我想从视频中隔离嘴巴区域，但我无法裁剪它

Question

我正在使用 mediapipe facedetector 解决方案裁剪嘴部区域。我成功地在嘴巴区域制作了边界框，但我无法裁剪视频。

这是我的代码：

import cv2
import mediapipe as mp
import numpy as np


mpFaceDetection = mp.solutions.face_detection
faceDetection = mpFaceDetection.FaceDetection(model_selection=1)

cap = cv2.VideoCapture("Data/ABOUT_00003.mp4")
offy = 25
offx = 40
frames = []
while True:
    success, image = cap.read()
    imgRGB = cv2.cvtColor(image, cv2.COLOR_BGR2RGB)
    results = faceDetection.process(imgRGB)
    if results.detections:
        for lips in results.detections:
            landmarks = lips.location_data.relative_keypoints
            mouth = (int(landmarks[3].x * image.shape[1]), int(landmarks[3].y * image.shape[0]))
            mouth = np.array(mouth)
        x = mouth[0]
        y = mouth[1]
        frames.append(image[y+offy:y-offy,x-offx:x+offx,:])
    cap.release()
    for frame in frames:
        cv2.imshow('frame', frame)
        cv2.waitKey(0)
    cv2.destroyAllWindows()

它给出了“cv2.imshow('frame', frame) cv2.error: OpenCV(4.7.0) D: \opencv-python\opencv-python\opencv\modules\highgui\src\window.cpp:971: 错误: (-215:断言失败) size.width>0 && size.height>0 函数 'cv::imshow'

如果我尝试裁剪图像，则会显示相同的错误。请指导我。