平均颜色

import cv2
import numpy as np
o=cv2.imread('C:/Users/xpp/Desktop/coins.png')#原始图像
cv2.imshow("original",o)
gray=cv2.cvtColor(o,cv2.COLOR_BGR2GRAY)#将彩色图片转换为灰度图片
ret,binary=cv2.threshold(gray,127,255,cv2.THRESH_BINARY)#将灰度图片转换为二值图片
contours,hierarchy=cv2.findContours(binary,cv2.RETR_LIST,cv2.CHAIN_APPROX_SIMPLE)#计算图像轮廓
n=len(contours)
contoursImg=[]
for i in range(n):
    temp=np.zeros(o.shape,np.uint8)
    contoursImg.append(temp)
cnt=contours[i]
mask=np.zeros(gray.shape,np.uint8) 
cv2.drawContours(mask,[cnt],0,(255,255,255),-1)#绘制图像实心轮廓
meanVal=cv2.mean(o,mask=mask)#计算平均颜色
print("meanVal=\n",meanVal)
masko=np.zeros(o.shape,np.uint8)
cv2.drawContours(masko,[cnt],-1,(255,255,255),-1)#绘制图像实心轮廓
loc=cv2.bitwise_and(o,masko)#按与位运算
cv2.imshow("mask",loc)
cv2.waitKey()
cv2.destroyAllWindows()