分块压缩感知(BCS)适用于图像信号的压缩感知(CS)处理.当采样率较低时,BCS迭代阈值投影(BCS-SPL)算法对图像纹理部分重构质量差,针对此不足,提出基于全变差分自适应采样率BCS正交匹配追踪(Total Variation based Sampling Adaptive Bloc...分块压缩感知(BCS)适用于图像信号的压缩感知(CS)处理.当采样率较低时,BCS迭代阈值投影(BCS-SPL)算法对图像纹理部分重构质量差,针对此不足,提出基于全变差分自适应采样率BCS正交匹配追踪(Total Variation based Sampling Adaptive Block Compressed Sensing w ith OM P,TVSA-BCS-OM P)算法,该算法对图像重叠分块以消除重构结果的块效应,根据图像子块的纹理复杂度自适应分配采样率,并且子块的纹理复杂度用各自的全变差分进行测量,从而全变差分较大的子块可获得更高采样率.各子块由纹理分配采样率保留变换域下的非零系数,分别进行CS采样以及OMP重构.实验结果显示,当图像初始采样率较低(低于0.2)时,TVSA-BCS-OMP算法的重构精度始终高于BCS-SPL算法,特别是对图像纹理块的重构质量更高,并且前者的重构时间比后者更低.展开更多
An image can be decomposed into the structural component and the geometric texturalcomponent.Based on this idea,an efficient two-layered compressing algorithm is proposed,which uses2nd generation bandelets and wavelet...An image can be decomposed into the structural component and the geometric texturalcomponent.Based on this idea,an efficient two-layered compressing algorithm is proposed,which uses2nd generation bandelets and wavelets.First,an original image is decomposed into the structuralcomponent and the textural component,and then these two components are compressed using waveletsand 2nd generation bandelets respectively.Numerical tests show that the proposed method worksbetter than the bandelets and JPEG2000 in some specific SAR scene.展开更多
Airborne electromagnetic transient method enjoys the advantages of high-efficiency and the high resolution of electromagnetic anomalies,especially suitable for mining detection around goaf areas and deep exploration o...Airborne electromagnetic transient method enjoys the advantages of high-efficiency and the high resolution of electromagnetic anomalies,especially suitable for mining detection around goaf areas and deep exploration of minerals.In this paper,we calculated the full-wave airborne transient electromagnetic data,according to the result of numerical research,the advantage of switch-off time response in electromagnetic detection was proofed via experiments.Firstly,based on the full-wave airborne transient electromagnetic system developed by Jilin University(JLU-ATEMI),we proposed a method to compute the full-waveform electromagnetic(EM)data of 3D model using the FDTD approach and convolution algorithm,and verify the calculation by the response of homogenous half-space.Then,through comparison of switch-off-time response and off-time response,we studied the effect of ramp time on anomaly detection.Finally,we arranged two experimental electromagnetic detection,the results indicated that the switch-off-time response can reveal the shallow target more effectively,and the full-waveform airborne electromagnetic system is an effective technique for shallow target detection.展开更多
By means of the continuous Glimm functional, a proof is given on the global existence of classical solutions to Cauchy problem for general first order quasilinear hyperbolic systems with small initial total variation.
文摘分块压缩感知(BCS)适用于图像信号的压缩感知(CS)处理.当采样率较低时,BCS迭代阈值投影(BCS-SPL)算法对图像纹理部分重构质量差,针对此不足,提出基于全变差分自适应采样率BCS正交匹配追踪(Total Variation based Sampling Adaptive Block Compressed Sensing w ith OM P,TVSA-BCS-OM P)算法,该算法对图像重叠分块以消除重构结果的块效应,根据图像子块的纹理复杂度自适应分配采样率,并且子块的纹理复杂度用各自的全变差分进行测量,从而全变差分较大的子块可获得更高采样率.各子块由纹理分配采样率保留变换域下的非零系数,分别进行CS采样以及OMP重构.实验结果显示,当图像初始采样率较低(低于0.2)时,TVSA-BCS-OMP算法的重构精度始终高于BCS-SPL算法,特别是对图像纹理块的重构质量更高,并且前者的重构时间比后者更低.
文摘An image can be decomposed into the structural component and the geometric texturalcomponent.Based on this idea,an efficient two-layered compressing algorithm is proposed,which uses2nd generation bandelets and wavelets.First,an original image is decomposed into the structuralcomponent and the textural component,and then these two components are compressed using waveletsand 2nd generation bandelets respectively.Numerical tests show that the proposed method worksbetter than the bandelets and JPEG2000 in some specific SAR scene.
基金Project(41674109) supported by the National Natural Science Foundation of China
文摘Airborne electromagnetic transient method enjoys the advantages of high-efficiency and the high resolution of electromagnetic anomalies,especially suitable for mining detection around goaf areas and deep exploration of minerals.In this paper,we calculated the full-wave airborne transient electromagnetic data,according to the result of numerical research,the advantage of switch-off time response in electromagnetic detection was proofed via experiments.Firstly,based on the full-wave airborne transient electromagnetic system developed by Jilin University(JLU-ATEMI),we proposed a method to compute the full-waveform electromagnetic(EM)data of 3D model using the FDTD approach and convolution algorithm,and verify the calculation by the response of homogenous half-space.Then,through comparison of switch-off-time response and off-time response,we studied the effect of ramp time on anomaly detection.Finally,we arranged two experimental electromagnetic detection,the results indicated that the switch-off-time response can reveal the shallow target more effectively,and the full-waveform airborne electromagnetic system is an effective technique for shallow target detection.
文摘By means of the continuous Glimm functional, a proof is given on the global existence of classical solutions to Cauchy problem for general first order quasilinear hyperbolic systems with small initial total variation.
