c++ - Opencv2.4.9 SimpleBlobDetector 掩码不起作用

Question

我已仔细阅读此网站以寻求解释，但无济于事...希望有人知道答案。

我正在使用 simpleBlobDetector 来跟踪一些 Blob 。我想通过检测方法指定一个 mask ，但由于某种原因， mask 似乎不起作用——我的关键点显示在整个图像上。以下是我的一些代码片段:

Mat currFrame;
Mat mask;
Mat roi;
cv::Ptr<cv::FeatureDetector> blob_detector = new cv::SimpleBlobDetector(params);//custom set of params I've left out for legibility 
blob_detector->create("SimpleBlob");

vector<cv::KeyPoint> myblob;

while(true)
{   
    captured >> currFrame; // get a new frame from camera >> is grab and retrieve in one go, note grab does not allow frame to be modified but edges can be

    // do nothing if frame is empty
    if(currFrame.empty())
    {
        break;
    }

    /******************** make mask***********************/
    mask = Mat::zeros(currFrame.size(),CV_8U);
    roi = Mat(mask,Rect(400,400,400,400));
    roi = 255;

    /******************** image cleanup with some filters*/
    GaussianBlur(currFrame,currFrame, Size(5,5), 1.5, 1.5);
    cv::medianBlur(currFrame,currFrame,3);

    blob_detector->detect(fgMaskMOG,myblob,mask);//fgMaskMOG is currFrame after some filtering and background subtraction
    cv::drawKeypoints(fgMaskMOG,myblob,fgMaskMOG,Scalar::all(-1), DrawMatchesFlags::DRAW_RICH_KEYPOINTS );

    imshow("mogForeground", fgMaskMOG);
    imshow("original", currFrame);
    imshow("mask",mask);
    if(waitKey(1) != -1)
        break;
}

事实是，我确认我的面具是通过使用此处描述的 SurfFeatureDetector 正确制作的 (OpenCV: howto use mask parameter for feature point detection (SURF)) 如果有人能看出我的面具有什么问题，我将非常感谢您的帮助。抱歉乱码!

Answer 1

我遇到了同样的问题，找不到解决办法，所以我自己检查掩码解决了:

blob_detector->detect(img, keypoints);

std::vector<cv::KeyPoint> keypoints_in_range;

for (cv::KeyPoint &kp : keypoints)
    if (mask.at<char>(kp.pt) > 0)
         keypoints_in_range.push_back(kp)