OpenCV联通组件扫描
注:黑色背景
void ccl_demo()
{
QString appPath = QCoreApplication::applicationDirPath();
QString imagePath = appPath + "/rice.png";
Mat img = cv::imread(imagePath.toStdString());
if (img.empty()) {
return;
}
namedWindow("input", WINDOW_AUTOSIZE);
imshow("input", img);
//高斯模糊:降噪
GaussianBlur(img, img, Size(3, 3),0);
//To gray image
Mat gray, binary;
cvtColor(img, gray, COLOR_BGR2GRAY);
imshow("gray", gray);
//OTSU
double m_otsu = threshold(gray, binary, 0, 255, THRESH_BINARY | THRESH_OTSU);
imshow("BINARY", binary);
ccl_stats_demo(binary);
}
void ccl_stats_demo(Mat &image)
{
Mat labels = Mat::zeros(image.size(), CV_32S);
Mat stats, centrolds;
int num_labels = connectedComponentsWithStats(image,labels,stats,centrolds,8, CV_32S, CCL_DEFAULT);
vector<Vec3b> colorTable(num_labels);
RNG rng(12345);
//background color
colorTable[0] = Vec3b(0, 0, 0);
for (int i = 1; i < num_labels; i++)
{
colorTable[i] = Vec3b(rng.uniform(0, 256), rng.uniform(0, 256), rng.uniform(0, 256));
}
Mat result = Mat::zeros(image.size(), CV_8UC3);
int w = result.cols;
int h = result.rows;
for (int row = 0; row < h; row++)
{
for (int col = 0; col < w; col++)
{
int label = labels.at<int>(row, col);
result.at<Vec3b>(row, col) = colorTable[label];
}
}
for (int i = 1; i < num_labels; i++)
{
//center
int cx = centrolds.at<double>(i, 0);
int cy = centrolds.at<double>(i, 1);
//rectangle
int x = stats.at<int>(i, CC_STAT_LEFT);
int y = stats.at<int>(i, CC_STAT_TOP);
int w = stats.at<int>(i, CC_STAT_WIDTH);
int h = stats.at<int>(i, CC_STAT_HEIGHT);
int area = stats.at<int>(i, CC_STAT_AREA);
circle(result, Point(cx, cy), 3, Scalar(0, 0, 255), 2, 8, 0);
Rect box(x, y, w, h);
rectangle(result, box, Scalar(0, 255, 0), 2, 8, 0);
putText(result, format("%d", area), Point(x,y), FONT_HERSHEY_PLAIN, 1.0, Scalar(0, 255, 255), 1);
}
putText(result, format("number:%d", num_labels-1), Point(10, 10), FONT_HERSHEY_PLAIN, 1.0, Scalar(0, 0, 255), 1);
imshow("CCL demo", result);
}