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

mrjj

Hi
The docs for rubberband shows how to use it.

copy just returns copy
so its just
QPixmap area=orgpix->copy ( rect from rubberband );
you can see here
https://stackoverflow.com/questions/7010611/how-can-i-crop-an-image-in-qt

for the video part , this might help
http://omg-it.works/how-to-grab-video-frames-directly-from-qcamera/#acceptLicense

robotsandi

Hi
QRect rect(10, 20, 30, 40);
QPixmap original('image.png');
QPixmap cropped = original.copy(rect);
the following code is working on image how i can put video in place of image

mrjj

@robotsandi
Is it from a camera?

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);
}