Revision history [back]

iirc, older opencv versions had sometmes problems writing png or jpeg files, when there was no compression info supplied, so for png:

vector<int> flags; 
flags.push_back(CV_IMWRITE_PNG_COMPRESSION);
flags.push_back(9);  // [0-9]
imwrite("C:\\Frames\\frame.png",frame,flags);

or jpeg:

vector<int> flags; 
flags.push_back(CV_IMWRITE_JPEG_QUALITY);
flags.push_back(99); // [0-99] 
imwrite("C:\\Frames\\frame.jpg",frame,flags);

also, doublecheck if your frame was valid:

cap >> frame;
if ( ! frame.empty() )
{
     // save to disk
}