原文:
图像滤镜艺术---Wave滤镜
Wave Filter水波滤镜
水波滤镜是通过坐标变换来模拟水波效果，使图像呈现出水波的特效。这个滤镜有一个可调参数：水波的扭曲程度。
代码如下;
//
///
/// Wave Filter
///
/// Source image.
/// The degree of wave,0-100.
/// The result image.
private Bitmap WaveFilterProcess(Bitmap srcBitmap, int degree)
{
Bitmap a = new Bitmap(srcBitmap);
int w = a.Width;
int h = a.Height;
degree = degree * 32 / 100;
degree = Math.Max(0, Math.Min(32, degree));
Bitmap dst = new Bitmap(w, h);
System.Drawing.Imaging.BitmapData srcData = a.LockBits(new Rectangle(0, 0, w, h), System.Drawing.Imaging.ImageLockMode.ReadWrite, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
System.Drawing.Imaging.BitmapData dstData = dst.LockBits(new Rectangle(0, 0, w, h), System.Drawing.Imaging.ImageLockMode.ReadWrite, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
unsafe
{
byte* pIn = (byte*)srcData.Scan0.ToPointer();
byte* pOut = (byte*)dstData.Scan0.ToPointer();
byte* p = null;
int stride = srcData.Stride - w * 4;
int newX = 0, newY = 0;
double PI2 = Math.PI * 2.0;
for (int y = 0; y < h; y++)
{
for (int x = 0; x < w; x++)
{
newX = (int)(degree * Math.Sin(PI2 * y / 128.0)) + x;
newY = (int)(degree * Math.Cos(PI2 * x / 128.0)) + y;
newX = Math.Min(w - 1, Math.Max(0, newX));
newY = Math.Min(h - 1, Math.Max(0, newY));
p = pIn + newY * srcData.Stride + newX * 4;
pOut[0] = (byte)p[0];
pOut[1] = (byte)p[1];
pOut[2] = (byte)p[2];
pOut[3] = (byte)255;
pOut += 4;
}
pOut += stride;
}
a.UnlockBits(srcData);
dst.UnlockBits(dstData);
}
return dst;
}
效果图如下：
原图
水波滤镜效果图
最后放上一个完整的C#版程序Demo下载地址：http://www.zealpixel.com/thread-59-1-1.html
