QT中Camera相机调用
一：摄像头配置
1、创建摄像头类，获取电脑端的所有摄像头
cameras = QCameraInfo::availableCameras(); //获取所有相机的列表
if (cameras.count() > 0)
{
for(const QCameraInfo &cameraInfo:cameras)
{
qDebug() << cameraInfo.description();
}
camera = new QCamera(cameras.at(0)); //初始化实例化第一个相机对象
}
2、设置取景器（将摄像头采集的图像放入一个屏幕中）
viewfinder=new QCameraViewfinder(ui->lblVideo);
viewfinder->resize(640, 480);
CamerimageCapture=new QCameraImageCapture(camera);
CamerimageCapture>setCaptureDestination(QCameraImageCapture::CaptureToFile);
3、将取景器与摄像头连接
camera->setCaptureMode(QCamera::CaptureStillImage);//将其采集为图片camera->setCaptureMode(QCamera::CaptureMode::CaptureViewfinder);//将采集到取景器中
camera->setViewfinder(viewfinder);
viewfinder->resize(640, 480);
4、设置默认摄像头的参数
//设置默认摄像头参数
QCameraViewfinderSettings set; //专门用于设置取景器参数，创建取景器类对象
set.setResolution(640, 480); //设置显示分辨率，以像素为单位设置取景器的分辨率
set.setMaximumFrameRate(75); //设置帧率，设置取景器的最小帧速率(以每秒帧数为单位)
camera->setViewfinderSettings(set); //设置取景器参数与相机匹配
5、设置相机列表选项
for(const QCameraInfo &cameraInfo:cameras)
{
qDebug() << “CameraInfo:” << cameraInfo;
ui->cameraSel->addItem(cameraInfo.description());
}
ui->cameraSel->setCurrentIndex(0);
注释：
cameraSel：为一个控件(QComboBox)；
ui->cameraSel->addItem(cameraInfo.description());把所有相机显示在控件中；
6、设置初始（默认）相机的分辨率选项
mResSize = camera->supportedViewfinderResolutions();//查询摄像头支持的分辨率
for (const QSize &msize:mResSize)
{
qDebug() << msize; //摄像头支持分辨率打印，打印相机支持的分辨率
ui->resolutionSel->addItem(QString::number(msize.width(), 10) + “" + QString::number(msize.height(), 10));
}
ui->resolutionSel->setCurrentIndex(0);//默认列表中第一个相机
resolutionSel：为一个控件(QComboBox)；
7、相机选项槽函数——相机显示QComboBox控件
//信号槽连接
connect(ui->cameraSel, QOverload::of(&QComboBox::activated), [=](int index)
{
for (int i = 0; i < mResSize.size(); i++)
{
ui->resolutionSel->removeItem(0);
}
//添加新相机的所有分辨率
mResSize.clear();
mResSize = camera->supportedViewfinderResolutions();
for (const QSize &msize:mResSize) {
qDebug() << msize; //摄像头支持分辨率打印
ui->resolutionSel->addItem(QString::number(msize.width(), 10) + "” + QString::number(msize.height(), 10));
}
ui->resolutionSel->setCurrentIndex(0);
});
connect(ui->resolutionSel, QOverload::of(&QComboBox::activated), [=](int index)
{
//重新设置摄像头参数
QCameraViewfinderSettings reset;
reset.setResolution(mResSize[index]);
camera->setViewfinderSettings(reset);
});
8、截图槽函数
connect(ui->screenShot, &QPushButton::clicked, ={
camera->setCaptureMode(QCamera::CaptureStillImage);//设置捕获模式为拍照，静态帧捕获
delete imageCapture;
imageCapture = new QCameraImageCapture(camera); //创建图像捕获类对象，与camera配合进行拍照
QString fileName = QFileDialog::getSaveFileName(); //获得保存路径
camera->searchAndLock(); //锁定相机
imageCapture->capture(fileName); //捕获图片并保存文件
camera->unlock(); //解除相机锁定
});
connect(imageCapture, SIGNAL(imageCaptured(int,QImage)), this, SLOT(rcv_image(int,QImage)));
9、关闭相机槽函数
void Widget::on_closeScreen_clicked()
{
delete camera;
camera->stop();
QApplication *app;
app->exit(0);
}
10、开启相机槽函数
void Widget::on_openScreen_clicked()
{
camera->stop();
delete camera;
camera->start();
fps_time.start(33);
}
11、完整代码
Widget.h
#ifndef WIDGET_H
#define WIDGET_H
#include Widget.cpp
#include "widget.h"
#include "ui_widget.h"
#include widget.ui
实际效果图
