visual quality. In this study, synthetic images with known quality levels were created for this purpose. The scoring accuracy of six quality metrics commonly used in the literature was compared with these test images and the results were evaluated

    Satellite Image Fusion in Various Domains

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    In order to find out the fusion algorithm which is best suited for the panchromatic and multispectral images, fusion algorithms, such as PCA and wavelet algorithms have been employed and analyzed. In this paper, performance evaluation criteria are also used for quantitative assessment of the fusion performance. The spectral quality of fused images is evaluated by the ERGAS and Q4. The analysis indicates that the DWT fusion scheme has the best definition as well as spectral fidelity, and has better performance with regard to the high textural information absorption. Therefore, as the study area is concerned, it is most suited for the panchromatic and multispectral image fusion. an image fusion algorithm based on wavelet transform is proposed for Multispectral and panchromatic satellite image by using fusion in spatial and transform domains. In the proposed scheme, the images to be processed are decomposed into sub-images with the same resolution at same levels and different resolution at different levels and then the information fusion is performed using high-frequency sub-images under the Multi-resolution image fusion scheme based on wavelets produces better fused image than that by the MS or WA schemes

    Principal Component Analysis based Image Fusion Routine with Application to Stamping Split Detection

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    This dissertation presents a novel thermal and visible image fusion system with application in online automotive stamping split detection. The thermal vision system scans temperature maps of high reflective steel panels to locate abnormal temperature readings indicative of high local wrinkling pressure that causes metal splitting. The visible vision system offsets the blurring effect of thermal vision system caused by heat diffusion across the surface through conduction and heat losses to the surroundings through convection. The fusion of thermal and visible images combines two separate physical channels and provides more informative result image than the original ones. Principal Component Analysis (PCA) is employed for image fusion to transform original image to its eigenspace. By retaining the principal components with influencing eigenvalues, PCA keeps the key features in the original image and reduces noise level. Then a pixel level image fusion algorithm is developed to fuse images from the thermal and visible channels, enhance the result image from low level and increase the signal to noise ratio. Finally, an automatic split detection algorithm is designed and implemented to perform online objective automotive stamping split detection. The integrated PCA based image fusion system for stamping split detection is developed and tested on an automotive press line. It is also assessed by online thermal and visible acquisitions and illustrates performance and success. Different splits with variant shape, size and amount are detected under actual operating conditions
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