/// <summary>
/// Mean Filter
/// </summary>
/// <param name="sourceBitmap">Set source Bitmap</param>
/// <param name="meanSize">Set mean size</param>
/// <returns></returns>
public static System.Drawing.Bitmap MeanFilter(this System.Drawing.Bitmap sourceBitmap,
int meanSize)
{
byte[] pixelBuffer = sourceBitmap.GetByteArray();
byte[] resultBuffer = new byte[pixelBuffer.Length];
double blue = 0.0, green = 0.0, red = 0.0;
double factor = 1.0 / (meanSize * meanSize);
int imageStride = sourceBitmap.Width * 4;
int filterOffset = meanSize / 2;
int calcOffset = 0, filterY = 0, filterX = 0;
for (int k = 0; k + 4 < pixelBuffer.Length; k += 4)
{
blue = 0; green = 0; red = 0;
filterY = -filterOffset;
filterX = -filterOffset;
while (filterY <= filterOffset)
{
calcOffset = k + (filterX * 4) +
(filterY * imageStride);
calcOffset = (calcOffset < 0 ? 0 :
(calcOffset >= pixelBuffer.Length - 2 ?
pixelBuffer.Length - 3 : calcOffset));
blue += pixelBuffer[calcOffset];
green += pixelBuffer[calcOffset + 1];
red += pixelBuffer[calcOffset + 2];
filterX++;
if (filterX > filterOffset)
{
filterX = -filterOffset;
filterY++;
}
}
resultBuffer[k] = ClipByte(factor * blue);
resultBuffer[k + 1] = ClipByte(factor * green);
resultBuffer[k + 2] = ClipByte(factor * red);
resultBuffer[k + 3] = 255;
}
return(resultBuffer.GetImage(sourceBitmap.Width, sourceBitmap.Height));
}
/// <summary>
/// Boolean Edge Detection Filter
/// </summary>
/// <param name="sourceBitmap">Set source Bitmap</param>
/// <param name="edgeFactor">Set edge factor</param>
/// <returns></returns>
public static System.Drawing.Bitmap BooleanEdgeDetectionFilter(
this System.Drawing.Bitmap sourceBitmap, float edgeFactor)
{
byte[] pixelBuffer = sourceBitmap.GetByteArray();
byte[] resultBuffer = new byte[pixelBuffer.Length];
Buffer.BlockCopy(pixelBuffer, 0, resultBuffer,
0, pixelBuffer.Length);
List <string> edgeMasks = GetBooleanEdgeMasks();
int imageStride = sourceBitmap.Width * 4;
int matrixMean = 0, pixelTotal = 0;
int filterY = 0, filterX = 0, calcOffset = 0;
string matrixPatern = String.Empty;
for (int k = 0; k + 4 < pixelBuffer.Length; k += 4)
{
matrixPatern = String.Empty;
matrixMean = 0; pixelTotal = 0;
filterY = -1; filterX = -1;
while (filterY < 2)
{
calcOffset = k + (filterX * 4) +
(filterY * imageStride);
calcOffset = (calcOffset < 0 ? 0 :
(calcOffset >= pixelBuffer.Length - 2 ?
pixelBuffer.Length - 3 : calcOffset));
matrixMean += pixelBuffer[calcOffset];
matrixMean += pixelBuffer[calcOffset + 1];
matrixMean += pixelBuffer[calcOffset + 2];
filterX += 1;
if (filterX > 1)
{
filterX = -1; filterY += 1;
}
}
matrixMean = matrixMean / 9;
filterY = -1; filterX = -1;
while (filterY < 2)
{
calcOffset = k + (filterX * 4) +
(filterY * imageStride);
calcOffset = (calcOffset < 0 ? 0 :
(calcOffset >= pixelBuffer.Length - 2 ?
pixelBuffer.Length - 3 : calcOffset));
pixelTotal = pixelBuffer[calcOffset];
pixelTotal += pixelBuffer[calcOffset + 1];
pixelTotal += pixelBuffer[calcOffset + 2];
matrixPatern += (pixelTotal > matrixMean
? "1" : "0");
filterX += 1;
if (filterX > 1)
{
filterX = -1; filterY += 1;
}
}
if (edgeMasks.Contains(matrixPatern))
{
resultBuffer[k] =
ClipByte(resultBuffer[k] * edgeFactor);
resultBuffer[k + 1] =
ClipByte(resultBuffer[k + 1] * edgeFactor);
resultBuffer[k + 2] =
ClipByte(resultBuffer[k + 2] * edgeFactor);
}
}
return(resultBuffer.GetImage(sourceBitmap.Width, sourceBitmap.Height));
}
