- 标题
- 摘要
- 关键词
- 实验方案
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Pre-treatment for preventing degradation of measurement accuracy from speckle noise in speckle interferometry
摘要： Speckle interferometers, which can measure three-dimensional deformations with the same sensitivity in each direction of a three-dimensional axis, have been employed in the industry. However, the measurement results of a complex shape deformation using this method do not always produce a smooth phase map due to the influence of speckle noise. In this paper, this problem that occurs with speckle noise, which is included in the speckle pattern, is discussed. In addition, the solution to the problem concerning speckle noise is discussed. An idea for noise reduction is proposed by using a simple speckle pattern intensity distribution model based on the interferometry. It is confirmed that the proposed method can reduce the influence of speckle noise to 1/1000 of the light source wavelength.
关键词： Noise reduction,Influence of speckle noise,High resolution deformation measurement,ESPI (electronic speckle pattern interferometry)
更新于2025-09-23 15:23:52
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[ACM Press the 2018 International Conference - Tianjin, China (2018.09.19-2018.09.21)] Proceedings of the 2018 International Conference on Electronics and Electrical Engineering Technology - EEET '18 - An Exploratory Analysis of Speckle Noise Removal Methods for Satellite Images
摘要： image processing procedure, Satellite images captured in a variety of modalities serve as the primary source for many applications. Satellite image processing extracts the image /spectral information represented in the form of pixels, classifies those pixels based on the similarity measures and further analyzes the inherent data, as per the requirements. The foremost objective of satellite processing is to automatically categorize the pixels in an image into the respective land cover class labels or themes. These pixels are classified by its spectral information and it is determined by the relative reflectance in various bands of wavelength. The accuracy and outcomes of any satellite the application domain, directly depends on its quality. Satellite images are invariably degraded by speckle noise. Hence, preprocessing the images for speckle noise suppression and/or cloud removal is deemed an inevitable component in satellite image processing. Researchers have proposed a spectrum of methods for speckle noise/cloud removal. A detailed review on the significant research publications on speckle noise removal are summarized in this article. The consolidation of methodology merits and demerits of the select research articles are presented in this paper. This review article on speckle noise removal is designed as a ready-reference for those researchers working in satellite image processing. irrespective of
关键词： RADAR,SAR,Review,Speckle Noise,Satellite images,Noise filters,Literature Survey
更新于2025-09-23 15:23:52
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Speckle Noise Reduction of Medical Imaging via Logistic Density in Redundant Wavelet Domain
摘要： In the digital world, artificial intelligence tools and machine learning algorithms are widely applied in analysis of medical images for identifying diseases and make diagnoses; for example, to make recognition and classification. Speckle noises affect all medical imaging systems. Therefore, reduction in corrupting speckle noises is very important, since it deteriorates the quality of the medical images and makes tasks such as recognition and classification difficult. Most existing denoising algorithms have been developed for the additive white Gaussian noise (AWGN). However, AWGN is not a speckle noise. Therefore, this work presents a novel speckle noise removal algorithm within the framework of Bayesian estimation and wavelet analysis. This research focuses on noise reduction by the Bayesian with wavelet-based method because it provides good efficiency in noise reduction and spends short time in processing. The subband decomposition of a logarithmically transformed image is best described by a family of heavy-tailed densities such as Logistic distribution. Then, this research proposes the maximum a posteriori (MAP) estimator assuming Logistic random vectors for each parent-child wavelet coefficient of noise-free log-transformed data and log-normal density for speckle noises. Moreover, a redundant wavelet transform, i.e., the cycle-spinning method, is applied in our proposed methods. In our experiments, our proposed methods give promising denoising results.
关键词： wavelet transforms.,Bayesian estimation,speckle noise,non-Gaussian model
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 - Speckle Noise Reduction of Time Series Sar Images Based on Wavelet Transform and Kalman Filter
摘要： Synthetic Aperture Radar (SAR) imaging systems can provide valuable sources of earth observation data for various applications. Speckle noise reduction of images produced by these systems is a challenging issue. In this paper, a novel method is proposed for reducing the speckle noise from time series SAR images. This method is mainly based on wavelet transform and Kalman filter. The proposed method is applied to a time series SAR images acquired by Sentinel-1 over Tehran, Iran. To demonstrate the performance of the proposed method, both qualitative and quantitative evaluations are reported compared to those of conventional speckle filtering methods. The experimental results show the good performance and efficiency of the proposed method for the speckle reduction of multitemporal SAR images. As well, the results show that the proposed method can preserve the major edge structures and the spatial resolution while reducing the time of processing.
关键词： wavelet transform,speckle noise reduction,kalman filter,Time series SAR images
更新于2025-09-23 15:21:21
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[IEEE 2019 6th International Conference on Systems and Informatics (ICSAI) - Shanghai, China (2019.11.2-2019.11.4)] 2019 6th International Conference on Systems and Informatics (ICSAI) - An electromagnetic and piezoelectric coupled energy harvester using cantilever beam for low frequency vibration
摘要： With the emergence of the Microsoft Kinect sensor, many developer communities and research groups have found countless uses and have already published a wide variety of papers that utilize the raw depth images for their specific goals. New methods and applications that use the device generally require an appropriately large ensemble of data sets with accompanying ground truth for testing purposes, as well as accurate models that account for the various systematic and stochastic contributors to Kinect errors. Current error models, however, overlook the intermediate infrared (IR) images that directly contribute to noisy depth estimates. We, therefore, propose a high fidelity Kinect IR and depth image predictor and simulator that models the physics of the transmitter/receiver system, unique IR dot pattern, disparity/depth processing technology, and random intensity speckle and IR noise in the detectors. The model accounts for important characteristics of Kinect’s stereo triangulation system, including depth shadowing, IR dot splitting, spreading, and occlusions, correlation-based disparity estimation between windows of measured and reference IR images, and subpixel refinement. Results show that the simulator accurately produces axial depth error from imaged flat surfaces with various tilt angles, as well as the bias and standard lateral error of an object’s horizontal and vertical edge.
关键词： simulation,Computer-aided design (CAD),Microsoft Kinect,infrared (IR) dot pattern,structured-light 3-D scanner,speckle noise
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Integration of Photovoltaic Systems into Smart Grids Demonstration of Solar-, Storage and E-Mobility Applications within a Secure Energy Information Network in Germany
摘要： With the emergence of the Microsoft Kinect sensor, many developer communities and research groups have found countless uses and have already published a wide variety of papers that utilize the raw depth images for their specific goals. New methods and applications that use the device generally require an appropriately large ensemble of data sets with accompanying ground truth for testing purposes, as well as accurate models that account for the various systematic and stochastic contributors to Kinect errors. Current error models, however, overlook the intermediate infrared (IR) images that directly contribute to noisy depth estimates. We, therefore, propose a high fidelity Kinect IR and depth image predictor and simulator that models the physics of the transmitter/receiver system, unique IR dot pattern, disparity/depth processing technology, and random intensity speckle and IR noise in the detectors. The model accounts for important characteristics of Kinect’s stereo triangulation system, including depth shadowing, IR dot splitting, spreading, and occlusions, correlation-based disparity estimation between windows of measured and reference IR images, and subpixel refinement. Results show that the simulator accurately produces axial depth error from imaged flat surfaces with various tilt angles, as well as the bias and standard lateral error of an object’s horizontal and vertical edge.
关键词： simulation,Computer-aided design (CAD),Microsoft Kinect,infrared (IR) dot pattern,structured-light 3-D scanner,speckle noise
更新于2025-09-19 17:13:59
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[IEEE 2018 IEEE 13th International Scientific and Technical Conference on Computer Sciences and Information Technologies (CSIT) - Lviv, Ukraine (2018.9.11-2018.9.14)] 2018 IEEE 13th International Scientific and Technical Conference on Computer Sciences and Information Technologies (CSIT) - The Methods for Evaluating the Quality of Images with Different Types of Noise
摘要： In the context of evaluating the quality of image recognition systems, it's worth noting that noise is not the only type of interference. Performing such actions on the image as, for example, purposeful modification, rotation or zooming of the image will also have a negative effect on the image resolution. It has been established that one of the reasons for the complication of the decision-making process is the deterioration of the quality of the input information obtained on the basis of various images due to overlaying noise on them, which may have different origin and characteristics. Studying a certain class of noise in the context of considering it as a function allows you to focus on determining its parameters, the degree of influence of these parameters and the artificial noise generation. An overview of the noise of different types and their effects was performed for further evaluation of recognition systems. Noises that arise in this case, are subject to classification in order to study, formalize and further eliminate or minimize their harmful effects. Studying a certain class of noise in the context of considering it as a function allows you to focus on determining its parameters, the degree of influence of these parameters and the artificial noise generation.
关键词： recognition systems quality evaluation,speckle noise,Perlin noise,Gaussian noise,Poisson noise,noise overlaying methods,photographic film grains noise
更新于2025-09-11 14:15:04
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Speckle Noise Reduction by Fiber Scrambling for Improving the Measurement Precision of an Airborne Wind Lidar System
摘要： Optical guidance of coherent light in multimode fibers involves the generation of a speckle pattern at the fiber output due to the interference of the modes traveling in the fiber. Since the speckle pattern is sensitive to external perturbations (temperature, stress) as well as polarization and wavelength changes of the guided light, speckle noise is introduced limiting the quality and precision of fiber-coupled devices employed in various spectroscopic and imaging applications such as optical coherence tomography or differential absorption lidar. Speckle noise was also identified as one of the major contributors to the random error of an airborne direct-detection Doppler wind lidar which is a key instrument for the validation of the first spaceborne wind lidar Aeolus providing vertical wind profiles of the Earth. Significant reduction of the internal reference response fluctuations has been accomplished by integrating a fiber scrambler in front of the multimode fiber. The mode scrambler (GiGa Concept Inc.) is based on two counter-rotating step motors which squeeze a portion of a fiber at a time constant of a few milliseconds. Compressional and torsional stress of the fiber gives rise to local and stress-induced birefringence during these motions. This leads to a decorrelation of the modes supported by the fiber, thus homogenizing the intensity distribution at the fiber output and diminishing speckle noise. As a result, the response variations of the internal reference signal are lowered to 1.1 MHz (Mie) and 4.2 MHz (Rayleigh), which corresponds to a reduction in random wind error by a factor of about five (0.2 m/s) and two (0.8 m/s), respectively. In addition, the intensity fluctuations are decreased by 55% (Mie) and 22% (Rayleigh). Smoothing of the speckle pattern hence has a large impact on the measurement precision of the wind lidar and demonstrates the potential of fiber scramblers for improving the performance of fiber-coupled spectroscopic and imaging instruments suffering from speckle noise in general.
关键词： measurement precision,speckle noise,fiber scrambling,airborne wind lidar
更新于2025-09-11 14:15:04
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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 - An Adaptive Multilooking Scheme for Multi-Temporal Insar Data
摘要： Multilooking is an effective speckle reduction tool for InSAR images. However, it has some limitations. Based on the De-specKS and NL-SAR algorithms, an adaptive multilooking scheme for multi-temporal InSAR data has been proposed in this paper. Simulated and real SAR datasets have been employed to evaluate the performance of this scheme. The results show that, by taking advantages of DespecKS and NL-SAR, the proposed scheme presents better detail preservation and speckle noise reduction performances comparing with these two advanced and classical multilooking algorithms.
关键词： Speckle noise reduction,multi-temporal InSAR data,NL-SAR,DespecKS,adaptive multi-looking
更新于2025-09-10 09:29:36
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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 - A Speckle Reduction Model for Sar Images Based on Beltrami Regularization
摘要： A novel variational model is proposed to remove the multiplication noise in the synthetic aperture radar (SAR) images to provide a high quality of interpretation of SAR data. The model consists of the data fidelity term and Beltrami regularization term. The former ensures the convexity of the model and avoids the nonlinear image transformation. The latter restrains the staircase-like artifacts caused by total variation (TV) regularization and preserves the geometric structure of the image effectively. Experiments on both synthetic and real SAR data demonstrate that, compared with three state-of-the-art methods, the proposed method achieves competitive results both visually and quantitatively.
关键词： Beltrami regularization,speckle noise,SAR images
更新于2025-09-10 09:29:36