How to fix the insufficient memory error (openCV) - c++

Question

Please help how to handle this problem:
OpenCV Error: Insufficient memory (Failed to allocate 921604 bytes) in
unknown function, file
........\ocv\opencv\modules\core\src\alloc.cpp, line 52
One of my method using cv::clone and pointer
The code is:
There is a timer every 100ms;
In the timer event, I call this method:
void DialogApplication::filterhijau(const Mat &image, Mat &result) {
cv::Mat resultfilter = image.clone();
int nlhijau = image.rows;
int nchijau = image.cols*image.channels();;
for(int j=0; j<nlhijau; j++) {
uchar *data2=resultfilter.ptr<uchar> (j); //alamat setiap line pada result
for(int i=0; i<nchijau; i++) {
*data2++ = 0; //element B
*data2++ = 255; //element G
*data2++ = 0; //element R
}
// free(data2); //I add this line but the program hung up
}
cv::addWeighted(resultfilter,0.3,image,0.5,0,resultfilter);
result=resultfilter;
}

Answer 1

The clone() method of a cv::Mat performs a hard copy of the data. So the problem is that for each filterhijau() a new image is allocated, and after hundreds of calls to this method your application will have occupied hundreds of MBs (if not GBs), thus throwing the Insufficient Memory error.
It seems like you need to redesign your current approach so it occupies less RAM memory.

Answer 2

I faced this error before, I solved it by reducing the size of the image while reading them and sacrificed some resolution.
It was something like this in Python:
# Open the Video
cap = cv2.VideoCapture(videoName + '.mp4')
i = 0
while cap.isOpened():
ret, frame = cap.read()
if not ret:
break
frame = cv2.resize(frame, (900, 900))
# append the frames to the list
images.append(frame)
i += 1
cap.release()
N.B. I know it's not the most optimum solution for the problem but, it was enough for me.