public static ConnectedComponent FromMoments(Moments moments)
{
var component = new ConnectedComponent();
component.Area = moments.M00;
// Cemtral moments can only be computed for components with non-zero area
if (moments.M00 > 0)
{
// Compute centroid components
var x = moments.M10 / moments.M00;
var y = moments.M01 / moments.M00;
component.Centroid = new Point2f((float)x, (float)y);
// Compute second-order central moments
var miu20 = moments.M20 / moments.M00 - x * x;
var miu02 = moments.M02 / moments.M00 - y * y;
var miu11 = moments.M11 / moments.M00 - x * y;
// Compute orientation and major/minor axis length
var b = 2 * miu11;
component.Orientation = 0.5 * Math.Atan2(b, miu20 - miu02);
var deviation = Math.Sqrt(b * b + Math.Pow(miu20 - miu02, 2));
component.MajorAxisLength = Math.Sqrt(6 * (miu20 + miu02 + deviation));
component.MinorAxisLength = Math.Sqrt(6 * (miu20 + miu02 - deviation));
}
else
{
component.Centroid = new Point2f(float.NaN, float.NaN);
component.Orientation = double.NaN;
}
return(component);
}
public override IObservable <ConnectedComponentCollection> Process(IObservable <Contours> source)
{
return(source.Select(input =>
{
var currentContour = input.FirstContour;
var output = new ConnectedComponentCollection(input.ImageSize);
while (currentContour != null)
{
var component = ConnectedComponent.FromContour(currentContour);
currentContour = currentContour.HNext;
output.Add(component);
}
return output;
}));
}
public IObservable <ConnectedComponentCollection> Process(IObservable <Tuple <Contours, IplImage> > source)
{
return(source.Select(input =>
{
var image = input.Item2;
var contours = input.Item1;
var currentContour = contours.FirstContour;
var output = new ConnectedComponentCollection(image.Size);
while (currentContour != null)
{
var component = ConnectedComponent.FromContour(currentContour);
component.Patch = image.GetSubRect(component.Contour.Rect);
currentContour = currentContour.HNext;
output.Add(component);
}
return output;
}));
}
public IObservable <ConnectedComponent> Process(IObservable <Seq> source)
{
return(source.Select(input => ConnectedComponent.FromContour(input)));
}
public IObservable <ConnectedComponent> Process(IObservable <IplImage> source)
{
return(source.Select(input => ConnectedComponent.FromImage(input, binary: true)));
}