This is function to get the color from a given Mat image,
string getColorFromPx(Mat src, uint16_t x, uint16_t y){ Point pt = Point(x, y); //Mat img = (src).clone(); Vec3b& levelPxImg = imgHSV.at<vec3b>(y, x); if ((levelPxImg[0] != NULL) && (levelPxImg[1] != NULL) && (levelPxImg[2] != NULL)){ //H(openCV) / 2 = H (HSV_Real); if (levelPxImg[0] > 170 && levelPxImg[0] < 180) return "R"; else if (levelPxImg[0] > 107 && levelPxImg[0] < 122) return "B"; else return "xx"; } }
the program can work for a period time after that it notify an error as below:
" First-chance exception at 0x00007FF64C1C30A3 in OpenCVex1.exe: 0xC0000005: Access violation reading location 0x0000000000000018. If there is a handler for this exception, the program may be safely continued. "
and current breakpoint is halted at return line as below: int compare(const _Elem *_Ptr) const { // compare [0, _Mysize) with [_Ptr, <null>) _DEBUG_POINTER(_Ptr); -------> return (compare(0, this->_Mysize, _Ptr, _Traits::length(_Ptr))); } (this function locate in VS/include/xstring file).
Please take a look and help me to show problem.