public static bool Smooth(Bitmap b, int nWeight)
{
	ConvMatrix m = new ConvMatrix();
	m.SetAll(1);
	m.Pixel = nWeight;
	m.Factor = nWeight + 8;

	return  BitmapFilter.Conv3x3(b, m);
}


public static bool GaussianBlur(Bitmap b, int nWeight)
{
	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);
}



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 static bool Conv3x3(Bitmap b, ConvMatrix m)
{
	if (0 == m.Factor) return false;

	Bitmap bSrc = (Bitmap)b.Clone(); 

	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 - 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;
}