我想用BitmapData 的方式处理图片 产生‘柔化’效果，下面是我写的一个函数：

Question

private void Image_Soften(){try{int Height = this.pictureBox1.Image.Height;int Width = this.pictureBox1.Image.Width;Bitmap bitmap = new Bitmap(Width, Height, PixelFormat.Format32bppRgb);Bitmap MyBitmap = (Bitmap)this.pictureBox1.Image;BitmapData oldData = MyBitmap.LockBits(new Rectangle(0, 0, Width, Height), ImageLockMode.ReadOnly, PixelFormat.Format32bppRgb);BitmapData newData = bitmap.LockBits(new Rectangle(0, 0, Width, Height), ImageLockMode.ReadWrite, PixelFormat.Format32bppRgb);unsafe{byte* plos = (byte*)(oldData.Scan0.ToPointer());byte* pbg = (byte*)(newData.Scan0.ToPointer());//高斯模板int[] Gauss ={ 1, 2, 1, 2, 4, 2, 1, 2, 1 };for (int i = 1; i < Width - 1;i ++ ){for (int j = 1; j < Height; j++){int r = 0, g = 0, b = 0;int Index = 0;for (int col = -1; col <= 1; col++)for (int row = -1; row <= 1; row++){  r += plos[0] * Gauss[Index];g += plos[1] * Gauss[Index];b += plos[2] * Gauss[Index];Index++;}r /= 16;g /= 16;b /= 16;//处理颜色值溢出r = r > 255 ? 255 : r;r = r < 0 ? 0 : r;g = g > 255 ? 255 : g;g = g < 0 ? 0 : g;b = b > 255 ? 255 : b;b = b < 0 ? 0 : b;pbg[0] = (byte) r;pbg[1] = (byte)g;pbg[2] = (byte)b;plos += 4;pbg += 4;}}bitmap.UnlockBits(newData);MyBitmap.UnlockBits(oldData);this.pictureBox1.Image = bitmap;}}catch (Exception ex){MessageBox.Show(ex.Message, "信息提示");}}不知道出了什么错，经过这个函数处理后，不报错。但是效果没出来。

Answer 1

问题在这里：
for (int col = -1; col <= 1; col++)
for (int row = -1; row <= 1; row++)
{
r += plos[0] * Gauss[Index];
g += plos[1] * Gauss[Index];
b += plos[2] * Gauss[Index];
Index++;
}

如果我理解得不错的话，高斯算法是要去取周围的点的值，计算出当前点的值的。
但是你这个地方9次读取原像素颜色时，都是读的本点的。加权累计之后的平均数，当然还是等于本点的值。 
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调好的程序在下面。
中间对于指针的变化方面有bug.我改为计算偏移的方式了。

还有，这个程序处理完之后，会自动为图片加一个黑边。原因是没有处理最外的像素。如果要处理最边上的像素，就要在值旧值时考虑是不是已经越出边界。

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private void Image_Soften()
{
try
{
int Height = this.pictureBox1.Image.Height;
int Width = this.pictureBox1.Image.Width;
Bitmap bitmap = new Bitmap(Width, Height, PixelFormat.Format32bppRgb);
Bitmap MyBitmap = (Bitmap)this.pictureBox1.Image;

BitmapData oldData = MyBitmap.LockBits(new Rectangle(0, 0, Width, Height), ImageLockMode.ReadOnly, PixelFormat.Format32bppRgb);
BitmapData newData = bitmap.LockBits(new Rectangle(0, 0, Width, Height), ImageLockMode.ReadWrite, PixelFormat.Format32bppRgb);
unsafe
{
byte* plos = (byte*)(oldData.Scan0.ToPointer());
byte* pbg = (byte*)(newData.Scan0.ToPointer());
//高斯模板
int[] Gauss = { 1, 2, 1, 2, 4, 2, 1, 2, 1 };
for (int i = 1; i < Width - 1; i++)
{
for (int j = 1; j < Height - 1; j++)
{
int r = 0, g = 0, b = 0;
int Index = 0;

for (int col = -1; col <= 1; col++)
{
for (int row = -1; row <= 1; row++)
{
int off = ((j + row) *(Width) + (i + col)) * 4;
r += plos[off + 0] * Gauss[Index];
g += plos[off + 1] * Gauss[Index];
b += plos[off + 2] * Gauss[Index];
Index++;
}
}
r /= 16;
g /= 16;
b /= 16;
//处理颜色值溢出
r = r > 255 ? 255 : r;
r = r < 0 ? 0 : r;
g = g > 255 ? 255 : g;
g = g < 0 ? 0 : g;
b = b > 255 ? 255 : b;
b = b < 0 ? 0 : b;
int off2 = (j * Width + i) * 4;
pbg[off2 + 0] = (byte)r;
pbg[off2 + 1] = (byte)g;
pbg[off2 + 2] = (byte)b;
}
}
bitmap.UnlockBits(newData);
MyBitmap.UnlockBits(oldData);
this.pictureBox1.Image = bitmap;
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "信息提示");
}
}