OpenCV: memory corruption - c++

Question

I am trying to make a program work, but for some reason i get a memory corruption error.
I am only using the "videoprocess" method and not the imageprocess method.
When I target a specific video, it works only once. When I try to use it again on the same video, i get this kind of error:
*** Error in `./camack': malloc(): memory corruption: 0x000000000234b2c0 ***
I cant figure out where is the problem...
Here's the code:
//opencv
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/video/background_segm.hpp>
//C
#include <stdio.h>
//C++
#include <iostream>
#include <sstream>
using namespace cv;
using namespace std;
//global variables
Mat frame; //current frame
Mat fgMaskMOG; //fg mask generated by MOG method
Mat fgMaskMOG2; //fg mask fg mask generated by MOG2 method
Ptr<BackgroundSubtractor> pMOG; //MOG Background subtractor
Ptr<BackgroundSubtractor> pMOG2; //MOG2 Background subtractor
int keyboard;
//function declarations
void help();
void processVideo(char* videoFilename);
void processImages(char* firstFrameFilename);
void help()
{
cout
<< "--------------------------------------------------------------------------" << endl
<< "This program shows how to use background subtraction methods provided by " << endl
<< " OpenCV. You can process both videos (-vid) and images (-img)." << endl
<< endl
<< "Usage:" << endl
<< "./bs {-vid <video filename>|-img <image filename>}" << endl
<< "for example: ./bs -vid video.avi" << endl
<< "or: ./bs -img /data/images/1.png" << endl
<< "--------------------------------------------------------------------------" << endl
<< endl;
}
int main(int argc, char* argv[])
{
//print help information
help();
//check for the input parameter correctness
if(argc != 3) {
cerr <<"Incorret input list" << endl;
cerr <<"exiting..." << endl;
return EXIT_FAILURE;
}
//create GUI windows
namedWindow("Frame");
namedWindow("FG Mask MOG");
namedWindow("FG Mask MOG 2");
//create Background Subtractor objects
//NOTE HERE!!!!
pMOG= new BackgroundSubtractorMOG(); //MOG approach
pMOG2 = new BackgroundSubtractorMOG2(); //MOG2 approach
if(strcmp(argv[1], "-vid") == 0) {
//input data coming from a video
processVideo(argv[2]);
}
else if(strcmp(argv[1], "-img") == 0) {
//input data coming from a sequence of images
processImages(argv[2]);
}
else {
//error in reading input parameters
cerr <<"Please, check the input parameters." << endl;
cerr <<"Exiting..." << endl;
return EXIT_FAILURE;
}
//destroy GUI windows
destroyAllWindows();
return EXIT_SUCCESS;
}
void processVideo(char* videoFilename) {
//create the capture object
VideoCapture capture(videoFilename);
//VideoCapture capture(0);
if(!capture.isOpened()){
//error in opening the video input
cerr << "Unable to open video file: " << videoFilename << endl;
exit(EXIT_FAILURE);
}
//read input data. ESC or 'q' for quitting
while( (char)keyboard != 'q' && (char)keyboard != 27 ){
//read the current frame
if(!capture.read(frame)) {
cerr << "Unable to read next frame." << endl;
cerr << "Exiting..." << endl;
exit(EXIT_FAILURE);
}
//update the background model
//AND HERE!!!
pMOG->operator()(frame, fgMaskMOG);
pMOG2->operator()(frame, fgMaskMOG2);
//get the frame number and write it on the current frame
stringstream ss;
rectangle(frame, cv::Point(10, 2), cv::Point(100,20),
cv::Scalar(255,255,255), -1);
ss << capture.get(CV_CAP_PROP_POS_FRAMES);
string frameNumberString = ss.str();
putText(frame, frameNumberString.c_str(), cv::Point(15, 15),
FONT_HERSHEY_SIMPLEX, 0.5 , cv::Scalar(0,0,0));
//show the current frame and the fg masks
imshow("Frame", frame);
imshow("FG Mask MOG", fgMaskMOG);
imshow("FG Mask MOG 2", fgMaskMOG2);
//get the input from the keyboard
keyboard = waitKey( 30 );
}
//delete capture object
capture.release();
}
void processImages(char* fistFrameFilename) {
//read the first file of the sequence
frame = imread(fistFrameFilename);
if(!frame.data){
//error in opening the first image
cerr << "Unable to open first image frame: " << fistFrameFilename << endl;
exit(EXIT_FAILURE);
}
//current image filename
string fn(fistFrameFilename);
//read input data. ESC or 'q' for quitting
while( (char)keyboard != 'q' && (char)keyboard != 27 ){
//update the background model
//ALSO HERE!!!!
pMOG->operator()(frame, fgMaskMOG);
pMOG2->operator()(frame, fgMaskMOG2);
//get the frame number and write it on the current frame
size_t index = fn.find_last_of("/");
if(index == string::npos) {
index = fn.find_last_of("\\");
}
size_t index2 = fn.find_last_of(".");
string prefix = fn.substr(0,index+1);
string suffix = fn.substr(index2);
string frameNumberString = fn.substr(index+1, index2-index-1);
istringstream iss(frameNumberString);
int frameNumber = 0;
iss >> frameNumber;
rectangle(frame, cv::Point(10, 2), cv::Point(100,20),
cv::Scalar(255,255,255), -1);
putText(frame, frameNumberString.c_str(), cv::Point(15, 15),
FONT_HERSHEY_SIMPLEX, 0.5 , cv::Scalar(0,0,0));
//show the current frame and the fg masks
imshow("Frame", frame);
imshow("FG Mask MOG", fgMaskMOG);
imshow("FG Mask MOG 2", fgMaskMOG2);
//get the input from the keyboard
keyboard = waitKey( 30 );
//search for the next image in the sequence
ostringstream oss;
oss << (frameNumber + 1);
string nextFrameNumberString = oss.str();
string nextFrameFilename = prefix + nextFrameNumberString + suffix;
//read the next frame
frame = imread(nextFrameFilename);
if(!frame.data){
//error in opening the next image in the sequence
cerr << "Unable to open image frame: " << nextFrameFilename << endl;
exit(EXIT_FAILURE);
}
//update the path of the current frame
fn.assign(nextFrameFilename);
}
}
Can you help me on this one? thank you a lot

Answer 1

global vars are evil ! you should not use them.
here, Ptr<BackgroundSubtractor> pMOG2; will never get released
move it into main, and pass it as an arg to functions like processVideo()
also, all images passed to the BackgroundSubtractor must have the same size.

Answer 2

If you dont need the processImage part then remove it so that you can have a short code which is easy for you to understand. I have remove the irrelevant part. Here is the short code which is working fine here at my system;
//opencv
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/video/background_segm.hpp>
//C
#include <stdio.h>
//C++
#include <iostream>
#include <sstream>
using namespace cv;
using namespace std;
//global variables
Mat frame; //current frame
Mat fgMaskMOG; //fg mask generated by MOG method
Mat fgMaskMOG2; //fg mask fg mask generated by MOG2 method
Ptr<BackgroundSubtractor> pMOG; //MOG Background subtractor
Ptr<BackgroundSubtractor> pMOG2; //MOG2 Background subtractor
int keyboard;
//function declarations
void processVideo(char* videoFilename);
int main(int argc, char* argv[])
{
//create GUI windows
namedWindow("Frame");
namedWindow("FG Mask MOG");
namedWindow("FG Mask MOG 2");
//create Background Subtractor objects
//NOTE HERE!!!!
pMOG= new BackgroundSubtractorMOG(); //MOG approach
pMOG2 = new BackgroundSubtractorMOG2(); //MOG2 approach
if(strcmp(argv[1], "-vid") == 0) {
//input data coming from a video
processVideo(argv[2]);
}
//destroy GUI windows
destroyAllWindows();
return EXIT_SUCCESS;
}
void processVideo(char* videoFilename) {
//create the capture object
VideoCapture capture(videoFilename);
//VideoCapture capture(0);
if(!capture.isOpened()){
//error in opening the video input
cerr << "Unable to open video file: " << videoFilename << endl;
exit(EXIT_FAILURE);
}
//read input data. ESC or 'q' for quitting
while( (char)keyboard != 'q' && (char)keyboard != 27 ){
//read the current frame
if(!capture.read(frame)) {
cerr << "Unable to read next frame." << endl;
cerr << "Exiting..." << endl;
exit(EXIT_FAILURE);
}
//update the background model
//AND HERE!!!
pMOG->operator()(frame, fgMaskMOG);
pMOG2->operator()(frame, fgMaskMOG2);
//get the frame number and write it on the current frame
stringstream ss;
rectangle(frame, cv::Point(10, 2), cv::Point(100,20),
cv::Scalar(255,255,255), -1);
ss << capture.get(CV_CAP_PROP_POS_FRAMES);
string frameNumberString = ss.str();
putText(frame, frameNumberString.c_str(), cv::Point(15, 15),
FONT_HERSHEY_SIMPLEX, 0.5 , cv::Scalar(0,0,0));
//show the current frame and the fg masks
imshow("Frame", frame);
imshow("FG Mask MOG", fgMaskMOG);
imshow("FG Mask MOG 2", fgMaskMOG2);
//get the input from the keyboard
keyboard = waitKey( 30 );
}
//delete capture object
capture.release();
}