static Bitmap FilterLite(Bitmap source, PixelFormat format)
{
var result = new PrecisionBitmap(TileBuffer(source));
for (int y = 0; y < result.Height; y++)
{
for (int x = 0; x < result.Width; x++)
{
PrecisionColor oldPixel = result.GetPixel(x, y);
PrecisionColor newPixel = ApproximatePixel(oldPixel, format);
PrecisionColor error = oldPixel - newPixel;
result.SetPixel(x, y, newPixel);
int xP1 = GetActualPosition(x + 1, result.Width);
int xM1 = GetActualPosition(x - 1, result.Width);
int yP1 = GetActualPosition(y + 1, result.Height);
result.SetPixel(xP1, y, result.GetPixel(xP1, y) + error * 0.5);
result.SetPixel(xM1, yP1, result.GetPixel(xM1, yP1) + error * 0.25);
result.SetPixel(x, yP1, result.GetPixel(x, yP1) + error * 0.25);
}
}
return(result.ToBitmap());
}
static PrecisionColor ApproximatePixel(PrecisionColor color, PixelFormat format)
{
int rM;
int gM;
int bM;
if (format == PixelFormat.Format16bppRgb565)
{
rM = bM = 8;
gM = 4;
}
else if (format == PixelFormat.Format16bppRgb555 ||
format == PixelFormat.Format16bppArgb1555)
{
rM = gM = bM = 8;
}
else
{
throw new ArgumentOutOfRangeException("format", "Only supported formats are RGB555, RGB565 and ARGB1555.");
}
var r = (int)(color.R / rM) * rM;
var g = (int)(color.G / gM) * gM;
var b = (int)(color.B / bM) * bM;
return(new PrecisionColor(r, g, b));
}
static Bitmap Sierra3(Bitmap source, PixelFormat format)
{
var result = new PrecisionBitmap(TileBuffer(source));
double weight2 = 2 / 32d;
double weight3 = 3 / 32d;
double weight4 = 4 / 32d;
double weight5 = 5 / 32d;
for (int y = 0; y < result.Height; y++)
{
for (int x = 0; x < result.Width; x++)
{
PrecisionColor oldPixel = result.GetPixel(x, y);
PrecisionColor newPixel = ApproximatePixel(oldPixel, format);
PrecisionColor error = oldPixel - newPixel;
result.SetPixel(x, y, newPixel);
int xP1 = GetActualPosition(x + 1, result.Width);
int xP2 = GetActualPosition(x + 2, result.Width);
int xM1 = GetActualPosition(x - 1, result.Width);
int xM2 = GetActualPosition(x - 2, result.Width);
int yP1 = GetActualPosition(y + 1, result.Height);
int yP2 = GetActualPosition(y + 2, result.Height);
result.SetPixel(xP1, y, result.GetPixel(xP1, y) + error * weight5);
result.SetPixel(xP2, y, result.GetPixel(xP2, y) + error * weight3);
result.SetPixel(xM2, yP1, result.GetPixel(xM2, yP1) + error * weight2);
result.SetPixel(xM1, yP1, result.GetPixel(xM1, yP1) + error * weight4);
result.SetPixel(x, yP1, result.GetPixel(x, yP1) + error * weight5);
result.SetPixel(xP1, yP1, result.GetPixel(xP1, yP1) + error * weight4);
result.SetPixel(xP2, yP1, result.GetPixel(xP2, yP1) + error * weight2);
result.SetPixel(xM1, yP2, result.GetPixel(xM1, yP2) + error * weight2);
result.SetPixel(x, yP2, result.GetPixel(x, yP2) + error * weight3);
result.SetPixel(xP1, yP2, result.GetPixel(xP1, yP2) + error * weight2);
}
}
return(result.ToBitmap());
}
public void SetPixel(int x, int y, PrecisionColor cIn)
{
rgbValues[(y * Width + x) * 3] = cIn.B;
rgbValues[(y * Width + x) * 3 + 1] = cIn.G;
rgbValues[(y * Width + x) * 3 + 2] = cIn.R;
}
