Capturing Image Data Using C++11 Or Higher

Since version 2.33.0 Impact Acquire is shipped with a new header file: mvIMPACT_acquire_helper.h. This file which adds the classes mvIMPACT::acquire::helper::RequestProvider and mvIMPACT::acquire::helper::ThreadSafeQueue to the public interface.

The following code will illustrate how the RequestProvider class is used to capture data continuously and in a convenient way from a device. For more details please refer to mvIMPACT::acquire::helper::RequestProvider.

Note

This class requires a C++11 compliant compiler and might not be the right choice for complex applications! It intended use-case is for straight forward image acquisition tasks. When suitable it is extremly easy to use. See also the next chapter to find out how to use the API when you need more control over the acquisition process!

Attention

When using this class together with mvIMPACT::acquire::display::ImageDisplay the CPP_STANDARD_VERSION macro must be defined to a value greater than or equal to 11! If not some of the magic in mvIMPACT::acquire::display::ImageDisplay will not be compiled! As a consequence the auto-unlocking feature of the requests attached to the display will not work and might result in undefined behavior!

//-----------------------------------------------------------------------------
int main(int argc, char* argv[])
//-----------------------------------------------------------------------------
{
  mvIMPACT::acquire::DeviceManager devMgr;
  if( devMgr.deviceCount() == 0 )
  {
    cout << "No device found! Unable to continue!" << endl;
    char ch = getch();
    return 0;
  }
 
  cout << "Initializing the device. This might take some time..." << endl;
  // create an interface to the first device found
  mvIMPACT::acquire::Device* pDev = devMgr[0];
  try
  {
    pDev->open();
  }
  catch(mvIMPACT::acquire::ImpactAcquireException& e )
  {
    // this e.g. might happen if the same device is already opened in another process...
    cout << "An error occurred while opening the device(error code: " << e.errCode()
         << "). Press any key to end the application..." << endl;
    char ch = getch();
    return 0;
  }
  
  helper::RequestProvider requestProvider( pDev );
  requestProvider.acquisitionStart();
  for(size_t i = 0; i < 5; i++)
  {
    std::shared_ptr<Request> pRequest = requestProvider.waitForNextRequest();
    std::cout << "Image captured: " << pRequest->imageOffsetX.read() << "x" << pRequest->imageOffsetY.read() << "@" << pRequest->imageWidth.read() << "x" << pRequest->imageHeight.read() << std::endl;
  }
  requestProvider.acquisitionStop();
  return 0;
}

Based on the previous code, there is the SingleCapture.cpp sample which explains the image acquisition much more detailed. For continuous image acquisition tasks, please refer to the ContinuousCapture.cpp sample.

For a detailed summary of our samples, please refer to the Typical Usage Scenarios And Example Applications page.