OpenCV 4 with Python Blueprints - Second Edition

Tracking hand gestures in real time

Hand gestures are analyzed by the recognize function; this is where the real magic takes place. This function handles the entire process flow, from the raw grayscale image to a recognized hand gesture. It returns the number of fingers and the illustration frame. It implements the following procedure:

1. It extracts the user's hand region by analyzing the depth map (img_gray), and returns a hand region mask (segment), like this:

def recognize(img_gray: np.ndarray) -> Tuple[int,np.ndarray]:    # segment arm region    segment = segment_arm(img_gray) 

2. It performs contour analysis on the hand region mask (segment). Then, it returns the largest contour found in the image (contour) and any convexity defects (defects ...