c++

问题 I am trying to detect blur rate of the face images with below code. cv::Mat greyMat; cv::Mat laplacianImage; cv::Mat imageClone = LapMat.clone(); cv::resize(imageClone, imageClone, cv::Size(150, 150), 0, 0, cv::INTER_CUBIC); cv::cvtColor(imageClone, greyMat, CV_BGR2GRAY); Laplacian(greyMat, laplacianImage, CV_64F); cv::Scalar mean, stddev; // 0:1st channel, 1:2nd channel and 2:3rd channel meanStdDev(laplacianImage, mean, stddev, cv::Mat()); double variance = stddev.val[0] * stddev.val[0]; cv:

问题 I have a third party library as source code. It comes with a Visual Studio project that builds a .lib from it. I want to access the functionality from C# though, so I copied the project and changed it to create a dll. The DLL didn't contain any exported functions though, so I also created a module definition (.def) file, and added the functions I need in the EXPORTS section. This works for all the functions that are declared in extern "C" blocks. However, some of the functions that I need are

问题 I have tried to link boost in my CMakeList file by set(Boost_USE_STATIC_LIBS OFF) set(Boost_USE_MULTITHREADED ON) set(Boost_USE_STATIC_RUNTIME OFF) set(Boost_NO_SYSTEM_PATHS TRUE) set(Boost_INCLUDE_DIR /user/software/boost/boost-1.69-x86_64-cc7/include) set(Boost_LIBRARY_DIR /user/software/boost/boost-1.69-x86_64-cc7/lib) find_package(Boost 1.54 REQUIRED COMPONENTS filesystem program_options system) and i get the following warning when doing cmake CMake Warning at /user/software/cmake/cmake-3

问题 I have tried to link boost in my CMakeList file by set(Boost_USE_STATIC_LIBS OFF) set(Boost_USE_MULTITHREADED ON) set(Boost_USE_STATIC_RUNTIME OFF) set(Boost_NO_SYSTEM_PATHS TRUE) set(Boost_INCLUDE_DIR /user/software/boost/boost-1.69-x86_64-cc7/include) set(Boost_LIBRARY_DIR /user/software/boost/boost-1.69-x86_64-cc7/lib) find_package(Boost 1.54 REQUIRED COMPONENTS filesystem program_options system) and i get the following warning when doing cmake CMake Warning at /user/software/cmake/cmake-3

问题 I have tried to link boost in my CMakeList file by set(Boost_USE_STATIC_LIBS OFF) set(Boost_USE_MULTITHREADED ON) set(Boost_USE_STATIC_RUNTIME OFF) set(Boost_NO_SYSTEM_PATHS TRUE) set(Boost_INCLUDE_DIR /user/software/boost/boost-1.69-x86_64-cc7/include) set(Boost_LIBRARY_DIR /user/software/boost/boost-1.69-x86_64-cc7/lib) find_package(Boost 1.54 REQUIRED COMPONENTS filesystem program_options system) and i get the following warning when doing cmake CMake Warning at /user/software/cmake/cmake-3

问题 I need to implement following behavior: when server starts, it should check for existing servers using broadcast. Then it waits for answer. But, how to set any timeout for waiting? int optval = 1; char buff[BUFF_SIZE]; SOCKADDR_IN addr; int length = sizeof(addr); if (setsockopt(s, SOL_SOCKET, SO_BROADCAST, (char*)&optval, sizeof(optval)) == SOCKET_ERROR) throw(errors::SETSOCKOPT); addr->sin_family = AF_INET; addr->sin_port = htons(this->serverPort); addr->sin_addr.s_addr = INADDR_ANY; sendto

问题 I need to implement following behavior: when server starts, it should check for existing servers using broadcast. Then it waits for answer. But, how to set any timeout for waiting? int optval = 1; char buff[BUFF_SIZE]; SOCKADDR_IN addr; int length = sizeof(addr); if (setsockopt(s, SOL_SOCKET, SO_BROADCAST, (char*)&optval, sizeof(optval)) == SOCKET_ERROR) throw(errors::SETSOCKOPT); addr->sin_family = AF_INET; addr->sin_port = htons(this->serverPort); addr->sin_addr.s_addr = INADDR_ANY; sendto

问题 Having not found a 'boost' way of resetting an accumulator in C++, I came across a piece of code that seems to reset a boost accumulator. But don't understand how it is achieving it. The code is as below - #include <iostream> #include <boost/accumulators/accumulators.hpp> #include <boost/accumulators/statistics/stats.hpp> #include <boost/accumulators/statistics/mean.hpp> using namespace boost::accumulators; template< typename DEFAULT_INITIALIZABLE > inline void clear( DEFAULT_INITIALIZABLE&

问题 struct DATAs { char data1; short data2; short data3; float data4; int data5; short data6; unsigned short data7; short data8; char data9; }; void fixFile(char* filename) { std::ifstream InputFile; InputFile.open(filename, std::ios::binary); DATAs FileDatas; InputFile.read(reinterpret_cast<char*>(&FileDatas), sizeof(FileDatas)); } Why do I need to use "reinterpret_cast" for the reading instead of "InputFile.read(&FileDatas, sizeof(FileDatas))" ? 回答1: The type of the first argument to std:

问题 Closed . This question needs details or clarity. It is not currently accepting answers. Want to improve this question? Add details and clarify the problem by editing this post. Closed 11 months ago . Improve this question How to convert pixel/screen coordinates to cartesian coordinates(x,y)? The info I have on the pictures is (see image): vFov in degrees, hFov in degrees, pixel width, pixel height Basically what I want is to take any pixel on the image, and calculate the relative degrees it