/// <summary>
///
/// </summary>
/// <param name="b"></param>
/// <param name="nType"></param>
/// <param name="nThreshold"></param>
/// <returns></returns>
public static bool EdgeDetectConvolution(Bitmap b, short nType, byte nThreshold)
{
ConvMatrix m = new ConvMatrix();
// I need to make a copy of this bitmap BEFORE I alter it 80)
Bitmap bTemp = (Bitmap)b.Clone();
switch (nType)
{
case EDGE_DETECT_SOBEL:
m.SetAll(0);
m.TopLeft = m.BottomLeft = 1;
m.TopRight = m.BottomRight = -1;
m.MidLeft = 2;
m.MidRight = -2;
m.Offset = 0;
break;
case EDGE_DETECT_PREWITT:
m.SetAll(0);
m.TopLeft = m.MidLeft = m.BottomLeft = -1;
m.TopRight = m.MidRight = m.BottomRight = 1;
m.Offset = 0;
break;
case EDGE_DETECT_KIRSH:
m.SetAll(-3);
m.Pixel = 0;
m.TopLeft = m.MidLeft = m.BottomLeft = 5;
m.Offset = 0;
break;
}
BitmapFilter.Conv3x3(b, m);
switch (nType)
{
case EDGE_DETECT_SOBEL:
m.SetAll(0);
m.TopLeft = m.TopRight = 1;
m.BottomLeft = m.BottomRight = -1;
m.TopMid = 2;
m.BottomMid = -2;
m.Offset = 0;
break;
case EDGE_DETECT_PREWITT:
m.SetAll(0);
m.BottomLeft = m.BottomMid = m.BottomRight = -1;
m.TopLeft = m.TopMid = m.TopRight = 1;
m.Offset = 0;
break;
case EDGE_DETECT_KIRSH:
m.SetAll(-3);
m.Pixel = 0;
m.BottomLeft = m.BottomMid = m.BottomRight = 5;
m.Offset = 0;
break;
}
BitmapFilter.Conv3x3(bTemp, m);
// 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 bmData2 = bTemp.LockBits(new Rectangle(0, 0, b.Width, b.Height), ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);
int stride = bmData.Stride;
System.IntPtr Scan0 = bmData.Scan0;
System.IntPtr Scan02 = bmData2.Scan0;
unsafe
{
byte* p = (byte*)(void*)Scan0;
byte* p2 = (byte*)(void*)Scan02;
int nOffset = stride - b.Width * 3;
int nWidth = b.Width * 3;
int nPixel = 0;
for (int y = 0; y < b.Height; ++y)
{
for (int x = 0; x < nWidth; ++x)
{
nPixel = (int)Math.Sqrt((p[0] * p[0]) + (p2[0] * p2[0]));
if (nPixel < nThreshold) nPixel = nThreshold;
if (nPixel > 255) nPixel = 255;
p[0] = (byte)nPixel;
++p;
++p2;
}
p += nOffset;
p2 += nOffset;
}
}
b.UnlockBits(bmData);
bTemp.UnlockBits(bmData2);
return true;
}
/// <summary>
///
/// </summary>
/// <param name="b"></param>
/// <returns></returns>
public static bool EmbossLaplacian(Bitmap b)
{
ConvMatrix m = new ConvMatrix();
m.SetAll(-1);
m.TopMid = m.MidLeft = m.MidRight = m.BottomMid = 0;
m.Pixel = 4;
m.Offset = 127;
return BitmapFilter.Conv3x3(b, m);
}
/// <summary>
///
/// </summary>
/// <param name="b"></param>
/// <param name="nWeight"></param>
/// <returns></returns>
public static bool Sharpen(Bitmap b, int nWeight /* default to 11*/ )
{
ConvMatrix m = new ConvMatrix();
m.SetAll(0);
m.Pixel = nWeight;
m.TopMid = m.MidLeft = m.MidRight = m.BottomMid = -2;
m.Factor = nWeight - 8;
return BitmapFilter.Conv3x3(b, m);
}
/// <summary>
///
/// </summary>
/// <param name="b"></param>
/// <param name="nWeight"></param>
/// <returns></returns>
public static bool MeanRemoval(Bitmap b, int nWeight /* default to 9*/ )
{
ConvMatrix m = new ConvMatrix();
m.SetAll(-1);
m.Pixel = nWeight;
m.Factor = nWeight - 8;
return BitmapFilter.Conv3x3(b, m);
}
/// <summary>
///
/// </summary>
/// <param name="b"></param>
/// <param name="nWeight"></param>
/// <returns></returns>
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);
}
/// <summary>
///
/// </summary>
/// <param name="b"></param>
/// <param name="nWeight"></param>
/// <returns></returns>
public static bool Smooth(Bitmap b, int nWeight /* default to 1 */)
{
ConvMatrix m = new ConvMatrix();
m.SetAll(1);
m.Pixel = nWeight;
m.Factor = nWeight + 8;
return BitmapFilter.Conv3x3(b, m);
}