/// <summary>
/// Determina si un contorno es un circulo, verificando que tenga al menos 7 puntos y todos estén al mismo radio del centro
/// </summary>
/// <param name="MaxVariation"> Máxima desviacion permitida (0 a 1) </param>
/// <returns></returns>
public static bool isCircle(this VectorOfPoint contour, float MaxVariation = 0.2f)
{
bool result = false;
if (contour.Size >= 7)
{
Moments Moments = CvInvoke.Moments(contour);
Vector2 Center = Vector2.zero;
Center.x = (float)(Moments.M10 / Moments.M00);
Center.y = (float)(Moments.M01 / Moments.M00);
result = true;
Vector2[] pts = contour.ToVector2();
float MaxRadius = (pts[0] - Center).magnitude;
float MinRadius = MaxRadius;
float MinLimit = 1 - MaxVariation;
float MaxLimit = 1 + MaxVariation;
//Verifica que el radio sea consistente
for (int j = 1; j < pts.Length; j++)
{
float r = (pts[j] - Center).magnitude;
if (r > MaxRadius)
{
MaxRadius = r;
}
if (r < MinRadius)
{
MinRadius = r;
}
}
if (MinRadius / MaxRadius < MinLimit)
{
result = false;
}
//Verifica que el perímetro sea consistente
if (result)
{
double perimetroReal = CvInvoke.ArcLength(contour, true);
float Radio = (MaxRadius + MinRadius) * 0.5f;
float perimetroIdeal = 6.28f * Radio;
float factor = (float)(perimetroIdeal / perimetroReal);
if ((factor < MinLimit) || (factor > MaxLimit))
{
result = false;
}
}
pts = null;
}
return(result);
}
