反色，霓虹灯，浮雕

1。反色

Bitmap desc = new Bitmap(source.Width, source.Height);
BitmapData sourcedata = source.LockBits(new Rectangle(0, 0, source.Width, source.Height), 
                ImageLockMode.ReadOnly, PixelFormat.Format24bppRgb);
BitmapData descdata = desc.LockBits(new Rectangle(0, 0, desc.Width, desc.Height),
                ImageLockMode.WriteOnly, PixelFormat.Format24bppRgb);

unsafe
{
      byte* sourceptr = (byte*)sourcedata.Scan0;  
      byte* descptr = (byte*)descdata.Scan0;
      for (int x = 0; x < source.Height; x++)
      {
           for (int y = 0; y < source.Width; y++)
           {
                *(descptr++) = (byte)(255 - *(sourceptr++));
                *(descptr++) = (byte)(255 - *(sourceptr++));
                *(descptr++) = (byte)(255 - *(sourceptr++));
            }
            sourceptr += sourcedata.Stride - source.Width * 3;
            descptr += descdata.Stride - desc.Width * 3;
       }
}
source.UnlockBits(sourcedata);
desc.UnlockBits(descdata);

2。霓虹灯

Bitmap desc = new Bitmap(source.Width, source.Height);
BitmapData sourcedata = source.LockBits(new Rectangle(0, 0, source.Width, source.Height), 
                ImageLockMode.ReadOnly, PixelFormat.Format24bppRgb);
BitmapData descdata = desc.LockBits(new Rectangle(0, 0, desc.Width, desc.Height),
                ImageLockMode.WriteOnly, PixelFormat.Format24bppRgb);

unsafe
{
      byte* sourceptr = (byte*)sourcedata.Scan0;  
      byte* descptr = (byte*)descdata.Scan0;
      int step = source.Width * 3;
      double value;
      for (int x = 0; x < source.Height; x++)
      {
           for (int y = 0; y < source.Width; y++)
           {
                value = 2 * Math.Sqrt((*sourceptr - *(sourceptr + 3)) * (*sourceptr - *(sourceptr + 3)) +
                        (*sourceptr - *(sourceptr + step)) * (*sourceptr - *(sourceptr + step)));
                *(descptr++) = value > 255 ? (byte)255 : (byte)(value);
                sourceptr++;
            }
            sourceptr += sourcedata.Stride - source.Width * 3;
            descptr += descdata.Stride - desc.Width * 3;
       }
}
source.UnlockBits(sourcedata);
desc.UnlockBits(descdata);

3。浮雕

 Bitmap desc = new Bitmap(source.Width, source.Height);

BitmapData sourcedata = source.LockBits(new Rectangle(0, 0, source.Width, source.Height), 
                ImageLockMode.ReadOnly, PixelFormat.Format24bppRgb);
BitmapData descdata = desc.LockBits(new Rectangle(0, 0, desc.Width, desc.Height),
                ImageLockMode.WriteOnly, PixelFormat.Format24bppRgb);

unsafe
{
      byte* sourceptr = (byte*)sourcedata.Scan0;  
      byte* descptr = (byte*)descdata.Scan0;
      int step = (source.Width + 1) * 3;
      double value;
      for (int x = 0; x < source.Height; x++)
      {
           for (int y = 0; y < source.Width; y++)
           {
                value = Math.Abs(*(sourceptr - step) - *sourceptr + 128);
                *(descptr++) = value > 255 ? (byte)255 : (byte)(value);
                sourceptr++;
            }
            sourceptr += sourcedata.Stride - source.Width * 3;
            descptr += descdata.Stride - desc.Width * 3;
       }
}
source.UnlockBits(sourcedata);
desc.UnlockBits(descdata);