Qt调用摄像头（截取并保存图片）

http://blog.youkuaiyun.com/liang19890820/article/details/12782531 

Qt如何调用系统摄像设备进行显示、截图、录制？

    QCamera：系统摄像设备（摄像头）

    QCameraViewfinder：摄像取景器部件

    QCameraImageCapture：截图部件

capture按钮：用于截图（截图后在右上角显示）

save按钮：用于保存截取后的图片（此处测试路径为：F:\a.jpg）

exit按钮：退出界面

效果如下：

代码如下：

#include "test_capture.h"

Dialog::Dialog(QWidget *parent) :

QDialog(parent)

{

this->resize(600, 400);

camera = new QCamera();

view_finder = new QCameraViewfinder();

camera_image_capture = new QCameraImageCapture(camera);

capture_button = new QPushButton();

save_button = new QPushButton();

exit_button = new QPushButton(); 

display_label = new QLabel();

QHBoxLayout *main_layout = new QHBoxLayout();

QVBoxLayout *v_layout = new QVBoxLayout();

display_label->setFixedSize(150, 150);

display_label->setScaledContents(true);

v_layout->addWidget(display_label);

v_layout->addStretch();

v_layout->addWidget(capture_button);

v_layout->addWidget(save_button);

v_layout->addWidget(exit_button);

main_layout->addWidget(view_finder);

main_layout->addLayout(v_layout);

connect(capture_button, &QPushButton::clicked, this, &Dialog::captureImage);

connect(save_button, &QPushButton::clicked, this, &Dialog::saveImage);

connect(exit_button, &QPushButton::clicked, this, &Dialog::close);

connect(camera_image_capture, &QCameraImageCapture::imageCaptured, this, &Dialog::displayImage);

camera_image_capture->setCaptureDestination(QCameraImageCapture::CaptureToFile);

camera->setCaptureMode(QCamera::CaptureStillImage);

camera->setViewfinder(view_finder);

camera->start(); //启动摄像头

this->setLayout(main_layout);

this->translateLanguage();

}

Dialog::~Dialog()

{

}

void Dialog::translateLanguage()

{

this->setWindowTitle("testCapture");

capture_button->setText(tr("capture"));

save_button->setText(tr("save"));

exit_button->setText(tr("exit"));

}

void Dialog::displayImage(int id, QImage image)

{

display_label->setPixmap(QPixmap::fromImage(image));  

}

void Dialog::captureImage()

{

//截图

camera_image_capture->capture();  

}

void Dialog::saveImage()

{

const QPixmap *pixmap = display_label->pixmap();

if(pixmap)

{

pixmap->save("F:\\a.jpg");

}

}