c++ | 易学教程

Alternative to OpenCV fastNlMeansDenoising for real time application?

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问题 I'm currently using the below function to remove noise from two images of size (240x720). I'm currently computing this on my computer but would like to implement this in real time. However on my computer the function results in significant delays to the program. Is there an alternative to removing noise from an image that could work in real time? Gaussian blur perhaps? fastNlMeansDenoising(ipmOfLeftLaneRobust, ipmOfLeftLaneRobust,10,7,21); 回答1: Given a function fastNlMeansDenoising(InputArray

Initialize variable for omp reduction

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问题 The OpenMP standard specifies an initial value for a reduction variable. So do I have to initialize the variable and how would I do that in the following case: int sum; //... for(int it=0;i<maxIt;i++){ #pragma omp parallel { #pragma omp for nowait for(int i=0;i<ct;i++) arrayX[i]=arrayY[i]; sum = 0; #pragma omp for reduction(+:sum) for(int i=0;i<ct;i++) sum+=arrayZ[i]; } //Use sum } Note that I use only 1 parallel region to minimize overhead and to allow the nowait in the first loop. Using

Sublime Text 2 Run C++11 Code

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问题 I have the following code in Sublime Text 2: #include <iostream> #include <string> using std::cout; using std::string; int main() { string s("some string"); if (s.begin() != s.end()) // make sure s is not empty { auto it = s.begin(); // it denotes the first character in s *it = toupper(*it); // make that character uppercase } cout << s; return 0; } I can build C++11 code in Sublime by pressing ctrl-B as I changed my C++.sublime-build file to "cmd": ["g++", "-std=c++11", "${file}", "-o", "$

栈------表达式求值

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栈的应用---表达式求值 1.简单计算器 Problem Description 读入一个只包含 +, -, *, / 的非负整数计算表达式，计算该表达式的值。 Input 测试输入包含若干测试用例，每个测试用例占一行，每行不超过200个字符，整数和运算符之间用一个空格分隔。没有非法表达式。当一行中只有0时输入结束，相应的结果不要输出。 Output 对每个测试用例输出1行，即该表达式的值，精确到小数点后2位。 Sample Input 1 + 2 4 + 2 * 5 - 7 / 11 0 Sample Output 3.00 13.36 Source 浙大计算机研究生复试上机考试-2006年 #include <iostream> #include <stack> #include < string > #include <cstdio> using namespace std; stack < double > opnd; // 运算对象栈 stack< char > optr; // 运算符号栈 void f() // 取栈顶元素运算 { double tmp; char key= optr.top(); optr.pop(); double x= opnd.top(); opnd.pop(); double y= opnd.top(); opnd.pop(); switch

Is it safe to use LPCTSTR in a structure with the WM_COPYDATA message?

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问题 I have this structure: typedef struct tagCOPY_PACKET { TCHAR szFile[_MAX_PATH]; GUID guidSignature; } S_COPY_PACKET; I prepare to send data with WM_COPYDATA like this: CString strFile = GetFileToOpenFromFileExplorerPath(); S_COPY_PACKET sCopyDataPacket; _tcscpy_s(sCopyDataPacket.szFile, _MAX_PATH, strFile); sCopyDataPacket.guidSignature = CopyData_Signature; COPYDATASTRUCT cds; cds.dwData = COPYDATA_TYPE_MSA; cds.cbData = sizeof(sCopyDataPacket); cds.lpData = &sCopyDataPacket; DWORD_PTR

c++ log functions using template SFINAE for conditional compile

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问题 I am evaluating if it is possible to leverage C++11 features to replace logging Macros without any run-time additional cost. I come out with this demo: enum class LogLevel { Fatal = 0, DFatal = 1, Error = 2, Normal = 3, Verbose = 4, Debug = 5 }; constexpr LogLevel log_compiled = LogLevel::Normal; LogLevel log_runtime = LogLevel::Error; #ifdef NDEBUG constexpr LogLevel log_fatal = LogLevel::Fatal; #else constexpr LogLevel log_fatal = LogLevel::DFatal; #endif template <LogLevel L, typename std:

Does static library avoids name mangling issues?

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问题 I have a C++\MFC application written in Visual Studio 2003 SP1 links to an external static library "SomeExtStaticLib.lib". I also include the header files provided with "SomeExtStaticLib.lib" to create the objects in my application. SomeExtStaticLib.lib is a static library built with VC6. Now, I am migrating my application to Visual Studio 2008. I have very basic question. Should I also migrate the "SomeExtStaticLib.lib" to VS2008 compiled one? When I tried to use this VC6 compiled

【Qt开发】StyleSheet使用总结

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概述转眼七年过去了，我是一个彻底拥抱过MFC的人，记得老大的一个需求要把按钮做成圆角，并添加背景颜色，做前端html的可能认为很简单，然而放到MFC上那可真的是很...很麻烦的，自定义类继承Button ，新手估计还搞不定，怎么也有上百行代码，实在不友好，Qt诞生大大简化了这些工作，只需要使用QSS（Qt Style Sheet）就可以轻松做到，最近详细了解了QSS，做了个百度网盘的登录界面，整理好我会把源码放出来，供大家参考。 QSS语法 background-color:rgb(6, 168, 255);　　　背景色 color:red;　　　　　　　　　　　　　　字体颜色 border-radius:5px; 　　　　　　　　　　边框圆角半径 border:2px solid green;　　　　　　　　　边框2像素，实现，绿色 font:10pt;　　　　　　　　　　　　　　　字体大小10 设置QSS方法方法一：UI界面设置鼠标到按钮上右键，"改变样式表"，在编辑样式表对话框中添加QSS样式。方法二：程序添加每一个控件都有 setStyleSheet (const QString &styleSheet)方法，样式字符串直接传参即可，例： ui.pushButton1->setStyleSheet("QPushButton{background-color

Can't import PFX to Microsoft Sample Key Storage Provider (Cryptographic Provider Development Kit)

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问题 I'm trying to execute samples provided with "Cryptographic Provider Development Kit"; in this case an example specifically called KeyStorageProviderSample. In this sample, a new Key Storage Provider called "Microsoft Sample Key Storage Provider" is created in the system simply by executing the .exe with the -register param: symmclient -register At this point everything is ok; if I list the KSPs in the system I get the complete list: symmclient -enum The one just created, "Microsoft Sample Key

Boost Spirit: parse boolean expression and reduce to canonical normal form

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问题 I want to parse a common Boolean with just or , and and not operators, which I think I have done using Boost Spirit below. In phase 2 (or perhaps part of the parsing itself), I wish to transform the AST of the Boolean to disjunctive canonical normal form, which essentially "flattens" the expression and removes all grouping operators. In one of my attempts, I created the Boost static_visitor below, named Transformer . I started by trying to eliminate double not operators by just assigning a