private Color Nearest(double x, double y)//最近邻插值
{
if (x < 0 || y < 0 || x >= picWidth2 - 1 || y >= picHeight2 - 1)
{
return(Color.FromArgb(0, 0, 0));//越界返回黑色
}
int x1 = (int)Math.Floor(x);
int y1 = (int)Math.Floor(y);
double u = x - x1;
double v = y - y1;
if (u >= 0.5)
{
x1 = x1 + 1;
}
if (v >= 0.5)
{
y1 = y1 + 1;
}
return(OriginalPic2.GetPixel(x1, y1));
}
private Color Bilinear(double x, double y)//双线性插值
{
if (x < 0 || y < 0 || x >= picWidth2 - 1 || y >= picHeight2 - 1)
{
return(Color.FromArgb(0, 0, 0));//越界返回黑色
}
double R, G, B;
int x1 = (int)Math.Floor(x);
int y1 = (int)Math.Floor(y);
double u = x - x1;
double v = y - y1;
Matrix M1 = new Matrix(1, 2);
M1[0, 0] = 1 - u; M1[0, 1] = u;
Matrix M3 = new Matrix(2, 1);
M3[0, 0] = 1 - v;
M3[1, 0] = v;
Matrix M2 = new Matrix(2, 2);//利用矩阵求出插值后像素点的R,G,B
M2[0, 0] = OriginalPic2.GetPixel(x1, y1).R; M2[0, 1] = OriginalPic2.GetPixel(x1, y1 + 1).R;
M2[1, 0] = OriginalPic2.GetPixel(x1 + 1, y1).R; M2[1, 1] = OriginalPic2.GetPixel(x1 + 1, y1 + 1).R;
R = ((M1 * M2) * M3)[0, 0];
M2[0, 0] = OriginalPic2.GetPixel(x1, y1).G; M2[0, 1] = OriginalPic2.GetPixel(x1, y1 + 1).G;
M2[1, 0] = OriginalPic2.GetPixel(x1 + 1, y1).G; M2[1, 1] = OriginalPic2.GetPixel(x1 + 1, y1 + 1).G;
G = ((M1 * M2) * M3)[0, 0];
M2[0, 0] = OriginalPic2.GetPixel(x1, y1).B; M2[0, 1] = OriginalPic2.GetPixel(x1, y1 + 1).B;
M2[1, 0] = OriginalPic2.GetPixel(x1 + 1, y1).B; M2[1, 1] = OriginalPic2.GetPixel(x1 + 1, y1 + 1).B;
B = ((M1 * M2) * M3)[0, 0];
return(Color.FromArgb((int)R, (int)G, (int)B));
}
private void TPSchangeNegative(Matrix A)//TPS反变换变形
{
Matrix T = new Matrix(1, 71);
Matrix F = new Matrix(1, 2);
double distance;
for (int i = 0; i < picWidth2; i++)
{
for (int j = 0; j < picHeight2; j++)
{
for (int k = 0; k < 68; k++)//对新图像里的每个点构造矩形求取f(x,y)映射到2图中
{
distance = Math.Pow(i - Pic1Cor[k, 0], 2) + Math.Pow(j - Pic1Cor[k, 1], 2);
if (distance == 0)
{
T[0, k] = 0;
}
else
{
T[0, k] = distance * Math.Log(distance);
}
}
T[0, 68] = 1;
T[0, 69] = i;
T[0, 70] = j;
F = T * A;
if ((int)F[0, 0] < 0 || (int)F[0, 1] < 0 || (int)F[0, 0] >= picWidth2 || (int)F[0, 1] >= picHeight2)
{
NewPic.SetPixel(i, j, Color.FromArgb(0, 0, 0));
}
else
{
NewPic.SetPixel(i, j, OriginalPic2.GetPixel((int)F[0, 0], (int)F[0, 1]));
}
}
}
}
private Color Bicubic(double x, double y)//双三次插值
{
if (x < 1 || y < 1 || x >= picWidth2 - 2 || y >= picHeight2 - 2)
{
return(Color.FromArgb(0, 0, 0));//越界返回黑色
}
double R, G, B;
int x1 = (int)Math.Floor(x);
int y1 = (int)Math.Floor(y);
double u = x - x1;
double v = y - y1;
Matrix M1 = new Matrix(1, 4);
M1[0, 0] = S(1 + u); M1[0, 1] = S(u); M1[0, 2] = S(u - 1); M1[0, 3] = S(u - 2);
Matrix M3 = new Matrix(1, 4);
M3[0, 0] = S(1 + v); M3[0, 1] = S(v); M3[0, 2] = S(v - 1); M3[0, 3] = S(v - 2);
Matrix M2_R = new Matrix(4, 4);
Matrix M2_G = new Matrix(4, 4);
Matrix M2_B = new Matrix(4, 4);
for (int i = 0; i < 4; i++)
{
for (int j = 0; j < 4; j++)
{
M2_R[i, j] = OriginalPic2.GetPixel(x1 - 1 + i, y1 - 1 + j).R;
M2_G[i, j] = OriginalPic2.GetPixel(x1 - 1 + i, y1 - 1 + j).G;
M2_B[i, j] = OriginalPic2.GetPixel(x1 - 1 + i, y1 - 1 + j).B;
}
}
R = (M1 * M2_R * (M3.Transpose()))[0, 0];
G = (M1 * M2_G * (M3.Transpose()))[0, 0];
B = (M1 * M2_B * (M3.Transpose()))[0, 0];
if (R < 0)
{
R = 0;
}
else if (R > 255)
{
R = 255;
}
if (G < 0)
{
G = 0;
}
else if (G > 255)
{
G = 255;
}
if (B < 0)
{
B = 0;
}
else if (B > 255)
{
B = 255;
}
return(Color.FromArgb((int)R, (int)G, (int)B));
}
