[函数名称]

图像Prewitt边缘检测函数PrewittEdgeProcess(WriteableBitmap src)

[函数代码]

///<summary>

/// Smooth edge detection.

///</summary>

///<param name="src">Source image.</param>

///<returns></returns>

publicstaticWriteableBitmap PrewittEdgeProcess(WriteableBitmap src)14 Prewitt边缘检测

{

if(src!=null )

{

int w = src.PixelWidth;

int h = src.PixelHeight;

WriteableBitmap smoothImage =newWriteableBitmap(w,h);

byte[] temp = src.PixelBuffer.ToArray();

byte[] tempMask = (byte[])temp.Clone();

int b = 0, g = 0, r = 0;

for (int j = 1; j < h - 1; j++)

{

for (int i = 4; i < w * 4 - 4; i += 4)

{

if (i == 0 || i == w - 4 || j == 0 || j == h - 1)

{

temp[i + j * w * 4] = (byte)0;

temp[i + 1 + j * w * 4] = (byte)0;

temp[i + 2 + j * w * 4] = (byte)0;

}

else

{

b =Math.Abs(tempMask[i - 4 + (j - 1) * w * 4] + tempMask[i + (j - 1) * w * 4] + tempMask[i + 4 + (j - 1) * w * 4]

- tempMask[i - 4 + (j + 1) * w * 4] - tempMask[i + (j + 1) * w * 4] - tempMask[i + 4 + (j + 1) * w * 4]) +

Math.Abs(tempMask[i + 4 + (j - 1) * w * 4] + tempMask[i + 4 + j * w * 4] + tempMask[i + 4 + (j + 1) * w * 4]

- tempMask[i - 4 + (j - 1) * w * 4] - tempMask[i - 4 + j * w * 4] - tempMask[i - 4 + (j + 1) * w * 4]);

g =Math.Abs(tempMask[i - 4 + 1 + (j - 1) * w * 4] + tempMask[i + 1 + (j - 1) * w * 4] + tempMask[i + 1 + 4 + (j - 1) * w * 4]

- tempMask[i - 4 + 1 + (j + 1) * w * 4] - tempMask[i + 1 + (j + 1) * w * 4] - tempMask[i + 1 + 4 + (j + 1) * w * 4]) +

Math.Abs(tempMask[i + 1 + 4 + (j - 1) * w * 4] + tempMask[i + 1 + 4 + j * w * 4] + tempMask[i + 1 + 4 + (j + 1) * w * 4]

- tempMask[i - 4 + 1 + (j - 1) * w * 4] - tempMask[i - 4 + 1 + j * w * 4] - tempMask[i - 4 + 1 + (j + 1) * w * 4]);

r =Math.Abs(tempMask[i - 4 + 2 + (j - 1) * w * 4] + tempMask[i + 2 + (j - 1) * w * 4] + tempMask[i + 4 + 2 + (j - 1) * w * 4]

- tempMask[i - 4 + 2 + (j + 1) * w * 4] - tempMask[i + 2 + (j + 1) * w * 4] - tempMask[i + 4 + 2 + (j + 1) * w * 4]) +

Math.Abs(tempMask[i + 4 + 2 + (j - 1) * w * 4] + tempMask[i + 4 + 2 + j * w * 4] + tempMask[i + 4 + 2 + (j + 1) * w * 4]

- tempMask[i - 4 + 2 + (j - 1) * w * 4] - tempMask[i - 4 + 2 + j * w * 4] - tempMask[i - 4 + 2 + (j + 1) * w * 4]);

temp[i + j * w * 4] = (byte)(b > 0 ? (b < 255 ? b : 255) : 0);

temp[i + 1 + j * w * 4] = (byte)(g > 0 ? (g < 255 ? g : 255) : 0);

temp[i + 2 + j * w * 4] = (byte)(r > 0 ? (r < 255 ? r : 255) : 0);

}

b = 0; g = 0; r = 0;

}

}

Stream sTemp = smoothImage.PixelBuffer.AsStream();

sTemp.Seek(0,SeekOrigin.Begin);

sTemp.Write(temp, 0, w * 4 * h);

return smoothImage;

}

else

{

returnnull;

}

}