How to flip image from QCamera? - c++

Question

In QT Creator how we can filp the images from camera. I googled a lot but I didn't get a proper solution.
Following is my code.
mCamera = new QCamera;
mViewfinder = new QCameraViewfinder;
mLayout = new QVBoxLayout(ui->graphicsView);
mLayout->addWidget(mViewfinder);
mCamera->setViewfinder(mViewfinder);
mViewfinder->show();
mCamera->start();
I tried QCamera::FrontFace and QCamera::BackFace in constructor argument in QCamera like below
mCamera = new QCamera(QCamera::FrontFace);
and
mCamera = new QCamera(QCamera::BackFace );
But both have no difference.
In Python
video=cv2.flip(self.frame,1)
will solve the problem,
Any idea how to solve this ..
I am using Windows 10

Answer 1

QCamera::FrontFace and QCamera::BackFace are just positions of the camera. To achieve what you want, you should flip every image.
Create QCameraImageCapture and connect to its imageCaptured() signal.
auto imageCapture = new QCameraImageCapture( mCamera );
connect(imageCapture, &QCameraImageCapture::imageCaptured, [&](int id, const QImage &preview){
QImage flipped = preview.mirrored();
// do what you want with flipped image
})
Documentation says that mirrored(bool horizontal = false, bool vertical = true)
Returns a mirror of the image, mirrored in the horizontal and/or the vertical direction depending on whether horizontal and vertical are set to true or false.
UPDATE:
I found the camera and tested the code and realized that I forgot one important thing. You need to use a timer by which QCameraImageCapture will capture the image.
Create QTimer and connect to QTimer::timeout() signal:
connect (&timer, &QTimer::timeout, [&](){
camera->searchAndLock();
imageCapture->capture();
camera->unlock();
});
And after that start the timer. To show flipped image you can use just QLabel class with label->setPixmap(QPixmap::fromImage(flipped)) method.

Answer 2

Hai I changed my code as per the answer of #Allocse and its work for me
My full code will be
mCamera = new QCamera;
mCamera->start();
imageCapture = new QCameraImageCapture( mCamera );
connect (&timer, &QTimer::timeout, [&](){
mCamera->searchAndLock();
imageCapture->capture();
mCamera->unlock();
});
connect(imageCapture, &QCameraImageCapture::imageCaptured, [&](int id, const QImage &preview){
QImage flipped = preview.mirrored(true,false);
ui->videoFrame->setPixmap(QPixmap::fromImage(flipped));
});
timer.start();
Note :-mCamera and imageCapture should be declared in class decleration