
学习笔记
文章平均质量分 50
juliosun
这个作者很懒,什么都没留下…
展开
-
How do I change the default background color of all FIGURE objects created in MATLAB
A list of factory-defined graphics settings that can be manipulated can be obtained by executing this command at the MATLAB prompt:get(0,'Factory')To set the default color for all graphics objects, the 'defaultfigurecolor' property of the ROOT graph.转载 2020-08-05 11:51:06 · 376 阅读 · 0 评论 -
Kullback-Leibler Divergence Explained
In this post we're going to take a look at way of comparing two probability distributions called Kullback-Leibler Divergence (often shortened to just KL divergence). Very often in Probability and Stat转载 2017-08-04 23:34:56 · 1245 阅读 · 0 评论 -
pseudoinverse matrix
The Moore-Penrose pseudoinverse is a matrix B of the same dimensions as A' satisfying four conditions:A*B*A = AB*A*B = BA*B is HermitianB*A is HermitianThe computation is based on svd(A转载 2017-08-17 15:58:54 · 1211 阅读 · 0 评论 -
fisher information 的直观意义
作者:知乎用户链接:https://www.zhihu.com/question/26561604/answer/33275982来源:知乎著作权归作者所有。商业转载请联系作者获得授权,非商业转载请注明出处。首先我们看一下 Fisher Information 的定义:假设你观察到 i.i.d 的数据 服从一个概率分布,是你的目标参数(for simplicity转载 2017-05-11 21:39:48 · 4387 阅读 · 0 评论 -
Covariance Matrices and Data Distributions
Correlation between variables in a -dimensional dataset are often summarized by a covariance matrix. To get a better understanding of how correlation matrices characterize correlations between da转载 2017-06-12 23:22:31 · 473 阅读 · 0 评论 -
The Statistical Whitening Transform
In a number of modeling scenarios, it is beneficial to transform the to-be-modeled data such that it has an identity covariance matrix, a procedure known as Statistical Whitening. When data have an转载 2017-06-12 23:14:21 · 1083 阅读 · 0 评论 -
What is the Cramer-Rao Lower Bound?
What is the Cramer-Rao Lower Bound?The Cramer-Rao Lower Bound (CRLB) gives a lower estimate for the variance of an unbiased estimator. Estimators that are close to the CLRB are more unbiased (转载 2017-06-01 21:48:33 · 1934 阅读 · 0 评论 -
DICOM UIDs
转自:https://groups.google.com/forum/#!topic/comp.protocols.dicom/xh0ogPv31aIDefinitions:Study = collection of separate medical examinations for a certainpatient. A patient can have, in the same转载 2017-05-18 21:41:46 · 526 阅读 · 0 评论 -
Cmake environmental variables: how to make find_package, find_path and find_library work
Environment VariablesThese are environment variables which effect cmake behaviour.CMAKE_INCLUDE_PATH This is used when searching for include files e.g. using the FIND_PATH() command. If you转载 2015-09-08 19:14:49 · 1076 阅读 · 0 评论 -
latex equation displaystyle or textstyle
转载 2015-08-21 22:44:18 · 3189 阅读 · 0 评论 -
Bibtex如何使authors in the citation 最多显示两个
\usepackage{harvard}变成\usepackage[abbr]{harvard}转载 2015-08-13 22:02:21 · 772 阅读 · 0 评论 -
Bibtex 如何cite 不同格式
以harvard格式为例,如果使用的是harvard package, 可以用Orlov \citeyear{Orlov1976}显示的是 Orlov (1976)\citename{Orlov1976} (1976)显示的是 Orlov (1976)如果用的是natlib, \citet{Orlov1976}显示的是 Orlov (19转载 2015-08-13 22:10:04 · 4047 阅读 · 0 评论 -
CMake 使用总结
CMake使用总结 前言 做第一个linux项目时,Makefile是一行行敲入的,第二个项目后,开始使用cmake。至于为何选择cmake,倒不是觉得它有什么好,仅仅是因为当时项目组中的一个linux前辈向我们推荐了这个。经过一番研究之后,并在项目中使用,现将使用经验总结一下,供大家参考。 入门篇 学习一项新知识的时候,最好是从sample开始转载 2012-09-18 20:36:07 · 1236 阅读 · 0 评论 -
the complexity of solving a l0-norm optimization problem
the solution for a sparse recovery problem is given by:min||x||0min||x||0s.ty=Axs.ty=AxThe definition of ||x||0||x||0 is no. of non-zero entries in xx. This is also called the sparsi转载 2017-08-14 21:00:56 · 406 阅读 · 0 评论 -
算法的复杂度
算法的时间复杂度和空间复杂度-总结 通常,对于一个给定的算法,我们要做 两项分析。第一是从数学上证明算法的正确性,这一步主要用到形式化证明的方法及相关推理模式,如循环不变式、数学归纳法等。而在证明算法是正确的基础上,第二部就是分析算法的时间复杂度。算法的时间复杂度反映了程序执行时间随输入规模增长而增长的量级,在很大程度上能很好反映出算法的优劣与否。因此,作为程序员,掌握基本的转载 2017-08-25 21:33:52 · 499 阅读 · 0 评论 -
How to solve Permission denied (publickey) error when using Git?
the user have not generated a ssh public/private key pair set before ?This info is working on theChaw but can be applied to all other git repositories which support SSH pubkey authentications. (See...转载 2019-07-28 09:36:31 · 192 阅读 · 0 评论 -
如何理解Gabor滤波器
介绍我们已经知道,傅里叶变换是一种信号处理中的有力工具,可以帮助我们将图像从空域转换到频域,并提取到空域上不易提取的特征。但是经过傅里叶变换后,图像在不同位置的频度特征往往混合在一起,但是Gabor滤波器却可以抽取空间局部频度特征,是一种有效的纹理检测工具。Figure 1: A sinusoid and it's Fourier spectrum如何生成一个Gabor滤波器在二...转载 2018-08-28 05:50:24 · 1391 阅读 · 0 评论 -
Determinant of Jacobian of a displacement field
% J = jacobian(S)% Determinant of Jacobian of a displacement field%% Herve Lombaert, Jan. 8th, 2013%function det_J = jacobian(sx,sy,sz) % Gradients [gx_y,gx_x,gx_z] = gradient(sx); ...转载 2018-08-22 03:43:59 · 540 阅读 · 2 评论 -
work gitlab with git
最近准备迁移projects从github到gitlab, 因为有一些代码要放在private repository下。首先在gitlab网页上设置密码,ssh key可以忽略。打开git bash, 输入$ git remote add gitlab https://github.com/colddie/colddie.github.io.git$ git remote set-url...原创 2018-07-23 01:06:09 · 248 阅读 · 0 评论 -
crop image in given size imagej
you can use physical units in the Edit>Selection>Specify… dialog.Here is how you would do this in a macro:run("Specify...", "width=500 height=500 centered scaled");run("Crop");转载 2018-07-20 06:49:38 · 524 阅读 · 0 评论 -
Creating your own snippets in vs code
Snippets show in IntelliSense (Ctrl+Space) mixed with other suggestions as well as in a dedicated snippet picker (Insert Snippet in the Command Palette). There is also support for tab-completion: Enab...转载 2018-04-27 09:52:13 · 300 阅读 · 0 评论 -
canny 边缘检测
算法概述编辑Canny边缘检测算子是John F. Canny于 1986 年开发出来的一个多级边缘检测算法。更为重要的是 Canny 创立了边缘检测计算理论(Computational theory of edge detection)解释这项技术如何工作。通常情况下边缘检测的目的是在保留原有图像属性的情况下,显著减少图像的数据规模。目前有多种算法可以进行边缘检测,虽然Canny算法年代久远,但...转载 2018-04-05 18:15:45 · 1079 阅读 · 0 评论 -
fftshift - Shift zero-frequency component to center of spectrum
fftshiftShift zero-frequency component to center of spectrumcollapse all in pageSyntaxY = fftshift(X)Y = fftshift(X,dim)DescriptionexampleY = fftshift(X) rearranges a Fourier transform X by shifting t...转载 2018-04-11 17:03:38 · 850 阅读 · 0 评论 -
灰度行程矩阵 GLRLM
灰度行程矩阵(GLRLM,我不造这个中文翻译对不对啊,如果不对望告知)灰度行程矩阵用于描述像素值的分布下图左边是原图I,右图是0度构造的灰度共生矩阵,GLRLM[i,j]表示的是像素值为0度方向上连续j个i在原图I中出现的次数统计从任意像素点出发沿某个theta方向(例如45,09,135等)上连续j个像素点都具有灰度只i出现的概率我们可以提取如下特征GLD:度量灰度是否均匀,越大越均匀RLD:度...转载 2018-04-02 10:39:32 · 5706 阅读 · 7 评论 -
灰度共生矩阵(GLCM,Gray-Level Co-occurrence Matrix)
概念 由于纹理是由灰度分布在空间位置上反复出现而形成的,因而在图像空间中相隔某距离的两像素之间会存在一定的灰度关系,即图像中灰度的空间相关特性。灰度共生矩阵就是一种通过研究灰度的空间相关特性来描述纹理的常用方法。 灰度共生矩阵是涉及像素距离和角度的矩阵函数,它通过计算图像中一定距离和一定方向的两点灰度之间的相关性,来反映图像在方向、间隔、变化幅度及快慢上的综合信息。 灰度直方图是对图像上单个像素具...转载 2018-04-02 10:09:35 · 10345 阅读 · 0 评论 -
stochastic matrix
In mathematics, a stochastic matrix[1] (also termed probability matrix,[1] transition matrix,[1][2] substitution matrix, or Markov matrix[1]) is a square matrix[1] used to describe the trans转载 2017-11-09 21:33:52 · 627 阅读 · 0 评论 -
run a PowerShell script from a batch file
You need the -ExecutionPolicy parameter:Powershell.exe -executionpolicy remotesigned -File C:\Users\SE\Desktop\ps.ps1Otherwise PowerShell considers the arguments a line to execute and while Set转载 2017-09-12 18:40:39 · 501 阅读 · 0 评论 -
piecewise constant function 阶跃常函数
Piecewise Constant FunctionA function is said to be piecewise constant if it is locally constant in connected regions separated by a possibly infinite number of lower-dimensional boundaries. T转载 2015-06-27 00:25:17 · 2222 阅读 · 0 评论 -
并行处理思想与弗林(Flynn)分类
现代计算机发展历程可以分为两个明显的发展时代:串行计算时代、并行计算时代。并行计算机是由一组处理单元组成的,这组处理单元通过相互之间的通信与协作,以更快的速度共同完成一项大规模的计算任务。因此,并行计算机的两个最主要的组成部分是计算节点和节点间的通信与协作机制。并行计算机体系结构的发展也主要体现在计算节点性能的提高以及节点间通信技术的改进两方面。60年代初期,由于晶体管以及磁芯存储器的出现,处转载 2015-03-18 18:14:25 · 3296 阅读 · 0 评论 -
Distance Transform
•Thedistance transform provides a metric or measure of the separation of points inthe image. The bwdist function calculates thedistance between each pixel that is set to off (0) and the nearestnonzero转载 2014-08-13 22:05:10 · 920 阅读 · 0 评论 -
Jaccard index and dice coifficient
he Jaccard index, also known as the Jaccard similarity coefficient (originally coined coefficient de communauté by Paul Jaccard), is a statistic used for comparing the similarity and diversity of sa转载 2013-01-17 13:05:04 · 3158 阅读 · 0 评论 -
cmd 环境变量
注意的几点,1. 控制面板中可以直接改path, 立即生效, 在cmd中set可知. 但当前cmd无效,需要重新打开.2.path先后顺序,如果前面和后面路径都指向一个dll,那么前面的会被后面的覆盖.原创 2012-09-25 15:39:04 · 559 阅读 · 0 评论 -
The Data types reference sheet
The Data types reference sheetThe columns 8, 9, 10 shows what versions of SQL Server that supports the data type8 = SQL Server 20009 = SQL Server 200510 = SQL Server 2008Datatype转载 2012-08-14 14:57:52 · 612 阅读 · 0 评论 -
随机抽样一致(Random Sample Consensus, RANSAC)
RANSAC是“RANdom SAmple Consensus(随机抽样一致)”的缩写。它可以从一组包含“局外点”的观测数据集中,通过迭代方式估计数学模型的参数。它是一种不确定的算法——它有一定的概率得出一个合理的结果;为了提高概率必须提高迭代次数。该算法最早由Fischler和Bolles于1981年提出。图像检索中,RANSAC可以作为检索后的后续处理,对图像的中目标进行空间一致验证。转载 2012-03-12 16:47:37 · 4642 阅读 · 1 评论 -
Win7 安装 OpenCV2.3.1 到VS2010
Getting Started with OpenCV 2.3.1 in Microsoft Visual Studio 2010 in Windows 7 64-bitI was trying to install OpenCV 2.3.1 on my Windows 7 64-bit machine and i kept getting the error: The appli转载 2011-11-23 22:06:42 · 6482 阅读 · 0 评论 -
matlab 图像的灰度值翻转
简单的灰度图像可以通过InbertIm('example.jpg');实现灰度翻转,简单说就是白变黑,黑变白。可以自动侦测图像bit数,还有灰度范围。 function [invIm]=InvertIm(im, varargin)% InvertIm generalized image inversion (grayscale reversal)% invIm转载 2011-02-28 17:57:00 · 18568 阅读 · 0 评论 -
matlab画任意圆柱
function [Cylinder EndPlate1 EndPlate2] = cylinder3(X1,X2,r,n,cyl_color,closed,lines)%% This function constructs a cylinder connecting two center points % % Usage :% [Cylinder EndPlate1 EndP转载 2011-03-09 17:06:00 · 12902 阅读 · 5 评论 -
白噪声,高斯噪声,高斯白噪声
白噪声,就是说频谱为一常数;也就是说,其协方差函数在delay=0时不为0,在delay不等于0时值为零;换句话说,样本点互不相关。所以,“白”与“不白”是和分布没有关系。当随机的从高斯分布中获取采样值时,采样点所组成的随机过程就是“高斯白噪声”;同理,当随机的从均匀分布中获取采转载 2011-08-11 17:10:18 · 3533 阅读 · 0 评论 -
Coded Aperture Imaging
<br />学习multipinhole,涉及到optimize pinhole distribution,要看许多关于camera的问题。<br /> <br />传统的lens相机在普通光学领域应用较好,但在高能射线分析不好,原因是穿透力强,不易产生折射效应。所以x ray多用基于传统pinhole的camera,但问题是低resolution,还有光源和detector角度造成的模糊。<br /> <br /> <br />Mmm, gumballs...<br />This image was ta原创 2011-02-22 17:43:00 · 2306 阅读 · 1 评论 -
图像重建的迭代算法Iterative procedure for image reconstruction and OSEM
除了简单的back projection 和 改进的filtered back projection,用的更多的图像重建方法是迭代法,其中包括EM。下面是Medical imaging 里面用的较多的OSEM原创 2011-02-15 11:47:00 · 7338 阅读 · 1 评论