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Enhancing some separability criteria via equiangular tight frames
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作者 Liang Tang Fan Wu 《Communications in Theoretical Physics》 2025年第4期45-54,共10页
Improvement of the detection ability of quantum entanglement is one of the essential tasks in quantum computing and quantum information.Finite tight frames play a fundamental role in a wide variety of areas and,genera... Improvement of the detection ability of quantum entanglement is one of the essential tasks in quantum computing and quantum information.Finite tight frames play a fundamental role in a wide variety of areas and,generally,each application requires a specific class of frames and is closely related to quantum measurement.It is worth noting that a maximal set of complex equiangular vectors is closely related to a symmetric informationally complete measurement.Hence,our goal in this work is to propose a series of separability criteria assigned to a finite tight frame and some well-known inequalities in different quantum systems,respectively.In addition,some tighter criteria to detect entanglement for many-body quantum states are presented in arbitrary dimensions.Finally,the effectiveness of the proposed entanglement detection criteria is illustrated through some detailed examples. 展开更多
关键词 entanglement detection separability criterion bipartite systems finite tight frames
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A Note on Tight Frames 被引量:1
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作者 李登峰 战阴伟 《Chinese Quarterly Journal of Mathematics》 CSCD 2002年第4期48-51,共4页
Suppose that Φ(x)∈L 2(R) with compact support and V= span{Φ(x-k)|k∈Z}. In this note, we prove that if {Φ(x-k)k|k∈Z} is tight frame with bound 1 in V, then {Φ(x-k)|k∈Z} must be an orthonormal basis of V.
关键词 frame tight frame orthonormal basis
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Construction of Multivariate Tight Framelet Packets Associated with Dilation Matrix
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作者 Firdous A.Shah Abdullah 《Analysis in Theory and Applications》 CSCD 2015年第2期109-122,共14页
In this paper, we present a method for constructing multivariate tight framelet packets associated with an arbitrary dilation matrix using unitary extension principles. We also prove how to construct various tight fra... In this paper, we present a method for constructing multivariate tight framelet packets associated with an arbitrary dilation matrix using unitary extension principles. We also prove how to construct various tight frames for L2 (JRa) by replacing some mother framelets. 展开更多
关键词 WAVELET tight frame framelet packet matrix dilation extension principle Fouriertransform.
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A Robust Digital Watermarking Algorithm Based on Finite-Set Discrete Radon Transform Tight Frame
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作者 Jiangui Zhang Huibin Qi 《Journal of Computer and Communications》 2020年第12期123-133,共11页
<div style="text-align:justify;"> Digital watermarking technology plays a powerful role in the effective protection of digital media copyright, image authentication, image sharing, image information tr... <div style="text-align:justify;"> Digital watermarking technology plays a powerful role in the effective protection of digital media copyright, image authentication, image sharing, image information transmission and other fields. Driven by strong demand, digital image watermarking technology has aroused widespread research interest and has gradually developed into one of the most active research directions in information science. In this paper, we present a novel robust digital watermarking algorithm based on discrete radon transform tight frame in finite-set (FDRT). FDRT of the zero mean image is a tight frame, the frame boundary <em><strong>A</strong></em> = <em><strong>B</strong></em> = 1, the dual of the frame is itself. The decomposition and reconstruction of the FDRT tight frame will not cause the phenomenon of image distortion. The embedding of hidden watermark is to add a weak signal to the strong background of the original image. Watermark extraction is to effectively identify the embedded weak signal. The feasibility of the watermarking algorithm is analyzed from two aspects of information hiding and robustness. We select the independent Gaussian random vector as the watermark series, and the peak signal-to-noise ratio (PSNR) as the visual degradation criterion of the watermark image. Basing the FDRT compact stand dual operator, we derived the relationship among the strength parameter, square sum of watermark series, the PSNR. Using Checkmark system, the simulation results show that the algorithm is robust enough to some very important image processing attacks such as lossy compression, MAP, filtering, segmentation, edge enhancement, jitter, quadratic modulation and general geometric attack (scaling, rotation, shearing), etc. </div> 展开更多
关键词 Digital Watermarking Data Mining Discrete Radon Transform tight frame Copyright Protection Information Hiding Finite-Set
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Expansion of Frames to Tight Frames 被引量:7
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作者 Deng Feng LI Wen Chang SUN 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2009年第2期287-298,共12页
We show that every Bessel sequence (and therefore every frame) in a separable Hilbert space can be expanded to a tight frame by adding some elements. The proof is based on a recent generalization of the frame concep... We show that every Bessel sequence (and therefore every frame) in a separable Hilbert space can be expanded to a tight frame by adding some elements. The proof is based on a recent generalization of the frame concept, the g-frame, which illustrates that g-frames could be useful in the study of frame theory. As an application, we prove that any Gabor frame can be expanded to a tight frame by adding one window function. 展开更多
关键词 frame tight frame G-frame Gabor frame frame expansion
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Construction for a class of smooth wavelet tight frames 被引量:5
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作者 彭立中 王海辉 《Science in China(Series F)》 2003年第6期445-458,共14页
From the inequality |P(z)|2 + |P(-z)|2 ≤1, assuming that both of the low-pass filters and high-pass filters are unknown, we design compactly supported wavelet tight frames. The unknowing of low-pass filters allows th... From the inequality |P(z)|2 + |P(-z)|2 ≤1, assuming that both of the low-pass filters and high-pass filters are unknown, we design compactly supported wavelet tight frames. The unknowing of low-pass filters allows the design more freedom, and both the low-pass filters and high-pass filters have symmetries or anti-symmetries. We give the algorithm for filters with odd and even lengths separately, some concrete examples of wavelet tight frames with the length 4, 5, 6, 7, and at last we give the result of decomposing Lena image with them. 展开更多
关键词 wavelet tight frame compact support SMOOTHNESS symmetry (anti-symmetry).
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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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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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On Characterization of Nonuniform Tight Wavelet Frames on Local Fields
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作者 Owais Ahmad Neyaz A.Sheikh 《Analysis in Theory and Applications》 CSCD 2018年第2期135-146,共12页
In this article, we introduce a notion of nonuniform wavelet frames on local fields of positive characteristic. Furthermore, we gave a complete characterization of tight nonuniform wavelet frames on local fields of po... In this article, we introduce a notion of nonuniform wavelet frames on local fields of positive characteristic. Furthermore, we gave a complete characterization of tight nonuniform wavelet frames on local fields of positive characteristic via Fourier transform. Our results also hold for the Cantor dyadic group and the Vilenkin groups as they are local fields of positive characteristic. 展开更多
关键词 NONUNIFORM WAVELET frame tight WAVELET frame FOURIER transform.local field
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Asymptotic Boundary Forms for Tight Gabor Frames and Lattice Localization Domains
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作者 H. G. Feichtinger K. Nowak M. Pap 《Journal of Applied Mathematics and Physics》 2015年第10期1316-1342,共27页
We consider Gabor localization operators ?defined by two parameters, the generating function ?of a tight Gabor frame , indexed by a lattice , and a domain ?whose boundary consists of line segments connecting certain p... We consider Gabor localization operators ?defined by two parameters, the generating function ?of a tight Gabor frame , indexed by a lattice , and a domain ?whose boundary consists of line segments connecting certain points of . We provide an explicit formula for the boundary form , the normalized limit of the projection functional , where ?are the eigenvalues of the localization operators ?applied to dilated domains , R is an integer and is the area of the fundamental domain. The boundary form expresses quantitatively the asymptotic interactions between the generating function ?and the oriented boundary ?from the point of view of the projection functional, which measures to what degree a given trace class operator fails to be an orthogonal projection. Keeping the area of the localization domain ?bounded above corresponds to controlling the relative dimensionality of the localization problem. 展开更多
关键词 TOEPLITZ Operators Phase Space LOCALIZATION tight GABOR frameS Semi-Classical Limit
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一种压缩感知测量矩阵的联合优化算法
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作者 杨柳 白朝元 范平志 《西南交通大学学报》 北大核心 2025年第2期454-461,共8页
对于压缩感知算法,其测量矩阵与稀疏基之间的相关性往往决定了信号恢复精度.为提升大规模通信场景下压缩感知算法重构信号的性能,基于矩阵分解与等角紧框架理论对测量矩阵进行改进.首先,基于测量矩阵和稀疏基构造字典矩阵,并进一步构造G... 对于压缩感知算法,其测量矩阵与稀疏基之间的相关性往往决定了信号恢复精度.为提升大规模通信场景下压缩感知算法重构信号的性能,基于矩阵分解与等角紧框架理论对测量矩阵进行改进.首先,基于测量矩阵和稀疏基构造字典矩阵,并进一步构造Gram矩阵,利用特征值分解降低Gram矩阵的平均相关性;然后,基于等角紧框架理论与梯度缩减理论,通过使Gram矩阵逼近等角紧框架矩阵来减小Gram矩阵非主对角线元素的最大值,从而降低测量矩阵与稀疏基之间的最大相关性;最后,以正交匹配追踪(orthogonal matching pursuit,OMP)为重构算法进行仿真验证.仿真结果表明:相比于优化前,矩阵相关系数降低40%~50%;在信道估计与活跃用户检测中,本文在较高稀疏度下的算法错误估计数比其他优化算法降低50%以上,信道估计的均方误差相比其他矩阵提升3 dB,误码率性能提升2 dB. 展开更多
关键词 压缩感知 矩阵分解 等角紧框架理论 信道估计 活跃用户检测
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基于算子理论的紧连续广义K-框架的特征刻画
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作者 张伟 周凡淳 《数学进展》 北大核心 2025年第3期581-590,共10页
借助合适的算子工具,本文探讨紧连续广义K-框架的刻画.由于算子K的限制,连续广义K-框架的等价刻画未必适用于紧连续广义K-框架.给出对于紧连续广义K-框架的相应结果.通过算子K与紧连续广义K-框架的合成算子给出其特征刻画.最后,利用算子... 借助合适的算子工具,本文探讨紧连续广义K-框架的刻画.由于算子K的限制,连续广义K-框架的等价刻画未必适用于紧连续广义K-框架.给出对于紧连续广义K-框架的相应结果.通过算子K与紧连续广义K-框架的合成算子给出其特征刻画.最后,利用算子K给出紧连续广义K-框架成为紧连续广义框架的充分必要条件.例子显示所给结论是正确的. 展开更多
关键词 广义框架 连续广义框架 紧连续广义K-框架 合成算子
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ON NECESSARY AND SUFFICIENT CONDITIONS FOR DUALS OF WAVELET FRAMES
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作者 Zhang Zeyin Wang Jianzhong 《Acta Mathematica Scientia》 SCIE CSCD 1995年第1期6-14,共9页
This paper is concerned with the characterization of the duals of wavelet frames of L(2)(R).The sufficient and necessary conditions for them are obtained.
关键词 Waveiet anglysis frameS Dual frames Affine frames tight frames.
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基于数据驱动及多尺度非局部紧框架的乘性噪声去除
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作者 王安林 吴玉莲 《计算机应用文摘》 2025年第6期81-83,共3页
为了更有效地去除图像中的乘性噪声,提出了一种基于多尺度非局部紧框架的噪声去除算法。在图像的对数域中,该算法利用多尺度的非局部紧框架进行去噪处理,既考虑了图像灰度局部变化的稀疏性,又充分考虑了图像结构的全局重复性。随后,通... 为了更有效地去除图像中的乘性噪声,提出了一种基于多尺度非局部紧框架的噪声去除算法。在图像的对数域中,该算法利用多尺度的非局部紧框架进行去噪处理,既考虑了图像灰度局部变化的稀疏性,又充分考虑了图像结构的全局重复性。随后,通过指数变换和误差修正将图像恢复到真实的图像域。实验结果表明,该算法在去除乘性噪声方面具有显著的效果。 展开更多
关键词 乘性噪声 非局部 紧框架 去噪
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基于混沌魔方调节的压缩传感DNA图像加密
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作者 唐青林 詹旭 《四川轻化工大学学报(自然科学版)》 2025年第2期63-73,共11页
为提高图像加密传输过程中安全性和重构图像质量,通过基于自适应等角紧框架(ETF)及QR优化构造观测矩阵,根据马行棋规则混沌魔方置乱和混沌调节模板的压缩感知DNA编码进行图像加密。首先,筛出最优M序列与哈达玛矩阵构造观测矩阵,并通过... 为提高图像加密传输过程中安全性和重构图像质量,通过基于自适应等角紧框架(ETF)及QR优化构造观测矩阵,根据马行棋规则混沌魔方置乱和混沌调节模板的压缩感知DNA编码进行图像加密。首先,筛出最优M序列与哈达玛矩阵构造观测矩阵,并通过自适应步长收敛Gram至紧框架和QR分解优化。其次,利用安全散列算法(SHA)为混沌系统提供参数,根据提出的中国象棋中马字棋行棋规则及魔方混沌算法将图像进行置乱运算,再进行动态DNA编码。最后,由提出的混沌调节模板平滑灰度频数,降低相邻信息相关性从而抵御统计攻击,增强密图信息熵及传输安全。结果表明:重构图像PSNR为34.2642%,信息熵大于7.99999,相邻信息相关性低,NPCR均接近理论值,能有效抵抗明文攻击及统计攻击。 展开更多
关键词 压缩传感 自适应等角紧框架 观测矩阵 混沌映射 DNA编码
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Sparse Representation by Frames with Signal Analysis
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作者 Christopher Baker 《Journal of Signal and Information Processing》 2016年第1期39-48,共10页
The use of frames is analyzed in Compressed Sensing (CS) through proofs and experiments. First, a new generalized Dictionary-Restricted Isometry Property (D-RIP) sparsity bound constant for CS is established. Second, ... The use of frames is analyzed in Compressed Sensing (CS) through proofs and experiments. First, a new generalized Dictionary-Restricted Isometry Property (D-RIP) sparsity bound constant for CS is established. Second, experiments with a tight frame to analyze sparsity and reconstruction quality using several signal and image types are shown. The constant  is used in fulfilling the definition of D-RIP. It is proved that k-sparse signals can be reconstructed if  by using a concise and transparent argument1. The approach could be extended to obtain other D-RIP bounds (i.e. ). Experiments contrast results of a Gabor tight frame with Total Variation minimization. In cases of practical interest, the use of a Gabor dictionary performs well when achieving a highly sparse representation and poorly when this sparsity is not achieved. 展开更多
关键词 Compressed Sensing Total Variation Minimization l1-Analysis D-Restricted Isometry Property tight frames
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基于深度图像先验的高光谱图像去噪方法 被引量:2
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作者 马飞 王梓璇 刘思雨 《激光技术》 CAS CSCD 北大核心 2024年第3期379-386,共8页
为了避免现有的高光谱图像去噪优化模型仅考虑有限的高光谱内在结构特点、并未实现图像特征的精确表征的问题,采用了一种基于空谱深度图像先验与平滑的高光谱图像去噪方法,将紧框架变换与具有高表达与强学习能力的深度学习模型进行结合... 为了避免现有的高光谱图像去噪优化模型仅考虑有限的高光谱内在结构特点、并未实现图像特征的精确表征的问题,采用了一种基于空谱深度图像先验与平滑的高光谱图像去噪方法,将紧框架变换与具有高表达与强学习能力的深度学习模型进行结合,构建基于深度学习的噪声去除模型。首先在低秩矩阵分解的基础上,利用特定的深度图像先验学习潜在的空谱特征;然后分别构建端元与丰度矩阵的紧框架稀疏正则探究空谱局部平滑,并解决深度图像先验的半拟合问题;最后设计高效迭代算法实现模型求解。结果表明,基于空谱深度图像先验的方法在各种复杂的噪声干扰下均表现出较好的视觉恢复性能,峰值信噪比至少有1 dB以上的提升,得到了高质量的恢复图像。该方法为高光谱图像去噪提供了参考。 展开更多
关键词 图像处理 高光谱图像去噪 深度学习 紧框架 低秩矩阵分解
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改进五帧差法机器视觉气密性检测研究 被引量:3
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作者 刘纪飞 姜周曙 +4 位作者 陈磊 倪誉航 陈庆华 林剑 刘若清 《真空科学与技术学报》 CAS CSCD 北大核心 2024年第5期445-451,共7页
气密性是真空设备最重要的技术指标。在工业设备检漏中,传统皂泡法依赖人工目视,其检测准确性和效率取决于工作人员的专注度和操作技能。文章采用机器视觉技术,基于五帧差目标检测算法,进行检漏和漏点定位。由于传统帧差法存在部分画面... 气密性是真空设备最重要的技术指标。在工业设备检漏中,传统皂泡法依赖人工目视,其检测准确性和效率取决于工作人员的专注度和操作技能。文章采用机器视觉技术,基于五帧差目标检测算法,进行检漏和漏点定位。由于传统帧差法存在部分画面重叠、边缘信息缺失和处理高帧率视频效果较差等问题,文章提出用Otsu算子和Canny边缘检测共同改进五帧差法。首先对连续图像做差分并转化为二值图,然后对中间帧进行Canny边缘检测,将二值图和Canny边缘检测的结果进行逻辑运算、中值滤波和形态学处理,最后获得完整的皂泡目标。实验表明,新算法能够处理高帧率视频并获得更完整的皂泡轮廓信息,可用于机器视觉真空设备气密性检测。 展开更多
关键词 气密性 五帧差法 边缘算法 运动目标检测
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Migration scheme for imaging offset VSP data within local phase space
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作者 周艳辉 高静怀 +1 位作者 王保利 何洋洋 《Applied Geophysics》 SCIE CSCD 2010年第1期31-40,99,共11页
The imaging of offset VSP data in local phase space can improve the image of the subsurface structure near the well.In this paper,we present a migration scheme for imaging VSP data in a local phase space,which uses th... The imaging of offset VSP data in local phase space can improve the image of the subsurface structure near the well.In this paper,we present a migration scheme for imaging VSP data in a local phase space,which uses the Gabor-Daubechies tight framebased extrapolator(G-D extrapolator) and its high-frequency asymptotic expansion to extrapolate wavefields and also delineates an improved correlation imaging condition in the local angle domain.The results for migrating synthetic and real VSP data demonstrate that the application of the high-frequency G-D extrapolator asymptotic expansion can effectively decrease computational complexity.The local angle domain correlation imaging condition can be used to weaken migration artifacts without increasing computation. 展开更多
关键词 VSP data Gabor-Daubechies tight frame high-frequency asymptotic expansion imaging condition migration artifact
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带边界条件约束的非相干字典学习方法及其稀疏表示 被引量:10
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作者 汤红忠 张小刚 +2 位作者 陈华 程炜 唐美玲 《自动化学报》 EI CSCD 北大核心 2015年第2期312-319,共8页
从字典的相干性边界条件出发,提出一种基于极分解的非相干字典学习方法 (Polar decomposition based incoherent dictionary learning,PDIDL),该方法将字典以Frobenius范数逼近由矩阵极分解获取的紧框架,同时采用最小化所有原子对的内... 从字典的相干性边界条件出发,提出一种基于极分解的非相干字典学习方法 (Polar decomposition based incoherent dictionary learning,PDIDL),该方法将字典以Frobenius范数逼近由矩阵极分解获取的紧框架,同时采用最小化所有原子对的内积平方和作为约束,以降低字典的相干性,并保持更新前后字典结构的整体相似特性.采用最速梯度下降法和子空间旋转实现非相干字典的学习和优化.最后将该方法应用于合成数据与实际语音数据的稀疏表示.实验结果表明,本文方法学习的字典能逼近等角紧框架(Equiangular tight-frame,ETF),实现最大化稀疏编码,在降低字典相干性的同时具有较低的稀疏表示误差. 展开更多
关键词 字典学习 非相干字典 等角紧框架 稀疏表示
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