public Mat _01_DetectGrid4(Mat imgWhiteB, Mat imgBlackW, byte thValue, out Point2d[] Q4fnd, bool DispB)
{
//Acquiring convex hull
//Coordinate list of contour
Point[][] contours;
HierarchyIndex[] hierarchy;
Cv2.FindContours(imgBlackW, out contours, out hierarchy, RetrievalModes.Tree, ContourApproximationModes.ApproxSimple);
Size sz = imgWhiteB.Size();
int W = sz.Width, H = sz.Height, WW = (int)Math.Min(W * 0.4, H * 0.4);
try{
Mat checkImg = imgWhiteB.CvtColor(ColorConversionCodes.GRAY2BGR); //###### Gray->Color
foreach (var PP in contours.Where(p => p.Count() >= 4))
{
double Xmin = PP.Min(p => p.X);
double Xmax = PP.Max(p => p.X);
double Ymin = PP.Min(p => p.Y);
double Ymax = PP.Max(p => p.Y);
if ((Xmax - Xmin) < WW || (Ymax - Ymin) < WW)
{
continue;
}
//convex hull (clockwise:true counterclockwise)
var P = Cv2.ConvexHull(PP, clockwise: true).ToList();
double area = Cv2.ContourArea(P); //Area of convex hull
//if(area<WW*WW) continue;
List <Point2d> P2 = P.ConvertAll(q => new Point2d(q.X, q.Y));
Mat stdImg = CorrectDistortion(imgWhiteB, P2, out Point2d[] Q4, DispB: false);
Q4fnd = Q4;
if (stdImg == null)
{
return(null);
}
return(stdImg);
}
}
catch (Exception e) { WriteLine(e.Message + "\r" + e.StackTrace); }
Q4fnd = null;
return(null);
}