我在 SO 上找到了一些很棒的代码，并在我的应用程序中实现了它，虽然它正在“工作”，但模糊效果还不够强大，无法真正意识到（没有非常关注它）它实际上模糊了任何东西。
代码是（很长，抱歉）：
Bitmap screenshot = null;
void BlurForm()
{
/*
The best time (I assume) is to change the blur when the user as left the window,
as opposed to doing it when they want to open the window, since this may be a
little intensive.
*/
screenshot = null;
blurred.Image = null; // This variable is the PictureBox that's on the Form
screenshot = Screenshot.TakeSnapshot(this);
BitmapFilter.GaussianBlur(screenshot, 4);
blurred.Image = screenshot;
blurred.SendToBack();
}
public class ConvMatrix
{
public int TopLeft = 0, TopMid = 0, TopRight = 0;
public int MidLeft = 0, Pixel = 1, MidRight = 0;
public int BottomLeft = 0, BottomMid = 0, BottomRight = 0;
public int Factor = 1;
public int Offset = 0;
public void SetAll(int nVal)
{
TopLeft = TopMid = TopRight = MidLeft = Pixel = MidRight = BottomLeft = BottomMid = BottomRight = nVal;
}
}
public class BitmapFilter
{
private static bool Conv3x3(Bitmap b, ConvMatrix m)
{
// Avoid divide by zero errors
if (0 == m.Factor) return false;
Bitmap bSrc = (Bitmap)b.Clone();
// GDI+ still lies to us - the return format is BGR, NOT RGB.
BitmapData bmData = b.LockBits(new Rectangle(0, 0, b.Width, b.Height), ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);
BitmapData bmSrc = bSrc.LockBits(new Rectangle(0, 0, bSrc.Width, bSrc.Height), ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);
int stride = bmData.Stride;
int stride2 = stride * 2;
System.IntPtr Scan0 = bmData.Scan0;
System.IntPtr SrcScan0 = bmSrc.Scan0;
unsafe
{
byte* p = (byte*)(void*)Scan0;
byte* pSrc = (byte*)(void*)SrcScan0;
int nOffset = stride + 6 - b.Width * 3;
int nWidth = b.Width - 2;
int nHeight = b.Height - 2;
int nPixel;
for (int y = 0; y < nHeight; ++y)
{
for (int x = 0; x < nWidth; ++x)
{
nPixel = ((((pSrc[2] * m.TopLeft) + (pSrc[5] * m.TopMid) + (pSrc[8] * m.TopRight) +
(pSrc[2 + stride] * m.MidLeft) + (pSrc[5 + stride] * m.Pixel) + (pSrc[8 + stride] * m.MidRight) +
(pSrc[2 + stride2] * m.BottomLeft) + (pSrc[5 + stride2] * m.BottomMid) + (pSrc[8 + stride2] * m.BottomRight)) / m.Factor) + m.Offset);
if (nPixel < 0) nPixel = 0;
if (nPixel > 255) nPixel = 255;
p[5 + stride] = (byte)nPixel;
nPixel = ((((pSrc[1] * m.TopLeft) + (pSrc[4] * m.TopMid) + (pSrc[7] * m.TopRight) +
(pSrc[1 + stride] * m.MidLeft) + (pSrc[4 + stride] * m.Pixel) + (pSrc[7 + stride] * m.MidRight) +
(pSrc[1 + stride2] * m.BottomLeft) + (pSrc[4 + stride2] * m.BottomMid) + (pSrc[7 + stride2] * m.BottomRight)) / m.Factor) + m.Offset);
if (nPixel < 0) nPixel = 0;
if (nPixel > 255) nPixel = 255;
p[4 + stride] = (byte)nPixel;
nPixel = ((((pSrc[0] * m.TopLeft) + (pSrc[3] * m.TopMid) + (pSrc[6] * m.TopRight) +
(pSrc[0 + stride] * m.MidLeft) + (pSrc[3 + stride] * m.Pixel) + (pSrc[6 + stride] * m.MidRight) +
(pSrc[0 + stride2] * m.BottomLeft) + (pSrc[3 + stride2] * m.BottomMid) + (pSrc[6 + stride2] * m.BottomRight)) / m.Factor) + m.Offset);
if (nPixel < 0) nPixel = 0;
if (nPixel > 255) nPixel = 255;
p[3 + stride] = (byte)nPixel;
p += 3;
pSrc += 3;
}
p += nOffset;
pSrc += nOffset;
}
}
b.UnlockBits(bmData);
bSrc.UnlockBits(bmSrc);
return true;
}
public static bool GaussianBlur(Bitmap b, int nWeight /* default to 4*/)
{
ConvMatrix m = new ConvMatrix();
m.SetAll(1);
m.Pixel = nWeight;
m.TopMid = m.MidLeft = m.MidRight = m.BottomMid = 2;
m.Factor = nWeight + 12;
return BitmapFilter.Conv3x3(b, m);
}
}
class Screenshot
{
public static Bitmap TakeSnapshot(Control ctl)
{
Bitmap bmp = new Bitmap(ctl.Size.Width, ctl.Size.Height);
using (Graphics g = System.Drawing.Graphics.FromImage(bmp))
{
g.CopyFromScreen(
ctl.PointToScreen(ctl.ClientRectangle.Location),
new Point(0, 0), ctl.ClientRectangle.Size
);
}
return bmp;
}
}
我已经尝试更改其中的每个值，我更改哪个值都没有关系，我只是无法让它具有更强的模糊效果。如何增加高斯模糊的强度？
表格是 80% 不透明的，所以你会看到的模糊效果是窗户壁纸或表格后面的任何东西 - 但模糊了。唯一的问题（正如我所说的）是模糊一点也不强。