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941.
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943.
944.
The total variation model of Rudin, Osher, and Fatemi for image denoising is considered to be one of the best denoising models. Recently, by using the Bregman method, Goldstein and Osher obtained a very efficient algorithm for the solution of the ROF model. In this paper, we give a rigorous proof for the convergence of the Bregman method. We also indicate that a combination of the Bregman method with wavelet packet decomposition often enhances performance for certain texture rich images. 相似文献
945.
M. Wagner 《Journal of Optimization Theory and Applications》2009,140(3):543-576
In the present paper, we prove a substantially improved version of the Pontryagin maximum principle for convex multidimensional
control problems of Dieudonné-Rashevsky type. Although the range of the operator describing the first-order PDE system involved
in this problem has infinite codimension, we obtain first-order necessary conditions in a completely analogous form as in
the one-dimensional case. Furthermore, the adjoint variables are subjected to a Weyl decomposition.
We reformulate two basic problems of mathematical image processing (determination of optical flow and shape from shading problem)
within the framework of optimal control, which gives the possibility to incorporate hard constraints in the problems. In the
convex case, we state the necessary optimality conditions for these problems. 相似文献
946.
In this paper, we consider linearity measure for a bounded length curves. First, we define a new linearity measure for open curve segments, and then extend method to closed curves (contours). The derived measures (for both, open curve segments and closed curves) are invariant with respect to similarity transformations. The linearity measure for open curve segments picks the value 1 if and only if the measured open line segment is a perfect straight line segment while the established linearity measures for closed curves never reach 1, as preferred. 相似文献
947.
Digital holographic imaging fusion for a larger size object using compressive sensing is proposed. In this method, the high frequency component of the digital hologram under discrete wavelet transform is represented sparsely by using compressive sensing so that the data redundancy of digital holographic recording can be resolved validly, the low frequency component is retained totally to ensure the image quality, and multiple reconstructed images with different clear parts corresponding to a laser spot size are fused to realize the high quality reconstructed image of a larger size object. In addition, a filter combing high-pass and low-pass filters is designed to remove the zero-order term from a digital hologram effectively. The digital holographic experimental setup based on off-axis Fresnel digital holography was constructed. The feasible and comparative experiments were carried out. The fused image was evaluated by using the Tamura texture features. The experimental results demonstrated that the proposed method can improve the processing efficiency and visual characteristics of the fused image and enlarge the size of the measured object effectively. 相似文献
948.
YANG Mengchao JIN Xinyu YUAN Maokai LIU Fan LANG Yicong WU Zhongyu XIANG Liancheng ZHOU Chao OUYANG Bo JIN Wei MU Ying 《高等学校化学研究》2014,30(2):211-215
A laboratory-made tumor cell detection device was fabricated based on both surface plasmon resonance imaging(SPRi) and image processing.In this device,a gravity-induced flow injection chip(gFIC) was exploited to replace a pump.Also two charge coupled devices(CCDs) were used to detect HepG2 cells by SPRi and image processing,respectively.The results of two CCDs are associated.Protein A was used to modify the sensing surface.The inlet angle was carefully adjusted for the device to get an enhanced image.In the test,the contrast among cell solutions at different concentrations can be easily distinguished.The other CCD using image processing can tell false-positive in some degree.This detection is label-free,real time,and precise. 相似文献
949.
航空影像房屋提取方法的研究中大多基于灰度影像的区域生长算法,此类算法不仅忽略了不同材质的房屋所呈现的光谱特征对提取结果的影响,而且过于依赖种子像素的选取,处理效率不高。为了从高分辨率航空影像中实现房屋的自动检测,综合利用彩色信息与屋顶材料的光谱特征,采用影像分割原理,研究了房屋自动检测的方法。首先对RGB与HIS彩色空间进行转换,利用HIS空间各分量间不相关的特点和屋顶材料光谱特征进行影像分割,分离出红色瓦片屋顶与灰色水泥屋顶区域,并利用标记分水岭算法实现房屋区域的初始分割;然后计算各标记区域内的色调均值选取种子像斑样本,进而以像斑为单元在色调分量中进行区域生长,最后经过消除小斑和矩形拟合优化处理,得到轮廓清晰的房屋区域。与传统的基于像素区域分割算法相比,该方法整个过程无需人工干预且均在一维彩色空间进行处理,计算量明显降低,同时采用改进的基于像斑区域生长算法能够兼顾邻近区域内像素的几何结构信息,使算法精度得到显著提高,采用上述方法对高分辨率航空影像进行了实验,结果证明该方法有着较高的处理效率和准确性,具有实用价值。 相似文献
950.
In this paper, we study to use nonlocal bounded variation (NLBV) techniques
to decompose an image intensity into the illumination and reflectance components.
By considering spatial smoothness of the illumination component and nonlocal total variation (NLTV)
of the reflectance component in the decomposition framework, an energy functional is constructed.
We establish the theoretical results of the space of NLBV functions such as
lower semicontinuity, approximation and compactness.
These essential properties of NLBV functions are important tools to show
the existence of solution of the proposed energy functional.
Experimental results on both grey-level and color images are shown to illustrate the usefulness of the nonlocal total variation
image decomposition model,
and demonstrate the performance of the proposed method is better than the other testing methods. 相似文献