- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE 2018 12th International Conference on Communications (COMM) - Bucharest (2018.6.14-2018.6.16)] 2018 International Conference on Communications (COMM) - Supervized Change Detection for SAR Imagery Based on Processing of a Low Size Training Data Set by an Ensemble of Self-Organizing Maps
摘要： This paper presents a new method to improve accuracy of supervised change detection in Synthetic Aperture Radar (SAR) imagery. The model is based on the idea to apply a low size labeled dataset to the input of an Ensemble of Self-Organizing Maps (ESOM) for training data generation (TDG). The resulted synthetic data set produced by ESOM substitutes the initial authentically labeled sample set and it is used to train a supervised change detection classifier. The proposed method is evaluated using a TerraSAR-X image of 400x400 pixels acquired in the Fukushima region, Japan, before and after tsunami. As change detection classifiers we have comparatively considered Support Vector Machine (SVM), Nearest Neighbor (NN), the three-Nearest Neighbors (3-NN), and Likelihood Bayes classifier. The experimental results have confirmed the effectiveness of the proposed approach using only 100 authentic labeled pixels.
关键词： SAR images,ensemble of self-organizing maps (ESOM),virtual training data generation(VTDG),change detection
更新于2025-09-23 15:23:52
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Scalable appearance filtering for complex lighting effects
摘要： Realistic rendering with materials that exhibit high-frequency spatial variation remains a challenge, as eliminating spatial and temporal aliasing requires prohibitively high sampling rates. Recent work has made the problem more tractable, however existing methods remain prohibitively expensive when using large environmental lights and/or (correctly filtered) global illumination. We present an appearance model with explicit high-frequency micro-normal variation, and a filtering approach that scales to multi-dimensional shading integrals. By combining a novel and compact half-vector histogram scheme with a directional basis expansion, we accurately compute the integral of filtered high-frequency reflectance over large lights with angularly varying emission. Our approach is scalable, rendering images indistinguishable from ground truth at over 10× the speed of the state-of-the-art and with only 15% the memory footprint. When filtering appearance with global illumination, we outperform the state-of-the-art by ～ 30×.
关键词： glints,normal maps,summed area tables,spherical harmonics
更新于2025-09-23 15:23:52
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Barriers to and consequences of a solar-based energy transition in Greece
摘要： In Greece, the renewable energy potential and a low-quality building stock constitute the background of a possible low-carbon energy transition. This transition, however, faces significant uncertainties, ranging from long-term effects of the ongoing economic recession and technological lock-ins, to the stability of the regulatory framework and issues of public acceptance. Such uncertainties may eventually give rise to significant barriers to, as well as severe economic and social consequences of, the envisaged transition. Here, in a structured approach to eliciting the knowledge embedded in stakeholders, we identify such risks and explore their dynamics and role in a sustainable transition to a power system that is based on large-scale solar projects and prosuming in the residential sector. We then employ a modelling ensemble, consisting of a macroeconomic dynamic stochastic general equilibrium model and a business strategy assessment model, in order to quantify and evaluate the extent of the identified risks’ impact.
关键词： Modeling,Energy transitions,Fuzzy cognitive maps,Solar power,Greece,Self-consumption
更新于2025-09-23 15:22:29
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[IEEE ICASSP 2018 - 2018 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) - Calgary, AB (2018.4.15-2018.4.20)] 2018 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) - No-Reference Hdr Image Quality Assessment Method Based on Tensor Space
摘要： The full-reference image quality assessment (IQA) method are limited in practical applications. Here we propose a no-reference quality assessment method for high dynamic range (HDR) images based on tensor space. First, the tensor decomposition is used to generate three feature maps of an HDR image, considering color and structure information of the HDR image. Second, for a given HDR image, the corresponding multi-scale manifold structure features are extracted from the first feature map. For the second and third feature maps of the HDR image, multi-scale contrast features are extracted. Finally, the extracted features are aggregated by support vector regression to obtain the objective quality score of the HDR image. Experimental results show that the proposed method is superior to some representative full and no-reference methods, and even superior to the full-reference HDR IQA method, HDR-VDP-2.2, on the Nantes database. The proposed method has a higher consistency with human visual perception.
关键词： high dynamic range,feature maps,No-reference,image quality assessment,tensor space
更新于2025-09-23 15:22:29
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[IEEE 2018 Eighth International Conference on Image Processing Theory, Tools and Applications (IPTA) - Xi'an, China (2018.11.7-2018.11.10)] 2018 Eighth International Conference on Image Processing Theory, Tools and Applications (IPTA) - Comparative study of visual saliency maps in the problem of classification of architectural images with Deep CNNs
摘要： Incorporating Human Visual System (HVS) models into building of classifiers has become an intensively researched field in visual content mining. In the variety of models of HVS we are interested in so-called visual saliency maps. Contrarily to scan-paths they model instantaneous attention assigning the degree of interestingness/saliency for humans to each pixel in the image plane. In various tasks of visual content understanding, these maps proved to be efficient stressing contribution of the areas of interest in image plane to classifiers models. In previous works saliency layers have been introduced in Deep CNNs, showing that they allow reducing training time getting similar accuracy and loss values in optimal models. In case of large image collections efficient building of saliency maps is based on predictive models of visual attention. They are generally bottom-up and are not adapted to specific visual tasks. Unless they are built for specific content, such as 'urban images'-targeted saliency maps we also compare in this paper. In present research we propose a 'bootstrap' strategy of building visual saliency maps for particular tasks of visual data mining. A small collection of images relevant to the visual understanding problem is annotated with gaze fixations. Then the propagation to a large training dataset is ensured and compared with the classical GBVS model and a recent method of saliency for urban image content. The classification results within Deep CNN framework are promising compared to the purely automatic visual saliency prediction.
关键词： Mexican Culture,Saliency Maps,Deep Learning
更新于2025-09-23 15:22:29
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Use of Land Cover Maps as Indicators for Achieving Sustainable Development Goals
摘要： In this paper we propose method for land degradation indicators identification within the ERA-PLANET project. We also consider data sources that can be used for these purposes and consider the possibility of using high spatial resolution satellite-based classification maps. Project GEOEssential within the framework of the ERA-PLANET Project, using heterogeneous satellite data has the potential to make positive changes in land use. In this paper the ways of forming essential variables are described with specific attention to domain where and how it is possible to improve the state of productivity of land and to identify the non-proper use of land, which leads to desertification, forest degradation and the general degradation of land resources.
关键词： GEOEssential,Essential Variables,ERA-PLANET,classification maps
更新于2025-09-23 15:21:21
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Remote Welfare Monitoring of Rodents Using Thermal Imaging
摘要： Animal research has always played a crucial role in various medical and scientific breakthroughs. They offer, inter alia, insights into diseases mechanisms, genetic predisposition to a disease, and drug therapy. However, the use of animals for medical research is a cause of major controversies and debates in modern science. To warrant high bioethical standards, new directives have been being adopted to replace animal research whenever possible, to reduce the number of animals, and to refine the procedures to minimize stress and pain. Here, we present two new approaches, based on thermal imaging (a remote and passive technology), to assess respiratory rate (RR) as well as exploratory behavior and general activity in rodents. In animal research, these parameters are gold standards for welfare assessment. The approaches were validated in a study conducted with both rats and mice. To test the feasibility of our algorithm to estimate RR, thermal videos from anesthetized rodents were acquired. The capability of the second approach to monitor activity was tested with videos of Open Field tests. Regarding RR, a high agreement between thermal imaging and gold standard (electrocardiography-derived RR) was achieved. The mean relative error averaged 0.50 ± 0.15 breaths/min and 4.55 ± 2.94 breaths/min for rats and mice, respectively. The second approach was capable of monitoring and tracking the activity of the rodents very well. This paper demonstrates that thermal imaging is a promising and relevant alternative for monitoring of RR and activity in rodents, thus contributing to the remote assessment of animal welfare.
关键词： vital signs,infrared thermography,respiratory rate,remote monitoring,locomotor activity,motion heat maps,thermal imaging,animal research
更新于2025-09-23 15:21:01
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Pulse Wave Imaging in Carotid Artery Stenosis Human Patients in Vivo
摘要： Carotid stenosis involves narrowing of the lumen in the carotid artery potentially leading to a stroke, which is the third leading cause of death in the United States. Several recent investigations have found that plaque structure and composition may represent a more direct biomarker of plaque rupture risk compared with the degree of stenosis. In this study, pulse wave imaging was applied in 111 (n = 11, N = 13 plaques) patients diagnosed with moderate (>50%) to severe (>80%) carotid artery stenosis to investigate the feasibility of characterizing plaque properties based on the pulse wave-induced arterial wall dynamics captured by pulse wave imaging. Five (n = 5 patients, N = 20 measurements) healthy volunteers were also imaged as a control group. Both conventional and high-frame-rate plane wave radiofrequency imaging sequences were used to generate piecewise maps of the pulse wave velocity (PWV) at a single depth along stenotic carotid segments, as well as intra-plaque PWV mapping at multiple depths. Intra-plaque cumulative displacement and strain maps were also calculated for each plaque region. The Bramwell(cid:3)Hill equation was used to estimate the compliance of the plaque regions based on the PWV and diameter. Qualitatively, wave convergence, elevated PWV and decreased cumulative displacement around and/or within regions of atherosclerotic plaque were observed and may serve as biomarkers for plaque characterization. Intra-plaque mapping revealed the potential to capture wave re?ections between calci?ed inclusions and differentiate stable (i.e., calci?ed) from vulnerable (i.e., lipid) plaque components based on the intra-plaque PWV and cumulative strain. Quantitatively, one-way analysis of variance indicated that the pulse wave-induced cumulative strain was signi?cantly lower (p < 0.01) in the moderately and severely calci?ed plaques compared with the normal controls. As expected, compliance was also signi?cantly lower in the severely calci?ed plaques regions compared with the normal controls (p < 0.01). The results from this pilot study indicated the potential of pulse wave imaging coupled with strain imaging to differentiate plaques of varying stiffness, location and composition. Such ?ndings may serve as valuable information to compensate for the limitations of currently used methods for the assessment of stroke risk. (E-mail: ek2191@columbia.edu) ? 2018 World Federation for Ultrasound in Medicine & Biology. All rights reserved.
关键词： Arterial wall elasticity maps,Arterial wall motion,Atherosclerosis,Pulse wave velocity,Pulse wave imaging,High-frame-rate ultrasound,Calci?ed plaque,Arterial compliance
更新于2025-09-23 15:21:01
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Secure Image Compression Approach based on Fusion of 3D Chaotic Maps and Arithmetic Coding
摘要： The advances in digital image processing and communications have created a great demand for real–time secure image transmission over the networks. However, the development of effective, fast and secure dependent image compression encryption systems are still a research problem as the intrinsic features of images such as bulk data capacity and high correlation among pixels hinds the use of the traditional joint encryption compression methods. A new approach is suggested in this paper for partial image encryption compression that adopts chaotic 3D cat map to de-correlate relations among pixels in conjunction with an adaptive thresholding technique that is utilized as a lossy compression technique instead of using complex quantization techniques and also as a substitution technique to increase the security of the cipher image. The proposed scheme is based on employing both of lossless compression with encryption on the most significant part of the image after contourlet transform. However the least significant parts are lossy compressed by employing a simple thresholding rule and arithmetic coding to render the image totally unrecognizable. Due to the weakness of 3D cat map to chosen plain text attack, the suggested scheme incorporates a mechanism to generate random key depending on the contents of the image (context key). Several experiments were done on benchmark images to insure the validity of the proposed technique. The compression analysis and security outcomes indicate that the suggested technique is an efficacious and safe for real time image’s applications.
关键词： Cryptography,Chaotic maps,Joint compression encryption,Contourlet transform,Thresholding,Arithmetic coding
更新于2025-09-23 15:21:01
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Joint Image Compression and Encryption Using IWT with SPIHT, Kd-Tree and Chaotic Maps
摘要： Confidentiality and efficient bandwidth utilization require a combination of compression and encryption of digital images. In this paper, a new method for joint image compression and encryption based on set partitioning in hierarchical trees (SPIHT) with optimized Kd-tree and multiple chaotic maps was proposed. First, the lossless compression and encryption of the original images were performed based on integer wavelet transform (IWT) with SPIHT. Wavelet coefficients undergo diffusions and permutations before encoded through SPIHT. Second, maximum confusion, diffusion and compression of the SPIHT output were performed via the modified Kd-tree, wavelet tree and Huffman coding. Finally, the compressed output was further encrypted with varying parameter logistic maps and modified quadratic chaotic maps. The performance of the proposed technique was evaluated through compression ratio (CR) and peak-signal-to-noise ratio (PSNR), key space and histogram analyses. Moreover, this scheme passes several security tests, such as sensitivity, entropy and differential analysis tests. According to the theoretical analysis and experimental results, the proposed method is more secure and decreases the redundant information of the image more than the existing techniques for hybrid compression and encryption.
关键词： k-dimensional tree,chaotic maps,set partition in hierarchical trees,integer wavelet transform,encryption,image compression
更新于2025-09-23 15:21:01