Motion deblurring is a basic problem in the field of image processing and analysis. This paper proposes a new method of single image blind deblurring which can be significant to kernel estimation and non-blind deconvo...Motion deblurring is a basic problem in the field of image processing and analysis. This paper proposes a new method of single image blind deblurring which can be significant to kernel estimation and non-blind deconvolution. Experiments show that the details of the image destroy the structure of the kernel, especially when the blur kernel is large. So we extract the image structure with salient edges by the method based on RTV. In addition, the traditional method for motion blur kernel estimation based on sparse priors is conducive to gain a sparse blur kernel. But these priors do not ensure the continuity of blur kernel and sometimes induce noisy estimated results. Therefore we propose the kernel refinement method based on L0 to overcome the above shortcomings. In terms of non-blind deconvolution we adopt the L1/L2 regularization term. Compared with the traditional method, the method based on L1/L2 norm has better adaptability to image structure, and the constructed energy functional can better describe the sharp image. For this model, an effective algorithm is presented based on alternating minimization algorithm.展开更多
By applying smoothed l0norm（SL0）algorithm,a block compressive sensing（BCS）algorithm called BCS-SL0 is proposed,which deploys SL0 and smoothing filter for image reconstruction.Furthermore,BCS-ReSL0 algorithm is dev...By applying smoothed l0norm（SL0）algorithm,a block compressive sensing（BCS）algorithm called BCS-SL0 is proposed,which deploys SL0 and smoothing filter for image reconstruction.Furthermore,BCS-ReSL0 algorithm is developed to use regularized SL0（ReSL0）in a reconstruction process to deal with noisy situations.The study shows that the proposed BCS-SL0 takes less execution time than the classical BCS with smoothed projected Landweber（BCS-SPL）algorithm in low measurement ratio,while achieving comparable reconstruction quality,and improving the blocking artifacts especially.The experiment results also verify that the reconstruction performance of BCS-ReSL0 is better than that of the BCSSPL in terms of noise tolerance at low measurement ratio.展开更多
针对利用压缩感知进行波达方向(Direction of Arrival,DOA)估计时求解l_0范数NP难、噪声敏感等问题,提出一种基于近似l_0范数的实数化DOA估计算法(AL0-DOA)。对阵列接收数据的协方差矩阵进行Khatri-Rao(KR)积变换,将阵列多测量矢量模型...针对利用压缩感知进行波达方向(Direction of Arrival,DOA)估计时求解l_0范数NP难、噪声敏感等问题,提出一种基于近似l_0范数的实数化DOA估计算法(AL0-DOA)。对阵列接收数据的协方差矩阵进行Khatri-Rao(KR)积变换,将阵列多测量矢量模型转换为虚拟阵列单测量矢量模型,并通过降维和实数化进一步降低计算量,同时抑制噪声,提高DOA估计的准确性。利用信源在空间的稀疏性构造冗余字典,引入平滑函数来近似l_0范数,将无法直接求解l_0范数问题转化为平滑函数的最优化问题,可通过修正牛顿算法快速求解。仿真结果表明该算法计算快,精度较高,可对DOA进行有效估计。展开更多
The sparse recovery algorithms formulate synthetic aperture radar （SAR） imaging problem in terms of sparse representation （SR） of a small number of strong scatters＇ positions among a much large number of potentia...The sparse recovery algorithms formulate synthetic aperture radar （SAR） imaging problem in terms of sparse representation （SR） of a small number of strong scatters＇ positions among a much large number of potential scatters＇ positions, and provide an effective approach to improve the SAR image resolution. Based on the attributed scatter center model, several experiments were performed with different practical considerations to evaluate the performance of five representative SR techniques, namely, sparse Bayesian learning （SBL）, fast Bayesian matching pursuit （FBMP）, smoothed 10 norm method （SL0）, sparse reconstruction by separable approximation （SpaRSA）, fast iterative shrinkage-thresholding algorithm （FISTA）, and the parameter settings in five SR algorithms were discussed. In different situations, the performances of these algorithms were also discussed. Through the comparison of MSE and failure rate in each algorithm simulation, FBMP and SpaRSA are found suitable for dealing with problems in the SAR imaging based on attributed scattering center model. Although the SBL is time-consuming, it always get better performance when related to failure rate and high SNR.展开更多
It is challenging to consistently smooth natural images, yet smoothing results determine the quality of a broad range of applications in computer vision. To achieve consistent smoothing, we propose a novel optimizatio...It is challenging to consistently smooth natural images, yet smoothing results determine the quality of a broad range of applications in computer vision. To achieve consistent smoothing, we propose a novel optimization model making use of the redundancy of natural images, by defining a nonlocal concentration regularization term on the gradient. This nonlocal constraint is carefully combined with a gradientsparsity constraint, allowing details throughout the whole image to be removed automatically in a datadriven manner. As variations in gradient between similar patches can be suppressed effectively, the new model has excellent edge preserving, detail removal,and visual consistency properties. Comparisons with state-of-the-art smoothing methods demonstrate the effectiveness of the new method. Several applications,including edge manipulation, image abstraction,detail magnification, and image resizing, show the applicability of the new method.展开更多
基金Partially Supported by National Natural Science Foundation of China(No.61173102)
文摘Motion deblurring is a basic problem in the field of image processing and analysis. This paper proposes a new method of single image blind deblurring which can be significant to kernel estimation and non-blind deconvolution. Experiments show that the details of the image destroy the structure of the kernel, especially when the blur kernel is large. So we extract the image structure with salient edges by the method based on RTV. In addition, the traditional method for motion blur kernel estimation based on sparse priors is conducive to gain a sparse blur kernel. But these priors do not ensure the continuity of blur kernel and sometimes induce noisy estimated results. Therefore we propose the kernel refinement method based on L0 to overcome the above shortcomings. In terms of non-blind deconvolution we adopt the L1/L2 regularization term. Compared with the traditional method, the method based on L1/L2 norm has better adaptability to image structure, and the constructed energy functional can better describe the sharp image. For this model, an effective algorithm is presented based on alternating minimization algorithm.
基金Supported by the National Natural Science Foundation of China(61421001,61331021,61501029)
文摘By applying smoothed l0norm（SL0）algorithm,a block compressive sensing（BCS）algorithm called BCS-SL0 is proposed,which deploys SL0 and smoothing filter for image reconstruction.Furthermore,BCS-ReSL0 algorithm is developed to use regularized SL0（ReSL0）in a reconstruction process to deal with noisy situations.The study shows that the proposed BCS-SL0 takes less execution time than the classical BCS with smoothed projected Landweber（BCS-SPL）algorithm in low measurement ratio,while achieving comparable reconstruction quality,and improving the blocking artifacts especially.The experiment results also verify that the reconstruction performance of BCS-ReSL0 is better than that of the BCSSPL in terms of noise tolerance at low measurement ratio.
文摘针对利用压缩感知进行波达方向(Direction of Arrival,DOA)估计时求解l_0范数NP难、噪声敏感等问题,提出一种基于近似l_0范数的实数化DOA估计算法(AL0-DOA)。对阵列接收数据的协方差矩阵进行Khatri-Rao(KR)积变换,将阵列多测量矢量模型转换为虚拟阵列单测量矢量模型,并通过降维和实数化进一步降低计算量,同时抑制噪声,提高DOA估计的准确性。利用信源在空间的稀疏性构造冗余字典,引入平滑函数来近似l_0范数,将无法直接求解l_0范数问题转化为平滑函数的最优化问题,可通过修正牛顿算法快速求解。仿真结果表明该算法计算快,精度较高,可对DOA进行有效估计。
基金Project(61171133)supported by the National Natural Science Foundation of ChinaProject(11JJ1010)supported by the Natural Science Fund for Distinguished Young Scholars of Hunan Province,ChinaProject(61101182)supported by National Natural Science Foundation for Young Scientists of China
文摘The sparse recovery algorithms formulate synthetic aperture radar （SAR） imaging problem in terms of sparse representation （SR） of a small number of strong scatters＇ positions among a much large number of potential scatters＇ positions, and provide an effective approach to improve the SAR image resolution. Based on the attributed scatter center model, several experiments were performed with different practical considerations to evaluate the performance of five representative SR techniques, namely, sparse Bayesian learning （SBL）, fast Bayesian matching pursuit （FBMP）, smoothed 10 norm method （SL0）, sparse reconstruction by separable approximation （SpaRSA）, fast iterative shrinkage-thresholding algorithm （FISTA）, and the parameter settings in five SR algorithms were discussed. In different situations, the performances of these algorithms were also discussed. Through the comparison of MSE and failure rate in each algorithm simulation, FBMP and SpaRSA are found suitable for dealing with problems in the SAR imaging based on attributed scattering center model. Although the SBL is time-consuming, it always get better performance when related to failure rate and high SNR.
基金supported by the National Natural Science Foundation of China (Nos. 61332015, 61373078, 61272245, 61202148, and 61103150)the NSFC-Guangdong Joint Fund (No. U1201258)
文摘It is challenging to consistently smooth natural images, yet smoothing results determine the quality of a broad range of applications in computer vision. To achieve consistent smoothing, we propose a novel optimization model making use of the redundancy of natural images, by defining a nonlocal concentration regularization term on the gradient. This nonlocal constraint is carefully combined with a gradientsparsity constraint, allowing details throughout the whole image to be removed automatically in a datadriven manner. As variations in gradient between similar patches can be suppressed effectively, the new model has excellent edge preserving, detail removal,and visual consistency properties. Comparisons with state-of-the-art smoothing methods demonstrate the effectiveness of the new method. Several applications,including edge manipulation, image abstraction,detail magnification, and image resizing, show the applicability of the new method.
