Debug Assertion failed ! in detectAndDisplay function of face recognition openCv - c++

Question

I am trying to run the program and is building well but not able to debug. Capturing first frame and then giving below error.
I tried to check in debug mode and could figure out that
imshow(window_name, frame);
Error !!!
Here is the working code that is copied from OpenCV blog.
#include "opencv2/objdetect/objdetect.hpp"
#include "opencv2/video/video.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include <iostream>
#include <stdio.h>
using namespace std;
using namespace cv;
/** Function Headers */
void detectAndDisplay(Mat frame);
/** Global variables */
String face_cascade_name = "haarcascade_frontalface_alt.xml";
String eyes_cascade_name = "haarcascade_eye_tree_eyeglasses.xml";
CascadeClassifier face_cascade;
CascadeClassifier eyes_cascade;
string window_name = "Capture - Face detection";
RNG rng(12345);
/** #function main */
int main(int argc, const char** argv)
{
CvCapture* capture;
Mat frame;
//-- 1. Load the cascades
if (!face_cascade.load(face_cascade_name)) { printf("--(!)Error loading\n"); return -1; };
if (!eyes_cascade.load(eyes_cascade_name)) { printf("--(!)Error loading\n"); return -1; };
//-- 2. Read the video stream
capture = cvCaptureFromCAM(CV_CAP_ANY);
if (capture)
{
while (true)
{
frame = cvQueryFrame(capture);
//-- 3. Apply the classifier to the frame
if (!frame.empty())
{
detectAndDisplay(frame);
}
else
{
printf(" --(!) No captured frame -- Break!");
break;
}
int c = waitKey(10);
if ((char)c == 'c') { break; }
}
}
return 0;
}
/** #function detectAndDisplay */
void detectAndDisplay(Mat frame)
{
std::vector<Rect> faces;
Mat frame_gray;
cvtColor(frame, frame_gray, CV_BGR2GRAY);
equalizeHist(frame_gray, frame_gray);
//-- Detect faces
face_cascade.detectMultiScale(frame_gray, faces, 1.1, 2, 0 | CV_HAAR_SCALE_IMAGE, Size(30, 30));
for (size_t i = 0; i < faces.size(); i++)
{
Point center(faces[i].x + faces[i].width*0.5, faces[i].y + faces[i].height*0.5);
ellipse(frame, center, Size(faces[i].width*0.5, faces[i].height*0.5), 0, 0, 360, Scalar(255, 0, 255), 4, 8, 0);
Mat faceROI = frame_gray(faces[i]);
std::vector<Rect> eyes;
//-- In each face, detect eyes
eyes_cascade.detectMultiScale(faceROI, eyes, 1.1, 2, 0 | CV_HAAR_SCALE_IMAGE, Size(30, 30));
for (size_t j = 0; j < eyes.size(); j++)
{
Point center(faces[i].x + eyes[j].x + eyes[j].width*0.5, faces[i].y + eyes[j].y + eyes[j].height*0.5);
int radius = cvRound((eyes[j].width + eyes[j].height)*0.25);
circle(frame, center, radius, Scalar(255, 0, 0), 4, 8, 0);
}
}
//-- Show what you got
imshow(window_name, frame);
}
Error when value chosen in
capture = cvCaptureFromCAM(-1)
is -1.
I am getting GRey window with no Error.
imshow with Grey Window, No Error

Answer 1

I changed the Platform Toolset from Visual Studio 2015(v140) to Visual Studio 2013(v120) as in the figure attached. I do not know why but it worked.
Visual Studio 2015(v140)
Visual Studio 2013(v120)

Answer 2

It may happen, if your face ROI, out of frame bounds.
Because you trying to copy this region you getting memory error.
if(faces[i].x>=0 && faces[i].y >= 0 && faces[i].x+faces[i].width<frame_gray.cols && faces[i].y+faces[i].height < frame_gray.rows)
{
faceROI=frame_gray(faces[i]);
}