Solve error: 'class vtkImageActor' has no member named 'SetInput'

Replacement of SetInput() with SetInputData() and SetInputConnection()

someFilter->SetInput(someReader->GetOutput()); // Outdated

// Replace to the following:
someFilter->SetInputConnection(someReader->GetOutputPort());
someFilter->SetInputData(aDataObject);

For details, please see here.