private static void WarpImage(WarpOperace warp_op)
{
// Generovat v�sledek pro ka�d� v�stupn� pixel
for (int y = 0; y < B2.Height; y++) // cyklus p�es ��dky nov�ho obr�zku
{
for (int x = 0; x < B2.Width; x++) // cyklus p�es sloupce nov�ho obr�zku
{
double du, dv; // odpov�daj�c� sou�adnice v p�v. obr.
MapPixel(warp_op, x, y, out du, out dv); // mapov�n� jednotliv�ch pixel� (x, y do u, v) - double pro v�po�ty
// Interpolace k z�sk�n� v�sledn� hodnoty pixelu
int iu = (int)du; // integer - cel� ��st
int iv = (int)dv;
// Vyhod� pixely mimo obraz // rozm�ry star�ho obr�zku
if ((iu < 0) || (iu > B1.Width - 2) || (iv < 0) || (iv > B1.Height - 2))
{
B2.SetPixel(x, y, Color.White); // bod je mimo obr�zek - vybarv�me b�le
}
else // bod je uvnit� obr�zku - spo�teme jeho hodnotu
{
// vzd�lenosti od sousedn�ch pixel� (du je p�esn� hosnota, iu cel� ��slo)
double u0 = du - iu; // od lev�ho pixelu
double v0 = dv - iv; // od horn�ho
double u1 = 1 - u0; // od prav�ho
double v1 = 1 - v0; // od spodn�ho
byte r1, g1, b1, r2, g2, b2, r3, g3, b3, r4, g4, b4; // barvy sousedn�ch pixel� do rij, gij, bij (i,j=0,1)
Color c;
c = B1.GetPixel(iu, iv); // vlevo naho�e
r1 = c.R; g1 = c.G; b1 = c.B;
c = B1.GetPixel(iu, iv + 1); // vlevo dole
r2 = c.R; g2 = c.G; b2 = c.B;
c = B1.GetPixel(iu + 1, iv); // vpravo naho�e
r3 = c.R; g3 = c.G; b3 = c.B;
c = B1.GetPixel(iu + 1, iv + 1); // vpravo dole
r4 = c.R; g4 = c.G; b4 = c.B;
// biline�rn� interpolace: v�po�et v�en�ho pr�m�ru
// ry1 = r1*dy1 + r2*dy0, ry2 = r3*dy1 + r4*dy0, r = ry1*dx1 + ry2*dx0
int r = (int)(r1 * u1 * v1 + r2 * u1 * v0 + r3 * u0 * v1 + r4 * u0 * v0);
int g = (int)(g1 * u1 * v1 + g2 * u1 * v0 + g3 * u0 * v1 + g4 * u0 * v0);
int b = (int)(b1 * u1 * v1 + b2 * u1 * v0 + b3 * u0 * v1 + b4 * u0 * v0);
B2.SetPixel(x, y, Color.FromArgb(255, (byte)r, (byte)g, (byte)b));
}
}
}
}
private static void MapPixel(WarpOperace warp_op, int x, int y, out double u, out double v)
{
double xs = B2.Width / 2.0; // st�ed
double ys = B2.Height / 2.0;
double dx, dy, r1, r2; // pro n�kter� transformace
switch (warp_op)
{
case WarpOperace.Identita:
u = x;
v = y;
break;
case WarpOperace.Prevraceni: // podle svisl� osy
u = B2.Width - x;
v = y;
break;
case WarpOperace.Meritko: // zm�na m���tka
double meritko = (double)B1.Width / (double)B2.Width; // pro < 1 zvetsi, > 1 zmensi
u = meritko * x;
v = meritko * y;
//u = meritko * (x - xs) + xs;
//v = meritko * (y - ys) + ys;
break;
case WarpOperace.Vlna:
double A = 10; // amplituda (10)
double T = 50; // perioda (50)
u = x;
v = y - A * (Math.Sin(x / T * Math.PI) + 1) + 5;
break;
case WarpOperace.DvojitaVlna:
u = x - 10 * (Math.Sin(y / 50.0 * Math.PI) + 1) + 5;
v = y - 10 * (Math.Sin(x / 50.0 * Math.PI) + 1) + 5;
break;
case WarpOperace.Trojuhelnik:
dx = xs - x;
dx = dx * ys * 2 / (y + 1);
u = xs - dx;
v = y;
break;
case WarpOperace.Krouceni:
dx = xs - x;
dx = dx * (Math.Sin(y / 50.0 * Math.PI) / 2 + 1.5);
u = xs - dx;
v = y;
break;
case WarpOperace.RybiOko:
dx = x - xs;
dy = y - ys;
r1 = Math.Sqrt(dx * dx + dy * dy);
if (r1 == 0)
{
u = xs; v = ys;
}
else
{
double rmax = xs * 1.5; // maxim�ln� dosah
r2 = rmax / 2 * (1 / (1 - r1 / rmax) - 1);
u = dx * r2 / r1 + xs;
v = dy * r2 / r1 + ys;
}
break;
case WarpOperace.Spirala:
const double K = 100.0; // konstanta u spir�ly (= 100)
dx = x - xs;
dy = y - ys;
r1 = Math.Sqrt(dx * dx + dy * dy);
if (r1 == 0)
{
u = 0; v = 0;
}
else
{
double theta = Math.Atan2(dx, dy) - r1 / K + Math.PI / 2.0;
u = r1 * Math.Cos(theta);
v = r1 * Math.Sin(theta);
}
u = u + xs;
v = v + ys;
break;
case WarpOperace.Oblouk:
dx = xs - x;
dx = dx * (10 + ys / (2 * y + 10));
u = xs - 0.1 * dx;
v = y;
break;
default: // soum�rnost pod�l st�edu
u = 2 * xs - x;
v = 2 * ys - y;
break;
}
}
