686 research outputs found

    Long Range Automated Persistent Surveillance

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    This dissertation addresses long range automated persistent surveillance with focus on three topics: sensor planning, size preserving tracking, and high magnification imaging. field of view should be reserved so that camera handoff can be executed successfully before the object of interest becomes unidentifiable or untraceable. We design a sensor planning algorithm that not only maximizes coverage but also ensures uniform and sufficient overlapped camera’s field of view for an optimal handoff success rate. This algorithm works for environments with multiple dynamic targets using different types of cameras. Significantly improved handoff success rates are illustrated via experiments using floor plans of various scales. Size preserving tracking automatically adjusts the camera’s zoom for a consistent view of the object of interest. Target scale estimation is carried out based on the paraperspective projection model which compensates for the center offset and considers system latency and tracking errors. A computationally efficient foreground segmentation strategy, 3D affine shapes, is proposed. The 3D affine shapes feature direct and real-time implementation and improved flexibility in accommodating the target’s 3D motion, including off-plane rotations. The effectiveness of the scale estimation and foreground segmentation algorithms is validated via both offline and real-time tracking of pedestrians at various resolution levels. Face image quality assessment and enhancement compensate for the performance degradations in face recognition rates caused by high system magnifications and long observation distances. A class of adaptive sharpness measures is proposed to evaluate and predict this degradation. A wavelet based enhancement algorithm with automated frame selection is developed and proves efficient by a considerably elevated face recognition rate for severely blurred long range face images

    Multiresolution models in image restoration and reconstruction with medical and other applications

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    Deep learning for inverse problems in remote sensing: super-resolution and SAR despeckling

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    L'abstract è presente nell'allegato / the abstract is in the attachmen

    Tuning-free Plug-and-Play Hyperspectral Image Deconvolution with Deep Priors

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    Deconvolution is a widely used strategy to mitigate the blurring and noisy degradation of hyperspectral images~(HSI) generated by the acquisition devices. This issue is usually addressed by solving an ill-posed inverse problem. While investigating proper image priors can enhance the deconvolution performance, it is not trivial to handcraft a powerful regularizer and to set the regularization parameters. To address these issues, in this paper we introduce a tuning-free Plug-and-Play (PnP) algorithm for HSI deconvolution. Specifically, we use the alternating direction method of multipliers (ADMM) to decompose the optimization problem into two iterative sub-problems. A flexible blind 3D denoising network (B3DDN) is designed to learn deep priors and to solve the denoising sub-problem with different noise levels. A measure of 3D residual whiteness is then investigated to adjust the penalty parameters when solving the quadratic sub-problems, as well as a stopping criterion. Experimental results on both simulated and real-world data with ground-truth demonstrate the superiority of the proposed method.Comment: IEEE Trans. Geosci. Remote sens. Manuscript submitted June 30, 202

    Computational Imaging Approach to Recovery of Target Coordinates Using Orbital Sensor Data

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    This dissertation addresses the components necessary for simulation of an image-based recovery of the position of a target using orbital image sensors. Each component is considered in detail, focusing on the effect that design choices and system parameters have on the accuracy of the position estimate. Changes in sensor resolution, varying amounts of blur, differences in image noise level, selection of algorithms used for each component, and lag introduced by excessive processing time all contribute to the accuracy of the result regarding recovery of target coordinates using orbital sensor data. Using physical targets and sensors in this scenario would be cost-prohibitive in the exploratory setting posed, therefore a simulated target path is generated using Bezier curves which approximate representative paths followed by the targets of interest. Orbital trajectories for the sensors are designed on an elliptical model representative of the motion of physical orbital sensors. Images from each sensor are simulated based on the position and orientation of the sensor, the position of the target, and the imaging parameters selected for the experiment (resolution, noise level, blur level, etc.). Post-processing of the simulated imagery seeks to reduce noise and blur and increase resolution. The only information available for calculating the target position by a fully implemented system are the sensor position and orientation vectors and the images from each sensor. From these data we develop a reliable method of recovering the target position and analyze the impact on near-realtime processing. We also discuss the influence of adjustments to system components on overall capabilities and address the potential system size, weight, and power requirements from realistic implementation approaches

    Research on Landscape Design of Building Information Model in Ecological Restoration Projects of Cities along the Yangtze River

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    The urban landscape pattern, process and function have three-dimensional characteristics, and the three-dimensional analysis of urban landscape elements is one of the important trends in the development of urban landscape research. However, the current research on the visualization of urban landscape in three dimensions and the application of related models still needs to strengthen. Based on the research of the ecological restoration process, this paper combines the current situation of urban landscape construction along the Yangtze River in China and deduces the development trend of urban landscape planning. Based on Building information model (BIM), this article combines Revit software to design landscape construction drawings, and summarizes the specific design process and the current unsolvable problems. As an experimental building information model (BIM) software construction drawing design attempt, this article explores the urban ecological water conservancy landscape planning and design path, and demonstrates it in combination with specific cases. Therefore, this paper conducts modeling based on three-dimensional virtual landscape, which conducts virtual landscape design and provides technical ideas for the development of this technology
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