public ComputedOpticalFlow Compute()
{
var flowVectorImage = new Image<Bgr, byte>(currentImage.Bitmap);
var currentGray = currentImage.Convert<Gray, byte>();
var previousGray = previousImage.Convert<Gray, byte>();
velocityX = new Image<Gray, float>(previousImage.Size);
velocityY = new Image<Gray, float>(previousImage.Size);
CvInvoke.CalcOpticalFlowFarneback(
prev0: previousGray, next0: currentGray, flowX: velocityX, flowY: velocityY,
pyrScale: farnebackParameters.PyrScale, levels: farnebackParameters.Levels,
winSize: farnebackParameters.WinSize, iterations: farnebackParameters.Iterations,
polyN: farnebackParameters.PolyN, polySigma: farnebackParameters.PolySigma,
flags: OpticalflowFarnebackFlag.FarnebackGaussian);
var vectorFieldX = (int)Math.Round((double)currentGray.Width / WindowSize.Width);
var vectorFieldY = (int)Math.Round((double)currentGray.Height / WindowSize.Height);
var opticalFlowLineArray = new ComputedOpticalFlow.FlowLineVector[vectorFieldX * vectorFieldY];
for (int dirX = 0; dirX < vectorFieldX; dirX++)
{
for (int dirY = 0; dirY < vectorFieldY; dirY++)
{
LineSegment2DF flowVector = CalculateFlowVector(dirX, dirY);
AddToFlowLineArray(opticalFlowLineArray, vectorFieldX, dirX, dirY, flowVector);
if (ComputeFlowImage)
{
AddToFlowVectorImage(flowVectorImage, flowVector);
}
}
}
return new ComputedOpticalFlow { FlowVectorImage = flowVectorImage, FlowLineArray = opticalFlowLineArray };
}
private void AddToFlowLineArray(ComputedOpticalFlow.FlowLineVector[] opticalFlowLineArray, int vectorFieldX, int width, int height, LineSegment2DF flowVector)
{
opticalFlowLineArray[vectorFieldX * height + width] = new ComputedOpticalFlow.FlowLineVector
{
Line = flowVector,
OverThreshold = !VectorNoiseThreshold.HasValue || flowVector.Length > VectorNoiseThreshold.Value
};
}
