Capturing Image Data Using High-Level Helper Classes

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 might not be the right choice for complex applications! It intended use-case is for straight forward image acquisition tasks. When suitable it is extremely 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!

//-----------------------------------------------------------------------------
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.