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：

[函数代码]
///

/// Wallis sharpen process. ///

/// The source image.
///
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;  
        }  
    }  

[图象效果]