OpenCV如何提取图片中曲线

//寻找图像曲线上某个点的下一个点bool findNextPoint(vector<Point> &_neighbor_points, Mat &_image, Point _inpoint, int flag, Point& _outpoint, int &_outflag){ int i = flag; int count = 1; bool success = false; while (count <= 7) {  Point tmppoint = _inpoint + _neighbor_points[i];  if (tmppoint.x > 0 && tmppoint.y > 0 && tmppoint.x < _image.cols&&tmppoint.y < _image.rows)  {   if (_image.at<uchar>(tmppoint) == 255)   {    _outpoint = tmppoint;    _outflag = i;    success = true;    _image.at<uchar>(tmppoint) = 0;    break;   }  }  if (count % 2)  {   i += count;   if (i > 7)   {    i -= 8;   }  }  else  {   i += -count;   if (i < 0)   {    i += 8;   }  }  count++; } return success;}//寻找图像上的第一个点bool findFirstPoint(Mat &_inputimg, Point &_outputpoint){ bool success = false; for (int i = 0; i < _inputimg.rows; i++) {  uchar* data = _inputimg.ptr<uchar>(i);  for (int j = 0; j < _inputimg.cols; j++)  {   if (data[j] == 255)   {    success = true;    _outputpoint.x = j;    _outputpoint.y = i;    data[j] = 0;    break;   }  }  if (success)   break; } return success;}//寻找曲线 void findLines(Mat &_inputimg, vector<deque<Point>> &_outputlines){ vector<Point> neighbor_points = { Point(-1,-1),Point(0,-1),Point(1,-1),Point(1,0),Point(1,1),Point(0,1),Point(-1,1),Point(-1,0) }; Point first_point; while (findFirstPoint(_inputimg, first_point)) {  deque<Point> line;  line.push_back(first_point);  //由于第一个点不一定是线段的起始位置，双向找  Point this_point = first_point;  int this_flag = 0;  Point next_point;  int next_flag;  while (findNextPoint(neighbor_points, _inputimg, this_point, this_flag, next_point, next_flag))  {   line.push_back(next_point);   this_point = next_point;   this_flag = next_flag;  }  //找另一边  this_point = first_point;  this_flag = 0;  //cout << "flag:" << this_flag << endl;  while (findNextPoint(neighbor_points, _inputimg, this_point, this_flag, next_point, next_flag))  {   line.push_front(next_point);   this_point = next_point;   this_flag = next_flag;  }  if (line.size() > 10)  {   _outputlines.push_back(line);  } }}//随机取色 用于画线的时候Scalar random_color(RNG& _rng){ int icolor = (unsigned)_rng; return Scalar(icolor & 0xFF, (icolor >> 8) & 0xFF, (icolor >> 16) & 0xFF);}int main(){ Mat image = imread("images//2.bmp"); Mat gray; cvtColor(image, gray, CV_BGR2GRAY); vector<deque<Point>> lines; findLines(gray, lines); cout << lines.size() << endl; //draw lines Mat draw_img = image.clone(); RNG rng(123); Scalar color; for (int i = 0; i < lines.size(); i++) {  color = random_color(rng);  for (int j = 0; j < lines[i].size(); j++)  {   draw_img.at<Vec3b>(lines[i][j]) = Vec3b(color[0], color[1], color[2]);  } } imshow("draw_img", draw_img); imwrite("images//draw_img.bmp", draw_img); waitKey(0); system("pause"); return 0;}