private static bool isinside(PointDouble A, PointDouble B, PointDouble C, PointDouble D, PointDouble P)
{
double a = (B.X - A.X) * (P.Y - A.Y) - (B.Y - A.Y) * (P.X - A.X);
double b = (C.X - B.X) * (P.Y - B.Y) - (C.Y - B.Y) * (P.X - B.X);
double c = (D.X - C.X) * (P.Y - C.Y) - (D.Y - C.Y) * (P.X - C.X);
double d = (A.X - D.X) * (P.Y - D.Y) - (A.Y - D.Y) * (P.X - D.X);
if ((a > 0 && b > 0 && c > 0 && d > 0) || (a < 0 && b < 0 && c < 0 && d < 0))
{
return(true);
}
// AB X AP = (b.x - a.x, b.y - a.y) x (p.x - a.x, p.y - a.y) = (b.x - a.x) * (p.y - a.y) - (b.y - a.y) * (p.x - a.x);
// BC X BP = (c.x - b.x, c.y - b.y) x (p.x - b.x, p.y - b.y) = (c.x - b.x) * (p.y - b.y) - (c.y - b.y) * (p.x - b.x);
return(false);
}
public static T InversePerspective(T bitmap, List <HoughTransform.Line> lines)
{
var p01 = ret2linesP(lines[0], lines[1]);
var p02 = ret2linesP(lines[0], lines[2]);
var p03 = ret2linesP(lines[0], lines[3]);
var p12 = ret2linesP(lines[1], lines[2]);
var p13 = ret2linesP(lines[1], lines[3]);
var p23 = ret2linesP(lines[2], lines[3]);
List <PointDouble> p4s = new List <PointDouble>();
if (isokp(p01, bitmap) &&
isokp(p02, bitmap) &&
isokp(p13, bitmap) &&
isokp(p23, bitmap) &&
!(isinside(p01, p02, p13, p23, p03) || isinside(p01, p02, p13, p23, p12)))
{
p4s.Add(p01);
p4s.Add(p02);
p4s.Add(p13);
p4s.Add(p23);
}
if (isokp(p01, bitmap) &&
isokp(p03, bitmap) &&
isokp(p12, bitmap) &&
isokp(p23, bitmap) &&
!(isinside(p01, p03, p12, p23, p02) || isinside(p01, p03, p12, p23, p13)))
{
p4s.Add(p01);
p4s.Add(p03);
p4s.Add(p12);
p4s.Add(p23);
}
if (isokp(p02, bitmap) &&
isokp(p03, bitmap) &&
isokp(p12, bitmap) &&
isokp(p13, bitmap) &&
!(isinside(p02, p03, p12, p13, p01) || isinside(p02, p03, p12, p13, p23)))
{
p4s.Add(p02);
p4s.Add(p03);
p4s.Add(p12);
p4s.Add(p13);
}
double minx = bitmap.Width + 2;
foreach (var p in p4s)
{
if (p.X < minx)
{
minx = p.X;
}
}
double miny = bitmap.Height + 2;
foreach (var p in p4s)
{
if (p.Y < miny)
{
miny = p.Y;
}
}
p4s.Sort(
(A, B) =>
{
double disa = (A.X - minx) * (A.X - minx) + (A.Y - miny) * (A.Y - miny);
double disb = (B.X - minx) * (B.X - minx) + (B.Y - miny) * (B.Y - miny);
if (disa > disb)
{
return(1);
}
else
{
return(-1);
}
}
);
//短边
var AB = Math.Sqrt((p4s[0].X - p4s[1].X) * (p4s[0].X - p4s[1].X) + (p4s[0].Y - p4s[1].Y) * (p4s[0].Y - p4s[1].Y));
var CD = Math.Sqrt((p4s[3].X - p4s[2].X) * (p4s[3].X - p4s[2].X) + (p4s[3].Y - p4s[2].Y) * (p4s[3].Y - p4s[2].Y));
//长边
var AC = Math.Sqrt((p4s[0].X - p4s[3].X) * (p4s[0].X - p4s[3].X) + (p4s[0].Y - p4s[3].Y) * (p4s[0].Y - p4s[3].Y));
var BD = Math.Sqrt((p4s[1].X - p4s[2].X) * (p4s[1].X - p4s[2].X) + (p4s[1].Y - p4s[2].Y) * (p4s[1].Y - p4s[2].Y));
var imgw = 440;
var imgh = 140;
var img = (T)Activator.CreateInstance(bitmap.GetType(), new object[] { imgw, imgh });
PointDouble calPoint(int p1, int p2, int j, int i)
{
PointDouble result;
result.X = p4s[p1].X + (p4s[p2].X - p4s[p1].X) * (i + 1) / (imgw - 1);
result.Y = p4s[p1].Y + (p4s[p2].Y - p4s[p1].Y) * (j + 1) / (imgh - 1);
return(result);
}
(double k, double b) calLine(PointDouble p1, PointDouble p2)
{
double k = (p1.Y - p2.Y) / (p1.X - p2.X);
double b = p2.Y - (p1.Y - p2.Y) * p2.X / (p1.X - p2.X);
return(k, b);
}
for (int j = 0; j < imgh; j++)
{
for (int i = 0; i < imgw; i++)
{
PointDouble pac = calPoint(0, 2, j, i);
PointDouble pbd = calPoint(1, 3, j, i);
(double k1, double b1) = calLine(pac, pbd);
PointDouble pab = calPoint(0, 1, j, i);
PointDouble pcd = calPoint(2, 3, j, i);
(double k2, double b2) = calLine(pab, pcd);
PointDouble aimPoint;
aimPoint.X = (b2 - b1) / (k1 - k2);
aimPoint.Y = k1 * aimPoint.X + b1;
img[j, i] = bitmap[(int)aimPoint.Y, (int)aimPoint.X];
}
}
return(img);
}
