private static int K3MStep(int[,] map)
{
int pixelsThinned = 0,
mapWidth = map.GetLength(0),
mapHeight = map.GetLength(1);
List <(int x, int y)> border = new List <(int x, int y)>();
for (int x = 0; x < mapWidth; x++)
{
for (int y = 0; y < mapHeight; y++)
{
if (A0.Contains(PixelWeight(map, x, y)))
{
border.Add((x, y));
}
}
}
foreach (var(x, y) in border)
{
if (map[x, y] != 0 && A1.Contains(PixelWeight(map, x, y)))
{
map[x, y] = 0;
pixelsThinned++;
}
}
foreach (var(x, y) in border)
{
if (map[x, y] != 0 && A2.Contains(PixelWeight(map, x, y)))
{
map[x, y] = 0;
pixelsThinned++;
}
}
foreach (var(x, y) in border)
{
if (map[x, y] != 0 && A3.Contains(PixelWeight(map, x, y)))
{
map[x, y] = 0;
pixelsThinned++;
}
}
foreach (var(x, y) in border)
{
if (map[x, y] != 0 && A4.Contains(PixelWeight(map, x, y)))
{
map[x, y] = 0;
pixelsThinned++;
}
}
foreach (var(x, y) in border)
{
if (map[x, y] != 0 && A5.Contains(PixelWeight(map, x, y)))
{
map[x, y] = 0;
pixelsThinned++;
}
}
return(pixelsThinned);
}