goodFeaturesToTrack给出了零大小的矢量

我想用opencv 2.4.3上的goodFeatureToTrack()函数在lena的灰色图像上......但是，我总是得到一个零大小的矢量存储功能cv::Point2f ...我有尝试使用零掩码也，但在这种情况下，应用程序挂起..我试着玩质量水平值从0.01到0.001。但是仍然是矢量的大小是zero..any想法...以下是我的代码..goodFeaturesToTrack给出了零大小的矢量

#include <iostream> 
#include <opencv2/core/core.hpp> 
#include <opencv2/features2d/features2d.hpp> 
#include <opencv2/video/tracking.hpp> 
#include <opencv2/highgui/highgui.hpp> 
#include <vector> 

using namespace cv; 
using namespace std; 

int main() 
{ 
    Mat frameROI; 
    frameROI = imread("C:\\lena.jpg"); 
    std::vector<cv::Point2f> corners; 
    cvtColor(frameROI,frameROI,CV_RGB2GRAY); 

    //Mat mask(frameROI.size(), CV_8UC1); 
    //mask.setTo(Scalar::all(0)); 

    //goodFeaturesToTrack(frameROI,corners,10,0.001,10,mask,3,false,0.04); 
    goodFeaturesToTrack(frameROI,corners,10,0.001,10);//AFTER EDIT 
    cout<<"SIZE OF FEATURE VECTOR = "<<corners.size()<<endl; 

    imshow("VIDEO ROI",frameROI); 
    waitKey(); 

    return 0; 
}

OUTPUT：