查询词典 geometric distortion

Thismethod adopted affine transformation model and a Lie derivative-based analytical algorithm.We introduced the process and characters in extracting information of biological visionsystem, studied the feasibility of the generalized Gabor function used as receptive fieldfunction in extracting information and analyzed affine transformation group and Liederivatives. Finally, we deduced the mathematical denotation for Lie derivatives, i.e. theinfinitesimal generator of the geometric distortion in affine transformation.

对生物视觉信息提取的过程及特点进行了介绍，其中主要研究了广义Gabor函数作为感受野函数提取初级视觉信息的可行性；对仿射变换作为外界图像信息在视觉成像系统上的投影模型的原理进行了初步讨论；对Lie变换群微分算子用于提取仿射变换不变量的分析方法作了剖析，并推导了该方法中关键部分——仿射变换Lie微分算子的具体表达式，也就是几何变形无限小微分算子的计算表达式，使下一步编程实现该方法成为可能。

Experimental results show that our algorithm reduces the geometric distortion effectively and ensures the validity of the conformal mapping.

实验结果表明，该算法通过优化切割线和参数域边界有效地降低了三角形形状扭曲，并保证了参数化结果的合法性。

It introduces normal families, including equicontinuity, Arzela's theorem, Montel's and Marty's theorems, Zalcman's lemma; univalent functions, including Koebe's and de Branges' theorems; quasiconformal mappings, including conformal length, extremal length, geometric, analytic and metric definitions, quasiconformal extension, distortion theorem, quasicircle; iteration of rational functions, including fixed points, the Fatou and Julia sets, periodic points, Siegel disks, the Hausdorff measure and dimension, etc.

具体为：正规族，包括等度连续性、Arzela定理、Montel和Marty正规定则、Zalcman引理；单叶函数，包括Koebe定理和de Branges定理；拟共形映照，包括共形模、极值长度、几何、分析和距离定义、拟共形延拓、偏差定理，拟圆周等；有理函数的迭代，包括不动点、Fatou集和Julia集、周期点、Siegel盘、Hausdorff测度和维数，等等。在教学内容上充分体现综合性、前沿性。

Based on the intrinsic geometric relations between two images, the distortion parameters and fundamental matrix between the corrected images can be acquired automatically.

在计算机视觉的应用领域中，为了提高图像量测和三维重建的精度，必须对相机的畸变误差进行修正。

Its purpose is to transfer the original SAR image to defined map reference frame by projection, and correct some geometric distortion.

地理编码是星载SAR图象后处理的一个过程，它的目的在于把星载SAR原始图象投影到指定的地图坐标系上，并校正一些几何畸变。

In imaging system of ocular fundus, geometric distortion might be unavoidable, which is brought by taking photo at off angle. Based on anatomical and physiological characters of oculus, a mathematical model, suitable to medical visualization, is constructed.

本文根据眼球的解剖学和生理学特征建立了适于医学可视化的眼底数学模型，并且分析了眼底成像技术某些先验知识，根据畸变产生的原因提出了一种新的系统校正法消除眼底图像的几何畸变。

The method includes the following steps: firstly, a spherical neighborhood of present sample points is established by using the geometric spherical-modelling theory and all the sample points contained in the spherical neighborhood are adopted as candidate neighbor points, thus not only preserving the effectivity of the dimension reduction capability when data sets are sparse but also getting the advantages of low-sensitivity to isolated points and good stability of the preserved topological structure; then a data relevance matrix more matching semantics can be obtained by relevance measurement based on route clusters to update the candidate neighbor points in the spherical neighborhood and optimize the regular neighborhood space of the present sample points, thus improving the phenomenon that the dimension reduction of sample sets provided with folded curved faces is apt to suffer the integrated-structure distortion in case of heterogeneous data distribution.

首先利用几何开球原理建立当前样本点的球状邻域，将包含在球状邻域内的所有样本点作为候选近邻点，不但能够保持在数据集稀疏情况下的降维性能的有效性，而且具有对孤立点敏感性不高、保留拓扑结构稳定性好的优点。然后利用基于路径聚类的相关性度量得到更符合语义的数据相关性矩阵，用来对球状邻域内的候选近邻点进行更新，优化当前样本点的规则邻域空间，改善了当数据不均匀分布时在带有折叠弯曲面的样本集上降维容易出现整体结构扭曲的现象。

However, due to the irregular motion of the radar platform and the circular-scanning antenna beam, the inevitable geometric distortion on the focused images is necessary to be corrected.

校正由雷达平台不规则运动和天线圆周扫描导致的图像几何失真，是环视SAR成像处理中的关键步骤。

The method first embeds watermark into the geometric invariant Fourier-Mellin domain of an image to weaken the geometric distortion, brought by printing process, of the watermark in presswork, and the image is then used to create presswork via a legal printing process. Secondly, the method rectifies rescanned image from the presswork by using Radon transformation and the embedded watermark in it is detected. Since there is an obvious difference between the destruction degrees of the watermark caused respectively by legal and pirated printing process, we can judge whether a copy of presswork is valid or not just by computing the ratio of the successfully derived watermark and comparing it with a predefined threshold.

该方法先将水印嵌入到具有几何不变性的Fourier-Mellin域中，以削弱正版印刷过程中的几何失真对水印的破坏；再利用Radon变换对由扫描印刷品所获得的图像进行矫正，并从图像中提取嵌入的水印信息；由于正版和盗版印刷过程对水印的破坏程度区别明显，该方法最终通过计算水印提取的正确率来度量这种破坏，并将其与预先制定的阈值进行比较来判定印刷品的正伪。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。