Python opencv 根据HSV实现简单的颜色分类

# hsv_color_picker
"""
import cv2
import numpy as np

def nothing(x):
    pass

cv2.namedWindow("frame")
cv2.createTrackbar("H","frame",0,179,nothing)
cv2.createTrackbar("S","frame",255,255,nothing)
cv2.createTrackbar("V","frame",255,255,nothing)

img_hsv=np.zeros((250,500,3),np.uint8)

while True:
    h=cv2.getTrackbarPos("H","frame")
    s=cv2.getTrackbarPos("S","frame")
    v=cv2.getTrackbarPos("V","frame")

    img_hsv[:]=(h,s,v)
    img_bgr=cv2.cvtColor(img_hsv,cv2.COLOR_HSV2BGR)

    cv2.imshow("frame",img_bgr)
    key=cv2.waitKey(1)
    if key==27:
        break
cv2.destroyWindow()
"""

import cv2

cap=cv2.VideoCapture(1)
cap.set(cv2.CAP_PROP_FRAME_WIDTH,1280)
cap.set(cv2.CAP_PROP_FRAME_HEIGHT,720)


while True:
    _,frame=cap.read()
    hsv_frame=cv2.cvtColor(frame,cv2.COLOR_BGR2HSV)
    height,width,_=frame.shape

    cy,cx=height//2,width//2

    # 获取画面中心点像素值
    pixel_center=hsv_frame[cy,cx]
    hue_value=pixel_center[0]

    color="Undefined"
    if 0