Convert images from Pylon to Opencv in c++ - c++

Question

I want to convert stereo images captured by Basler cameras to opencv (Mat) format. In the below code i have converted images to opencv format, but in show stages, i can not show the images. please guide me.
Thanks
int main(int argc, char* argv[])
{
// The exit code of the sample application.
int exitCode = 0;
PylonInitialize();
Pylon::PylonAutoInitTerm autoInitTerm;//me
try
{
// Get the transport layer factory.
CTlFactory& tlFactory = CTlFactory::GetInstance();
// Get all attached devices and exit application if no device is found.
DeviceInfoList_t devices;
if (tlFactory.EnumerateDevices(devices) == 0)
{
throw RUNTIME_EXCEPTION("No camera present.");
}
CInstantCameraArray cameras(min(devices.size(), c_maxCamerasToUse));
// Create and attach all Pylon Devices.
for (size_t i = 0; i < cameras.GetSize(); ++i)
{
cameras[i].Attach(tlFactory.CreateDevice(devices[i]));
// Print the model name of the camera.
cout << "Using device " << cameras[i].GetDeviceInfo().GetModelName() << endl;
}
CGrabResultPtr ptrGrabResult;
CImageFormatConverter formatConverter;//me
formatConverter.OutputPixelFormat = PixelType_BGR8packed;//me
CPylonImage pylonImage;//me
// Create an OpenCV image
Mat openCvImage;//me
for (int i = 0; i < c_countOfImagesToGrab && cameras.IsGrabbing(); ++i)
{
cameras.RetrieveResult(5000, ptrGrabResult, TimeoutHandling_ThrowException);
intptr_t cameraContextValue = ptrGrabResult->GetCameraContext();
#ifdef PYLON_WIN_BUILD
#endif
// Print the index and the model name of the camera.
cout << "Camera " << cameraContextValue << ": " << cameras[cameraContextValue].GetDeviceInfo().GetModelName() << endl;
// Now, the image data can be processed.
cout << "GrabSucceeded: " << ptrGrabResult->GrabSucceeded() << endl;
cout << "SizeX: " << ptrGrabResult->GetWidth() << endl;
cout << "SizeY: " << ptrGrabResult->GetHeight() << endl;
const uint8_t *pImageBuffer = (uint8_t *)ptrGrabResult->GetBuffer();
cout << "Gray value of first pixel: " << (uint32_t)pImageBuffer[0] << endl << endl;
formatConverter.Convert(pylonImage, ptrGrabResult);//me
// Create an OpenCV image out of pylon image
openCvImage = cv::Mat(ptrGrabResult->GetHeight(), ptrGrabResult->GetWidth(), CV_8UC3, (uint8_t *)pylonImage.GetBuffer());//me
if (cameraContextValue == 0)
{
imshow("left camera", openCvImage);
imwrite("right_img.png", openCvImage);
}
else if (cameraContextValue == 1)
{
imshow("right camera", openCvImage);
imwrite("right_img.png", openCvImage);
}
Sleep(3000);
}
}
catch (const GenericException &e)
{
// Error handling
cerr << "An exception occurred." << endl
<< e.GetDescription() << endl;
exitCode = 1;
}
// Comment the following two lines to disable waiting on exit.
cerr << endl << "Press Enter to exit." << endl;
while (cin.get() != '\n');
// Releases all pylon resources.
PylonTerminate();
return exitCode;
}

Answer 1

You need to create a window to display an opencv image into, use :
namedWindow("left camera", CV_WINDOW_NORMAL);
imshow("left camera", openCvImage);
There is also a few mistakes in your code, i guess "right_img.png" should be change in "left_img.png", otherwise you will save only one image.
And this is redundant code
PylonInitialize();
Pylon::PylonAutoInitTerm autoInitTerm;
autoInitTerm is automatically calling PylonInitialize() and PylonTerminate(). So you should remove it or remove PylonInitialize() and PylonTerminate()

Answer 2

I think a waitKey(0) is required after the imshow to display the image.

Answer 3

add below piece of code. after completing for (size_t i = 0; i < cameras.GetSize(); ++i)
cameras.StartGrabbing(GrabStrategy_LatestImageOnly, GrabLoop_ProvidedByUser);
Add this to your code. and like above comments remove unnecessary code.