Finds corners with big eigenvalues in the image.

Declaration Syntax

C# | Visual Basic | Visual C++ |

public Point2D<float>[][] GoodFeaturesToTrack( int maxFeaturesPerChannel, double qualityLevel, double minDistance, int blockSize, bool useHarris, double k )

Parameters

- maxFeaturesPerChannel (Int32)
- The maximum features to be detected per channel

- qualityLevel (Double)
- Multiplier for the maxmin eigenvalue; specifies minimal accepted quality of image corners

- minDistance (Double)
- Limit, specifying minimum possible distance between returned corners; Euclidian distance is used.

- blockSize (Int32)
- Size of the averaging block, passed to underlying cvCornerMinEigenVal or cvCornerHarris used by the function

- useHarris (Boolean)
- If nonzero, Harris operator (cvCornerHarris) is used instead of default cvCornerMinEigenVal

- k (Double)
- Free parameter of Harris detector; used only if use_harris = true

Return Value

The good features for each channel

Remarks

The function first calculates the minimal eigenvalue for every source image pixel using cvCornerMinEigenVal function and stores them in eig_image. Then it performs non-maxima suppression (only local maxima in 3x3 neighborhood remain). The next step is rejecting the corners with the minimal eigenvalue less than quality_level?max(eig_image(x,y)). Finally, the function ensures that all the corners found are distanced enough one from another by considering the corners (the most strongest corners are considered first) and checking that the distance between the newly considered feature and the features considered earlier is larger than min_distance. So, the function removes the features than are too close to the stronger features