/// <summary>
/// Floyd-Steinberg error diffusion algorithm
/// </summary>
private void ErrorDiffusion()
{
dithering_texture = DirectBitmap.FromBitmap(original_texture.Bitmap);
int width = original_texture.Width;
int height = original_texture.Height;
int R, G, B;
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
Color px = dithering_texture.GetPixel(x, y);
R = FindClosestColor(px.R, Kr);
G = FindClosestColor(px.G, Kg);
B = FindClosestColor(px.B, Kb);
dithering_texture.SetPixel(x, y, Color.FromArgb(R, G, B));
float errr, errg, errb;
errr = (float)px.R - R;
errg = (float)px.G - G;
errb = (float)px.B - B;
if (x + 1 < width)
{
Color cx = dithering_texture.GetPixel(x + 1, y);
int r = cx.R + (int)errr * 7 / 16;
r = CorrectValue(r);
int g = cx.G + (int)errg * 7 / 16;
g = CorrectValue(g);
int b = cx.B + (int)errb * 7 / 16;
b = CorrectValue(b);
dithering_texture.SetPixel(x + 1, y, Color.FromArgb(r, g, b));
}
if (x - 1 >= 0 && y + 1 < height)
{
Color cx = dithering_texture.GetPixel(x - 1, y + 1);
int r = cx.R + (int)errr * 3 / 16;
r = CorrectValue(r);
int g = cx.G + (int)errg * 3 / 16;
g = CorrectValue(g);
int b = cx.B + (int)errb * 3 / 16;
b = CorrectValue(b);
dithering_texture.SetPixel(x - 1, y + 1, Color.FromArgb(r, g, b));
}
if (y + 1 < height)
{
Color cx = dithering_texture.GetPixel(x, y + 1);
int r = cx.R + (int)errr * 5 / 16;
r = CorrectValue(r);
int g = cx.G + (int)errg * 5 / 16;
g = CorrectValue(g);
int b = cx.B + (int)errb * 5 / 16;
b = CorrectValue(b);
dithering_texture.SetPixel(x, y + 1, Color.FromArgb(r, g, b));
}
if (x + 1 < width && y + 1 < height)
{
Color cx = dithering_texture.GetPixel(x + 1, y + 1);
int r = cx.R + (int)errr * 1 / 16;
r = CorrectValue(r);
int g = cx.G + (int)errg * 1 / 16;
g = CorrectValue(g);
int b = cx.B + (int)errb * 1 / 16;
b = CorrectValue(b);
dithering_texture.SetPixel(x + 1, y + 1, Color.FromArgb(r, g, b));
}
}
}
}
