//private IntPtr _sharedPtr;
/// <summary>
/// Create a shape context distance extractor
/// </summary>
/// <param name="comparer">The histogram cost extractor, use ChiHistogramCostExtractor as default</param>
/// <param name="transformer">The shape transformer, use ThinPlateSplineSphapeTransformer as default</param>
/// <param name="nAngularBins">Establish the number of angular bins for the Shape Context Descriptor used in the shape matching pipeline.</param>
/// <param name="nRadialBins">Establish the number of radial bins for the Shape Context Descriptor used in the shape matching pipeline.</param>
/// <param name="innerRadius">Set the inner radius of the shape context descriptor.</param>
/// <param name="outerRadius">Set the outer radius of the shape context descriptor.</param>
/// <param name="iterations">Iterations</param>
public ShapeContextDistanceExtractor(
HistogramCostExtractor comparer, IShapeTransformer transformer,
int nAngularBins = 12,
int nRadialBins = 4,
float innerRadius = 0.2f,
float outerRadius = 3,
int iterations = 3)
{
_ptr = ShapeInvoke.cveShapeContextDistanceExtractorCreate(nAngularBins, nRadialBins, innerRadius, outerRadius, iterations, comparer, transformer.ShapeTransformerPtr, ref _shapeDistanceExtractorPtr, ref _sharedPtr);
}