1.导入图像,并且将图像转灰度
using var img = new Image(_path);
using var grayImg = img.Convert();
2.自动二值化图像
using var inputGrayOut = new Image(grayImg.Size);
// 计算OTSU阈值
var threshold = CvInvoke.Threshold(grayImg, inputGrayOut, 0, 255, ThresholdType.BinaryInv | ThresholdType.Otsu);
// 二值化图像
using var binaryImage = inputGrayOut.ThresholdBinary(new Gray(threshold), new Gray(255));
3.图像裁剪,只留下迷宫区域,如果不裁剪会出现最外围的路径
using var dilated2 = new Mat();
CvInvoke.Dilate(binaryImage, dilated2, kernel, new Point(-1, -1), trackBar2.Value, BorderType.Default, new MCvScalar());
using Mat hierarchy3 = new Mat();
using VectorOfVectorOfPoint contours3 = new VectorOfVectorOfPoint();
CvInvoke.FindContours(dilated2, contours3, hierarchy3, RetrType.External, ChainApproxMethod.ChainApproxSimple);
using var binaryImage2=binaryImage.Copy(CvInvoke.BoundingRectangle(contours3[0]));
4.查找轮廓,并绘制在全黑图像上
using VectorOfVectorOfPoint contours = new VectorOfVectorOfPoint();
using Mat hierarchy = new Mat();
CvInvoke.FindContours(binaryImage2, contours, hierarchy, RetrType.External, ChainApproxMethod.ChainApproxSimple);
// 绘制在全黑图像上
using var draw = new Image(binaryImage2.Size);
CvInvoke.DrawContours(draw, contours, 0, new Bgr(255, 255, 255).MCvScalar,1);
5.膨胀
using var dilated = new Mat();
CvInvoke.Dilate(draw, dilated, kernel, new Point(-1, -1), trackBar2.Value, BorderType.Default, new MCvScalar());
6.腐蚀
using var eroded = new Mat();
CvInvoke.Erode(dilated, eroded, kernel, new Point(-1, -1), trackBar2.Value, BorderType.Default, new MCvScalar());
7.膨胀腐蚀相减
using var diff = new Mat();
CvInvoke.AbsDiff(dilated, eroded, diff);
8.在差异图diff中查找轮廓,并在原图上绘制轮廓(寻找最大边框绘画)
using VectorOfVectorOfPoint contours2 = new VectorOfVectorOfPoint();
using var hierarchy2 = new Mat();
//CvInvoke.CvtColor(diff, diff, ColorConversion.Bgr2Gray);
CvInvoke.FindContours(diff, contours2, hierarchy2, RetrType.External, ChainApproxMethod.ChainApproxSimple);
double maxArea = 0;
int maxAreaIndex = 0;
for (int i = 0; i < contours2.Size; i++)
{
double area = CvInvoke.ContourArea(contours2[i]);
if (area > maxArea)
{
maxArea = area;
maxAreaIndex = i;
}
}
CvInvoke.DrawContours(img, contours2, maxAreaIndex, new Bgr(0, 0, 255).MCvScalar, 2);