C++ Video Frame Acquisition and Background Subtraction

This function captures video frames from a specified URL, converts them to grayscale, and performs background subtraction using the absolute difference method. It also applies a threshold to create a binary image, and passes it on to another function named 'background_separation'. Finally, it releases the capture object and returns a boolean value indicating success or failure.

bool video_frame_acquisition(const string& url, Mat& currentframe, Mat& diffframe) {
	VideoCapture capture;
	bool result = capture.open(url);

	//检查是否成功打开
	if (!capture.isOpened())
	{
		cout << "打开文摄像头失败，url:" << url << endl;
		return 0;
	}
	Mat frame, tempframe, previousframe;
	int framenum = 0;
	Mat img1, img2;
	while (true) {
		tempframe = capture.read(frame);
		capture >> frame;
		tempframe = frame;
		framenum += 1;
		cvtColor(tempframe, currentframe, COLOR_BGR2GRAY);
		//capture.set(CAP_PROP_POS_FRAMES, framenum);
		if (framenum == 1) {
			cvtColor(tempframe, previousframe, COLOR_BGR2GRAY);
		}
		else {
			absdiff(currentframe, previousframe, diffframe);
			double minVal, maxVal;
			minMaxLoc(diffframe, &minVal, &maxVal);
			//cout << maxVal << endl;
			threshold(diffframe, img1, 45, 255.0, THRESH_BINARY);
			GasDetect::background_separation(img1, previousframe);
			//threshold(currentframe, img2, 150, 255.0, THRESH_BINARY_INV);
			//bitwise_and(img1, img2, currentframe);
		}
		cvtColor(tempframe, previousframe, COLOR_BGR2GRAY);
		waitKey(10);
	}
	
	capture.release();

	return 0;
}