private void GenerateBBox(ICollection <FaceInfo> boundingBoxCollection, Mat scores, Mat boxes, float scoreThreshold, int numAnchors)
{
for (var i = 0; i < numAnchors; i++)
{
if (scores.Channel(0)[i * 2 + 1] > scoreThreshold)
{
var rects = new FaceInfo();
var xCenter = boxes.Channel(0)[i * 4] * CenterVariance * this._Priors[i][2] + this._Priors[i][0];
var yCenter = boxes.Channel(0)[i * 4 + 1] * CenterVariance * this._Priors[i][3] + this._Priors[i][1];
var w = Math.Exp(boxes.Channel(0)[i * 4 + 2] * SizeVariance) * this._Priors[i][2];
var h = Math.Exp(boxes.Channel(0)[i * 4 + 3] * SizeVariance) * this._Priors[i][3];
rects.X1 = Clip(xCenter - w / 2.0, 1) * this._ImageW;
rects.Y1 = Clip(yCenter - h / 2.0, 1) * this._ImageH;
rects.X2 = Clip(xCenter + w / 2.0, 1) * this._ImageW;
rects.Y2 = Clip(yCenter + h / 2.0, 1) * this._ImageH;
rects.Score = Clip(scores.Channel(0)[i * 2 + 1], 1);
boundingBoxCollection.Add(rects);
}
}
}
private void NonMaximumSuppression(List <FaceInfo> input, ICollection <FaceInfo> output, NonMaximumSuppressionMode type = NonMaximumSuppressionMode.Blending)
{
input.Sort((f1, f2) => f1.Score.CompareTo(f2.Score));
var boxNum = input.Count;
var merged = new int[boxNum];
for (var i = 0; i < boxNum; i++)
{
if (merged[i] > 0)
{
continue;
}
var buf = new List <FaceInfo>
{
input[i]
};
merged[i] = 1;
var h0 = input[i].Y2 - input[i].Y1 + 1;
var w0 = input[i].X2 - input[i].X1 + 1;
var area0 = h0 * w0;
for (var j = i + 1; j < boxNum; j++)
{
if (merged[j] > 0)
{
continue;
}
var innerX0 = input[i].X1 > input[j].X1 ? input[i].X1 : input[j].X1;
var innerY0 = input[i].Y1 > input[j].Y1 ? input[i].Y1 : input[j].Y1;
var innerX1 = input[i].X2 < input[j].X2 ? input[i].X2 : input[j].X2;
var innerY1 = input[i].Y2 < input[j].Y2 ? input[i].Y2 : input[j].Y2;
var innerH = innerY1 - innerY0 + 1;
var innerW = innerX1 - innerX0 + 1;
if (innerH <= 0 || innerW <= 0)
{
continue;
}
var innerArea = innerH * innerW;
var h1 = input[j].Y2 - input[j].Y1 + 1;
var w1 = input[j].X2 - input[j].X1 + 1;
var area1 = h1 * w1;
var score = innerArea / (area0 + area1 - innerArea);
if (score > this._IouThreshold)
{
merged[j] = 1;
buf.Add(input[j]);
}
}
switch (type)
{
case NonMaximumSuppressionMode.Hard:
{
output.Add(buf[0]);
break;
}
case NonMaximumSuppressionMode.Blending:
{
var total = 0d;
for (var j = 0; j < buf.Count; j++)
{
total += Math.Exp(buf[j].Score);
}
var rects = new FaceInfo();
for (var j = 0; j < buf.Count; j++)
{
var rate = Math.Exp(buf[j].Score) / total;
rects.X1 += (float)(buf[j].X1 * rate);
rects.Y1 += (float)(buf[j].Y1 * rate);
rects.X2 += (float)(buf[j].X2 * rate);
rects.Y2 += (float)(buf[j].Y2 * rate);
rects.Score += (float)(buf[j].Score * rate);
}
output.Add(rects);
break;
}
default:
//{
// Console.WriteLine("wrong type of nms.");
// exit(-1);
//}
break;
}
}
#endregion
#endregion
}