[函数名称]
Ostu法图像二值化 WriteableBitmap OstuThSegment(WriteableBitmap src)
[函数代码]
////// Ostu method of image segmention. /// /// The source image. ///public static WriteableBitmap OstuThSegment(WriteableBitmap src) Ostu法阈值分割 { if (src != null) { int w = src.PixelWidth; int h = src.PixelHeight; WriteableBitmap dstImage = new WriteableBitmap(w, h); byte[] temp = src.PixelBuffer.ToArray(); byte[] tempMask = (byte[])temp.Clone(); //定义灰度图像信息存储变量 int[] srcData = new int[w * h]; //定义阈值变量 int Th = 0; ; //定义背景和目标像素数目变量N1,N2，灰度变量U1,U2，灰度和变量Sum1,Sum2，临时缓存变量Temp int N1 = 0, N2 = 0, Sum1 = 0, Sum2 = 0; //定义背景和目标像素比例变量W1,W2，图像整体平均灰度变量U，方差变量g，对比阈值变量TT double W1 = 0, W2 = 0, U1 = 0, U2 = 0, g = 0, TT = 0; for (int j = 0; j < h; j++) { for (int i = 0; i < w; i++) { srcData[i + j * w] = (int)((double)tempMask[i * 4 + j * w * 4] * 0.114 + (double)tempMask[i * 4 + 1 + j * w * 4] * 0.587 + (double)tempMask[i * 4 + 2 + j * w * 4] * 0.299); } } //寻找最大类间方差 for (int T = 0; T <= 255; T++) { for (int i = 0; i < srcData.Length; i++) { if (srcData[i] > T) { N2++; Sum2 += srcData[i]; } else { N1++; Sum1 += srcData[i]; } } W1 = (double)(N1 / (N1 + N2)); W2 = (double)(1.0 - W1); U1 = (N1 == 0 ? 0.0 : (Sum1 / N1)); U2 = (N2 == 0 ? 0.0 : (Sum2 / N2)); g = N1 * N2 * (U1 - U2) * (U1 - U2); if (g > TT) { TT = g; Th = T; } N1 = 0; N2 = 0; Sum1 = 0; Sum2 = 0; W1 = 0.0; W2 = 0.0; U1 = 0.0; U2 = 0.0; g = 0.0; } for (int j = 0; j < h; j++) { for (int i = 0; i < w; i++) { temp[i * 4 + j * w * 4] = temp[i * 4 + 1 + j * w * 4] = temp[i * 4 + 2 + j * w * 4] = (byte)(srcData[i + j * w] < Th ? 0 : 255); } } Stream sTemp = dstImage.PixelBuffer.AsStream(); sTemp.Seek(0, SeekOrigin.Begin); sTemp.Write(temp, 0, w * 4 * h); return dstImage; } else { return null; } }
