/// <summary>
/// 去除区域噪音，联通域降噪方式，去除连通点数小于阀值的连通区域
/// </summary>
/// <param name="binBytes">二进制数组</param>
/// <param name="gray">灰度值</param>
/// <param name="minAreaPoints">噪点阀值</param>
/// <returns></returns>
public static byte[,] ClearNoiseArea(this byte[,] binBytes, byte gray, int minAreaPoints)
{
int width = binBytes.GetLength(0), height = binBytes.GetLength(1);
byte[,] newBinBytes = binBytes.Copy();
// 遍历所有点，是黑点0，把与黑点连通的所有点灰度都改为1，下一个连通区域改为2，直到所有连通区域都标记完毕
Dictionary <byte, Point[]> areaPointDict = new Dictionary <byte, Point[]>();
byte setGray = 1;
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
if (IsBlack(newBinBytes[x, y]))
{
newBinBytes.FloodFill(new Point(x, y), setGray, out Point[] setPoints);
areaPointDict.Add(setGray, setPoints);
setGray++;
if (setGray >= 255)
{
setGray = 254;
}
}
}
}
// 筛选出区域点数小于阈值的区域，将原图相应点设置为白色
List <Point[]> pointsList =
areaPointDict.Where(m => m.Value.Length < minAreaPoints).Select(m => m.Value).ToList();
foreach (var points in pointsList)
{
foreach (var point in points)
{
binBytes[point.X, point.Y] = 255;
}
}
return(binBytes);
}