In inaccessible topographies such as the planetary surface, stereo analysis of in orbital imagery provides highly valuable data for scientific research. In order to fully utilize the data derived from imagesystems ca...
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ISBN:
(纸本)9781618394972
In inaccessible topographies such as the planetary surface, stereo analysis of in orbital imagery provides highly valuable data for scientific research. In order to fully utilize the data derived from imagesystems carried on various planetary orbiters, the generalised algorithms of stereo imageprocessing and photogrammetric Mars DTM extraction have been developed by Kim and Muller (2009). In this study, the integration and improvement of these algorithms were proposed. It is enhanced with the feed-forwarded model based matcher exploiting planetary topographic data hierarchy. Due to the successful "from medium to high" control strategy performed during processing, stable horizontal and vertical photogrammetric accuracy of resultant DTMs were achievable, even without directly measured ground control information. To demonstrate the potential of the stereo routines, the DTMs obtained from various orbital images such as HRSC (High Resolution Stereo Camera) of Mars Express, CTX (Context Camera) and HiRISE (High Resolution Imaging Science Experiment) of MRO (Mars Reconnaissance Orbiter) were processed in few sample test sites. The comparisons with the height spots of MOLA (Mars Obiter Laser Altimeter) showed high agreements and proved the effectiveness of overall processing strategy.
Diffusion-weighted imaging is a noninvasive method for detecting the diffusion of water molecules in living tissues, which requires high accuracy of the data. Diffusion-weighted images have a high degree of self-simil...
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As the most pervasive method of individual identification and document authentication, signatures present convincing evidence and provide an important form of indexing for effective document imageprocessing and retri...
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ISBN:
(纸本)9783540886891
As the most pervasive method of individual identification and document authentication, signatures present convincing evidence and provide an important form of indexing for effective document imageprocessing and retrieval in a broad range of applications. In this work, we developed a fully automatic signature-based document image retrieval system that handles: 1) Automatic detection and segmentation of signatures from document images and 2) Translation, scale, and rotation invariant signature matching for document image retrieval. We treat signature retrieval in the unconstrained setting of non-rigid shape matching and retrieval, and quantitatively study shape representations, shape matching algorithms, measures of dissimilarity, and the use of multiple query instances in document image retrieval. Extensive experiments using large real world collections of English and Arabic machine printed and handwritten documents demonstrate the excellent performance of our system. To the best of our knowledge, this is the first automatic retrieval system for general document images by using signatures as queries, without manual annotation of the image collection.
After giving a description of the three underlying standards of the digital video broadcasting system (DVB-S: satellite, DVB-C: cable and DVB-T: terrestrial), this paper discusses the synergy effects, which can be use...
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After giving a description of the three underlying standards of the digital video broadcasting system (DVB-S: satellite, DVB-C: cable and DVB-T: terrestrial), this paper discusses the synergy effects, which can be used to design a versatile multistandard digital television encoder with minimum hardware requirements. The paper shows the implementation possibilities of the signal-processingalgorithms in Complex Programmable Logic Devices (CPLDs) at the example of a highly integrated digital TV encoder, which has been realized at the Chair of Communications Technology for measurement purposes.
In secondary raw materials and recycling sectors, the products quality represents, more and more, the key issue to pursuit in order to be competitive in a more and more demanding market, where quality standards and pr...
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ISBN:
(纸本)9780819499417
In secondary raw materials and recycling sectors, the products quality represents, more and more, the key issue to pursuit in order to be competitive in a more and more demanding market, where quality standards and products certification play a preheminent role. These goals assume particular importance when recycling actions are applied. Recovered products, resulting from waste materials, and/or dismissed products processing, are, in fact, always seen with a certain suspect. An adequate response of the industry to the market can only be given through the utilization of equipment and procedures ensuring pure, high-quality production, and efficient work and cost. All these goals can be reached adopting not only more efficient equipment and layouts, but also introducing new processing logics able to realize a full control of the handled material flow streams fulfilling, at the same time, i) an easy management of the procedures, ii) an efficient use of the energy, iii) the definition and set up of reliable and robust procedures, iv) the possibility to implement network connectivity capabilities finalized to a remote monitoring and control of the processes and v) a full data storage, analysis and retrieving. Furthermore the ongoing legislation and regulation require the implementation of recycling infrastructure characterised by high resources efficiency and low environmental impacts, both aspects being strongly linked to the waste materials and/or dismissed products original characteristics. For these reasons an optimal recycling infrastructure design primarily requires a full knowledge of the characteristics of the input waste. What previously outlined requires the introduction of a new important concept to apply in solid waste recycling, the recycling-oriented characterization, that is the set of actions addressed to strategically determine selected attributes, in order to get goal-oriented data on waste for the development, implementation or improvement of recycling
The aim of this work is to render high-quality views of a dynamic scene from novel viewpoints in real-time. An online system available at our institute computes the visual hull as a geometry proxy to guide the renderi...
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ISBN:
(纸本)0819450235
The aim of this work is to render high-quality views of a dynamic scene from novel viewpoints in real-time. An online system available at our institute computes the visual hull as a geometry proxy to guide the rendering at interactive rates. Because only a sparse set of cameras distributed around the scene is used to record the scene, only an coarse model of the scene geometry can be recovered. To alleviate this problem, we render textured billboards defined by the voxel model of the visual hull, preserving details in the source images while achieving excellent performance. By exploiting multi-texturing capabilities of modern graphics hardware, real-time frame rates are attained. Our algorithm can be used as part of an inexpensive system to display 3D-videos, or ultimately even in live 3D-television. The user is able to watch the scene from an arbitrary viewpoint chosen interactively.
For a variety of tasks, complex imageprocessingalgorithms are a necessity to make UAVs more autonomous. Often, the processing of images of the on-board camera is performed on a ground station, which severely limits ...
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ISBN:
(纸本)9789897580918
For a variety of tasks, complex imageprocessingalgorithms are a necessity to make UAVs more autonomous. Often, the processing of images of the on-board camera is performed on a ground station, which severely limits the operating range of the UAV. Often, offline processing is used since it is difficult to find a suitable hardware platform to run a specific vision algorithm on-board the UAV. First of all, it is very hard to find a good trade-off between speed, power consumption and weight of a specific hardware platform and secondly, due to the variety of hardware platforms, it is difficult to find a suitable hardware platform and to estimate the speed the user's algorithm will run on that hardware platform. In this paper we tackle those problems by presenting a framework that automatically determines the most-suited hardware platform for each arbitrary complex vision algorithm. Additionally, our framework estimates the speed, power consumption and flight time of this algorithm for a variety of hardware platforms on a specific UAV. We demonstrate this methodology on two real-life cases and give an overview of the present top processing CPU-based platforms for on-board UAV imageprocessing.
This book constitutes the refereed proceedings of CVM 2025, the 13th International conference on Computational Visual Media, held in Hong Kong SAR, China, in April 2025.The 67 full papers were carefully reviewed and s...
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ISBN:
(数字)9789819658121
ISBN:
(纸本)9789819658114
This book constitutes the refereed proceedings of CVM 2025, the 13th International conference on Computational Visual Media, held in Hong Kong SAR, China, in April 2025.
The 67 full papers were carefully reviewed and selected from 335 submissions. The papers are organized in topical sections as follows:
Part I: Medical image Analysis, Detection and Recognition, image Enhancement and Generation, Vision Modeling in Complex Scenarios
Part II: 3D Geometry and Rendering, Generation and Editing, imageprocessing and Optimization
Part iii: image and Video Analysis, Multimodal Learning, Geometrical processing, Applications
We have implemented a prototype system consisting of a Java-based image viewer and a web server extension component for transmitting Magnetic Resonance images (MRI) to an image viewer, to test the performance of diffe...
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ISBN:
(纸本)0819440051
We have implemented a prototype system consisting of a Java-based image viewer and a web server extension component for transmitting Magnetic Resonance images (MRI) to an image viewer, to test the performance of different image retrieval techniques. We used full-resolution images, and images compressed/decompressed using the Set Partitioning in Hierarchical Trees (SPIHT) image compression algorithm. We examined the SPIHT decompression algorithm using both non-progressive and progressive transmission, focussing on the running times of the algorithm, client memory usage and garbage collection. We also compared the Java implementation with a native C++ implementation of the non-progressive SPIHT decompression variant. Our performance measurements showed that for uncompressed image retrieval using a 10Mbps Ethernet, a film of 16 MR images can be retrieved and displayed almost within interactive times. The native C++ code implementation of the client-side decoder is twice as fast as the Java decoder. If the network bandwidth is low, the high communication time for retrieving uncompressed images may be reduced by use of SPIHT-compressed images, although the image quality is then degraded. To provide diagnostic quality images, we also investigated the retrieval of up to 3 images on a MR film at full-resolution, using progressive SPIHT decompression. The Java-based implementation of progressive decompression performed badly, mainly due to the memory requirements for maintaining the image states, and the high cost of execution of the Java garbage collector. Hence, in systems where the bandwidth is high, such as found in a hospital intranet, SPIHT image compression does not provide advantages for image retrieval performance.
Conformal arrays (CFAs) possess certain desirable characteristics for deployment on unmanned aerial vehicles and other payload-limited platforms. However, the CFA non-planar geometry induces clutter non-stationarity, ...
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Conformal arrays (CFAs) possess certain desirable characteristics for deployment on unmanned aerial vehicles and other payload-limited platforms. However, the CFA non-planar geometry induces clutter non-stationarity, resulting in elevated signal-to-interference-plus-noise ratio (SINR) loss when applying conventional space-time adaptive processing (STAP) algorithms. Non-stationary clutter leads to covariance matrix estimation error and, consequently, an erroneous STAP frequency response. In this study, the authors examine two practical conformal antenna configurations: a belly-mounted canoe and a nose-mounted, chined shape. Using high-fidelity signal models, the authors show traditional STAP losses in excess of 10 dB because of the effects of clutter non-stationarity. The authors then investigate a number of ameliorating techniques compatible with standard STAP implementation, including localised processing, localised processing with time-varying weights, equivalent uniform linear array transformation, angle-Doppler warping and higher-order angle-Doppler warping. The authors demonstrate very good performance for the higher-order angle-Doppler warping method applied to the chined radome shape, with peak adaptive SINR losses reduced from nearly 16 dB for the uncompensated case to 3 dB of loss consistent with performance attainable in a homogeneous clutter environment. The authors also find good performance for three-dimensional angle-Doppler warping over azimuth, elevation and Doppler when applied to the tapered canoe shape, with uncompensated losses of roughly 14 dB reduced to 3 dB, again a level compatible with STAP applied in a homogeneous clutter environment. The authors thus show that CFA STAP can yield performance similar to that of a conventional planar array when using appropriate compensation methods.
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