import numpy as np
import cv2


def color_space(image):
    """色彩空间转换"""
    hsv = cv2.cvtColor(image, cv2.COLOR_BGR2HSV)
    hls = cv2.cvtColor(image, cv2.COLOR_BGR2HLS)
    ycrcb = cv2.cvtColor(image, cv2.COLOR_BGR2YCrCb)
    yuv = cv2.cvtColor(image, cv2.COLOR_BGR2YUV)

    h1 = np.hstack((hsv, hls))
    h2 = np.hstack((ycrcb, yuv))
    stack = np.vstack((h1, h2))

    return stack


# 读取图片
img = cv2.imread("beautiful_girl.jpg")

# 不同色彩空间
stack = color_space(img)

# 图片展示
cv2.imshow("stack", stack)
cv2.waitKey(0)
cv2.destroyAllWindows()

import numpy as np
import cv2


def video_capture():
    """读取视频"""
    
    # 从摄像头获取视频
    capture = cv2.VideoCapture(0)
    
    # 循环
    while (True):

        # 读取一帧
        ret, frame = capture.read()

        # 如果读取帧, 返回值为False, break
        if ret == False:
            break

        # 设置颜色阈值
        lower = np.array([0, 0, 0])
        upper = np.array([100, 100, 255])
        mask = cv2.inRange(frame, lowerb=lower, upperb=upper)
        
        # 展示
        cv2.imshow("video", frame)
        cv2.imshow("mask", mask)

        # 按下q键退出
        if cv2.waitKey(20)  0xFF == ord("q"):
            break


if __name__ == "__main__":
    video_capture()