public static uint[] Conv3x3(uint[] data, int bpp, int width, int height, ConvMatrix m)
{
uint average = 0;
return Conv3x3(data, bpp, width, height, m, ref average, false, false);
}
public static uint[] Conv3x3(uint[] data, int bpp, int width, int height, ConvMatrix m, ref uint average, bool calculateAverage, bool cutEdges)
{
// Avoid divide by zero errors
if (0 == m.Factor)
return data;
if (width * height != data.Length)
throw new ArgumentException();
uint[] result = new uint[cutEdges ? (width - 1) * (height - 1) : data.Length];
uint maxValue = GetMaxValueForBitPix(bpp);
int nPixel;
double sum = 0;
const double FOUR_PIXEL_FACTOR = 9.0 / 4.0;
const double SIX_PIXEL_FACTOR = 9.0 / 6.0;
for (int y = 0; y < height; ++y)
{
for (int x = 0; x < width; ++x)
{
if (cutEdges && (x == 0 || y == 0 || x == width - 1 || y == height - 1))
continue;
if (y == 0 && x == 0)
{
// . . .
// . # #
// . # #
nPixel = (int)Math.Round((
(data[0] * m.Pixel) +
(data[1] * m.MidRight) +
(data[width] * m.BottomMid) +
(data[width + 1] * m.BottomRight)
) * FOUR_PIXEL_FACTOR);
}
else if (y == height - 1 && x == 0)
{
// . # #
// . # #
// . . .
nPixel = (int)Math.Round((
(data[width * (height - 2)] * m.TopMid) +
(data[width * (height - 2) + 1] * m.TopRight) +
(data[width * (height - 1)] * m.Pixel) +
(data[width * (height - 1) + 1] * m.MidRight)
) * FOUR_PIXEL_FACTOR);
}
else if (y == 0 && x == width - 1)
{
// . . .
// # # .
// # # .
nPixel = (int)Math.Round((
(data[width - 2] * m.MidLeft) +
(data[width - 1] * m.Pixel) +
(data[2 * width - 2] * m.BottomLeft) +
(data[2 * width - 1] * m.BottomMid)
) * FOUR_PIXEL_FACTOR);
}
else if (y == height - 1 && x == width - 1)
{
// # # .
// # # .
// . . .
nPixel = (int)Math.Round((
(data[width * height - width - 1] * m.TopLeft) +
(data[width * height - width - 2] * m.TopMid) +
(data[width * height - 2] * m.MidLeft) +
(data[width * height - 1] * m.Pixel)
) * FOUR_PIXEL_FACTOR);
}
else if (y == 0)
{
// . . .
// # # #
// # # #
nPixel = (int)Math.Round((
(data[x - 1 + y * width] * m.MidLeft) +
(data[x + y * width] * m.Pixel) +
(data[x + 1 + y * width] * m.MidRight) +
(data[x - 1 + (y + 1) * width] * m.BottomLeft) +
(data[x + (y + 1) * width] * m.BottomMid) +
(data[x + 1 + (y + 1) * width] * m.BottomRight)
) * SIX_PIXEL_FACTOR);
}
else if (x == 0)
{
// . # #
// . # #
// . # #
nPixel = (int)Math.Round((
(data[x + (y - 1) * width] * m.TopMid) +
(data[x + 1 + (y - 1) * width] * m.TopRight) +
(data[x + y * width] * m.Pixel) +
(data[x + 1 + y * width] * m.MidRight) +
(data[x + (y + 1) * width] * m.BottomMid) +
(data[x + 1 + (y + 1) * width] * m.BottomRight)
) * SIX_PIXEL_FACTOR);
}
else if (y == height - 1)
{
// # # #
// # # #
// . . .
nPixel = (int)Math.Round((
(data[x - 1 + (y - 1) * width] * m.TopLeft) +
(data[x + (y - 1) * width] * m.TopMid) +
(data[x + 1 + (y - 1) * width] * m.TopRight) +
(data[x - 1 + y * width] * m.MidLeft) +
(data[x + y * width] * m.Pixel) +
(data[x + 1 + y * width] * m.MidRight)
) * SIX_PIXEL_FACTOR);
}
else if (x == width - 1)
{
// # # .
// # # .
// # # .
nPixel = (int)Math.Round((
(data[x - 1 + (y - 1) * width] * m.TopLeft) +
(data[x + (y - 1) * width] * m.TopMid) +
(data[x - 1 + y * width] * m.MidLeft) +
(data[x + y * width] * m.Pixel) +
(data[x - 1 + (y + 1) * width] * m.BottomLeft) +
(data[x + (y + 1) * width] * m.BottomMid)
) * SIX_PIXEL_FACTOR);
}
else
{
// # # #
// # # #
// # # #
nPixel = (int)Math.Round(
(data[x - 1 + (y - 1) * width] * m.TopLeft) +
(data[x + (y - 1) * width] * m.TopMid) +
(data[x + 1 + (y - 1) * width] * m.TopRight) +
(data[x - 1 + y * width] * m.MidLeft) +
(data[x + y * width] * m.Pixel) +
(data[x + 1 + y * width] * m.MidRight) +
(data[x - 1 + (y + 1) * width] * m.BottomLeft) +
(data[x + (y + 1) * width] * m.BottomMid) +
(data[x + 1 + (y + 1) * width] * m.BottomRight));
}
if (cutEdges)
{
if (nPixel < 0)
result[(x - 1) + (y - 1) * width] = 0;
else if (nPixel > maxValue)
result[(x - 1) + (y - 1) * width] = maxValue;
else
result[(x - 1) + (y - 1) * width] = (uint)nPixel;
if (calculateAverage)
sum += result[(x - 1) + (y - 1) * width];
}
else
{
//if (x == 0 || y == 0 || x == width - 1 || y == height - 1)
// nPixel = (int)data[x + y * width];
if (nPixel < 0)
result[x + y * width] = 0;
else if (nPixel > maxValue)
result[x + y * width] = maxValue;
else
result[x + y * width] = (uint)nPixel;
if (calculateAverage)
sum += result[x + y * width];
}
}
}
if (calculateAverage)
average = (uint)Math.Round(sum / (width * height));
return result;
}
// http://www.student.kuleuven.be/~m0216922/CG/filtering.html
public static uint[,] Conv3x3(uint[,] data, int bpp, ConvMatrix m)
{
// Avoid divide by zero errors
if (0 == m.Factor)
return data;
uint[,] result = new uint[data.GetLength(0), data.GetLength(1)];
int nWidth = data.GetLength(0) - 2;
int nHeight = data.GetLength(1) - 2;
int nPixel;
for (int y = 0; y < nHeight; ++y)
{
for (int x = 0; x < nWidth; ++x)
{
nPixel = (int)Math.Round((((data[x, y] * m.TopLeft) +
(data[x + 1, y] * m.TopMid) +
(data[x + 2, y] * m.TopRight) +
(data[x, y + 1] * m.MidLeft) +
(data[x + 1, y + 1] * m.Pixel) +
(data[x + 2, y + 1] * m.MidRight) +
(data[x, y + 2] * m.BottomLeft) +
(data[x + 1, y + 2] * m.BottomMid) +
(data[x + 2, y + 2] * m.BottomRight))
/ m.Factor) + m.Offset);
uint maxValue = GetMaxValueForBitPix(bpp);
if (nPixel < 0)
result[x + 1, y + 1] = 0;
else if (nPixel > maxValue)
result[x + 1, y + 1] = maxValue;
else
result[x + 1, y + 1] = (uint)nPixel;
}
}
return result;
}