从0开始学习opencv（一）-配置环境

Posted on 2019-10-27 Edited on 2022-01-28 In 游戏

Mac环境，安装OpenCV，VScode调试C++程序

环境说明

macOS版本 catalina 10.15版本
opencv3
vscode

步骤

安装XCode工具Command Line **sudo** xcode-select --install

安装homebrew，可以用Homebrew安装很多东西

1	/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

brew下载后发生很慢的情况，是因为某种不可描述的原因。这时候需要国内镜像

git -C "$(brew --repo)" remote set-url origin https://mirrors.tuna.tsinghua.edu.cn/git/homebrew/brew.git

git -C "$(brew --repo homebrew/core)" remote set-url origin https://mirrors.tuna.tsinghua.edu.cn/git/homebrew/homebrew-core.git

git -C "$(brew --repo homebrew/cask)" remote set-url origin https://mirrors.tuna.tsinghua.edu.cn/git/homebrew/homebrew-cask.git

brew update

安装cmake，如果你用的homebrew方式安裝opencv那麼CMake就不是必須的.

到https://cmake.org/download/下下载cmake安装包安装

或者使用brew install cmake

安装opencv,使用brew安装brew install opencv@3

如果遇到Cloning into '/Users/wangwenwei/Library/Caches/Homebrew/aom--git'... fatal: unable to access 'https://aomedia.googlesource.com/aom.git/': Failed to connect to aomedia.googlesource.com port 443: Operation timed out肯定又是因为某种不可描述的问题，无法安装aom

解决方法如下：

$ wget https://raw.githubusercontent.com/Homebrew/homebrew-core/master/Formula/aom.rb
 
# 用本站提供的一份代码拷贝来替代原来的地址
$ sed -i "" "s/https:\/\/aomedia\.googlesource\.com\/aom\.git/https:\/\/www.mobibrw.com\/wp-content\/uploads\/2019\/04\/aom.zip/g" aom.rb
 
$ brew uninstall --ignore-dependencies aom
 
$ brew install --build-from-source aom.rb --env=std

(如果某种不可描述的原因连wget都不行，则直接访问https://raw.githubusercontent.com/Homebrew/homebrew-core/master/Formula/aom.rb把内容拷贝到aom.rb)

写个demo测试gcc可用性

新建编辑main.cpp

/// ./main.cpp
#include <stdio.h>
#include <iostream>

int main(int argc, const char * argv[]) {
    std::cout << "absurd!\n";
    return 0;
}

命令：

absurd$ g++ -g ./main.cpp -o ./main.o
absurd$ ./main.o
absurd!
absurd$

配置pkg-config

由 brew list opencv可以看到现在opencv的路径，拷贝相关配置

1	cp /usr/local/Cellar/opencv/4.1.2/lib/pkgconfig/opencv4.pc /usr/local/lib/pkgconfig/opencv.pc

配置bash环境（永久的走/etc/profile）

1
2
3

absurd$ echo PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/usr/local/lib/pkgconfig >> ~/.bash_profile
absurd$ echo export PKG_CONFIG_PATH >> ~/.bash_profile
absurd$ source ~/.bash_profile

配置完后执行

pkg-config opencv --libs --cflags opencv

测试opencv的DEMO

新建test.cpp

#include <opencv2/opencv.hpp> //头文件
using namespace cv; //包含cv命名空间

int main()
{
	// 【1】读入一张图片
	Mat img=imread("1.jpg");
	// 【2】在窗口中显示载入的图片
	imshow("【载入的图片】",img);
	// 【3】等待6000 ms后窗口自动关闭
	waitKey(6000);
}

编译g++ pkg-config opencv –libs –cflags opencv ./test.cpp -o ./test.o,

执行./test.o

可以看到弹出图片

下载安装vscode，https://code.visualstudio.com/

安装插件C/C++、C++ Intellisense、C++ Clang Command Adapter、Chinese (Simplified) Language Pack for Visual Studio Code（中文语言包，看个人喜好）

配置vscode

“command+shift+p”打开命令行工具窗口，输入或者选择“Edit Configurations”命令。

此时会在当前工作空间目录生成.vscode配置目录，同时在配置目录会生成一个c_cpp_properties.json文件。

includePath使用的opencv通过 ~ brew list opencv@3获取到include

{
    "configurations": [
        {
            "name": "Mac",
            "includePath": [
                "/usr/local/include",
                "/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk/usr/bin",
                "/usr/local/Cellar/opencv@3/3.4.5_6/include/",      
                "${workspaceFolder}/**"
            ],
            "defines": [],
            "macFrameworkPath": [
                "/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/System/Library/Frameworks"
            ],
            "compilerPath": "/usr/bin/clang",
            "cStandard": "c11",
            "cppStandard": "c++17",
            "intelliSenseMode": "clang-x64"
        }
    ],
    "version": 4
}

“command+shift+p”打开命令行工具窗口，输入或者选择“Tasks: Configure Task”

配置 tasks.json文件

{
// 有关 tasks.json 格式的文档，请参见
    // https://go.microsoft.com/fwlink/?LinkId=733558
    "version": "2.0.0",
    "tasks": [
        {
            "type": "shell",
            "label": "g++ build active file",
            "command": "/usr/bin/g++",
            "args": [
                "-g",
                "${file}",
                "-o",
                "${fileDirname}/${fileBasenameNoExtension}.out",
                "`pkg-config",
                "--libs",
                "--cflags",
                "opencv`"
            ],
            "options": {
                "cwd": "/usr/bin"
            },
            "problemMatcher": [
                "$gcc"
            ],
            "group": "build"
        }
    ]
}

配置launch.json。“command+shift+p”打开命令行工具窗口，输入或者选择Debug: Open launch.json命令。

{
    // 使用 IntelliSense 了解相关属性。 
    // 悬停以查看现有属性的描述。
    // 欲了解更多信息，请访问: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "name": "g++ build active file",
            "type": "cppdbg",
            "request": "launch",
            "program": "${workspaceFolder}/${fileBasenameNoExtension}.out",
            "args": [],
            "stopAtEntry": false,
            "cwd": "${workspaceFolder}",
            "environment": [ {"name": "PKG_CONFIG_PATH", "value": "/usr/local/lib/pkgconfig"},   // 這是opencv解壓碼後創建的release目錄下的unix-install, 要保證該目錄下下有opencv.pc文件
                {"name": "DYLD_LIBRARY_PATH", "value": "/usr/local/opencv/build/lib"}   // 這個是你在編譯時，opencv make時`CMAKE_INSTALL_PREFIX`指定的目錄
            ],
            "externalConsole": true,
            "MIMode": "lldb",
            "preLaunchTask":"g++ build active file"
        }
    ]
}

开始调试

调试如果出现图片就是成功了

如果类似上图显示波浪形，就是c_cpp_properties.json的includePath没有引用到正确的库，配置下就好了