FastRetinaKeypointDetector Class

[SerializableAttribute]
public class FastRetinaKeypointDetector : BaseSparseFeatureExtractor<FastRetinaKeypoint>

<SerializableAttribute>
Public Class FastRetinaKeypointDetector
	Inherits BaseSparseFeatureExtractor(Of FastRetinaKeypoint)

Bitmap lena = Resources.lena512;

// The freak detector can be used with any other corners detection
// algorithm. The default corners detection method used is the FAST
// corners detection. So, let's start creating this detector first:
// 
var detector = new FastCornersDetector(60);

// Now that we have a corners detector, we can pass it to the FREAK
// feature extraction algorithm. Please note that if we leave this
// parameter empty, FAST will be used by default.
// 
var freak = new FastRetinaKeypointDetector(detector);

// Now, all we have to do is to process our image:
List<FastRetinaKeypoint> points = freak.ProcessImage(lena);

// Afterwards, we should obtain 83 feature points. We can inspect
// the feature points visually using the FeaturesMarker class as
// 
FeaturesMarker marker = new FeaturesMarker(points, scale: 20);

// And showing it on screen with
ImageBox.Show(marker.Apply(lena));

// We can also inspect the feature vectors (descriptors) associated
// with each feature point. In order to get a descriptor vector for
// any given point, we can use
// 
byte[] feature = points[42].Descriptor;

// By default, feature vectors will have 64 bytes in length. We can also
// display those vectors in more readable formats such as HEX or base64
// 
string hex = points[42].ToHex();
string b64 = points[42].ToBase64();

// The above base64 result should be:
// 
//  "3W8M/ev///ffbr/+v3f34vz//7X+f0609v//+++/1+jfq/e83/X5/+6ft3//b4uaPZf7ePb3n/P93/rIbZlf+g=="