import cv2

import numpy as np

import matplotlib.pyplot as plt

import math

cap=cv2.VideoCapture(0)

#rgb颜色转化为对应的hsv颜色

if not cap.isOpened():

    print('摄像头打开失败')

else:

    print('摄像头打开成功')

def rgb2hsv(r, g, b):

    r, g, b = r/255.0, g/255.0, b/255.0

    mx = max(r, g, b)

    mn = min(r, g, b)

    m = mx-mn

    if mx == mn:

        h = 0

    elif mx == r:

        if g >= b:

            h = ((g-b)/m)*60

        else:

            h = ((g-b)/m)*60 + 360

    elif mx == g:

        h = ((b-r)/m)*60 + 120

    elif mx == b:

        h = ((r-g)/m)*60 + 240

    if mx == 0:

        s = 0

    else:

        s = m/mx

    v = mx

    H = h / 2

    S = s * 255.0

    V = v * 255.0

    return H, S, V

# lower_red=np.array([0,43,46])

# upper_red=np.array([15,255,255])

lower_red = np.array(rgb2hsv(146,128,128),dtype=np.int32)

upper_red = np.array(rgb2hsv(127,133,156),dtype=np.int32)

while(1):

    ret,frame=cap.read()

    hsv=cv2.cvtColor(frame,cv2.COLOR_BGR2HSV)

    #根据阈值构建掩模

    mask=cv2.inRange(hsv,lower_red,upper_red)

    #对图像和掩模进行位运算

    res=cv2.bitwise_and(frame,frame,mask=mask)

    cv2.imshow('iframe',frame)

    cv2.imshow('mask',mask)

    cv2.imshow('res',res)

    k=cv2.waitKey(1)&0xFF

    if k==27:

        break

        cv2.destroyAllWindows()