OpenCV 4 with Python Blueprints - Second Edition

Understanding the GUI constructor

The BaseLayout constructor accepts an ID (-1), a title string ('Fun with Filters'), a video capture object, and an optional argument that specifies the number of frames per second. Then, the first thing to do in the constructor is to try to read a frame from the captured object in order to determine the image size:

    def __init__(self,                 capture: cv2.VideoCapture,                 title: str = None,                 parent=None,                 window_id: int = -1,  # default value                 fps: int = 10):        self.capture = capture
        _, frame = self._acquire_frame()        self.imgHeight, self.imgWidth = frame.shape[:2]

We will use the image size to prepare a buffer that will store each video frame as a bitmap and to set the size of the GUI. Because we want to display a bunch of ...