HOGDescriptor.computer error [closed]

edit

Hi, I am tring to use HOGDescriptor of OpenCv3.0 under VS2012 to compute the hog features.And my codes is as flows:

cv::Mat img=cv::imread("D:\pictures\1.bmp";

if(img.data==NULL){
   cout<<"load pictures error"<<endl;
}

if(img.cols!=hog.winSize.width||img.rows!=hog.winSize.height) {
    count<<"the size of pictures is wrong"<<endl;
}

cv::HOGDescriptor;

hog(cv::Size(64,64),cv::Size(16,16),cv::Size(8,8),cv::Size(8,8),9);

vector featureVec;

hog.compute(img,featureVec);

//fails，"Access error occurred while writing position 0 x00477218”

I examine the codes many times, and don't why.

Please help me. Thank you.