首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Total variation (TV) has been proved very successful in image processing, and it has been combined with various non-quadratic fidelities for non-Gaussian noise removal. However, these models are hard to solve because TV is non-differentiable and nonlinear, and non-quadratic fidelity term is also nonlinear and even non-differentiable for some special cases. This prevents their widespread use in practical applications. Very recently, it was found that the augmented Lagrangian method is extremely efficient for this kind of models. However, only the single-channel case (e.g., gray images) is considered. In this paper, we propose a general computational framework based on augmented Lagrangian method for multichannel TV minimization with non-quadratic fidelity, and then show how to apply it to two special cases: L1 and Kullback-Leibler (KL) fidelities, two common and important data terms for blurry images corrupted by impulsive noise or Poisson noise, respectively. For these typical fidelities, we show that the sub-problems either can be fast solved by FFT or have closed form solutions. The experiments demonstrate that our algorithm can fast restore high quality images.  相似文献   

2.
In this paper, an effective image deblurring model is proposed to preserve sharp image edges by suppressing the stair-casing arising in the total variation (TV) based method by using the anisotropic total variation. To solve the difficult L1 norm problems, the split Bregman iteration is employed. Several synthetic degraded images are used for experiments. Comparison results are also made with total variation and nonlocal total variation based method. Experimental results show that the proposed method not only is robust to noise and different blur kernels, but also performs well on blurring images with more detailed textures, and the stair-casing effect is well suppressed.  相似文献   

3.
振动退化图像的恢复算法面临的主要问题是在比较宽松的约束条件下对模糊图像的快速恢复。在对国内外的振动模糊图像恢复算法进行充分研究的前提下,提出一种快速有效的算法。首先应用伪白化叠加的方法得到与点扩展函数对应的调制传递函数,然后根据最小相位的理论,解线性方程组得到点扩展函数。在较少的约束条件下避免了传统算法循环迭代计算复杂、费时等缺点,实验结果表明,恢复效果较好,抗噪声能力强。  相似文献   

4.
To solve the problem of the staircase effect and removing mixed noise, including Gaussian and salt and pepper noise, which can occur during image formation and transmission, a total variation-based denoising model using an edge detection function is proposed. Moreover, an improved split Bregman iteration method is used to solve the nonlinear problem. The results of comparative experiments demonstrate that the proposed model removes Gaussian and salt and pepper noise while maintaining detailed features.  相似文献   

5.
基于各向异性规整化的总变分盲复原算法研究   总被引:2,自引:1,他引:2       下载免费PDF全文
针对大气湍流退化图像复原问题,提出了一种基于各向异性和非线性规整化的总变分盲复原新算法,该算法主要结合图像和湍流点扩展函数的一些性质采用基于各向异性的空间自适应规整化处理,建立了具有非线性和空间各向异性的规整化函数,使其在恢复目标图像和估计点扩展函数时能自适应地进行梯度平滑。最后,通过交替最小化方案来极小化代价函数和通过定点迭代策略将非线性方程进行线性化处理,快速地估计点扩展函数和恢复图像。在微机上对数字模拟和实际退化图像进行了一系列恢复实验,验证了算法的有效性和稳健性。  相似文献   

6.
Total variation blind deconvolution employing split Bregman iteration   总被引:1,自引:0,他引:1  
Blind image deconvolution is one of the most challenging problems in image processing. The total variation (TV) regularization approach can effectively recover edges of image. In this paper, we propose a new TV blind deconvolution algorithm by employing split Bregman iteration (called as TV-BDSB). Considering the operator splitting and penalty techniques, we present also a new splitting objective function. Then, we propose an extended split Bregman iteration to address the minimizing problems, the latent image and the blur kernel are estimated alternately. The TV-BDSB algorithm can greatly reduce the computational cost and improve remarkably the image quality. Experiments are conducted on both synthetic and real-life degradations. Comparisons are also made with some existing blind deconvolution methods. Experimental results indicate the advantages of the proposed algorithm.  相似文献   

7.
钟毅  梁卉宜 《信息技术》2020,(5):160-164
传统的模糊图像盲复原算法的纹理复杂度高,降低了模糊图像的质量。为此,文中设计了基于纹理复杂度的含噪模糊图像盲复原算法。首先,分析含噪模糊图像的噪声特点,在保留原有图像信息的前提下计算垂直方向和水平方向的扩散系数,得到ADF在含噪模糊图像上的表达,完成含噪模糊图像的去噪预处理。通过建立含噪模糊图像的数学模型描述其退化过程,继而构建含噪模糊图像降质模型。最后,在纹理复杂度分析的基础上,完成奇异值分解检测和alpha通道的计算,通过合成操作实现含噪模糊图像的盲复原算法的设计。实验结果表明,相比于传统盲复原算法,在所提算法下,图像的纹理复杂度低,图像质量得以提升,且复原结果的误差较小,算法整体有效性较高。  相似文献   

8.
泊松噪声模糊图像的边缘保持变分复原算法   总被引:1,自引:0,他引:1  
从贝叶斯估计出发,构造了一种新的变分模型,用于复原被泊松噪声污染的模糊图像.首先讨论了模型正则化项中具有边缘保持能力的函数选取以及模型求解的相关问题,然后将变分模型的求解转化为可快速求解的非线性扩散方程,给出了正则化参数选取的初步空间自适应方法,可以区分平滑区域和图像边缘自适应的调节参数.实验结果表明,本文方法的复原效果整体上优于传统的迭代正则化方法,复原图像的边缘得到了有效的保护,泊松噪声的抑制效果明显,复原图像提高的改进信噪比(ISNR)要比迭代正则化方法平均提高1 dB以上.  相似文献   

9.
为了提高受损数字图像修复质量,将整体变分模型用于图像修复。采用Matlab编程工具对修复过程进行了仿真实现,克服了直接求解偏微分方程的困难。发现随着迭代次数的增加,被修复区域接近原图质量,当受损区域较小且受损区域灰度梯度不大时,看不出明显的修复痕迹。仿真实验结果表明,该算法复原图像的视觉质量好,算法收敛快,特别适合于线状裂痕的图像修补。  相似文献   

10.
In this paper, we propose a new three-stage model for multiplicative noise removal. In the first stage, sparse and redundant representation is used to approximate the log-image. The K-SVD algorithm is used to train a redundant dictionary, which can describe the log-image sparsity. Then in the second stage, we use the total variation (TV) method to amend the image obtained. At last, via an exponential function and bias correction, the result is transformed back from the log-domain to the real one. Our method combines the advantages of sparse and redundant representation over trained dictionary and TV method. Experimental results show that the new model is more effective to filter out multiplicative noise than the state-of-the-art models.  相似文献   

11.
Although the use of blind deconvolution of image restoration is a widely known concept, little literatures have discussed in detail its application in the problem of restoration of underwater range-gated laser images. With the knowledge of the point spread function (PSF) and modulation transfer function (MTF) of water,underwater images can be better restored or enhanced. We first review image degradation process and Wells' small angle approximation theory, and then provide an image enhancement method for our underwater laser imaging system by blind deconvolution method based on small angle approximation. We also introduce a modified normalized mean square error (NMSE) method to validate the convergence of the blind deconvolution algorithm which is applied in our approach. The results of different initial guess of blind deconvolution are compared and discussed. Moreover, restoration results are obtained and discussed by intentionally changing the MTF parameters and using non-model-based PSF as the initial guess.  相似文献   

12.
基于盲解卷积的红外烟幕干扰图像去噪方法   总被引:1,自引:0,他引:1  
汪伟  程翔  唐力伟  王平 《激光与红外》2009,39(7):769-772
介绍了多频谱红外烟幕弹爆炸后,红外热像仪所采集图像产生噪声的原因及噪声模型;并根据烟幕干扰退化图像噪声的点扩展函数难以准确描述的特性,应用频域迭代盲解卷积算法进行红外图像去噪,根据算法原理并结合烟幕干扰图像的噪声特点,对算法进行了适当的改进。实验证明,该方法去噪效果明显,有效地克服了维纳滤波等传统图像去噪方法使图像变模糊的现象,并使烟幕干扰图像的有效区域得到增强。  相似文献   

13.
该文提出一种新的基于积分微分方程的泊松噪声去除算法。首先讨论了经典的总变差(TV)最小模型,在此基础上提出一种新的变分多尺度分层图像表示方法,然后在逆尺度空间上积分尺度图像从而得到了新的积分微分方程。这种新的积分微分方程含有一个单调增加的尺度函数。通过选取适当的尺度函数,该方程可以有效地去除泊松型噪声。数值实验证明了该算法比经典的TV和四阶偏微分方程算法具有更好的去噪效果。  相似文献   

14.
In this paper, we propose a single image deblurring algorithm to remove spatially variant defocus blur based on the estimated blur map. Firstly, we estimate the blur map from a single image by utilizing the edge information and K nearest neighbors (KNN) matting interpolation. Secondly, the local kernels are derived by segmenting the blur map according to the blur amount of local regions and image contours. Thirdly, we adopt a BM3D-based non-blind deconvolution algorithm to restore the latent image. Finally, ringing artifacts and noise are detected and removed, to obtain a high quality in-focus image. Experimental results on real defocus blurred images demonstrate that our proposed algorithm outperforms some state-of-the-art approaches.  相似文献   

15.
16.
During scanning and transmission, images can be corrupted by salt and pepper noise, which negatively affects the quality of subsequent graphic vectorization or text recognition. In this paper, we present a new algorithm for salt and pepper noise suppression in binary images. The algorithm consists of the computation of block prior probabilities from training noise-free images; noise level estimation; and the maximum a posteriori probability estimation of each image block. Our experiments show that the proposed method performs significantly better than the state of the art techniques.  相似文献   

17.
该文首先从变分学的角度分析Le等人(2007)基于全变差的图像泊松去噪模型,得到该模型解的一框式约束限制。在此基础上,结合交替方向乘子算法(ADMM),给出了基于框式约束的快速全变差图像泊松去噪算法,并证明了该算法的收敛性。最后,数值实验结果验证了该快速算法的可行性与有效性。  相似文献   

18.
王满  文有为  陈智斌 《激光技术》2017,41(2):289-295
为了达到全变差噪声消除的图像去噪目的,将去噪问题转换为优化问题。采用了结合广义最小残差法的半光滑牛顿法来解决相关优化问题,求解非对称线性方程组,进行了理论分析和实验验证,取得了将该方法与其它方法应用于1维信号、2维图像去噪实验的大量可行数据。结果表明,结合广义最小残差法的半光滑牛顿法的收敛速度比结合预处理共轭梯度法的半光滑牛顿法和交替方向乘子法更快,而且能够有效地消除噪声。  相似文献   

19.
局部变分有效地增强图像的轮廓信息,但不可避免地模糊图像的细节并在平滑区域产生阶梯效应。非局部变分能有效重构图像的纹理信息,但同时会破坏图像的结构轮廓信息。考虑到局部与非局部变分的互补性,提出了一种基于图像局部梯度与非局部梯度的复合变分模型,并通过Bregman交替迭代极小化图像的局部梯度与非局部梯度的L1范数,使去噪后的图像在去除噪声的同时更好地保留图像的结构与细节信息。对比实验证明,提出的复合变分模型有效地利用了图像的局部变分与非局部变分的优点,在图像评价的主客观方面都表现出了更好的性能。  相似文献   

20.
针对总变分去噪模型容易导致阶梯效应的缺陷,提 出了一种新的乘性噪声去噪模型。在新模型中,二阶总广义变分(TGV)是正则项,它能自动平 衡一阶和二阶导数项,使得新模型在去除乘性噪声的同时不但能够保 持图像的边缘信息,而且还能去除阶梯效应。为了有效的计算该模型,设计了一个快速迭代算 法。在算法中,首先采用分裂方法和交替方向法将原问题变为两个相关的子问题,然后分别对 子问题利用牛顿法和原始-对偶算法。实验结果表明,与同类模型相比,本文方法无论是在视 觉效果还是定量指标,如峰值信噪比(PSNR)等都有明显地提高。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号