图像分割基本流程（图像分割与轮廓的绘制）

今天练习了简单的图像分割与轮廓的绘制，以及在轮廓内的分量分析.

画出所有的轮廓出来

Mat src_img = imread(path); Mat gray_img; Mat bin_img; cvtColor(src_img, gray_img, COLOR_BGR2GRAY);

灰度均值

Scalar gray_mean = mean(gray_img); cout << gray_mean(0); threshold(gray_img, bin_img, 90, 255, THRESH_BINARY); 寻找全部轮廓 vector<vector<Point>>contours; vector<Vec4i>hierarchy; findContours(bin_img, contours, hierarchy, RETR_CCOMP, CHAIN_APPROX_SIMPLE); for (int i = 0; i < hierarchy.size(); i ) { Scalar color = Scalar(rand() % 255, rand() % 255, rand() % 255); drawContours(src_img, contours, i, color,5, 8, hierarchy); } 从所有的轮廓中找到寻找最大轮廓 double maxarea = 0; int maxAreaIdx = 0; for (int index = contours.size() - 1; index >= 0; index--) { double tmparea = fabs(contourArea(contours[index])); if (tmparea > maxarea) { maxarea = tmparea; maxAreaIdx = index;//记录最大轮廓的索引号 } } //Scalar color = Scalar(rand() % 255, rand() % 255, rand() % 255); //drawContours(src_img, contours, maxAreaIdx, color, 5, 8, hierarchy);

求出最大轮廓的内切圆，这样更加精确的bgr分量进行分析。

Rect r = boundingRect(contours[maxAreaIdx]); int nL = r.x, nR = r.br().x; //轮廓左右边界 int nT = r.y, nB = r.br().y; //轮廓上下边界 int dist = 0; int maxdist = 0; Point center1; for (int i = nL; i < nR; i ) //列 { for (int j = nT; j < nB; j ) //行 { //计算轮廓内部各点到最近轮廓点的距离 dist = pointPolygonTest(contours[maxAreaIdx], Point(i, j), true); if (dist > maxdist) { //求最大距离，只有轮廓最中心的点才距离最大 maxdist = dist; center1 = Point(i, j); } } } int radius = maxdist; //圆半径 Point center = center1; circle(src_img, center1 , radius, Scalar(0, 0, 0), 3, 8);

//

int point_idx_b_sum = 0; int point_idx_g_sum = 0; int point_idx_r_sum = 0; vector<int> b_vec; vector<int> g_vec; vector<int> r_vec; for (int i = nL; i < nR; i ) //列 { for (int j = nT; j < nB; j ) //行 { //计算轮廓内部各点到最近轮廓点的距离 dist = pointPolygonTest(contours[maxAreaIdx], Point(i, j), true); b_vec.push_back(src_img.at<Vec3b>(Point(i, j))[0]); g_vec.push_back(src_img.at<Vec3b>(Point(i, j))[1]); r_vec.push_back(src_img.at<Vec3b>(Point(i, j))[2]); //printf("b=%d\t", src_img.at<Vec3b>(Point(i, j))[0]); } } //cout << b_vec.size(); for (vector<int>::iterator iter = b_vec.begin(); iter != b_vec.end(); iter ) { point_idx_b_sum = point_idx_b_sum *iter; } for (vector<int>::iterator iter = g_vec.begin(); iter != g_vec.end(); iter ) { point_idx_g_sum = point_idx_g_sum *iter; } for (vector<int>::iterator iter = r_vec.begin(); iter != r_vec.end(); iter ) { point_idx_r_sum = point_idx_r_sum *iter; } cout << path << " " << "b=" << point_idx_b_sum / b_vec.size() << endl; cout << path << " " << "g=" << point_idx_g_sum / b_vec.size() << endl; cout << path << " " << "r=" << point_idx_r_sum / b_vec.size(); }

输出结果