/// <summary>
/// Creates a new ImageDetection from a given image, set of points and values. It also populates it with <see cref="ObjectPhotometry"/>, <see cref="ObjectPoints"/>,
/// and <see cref="ObjectSize"/> properties.
/// </summary>
/// <param name="Image">Image on which the object was detected.</param>
/// <param name="Points">The set of points on the image where it has been detected.</param>
/// <param name="Values">The set of pixel intensitities.</param>
/// <returns>A new instance of ImageDetection with the specified extension properties.</returns>
public static ImageDetection CreateDetection(Image Image, IEnumerable <PixelPoint> Points, IEnumerable <double> Values)
{
IWCSProjection Transform = Image.Transform;
PixelPoint[] PixPoints = Points.ToArray();
double[] PixValues = Values.ToArray();
EquatorialPoint[] EquatorialPoints = Transform.GetEquatorialPoints(PixPoints);
double Xmean = 0, Ymean = 0;
double XXP = 0, XYP = 0, YYP = 0;
double XXB = 0, XYB = 0, YYB = 0;
double Flux = 0;
double XBmean = 0, YBmean = 0;
for (int i = 0; i < PixPoints.Length; i++)
{
PixelPoint pt = PixPoints[i];
double Val = PixValues[i];
Xmean += pt.X; Ymean += pt.Y;
XBmean += Val * pt.X; YBmean += Val * pt.Y;
XXB += pt.X * pt.X * Val; XYB += pt.X * pt.Y * Val; YYB += pt.Y * pt.Y * Val;
XXP += pt.X * pt.X; XYP += pt.X * pt.Y; YYP += pt.Y * pt.Y;
Flux += Val;
}
Xmean /= PixPoints.Length; Ymean /= PixPoints.Length;
XBmean /= Flux; YBmean /= Flux; XXB /= Flux; XYB /= Flux; YYB /= Flux;
XXP /= PixPoints.Length; XYP /= PixPoints.Length; YYP /= PixPoints.Length;
XXB -= XBmean * XBmean; XYB -= XBmean * YBmean; YYB -= YBmean * YBmean;
XXP -= Xmean * Xmean; XYP -= Xmean * Ymean; YYP -= Ymean * Ymean;
PixelPoint BarycenterPP = new PixelPoint()
{
X = XBmean, Y = YBmean
};
EquatorialPoint BarycenterEP = Transform.GetEquatorialPoint(BarycenterPP);
Position Pos = new Position(BarycenterEP, BarycenterPP);
SourceEllipse BarycentricEllipse = new SourceEllipse(XXB, XYB, YYB);
SourceEllipse PixelEllipse = new SourceEllipse(XXP, XYP, YYP);
ObjectSize Shape = new ObjectSize()
{
BarycentricEllipse = BarycentricEllipse, PixelEllipse = PixelEllipse
};
ImageDetection Detection = new ImageDetection(Pos, Image.GetProperty <ObservationTime>(), Image);
Detection.AppendProperty(Shape);
Detection.AppendProperty(new ObjectPhotometry()
{
Flux = Flux
});
Detection.AppendProperty(new ObjectPoints()
{
PixelPoints = PixPoints, PixelValues = PixValues, EquatorialPoints = EquatorialPoints
});
return(Detection);
}
/// <summary>
/// Creates a tracklet from a set of detections.
/// </summary>
/// <param name="Detections">Input detections; one per image.</param>
/// <returns>A new Tracklet instance.</returns>
public static Tracklet CreateTracklet(ImageDetection[] Detections)
{
long[] Ticks = Detections.Select((x) => x.Time.Time.Ticks).ToArray();
Array.Sort(Ticks, Detections);
EquatorialPoint[] ValidEP = new EquatorialPoint[Detections.Length];
double[] ValidTimes = new double[Detections.Length];
DateTime ZeroTime = Detections[0].Time.Time;
WCS.IWCSProjection Projection = Detections[0].ParentImage.Transform;
for (int i = 0; i < Detections.Length; i++)
{
ValidEP[i] = Detections[i].Barycenter.EP;
ValidTimes[i] = (Detections[i].Time.Time - ZeroTime).TotalSeconds;
}
var XRA = ValidEP.Select((x) => x.RA).ToArray();
var XDec = ValidEP.Select((x) => x.Dec).ToArray();
var RAreg = LinearRegression.ComputeLinearRegression(ValidTimes, XRA);
var Decreg = LinearRegression.ComputeLinearRegression(ValidTimes, XDec);
var RADecreg = LinearRegression.ComputeLinearRegression(XRA, XDec);
double ResRA = LineFit.ComputeResidualSqSum(RAreg, ValidTimes, XRA);
double ResDec = LineFit.ComputeResidualSqSum(Decreg, ValidTimes, XDec);
EquatorialVelocity ev = new EquatorialVelocity()
{
RAvel = RAreg.Slope, Decvel = Decreg.Slope
};
TrackletVelocityRegression tvr = new TrackletVelocityRegression()
{
R_TR = RAreg.PearsonR, R_TD = Decreg.PearsonR, R_RD = RADecreg.PearsonR,
S_TR = ResRA, S_TD = ResDec, ZeroTime = ZeroTime, P_TD = Decreg, P_TR = RAreg
};
TrackletVelocity tvel = new TrackletVelocity()
{
EquatorialVelocity = ev,
PixelVelocity = Projection.GetPixelVelocity(ev),
SphericalVelocity = Math.Sqrt(ev.Decvel * ev.Decvel + ev.RAvel * ev.RAvel * Math.Cos(XRA[0]) * Math.Cos(XRA[0]))
};
return(new Tracklet(Detections, tvel, tvr));
}
/// <summary>Creates a new instance of given equatorial coordinates and image coordinates.</summary>
/// <param name="EqPoint">Equatorial coordinates.</param>
/// <param name="PixPoint">Image coordinates.</param>
public Position(EquatorialPoint EqPoint, PixelPoint PixPoint)
{
EP = EqPoint; PP = PixPoint;
}
