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DATA-DRIVEN TIGHT FRAME CONSTRUCTION FOR IMPULSIVE NOISE REMOVAL
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作者 Yang Chen Chunlin Wu 《Journal of Computational Mathematics》 SCIE CSCD 2022年第1期89-107,共19页
The method of data-driven tight frame has been shown very useful in image restoration problems.We consider in this paper extending this important technique,by incorporating L_(1) data fidelity into the original data-d... The method of data-driven tight frame has been shown very useful in image restoration problems.We consider in this paper extending this important technique,by incorporating L_(1) data fidelity into the original data-driven model,for removing impulsive noise which is a very common and basic type of noise in image data.The model contains three variables and can be solved through an efficient iterative alternating minimization algorithm in patch implementation,where the tight frame is dynamically updated.It constructs a tight frame system from the input corrupted image adaptively,and then removes impulsive noise by the derived system.We also show that the sequence generated by our algorithm converges globally to a stationary point of the optimization model.Numerical experiments and comparisons demonstrate that our approach performs well for various kinds of images.This benefits from its data-driven nature and the learned tight frames from input images capture richer image structures adaptively. 展开更多
关键词 tight frame Impulsive noise Sparse approximation data-driven Convergence analysis
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Data-Driven Tight Frame for Multi-channel Images and Its Application to Joint Color-Depth Image Reconstruction 被引量:2
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作者 Jin Wang Jian-Feng Cai 《Journal of the Operations Research Society of China》 EI CSCD 2015年第2期99-115,共17页
In image restoration,we usually assume that the underlying image has a good sparse approximation under a certain system.Wavelet tight frame system has been proven to be such an efficient system to sparsely approximate... In image restoration,we usually assume that the underlying image has a good sparse approximation under a certain system.Wavelet tight frame system has been proven to be such an efficient system to sparsely approximate piecewise smooth images.Thus,it has been widely used in many practical image restoration problems.However,images from different scenarios are so diverse that no static wavelet tight frame system can sparsely approximate all of themwell.To overcome this,recently,Cai et.al.(Appl Comput Harmon Anal 37:89–105,2014)proposed a method that derives a data-driven tight frame adapted to the specific input image,leading to a better sparse approximation.The data-driven tight frame has been applied successfully to image denoising and CT image reconstruction.In this paper,we extend this data-driven tight frame construction method to multi-channel images.We construct a discrete tight frame system for each channel and assume their sparse coefficients have a joint sparsity.The multi-channel data-driven tight frame construction scheme is applied to joint color and depth image reconstruction.Experimental results show that the proposed approach has a better performance than state-of-the-art joint color and depth image reconstruction approaches. 展开更多
关键词 data-driven tight frame Group sparsity Image reconstruction
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自适应数据驱动的紧框架微地震数据随机噪声压制 被引量:7
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作者 唐杰 张文征 +1 位作者 梁雨薇 谷玉田 《石油地球物理勘探》 EI CSCD 北大核心 2019年第5期954-961,I0007,共9页
地面微地震数据的信噪比很低,严重影响初至拾取的精度及反演结果的可靠性。本文首先采用基于弱纹理块的噪声估计方法求取含噪微地震数据中的噪声方差,然后采用数据驱动紧框架方法去噪,有效地压制实际微地震数据中的随机噪声,提高数据的... 地面微地震数据的信噪比很低,严重影响初至拾取的精度及反演结果的可靠性。本文首先采用基于弱纹理块的噪声估计方法求取含噪微地震数据中的噪声方差,然后采用数据驱动紧框架方法去噪,有效地压制实际微地震数据中的随机噪声,提高数据的信噪比。理论模型和实际资料的处理结果表明,该方法可以去除传统方法在低信噪比数据去噪后引入的背景斑块,且去噪后的信噪比得到了极大的提高。因此,相对于传统的方法,本文方法具有显著的优势及较好的应用价值。 展开更多
关键词 噪声方差估计 数据驱动紧框架 地震去噪 弱纹理块 微地震
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扣件式钢管支承架构配件及搭设质量现场调查与分析 被引量:7
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作者 王文鹏 孔纯威 +1 位作者 赵吉祥 宋建学 《河南城建学院学报》 CAS 2018年第1期7-10,共4页
为了给支承架设计计算提供参数依据,对建筑、市政10个工地支承架随机抽检,实地调查钢管壁厚、扣件重量、扣件螺栓拧紧力矩等指标。结果表明:基于当前支承架钢管与扣件的实际情况及搭设质量现状,支承架设计中钢管壁厚宜取为2.7 mm;抽检... 为了给支承架设计计算提供参数依据,对建筑、市政10个工地支承架随机抽检,实地调查钢管壁厚、扣件重量、扣件螺栓拧紧力矩等指标。结果表明:基于当前支承架钢管与扣件的实际情况及搭设质量现状,支承架设计中钢管壁厚宜取为2.7 mm;抽检工程中仅10%左右扣件拧紧力矩达到规范要求,实际工程中必须加大拧紧力矩抽检比例;抽检扣件拧紧力矩集中在20~40 N·m,扣件抗滑承载力应据此折减。 展开更多
关键词 土木工程施工 支承架 脚手架 现场抽检 壁厚 拧紧力矩
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轻木结构的乡村学校——香港学生团体在柬埔寨的建筑实践 被引量:1
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作者 黄浩文 麥文熙 +1 位作者 朱竞翔 彭嫱 《建筑学报》 北大核心 2014年第12期96-100,共5页
介绍了由香港学生团体"梦·行动"采用轻木结构建造的3所柬埔寨乡村学校的简明空间设计及其材料与建造组织。3所学校所共用的轻木框架结构系统可以高效低价地实现基本空间要求,而结构布局、构件、节点方面的细致优化将传... 介绍了由香港学生团体"梦·行动"采用轻木结构建造的3所柬埔寨乡村学校的简明空间设计及其材料与建造组织。3所学校所共用的轻木框架结构系统可以高效低价地实现基本空间要求,而结构布局、构件、节点方面的细致优化将传统手工艺与精确的设计新要求逐步联合起来。 展开更多
关键词 柬埔寨乡村学校 轻木结构 框架建造系统 设计演化 “梦·行动”
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