How to Remove center block of PolygonZone

[edison44851]

I am using PolygonZone and PolygonZoneAnnotator. I just need the zone, but I won't count anything. I disabled counting, but there is still an area in the centre of the zone. I want to remove the centre red block or make it invisible. Can anyone teach me?

import cv2
import argparse
import supervision as sv
from ultralytics import YOLO
import numpy as np

ZONE_POLYGON = np.array([
    [56, 56],
    [1224, 56],
    [1224, 664],
    [56, 664]
])

def parse_arguments() -> argparse.Namespace:
    parser = argparse.ArgumentParser(description="YOLOv8 Live")
    parser.add_argument("--webcam-resolution", default=[1280, 720], nargs=2, type=int)
    args = parser.parse_args()
    return args


def main():
    args = parse_arguments()
    frame_width, frame_height = args.webcam_resolution  # note that we use underscore instead of hyphen

    model = YOLO("yolov8l.pt")
    box_annotator = sv.BoxAnnotator(thickness=2, text_thickness=2, text_scale=1)

    zone = sv.PolygonZone(polygon=ZONE_POLYGON, frame_resolution_wh=tuple(args.webcam_resolution))
    zone_annotator = sv.PolygonZoneAnnotator(zone=zone, color=sv.Color.red(), text_scale=0)

    cap = cv2.VideoCapture(0)
    cap.set(cv2.CAP_PROP_FRAME_WIDTH, frame_width)
    cap.set(cv2.CAP_PROP_FRAME_HEIGHT, frame_height)

    while True:
        retval, frame = cap.read()

        result = model(frame, agnostic_nms=True)[0]
        detections = sv.Detections.from_ultralytics(result)
        labels = [
            f"{model.model.names[class_id]} {confidence:0.2f}"
            for _, _, confidence, class_id, _,
            in detections
        ]

        mask = zone.trigger(detections=detections)
        # detections_filtered = detections[mask]
        frame = box_annotator.annotate(scene=frame, detections=detections, labels=labels)
        frame = zone_annotator.annotate(scene=frame, label=None)
        cv2.imshow("yolov8", frame)

        print(detections)

        # if 'ESC' is pressed, break the VideoCapture
        if cv2.waitKey(30) == 27:
            print(frame.shape)
            break


if __name__ == "__main__":
    main()