/// <summary>
/// Performs non maximum suppression given boxes and corresponding scores.
/// </summary>
/// <param name="bboxes">a set of bounding boxes to apply NMS.</param>
/// <param name="scores">a set of corresponding confidences.</param>
/// <param name="scoreThreshold">a threshold used to filter boxes by score.</param>
/// <param name="nmsThreshold">a threshold used in non maximum suppression.</param>
/// <param name="indices">the kept indices of bboxes after NMS.</param>
/// <param name="eta">a coefficient in adaptive threshold formula</param>
/// <param name="topK">if `>0`, keep at most @p top_k picked indices.</param>
// ReSharper disable once IdentifierTypo
public static void NMSBoxes(IEnumerable <Rect2d> bboxes, IEnumerable <float> scores,
float scoreThreshold, float nmsThreshold,
out int[] indices,
float eta = 1.0f, int topK = 0)
{
if (bboxes == null)
{
throw new ArgumentNullException(nameof(bboxes));
}
if (scores == null)
{
throw new ArgumentNullException(nameof(scores));
}
// ReSharper disable once IdentifierTypo
using (var bboxesVec = new VectorOfRect2d(bboxes))
using (var scoresVec = new VectorOfFloat(scores))
using (var indicesVec = new VectorOfInt32())
{
NativeMethods.dnn_NMSBoxes_Rect2d(
bboxesVec.CvPtr, scoresVec.CvPtr, scoreThreshold, nmsThreshold,
indicesVec.CvPtr, eta, topK);
indices = indicesVec.ToArray();
}
}
/// <summary>
/// Returns a reference to a storage for the tracked objects, each object corresponds to one tracker algorithm
/// </summary>
/// <returns></returns>
public Rect2d[] GetObjects()
{
using var bbVec = new VectorOfRect2d();
NativeMethods.HandleException(
NativeMethods.tracking_MultiTracker_getObjects(ptr, bbVec.CvPtr));
GC.KeepAlive(this);
return(bbVec.ToArray());
}
/// <summary>
/// Update the current tracking status.
/// </summary>
/// <param name="image">input image</param>
/// <param name="boundingBox">the tracking result, represent a list of ROIs of the tracked objects.</param>
/// <returns></returns>
public bool Update(InputArray image, out Rect2d[] boundingBox)
{
if (image == null)
{
throw new ArgumentNullException(nameof(image));
}
using var bbVec = new VectorOfRect2d();
NativeMethods.HandleException(
NativeMethods.tracking_MultiTracker_update2(ptr, image.CvPtr, bbVec.CvPtr, out var ret));
boundingBox = bbVec.ToArray();
GC.KeepAlive(image);
GC.KeepAlive(this);
return(ret != 0);
}
