原文:Win8 Metro(C#)数字图像处理--2.61哈哈镜效果
[函数名称]
哈哈镜效果函数 WriteableBitmap DistortingMirrorProcess(WriteableBitmap src, int x, int y)
[算法说明]
哈哈镜效果图像实际上是一种图像形变特效而已，对于这个特效，我们可以通过三角变换来实现。
1，对于哈哈镜效果变换，首先它有两个参数，原点坐标和特效影响因子。
对于图像中的像素点P(x,y)，假设原点坐标为X，Y，那么，根据三角函数变换可以得到：
当前像素P的相对坐标cX,cY:
/// <summary>
/// Distorting mirror process.
/// </summary>
/// <param name="src">The source image.</param>
/// <param name="x">Origin of coordinates in x direction.</param>
/// <param name="y">Origin of coordinates in y direction.</param>
/// <returns></returns>
public static WriteableBitmap DistortingMirrorProcess(WriteableBitmap src, int x, int y)////哈哈镜特效
{
if (src != null)
{
int w = src.PixelWidth;
int h = src.PixelHeight;
WriteableBitmap srcImage = new WriteableBitmap(w, h);
byte[] temp = src.PixelBuffer.ToArray();
byte[] tempMask = (byte[])temp.Clone();
int radius = 0;
double theta = 0;
int tX = 0;
int tY = 0;
int mapX = 0;
int mapY = 0;
int mapR=0;
for (int j = 0; j < h; j++)
{
for (int i = 0; i < w; i++)
{
tX = i - x;
tY = j - y;
theta = Math.Atan2((double)tY, (double)tX);
radius = (int)Math.Sqrt((double)(tX * tX + tY * tY));
mapR = (int)(Math.Sqrt((double)radius * 100));
mapX = x + (int)(mapR * Math.Cos(theta));
mapY = y + (int)(mapR * Math.Sin(theta));
temp[i * 4 + j * w * 4] = tempMask[mapX * 4 + mapY * w * 4];
temp[i * 4 + 1 + j * w * 4] = tempMask[mapX * 4 + 1 + mapY * w * 4];
temp[i * 4 + 2 + j * w * 4] = tempMask[mapX * 4 + 2 + mapY * w * 4];
}
}
Stream sTemp = srcImage.PixelBuffer.AsStream();
sTemp.Seek(0, SeekOrigin.Begin);
sTemp.Write(temp, 0, w * 4 * h);
return srcImage;
}
else
{
return null;
}
}
[图像效果]
