http://www.emgu.com
Only features with keypoint.hessian larger than that are extracted. good default value is ~300-500 (can depend on the average local contrast and sharpness of the image). user can further filter out some features based on their hessian values and other characteristics

Namespace: Emgu.CV.Structure
Assembly: Emgu.CV (in Emgu.CV.dll) Version: 2.3.0.1416 (2.3.0.1416)

Syntax

C#
public double HessianThreshold
Visual Basic
Public HessianThreshold As Double
Visual C++
public:
double HessianThreshold

See Also