2、 qt平台opencv引入，和工程搭建

news2024/9/20 16:32:04

1. 准备工作

opencv 编译，参考： https://blog.csdn.net/qq_51355375/article/details/140857966
vscode qt cmake工程创建及环境搭建： https://blog.csdn.net/qq_51355375/article/details/140752130

2. 引入opencv 头文件和链接库

2.1 配置环境变量

将目录 opecv 安装目录\install\x64\mingw\bin 配置到环境变量，不然代码运行时会找不到动态库。
在这里插入图片描述

2.2 cmake 配置，添加opencv 头文件，依赖

# 查找库和头文件路径， opencv 安装 install目录
list(APPEND CMAKE_PREFIX_PATH "D:/workspace-opencv/opencv-4.10.0/build_qt_mingw/install")  
# 查找OpenCV 
find_package(OpenCV REQUIRED)

# 链接OpenCV库
target_link_libraries(${PROJECT_NAME} PRIVATE Qt${QT_VERSION_MAJOR}::Widgets ${OpenCV_LIBS})
 
# 包含OpenCV的头文件目录
target_include_directories(${PROJECT_NAME} PRIVATE ${OpenCV_INCLUDE_DIRS})

CmakeLists.txt

cmake_minimum_required(VERSION 3.5)

project(app VERSION 0.1 LANGUAGES CXX)

set(CMAKE_AUTOUIC ON)
set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTORCC ON)

set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

# 查找库和头文件路径， opencv 安装 install目录
list(APPEND CMAKE_PREFIX_PATH "D:/workspace-opencv/opencv-4.10.0/build_qt_mingw/install")  
# 查找OpenCV 
find_package(OpenCV REQUIRED)

message(STATUS "OpenCV : ${OpenCV}") 
message(STATUS "OpenCV found: ${OpenCV_FOUND}")  
message(STATUS "OpenCV include dirs: ${OpenCV_INCLUDE_DIRS}")  
message(STATUS "OpenCV libraries: ${OpenCV_LIBS}")


find_package(QT NAMES QT6 QT5 REQUIRED COMPONENTS Widgets)
find_package(Qt${QT_VERSION_MAJOR} REQUIRED COMPONENTS Widgets) 

include_directories(${PROJECT_SOURCE_DIR}/include)



file(GLOB_RECURSE SRC_CPP_FILES src/*.cpp)  
file(GLOB_RECURSE SRC_HEADER_FILES include/*.h) 
set(PROJECT_SOURCES ${SRC_CPP_FILES} ${SRC_HEADER_FILES}) 
message(STATUS "src:${PROJECT_SOURCES}")


if(${QT_VERSION_MAJOR} GREATER_EQUAL 6)
    qt_add_executable(app
        MANUAL_FINALIZATION
        ${PROJECT_SOURCES}
    )
# Define target properties for Android with Qt 6 as:
#    set_property(TARGET qt_cmake_template APPEND PROPERTY QT_ANDROID_PACKAGE_SOURCE_DIR
#                 ${CMAKE_CURRENT_SOURCE_DIR}/android)
# For more information, see https://doc.qt.io/qt-6/qt-add-executable.html#target-creation
else()
    if(ANDROID)
        add_library(${PROJECT_NAME} SHARED
            ${PROJECT_SOURCES}
        )
# Define properties for Android with Qt 5 after find_package() calls as:
#    set(ANDROID_PACKAGE_SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/android")
    else()
        add_executable(${PROJECT_NAME}
            ${PROJECT_SOURCES}
        )
    endif()
endif()

# 链接OpenCV库
target_link_libraries(${PROJECT_NAME} PRIVATE Qt${QT_VERSION_MAJOR}::Widgets ${OpenCV_LIBS})
 
# 包含OpenCV的头文件目录
target_include_directories(${PROJECT_NAME} PRIVATE ${OpenCV_INCLUDE_DIRS})


set_target_properties(${PROJECT_NAME} PROPERTIES
    MACOSX_BUNDLE_GUI_IDENTIFIER my.example.com
    MACOSX_BUNDLE_BUNDLE_VERSION ${PROJECT_VERSION}
    MACOSX_BUNDLE_SHORT_VERSION_STRING ${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}
    MACOSX_BUNDLE OFF
    WIN32_EXECUTABLE OFF
)

install(TARGETS ${PROJECT_NAME}
    BUNDLE DESTINATION .
    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR})

if(QT_VERSION_MAJOR EQUAL 6)
    qt_finalize_executable(${PROJECT_NAME})
endif()

2.3 qDebug cout printf 等输出控制台没反应

修改cmake配置，为OFF

 MACOSX_BUNDLE OFF
 WIN32_EXECUTABLE OFF

在这里插入图片描述

3. 测试

#include "widget.h"
#include <QLabel>
#include <QVBoxLayout>
#include <qglobal.h>
#include <qimage.h>
#include <qpixmap.h>
#include <QDebug>
QImage Widget::Mat2QImage(cv::Mat mat)  
{  
    switch (mat.type()) {  
        // 8-bit, 4-channel  
        case CV_8UC4:  
        {  
            QImage image(mat.data, mat.cols, mat.rows, mat.step, QImage::Format_ARGB32);  
            return image.copy();  
        }  
        // 8-bit, 3-channel  
        case CV_8UC3:  
        {  
            QImage image(mat.data, mat.cols, mat.rows, mat.step, QImage::Format_RGB888);  
            image = image.rgbSwapped(); // OpenCV reads images in BGR, Qt uses RGB  
            return image.copy();  
        }  
        // 8-bit, 1-channel  
        case CV_8UC1:  
        {  
            QImage image(mat.cols, mat.rows, QImage::Format_Grayscale8);  
            uchar *pSrc = mat.data;  
            for(int y = 0; y < mat.rows; ++y)  
            {  
                memcpy(image.scanLine(y), pSrc, mat.cols);  
                pSrc += mat.step;  
            }  
            return image;  
        }  
        default:  
            return QImage();  
    }  
}

Widget::Widget(QWidget *parent) : QWidget(parent) {
    this->setWindowTitle("vscode");
    this->resize(500, 400);
    QLabel *label = new QLabel(this);
    QVBoxLayout *vbox = new QVBoxLayout(this);
    vbox->addWidget(label);
    qDebug() << "Image load before ========= " ;

    // 加载图像
    cv::Mat image = cv::imread("C:/Users/ylp/Pictures/壁纸/22.jpeg");
    qDebug() << "Image。empty: " << image.empty();
    if (!image.empty()) {
        QImage qimage = Mat2QImage(image);
        label->setPixmap(QPixmap::fromImage(qimage));
    }
    
}

Widget::~Widget() {

}

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include <qimage.h>
#include <opencv2/opencv.hpp>
#include <opencv2/imgcodecs/imgcodecs.hpp>



class Widget : public QWidget 
{
    Q_OBJECT

    public: 
        Widget(QWidget *parent = nullptr);
        ~Widget();

    private:
        QImage *image;
        QImage Mat2QImage(cv::Mat src);
};

#endif

#include "widget.h"

#include <QApplication>
#include <QDebug>

int main(int argc, char* argv[]) {
    QApplication app(argc, argv);
    Widget w;
    w.show();
    return app.exec();
}