OpenCV4图像分析之BLOB特征分析

-根据BLOB面积过滤-根据灰度/颜色值过滤-根据圆度过滤-根据长轴与短轴过滤-根据凹凸进行过滤

对应的参数列表如下：

SimpleBlobDetector::Params::Params()bool        filterByAreabool        filterByCircularitybool        filterByColorbool        filterByConvexitybool        filterByInertiafloat        maxAreafloat        maxCircularityfloat        maxConvexityfloat        maxInertiaRatiofloat        maxThresholdfloat        minAreafloat        minCircularityfloat        minConvexityfloat        minDistBetweenBlobsfloat        minInertiaRatio

#include "opencv2/opencv.hpp"
#include 

using namespace cv;
using namespace std;

int main(int argc, char** argv)
{
    // 加载图像
    Mat src = imread("D:/lena.jpg");
    Mat gray;
    cvtColor(src, gray, COLOR_BGR2GRAY);
    cv::imshow("输入图像", src);

    // 初始化参数设置
    SimpleBlobDetector::Params params;
    params.minThreshold = 10;
    params.maxThreshold = 240;
    params.filterByArea = true;
    params.minArea = 50;
    params.filterByCircularity = true;
    params.minCircularity = 0.1;
    params.filterByConvexity = true;
    params.minConvexity = 0.5;
    params.filterByInertia = true;
    params.minInertiaRatio = 0.5;

    // 创建BLOB Detetor
    Ptr detector = SimpleBlobDetector::create(params);

    // BLOB分析与显示
    Mat result;
    vector keypoints;
    detector->detect(gray, keypoints);
    for (auto kpt : keypoints) {
        std::cout << "key point radius: " << kpt.size << std::endl;
        cv::circle(src, kpt.pt, 2, cv::Scalar(0, 255, 0), 2, 8, 0);
        cv::circle(src, kpt.pt, kpt.size/2, cv::Scalar(255, 0, 255), 3, 8, 0);
    }
    imshow("Blob检测-OpenCV学堂", src);
    waitKey(0);
}

thresholdStep = 10;minThreshold = 50;maxThreshold = 220;minRepeatability = 2;minDistBetweenBlobs = 10;
filterByColor = true;blobColor = 0;
filterByArea = true;minArea = 25;maxArea = 5000;
filterByCircularity = false;minCircularity = 0.8f;maxCircularity = std::numeric_limits::max();
filterByInertia = true;//minInertiaRatio = 0.6;minInertiaRatio = 0.1f;maxInertiaRatio = std::numeric_limits::max();
filterByConvexity = true;//minConvexity = 0.8;minConvexity = 0.95f;maxConvexity = std::numeric_limits::max();
collectContours = false;

static void validateParameters(const SimpleBlobDetector::Params& p)
{
  if (p.thresholdStep <= 0)
      CV_Error(Error::StsBadArg, "thresholdStep>0");

  if (p.minThreshold > p.maxThreshold || p.minThreshold < 0)
      CV_Error(Error::StsBadArg, "0<=minThreshold<=maxThreshold");

  if (p.minDistBetweenBlobs <=0 )
      CV_Error(Error::StsBadArg, "minDistBetweenBlobs>0");

  if (p.minArea > p.maxArea || p.minArea <=0)
      CV_Error(Error::StsBadArg, "0);

  if (p.minCircularity > p.maxCircularity || p.minCircularity <= 0)
      CV_Error(Error::StsBadArg, "0);

  if (p.minInertiaRatio > p.maxInertiaRatio || p.minInertiaRatio <= 0)
      CV_Error(Error::StsBadArg, "0);

  if (p.minConvexity > p.maxConvexity || p.minConvexity <= 0)
      CV_Error(Error::StsBadArg, "0);
}

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