opencv buffer and remember


I am trying to replicate Andy Best’s falling bubbles at

I do not know how to store openCv buffer into an object and secondly, how to use the opencv.remember() function in openframeworks. The following code from the above tutorial is where the two functions are being performed.

movementImg = opencv.image();

opencv.remember(OpenCV.SOURCE, OpenCV.FLIP_HORIZONTAL);

Could someone please share how to write the above statements in openframeworks?