原文:Win8 Metro(C#)数字图像处理–2.37Wallis图象锐化
[函数名称]
Wallis图象锐化 WallisSharpen(WriteableBitmap src)
[算法说明]
Wallis锐化算法是在拉普拉斯算子的基础上，考虑人的视觉特性中包含一个对数环节，因此在锐化时，采用对数处理的方法进行改进，公式如下：
<strong><span style="font-size:14px;">[函数代码]</span></strong>
/// <summary>
/// Wallis sharpen process.
/// </summary>
/// <param name="src">The source image.</param>
/// <returns></returns>
public static WriteableBitmap WallisSharpen(WriteableBitmap src)////37Wallis锐化函数
{
if (src != null)
{
int w = src.PixelWidth;
int h = src.PixelHeight;
WriteableBitmap sharpenImage = new WriteableBitmap(w, h);
byte[] temp = src.PixelBuffer.ToArray();
byte[] tempMask = (byte[])temp.Clone();
double b = 0, g = 0, r = 0, srR = 0, srG = 0, srB = 0;
for (int j = 1; j < h - 1; j++)
{
for (int i = 4; i < w * 4 - 4; i += 4)
{ srB = tempMask[i + j * w * 4];
srG = tempMask[i + 1 + j * w * 4];
srR = tempMask[i + 2 + j * w * 4];
b = 46*Math.Abs(5 * Math .Log(srB+1) - Math .Log(tempMask[i - 4 + j * w * 4]+1) - Math .Log(tempMask[i + 4 + j * w * 4]+1) - Math .Log(tempMask[i + (j - 1) * w * 4]+1) - Math .Log(tempMask[i + (j + 1) * w * 4]+1));
g = 46*Math.Abs(5 * Math .Log(srG+1) - Math .Log(tempMask[i - 4 + 1 + j * w * 4]+1) - Math .Log(tempMask[i + 4 + 1 + j * w * 4]+1) - Math .Log(tempMask[i + 1 + (j - 1) * w * 4]+1) - Math .Log(tempMask[i + 1 + (j + 1) * w * 4]+1));
r = 46*Math.Abs(5 * Math .Log(srR+1) - Math .Log(tempMask[i - 4 + 2 + j * w * 4]+1) - Math .Log(tempMask[i + 4 + 2 + j * w * 4]+1) - Math .Log(tempMask[i + 2 + (j - 1) * w * 4]+1) - Math .Log(tempMask[i + 2 + (j + 1) * w * 4]+1));
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; srR = 0; srG = 0; srB = 0;
}
}
Stream sTemp = sharpenImage.PixelBuffer.AsStream();
sTemp.Seek(0, SeekOrigin.Begin);
sTemp.Write(temp, 0, w * 4 * h);
return sharpenImage;
}
else
{
return null;
}
}
<strong><span style="font-size:14px;">[图象效果]</span></strong>
