I want to crop a selected a rectangle area in live video feed and save those area or image in my local drive

robotsandi

i am also able to stop the camera and can i store that image in buffer to use those image.

mrjj

@robotsandi
Ok if you already can grab images, you simply load it with full path from where you store it
or simply display it in QLabel ( as pixmap) and use rubberband to grab the area. ( or fixed in code if only needing that)
Or if you can just stop the video and it still displays last image, then directly on that.

robotsandi

@mrjj
yes, i just stop the video and it still displays the last image,
but how can i directly it

void MainWindow::on_pushButton_clicked()
{
mCamera->setViewfinder(mCameraViewfinder);
mLayout->addWidget(mCameraViewfinder);
mLayout->setMargin(0);
ui->scrollArea->setLayout(mLayout);
mCamera->start();
}

void MainWindow::on_pushButton_2_clicked()
{
mCamera->stop();
}

robotsandi

@mrjj Plese help me.

mrjj

@robotsandi
well i dont know for sure.
I think you have to use a
http://doc.qt.io/qt-5/qcameraimagecapture.html#details
to get an image.
But why not just copy from what ever is on screen ?
Do you also need image first?

robotsandi

@mrjj
mCamera->setCaptureMode(QCameraImageCapture::CaptureToBuffer);
how to stope image to use this code

mrjj

Hi
I think you just connect image capture to it
imageCapture = new QCameraImageCapture(camera);
and hook up to
http://doc.qt.io/qt-5/qcameraimagecapture.html#imageCaptured
to get signal and image when its ready

mrjj

Hi
maybe this sample is good start ?
http://doc.qt.io/qt-5/qtmultimedia-multimediawidgets-camera-example.html

It can grab photo.

robotsandi

@mrjj
Hi
I have 4 coordinate (x1, y1, x2, y2)
(x1, y1) is for press mouse button or (x2, y2) for release mouse button
how can i fine height and weight.
please, can you explain me:

mrjj

@robotsandi
Well you can just cheat
QRect area( x1,y1,x2,y2 ) ;
( or as QPoint if you have that QRect area( p1, p2 ) )
then you can just ask it

area.width()
area.height()

else its
int w= x2 - x1;
int h=y2-y1;

robotsandi

@mrjj
How to save image
int width = x2-x1;
int height = y2-y1;
QPixmap original("mCameraImageCapture");
//QPixmap cropped = original.copy(rect);
QPixmap cropped = original.copy(x1, y1, width, height);

robotsandi

@robotsandi
mCameraImageCapture->setCaptureDestination(QCameraImageCapture::CaptureToBuffer);
QImageEncoderSettings imageEncoderSettings;
imageEncoderSettings.setCodec("imag/jpeg");
imageEncoderSettings.setResolution(1600,1200);
mCameraImageCapture->setEncodingSettings(imageEncoderSettings);

mrjj

.setCodec("imag/jpeg");

Is that correct?
Seems to miss an e

robotsandi

@mrjj
yes this is correct

robotsandi

@robotsandi
Is that correct
mCameraImageCapture->setCaptureDestination(QCameraImageCapture::CaptureToBuffer);
to mCameraImage Capture is store image in buffer??

robotsandi

@robotsandi
QPixmap original("mCameraImageCapture");
QPixmap cropped = original.copy(x1, y1, width, height);
cropped.save(filename);
is pic is not save

mrjj

Yes it think its ok.
But not used in sample so might not be needed.
They just setup
imageCapture = new QCameraImageCapture(camera);
and hook up signal
connect(imageCapture, &QCameraImageCapture::imageCaptured, this, &Camera::processCapturedImage);
and then do

void Camera::processCapturedImage(int requestId, const QImage& img)
{
    Q_UNUSED(requestId);
    QImage scaledImage = img.scaled(ui->viewfinder->size(),
                                    Qt::KeepAspectRatio,
                                    Qt::SmoothTransformation);

    ui->lastImagePreviewLabel->setPixmap(QPixmap::fromImage(scaledImage));

    // Display captured image for 4 seconds.
    displayCapturedImage();
    QTimer::singleShot(4000, this, &Camera::displayViewfinder);
}