最优拟合多边形框

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
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)
adp=o.copy()
epsilon=0.1*cv2.arcLength(contours[i],True)#计算轮廓长度
approx=cv2.approxPolyDP(contours[i],epsilon,True)#计算逼近多边形
adp=cv2.drawContours(adp,[approx],0,(0,0,255),2)#绘制图像轮廓
cv2.imshow("result0.1",adp)
adp=o.copy()
epsilon=0.09*cv2.arcLength(contours[i],True)#计算轮廓长度
approx=cv2.approxPolyDP(contours[i],epsilon,True)#计算逼近多边形
adp=cv2.drawContours(adp,[approx],0,(0,0,255),2)#绘制图像轮廓
cv2.imshow("result0.09",adp)
adp=o.copy()
epsilon=0.055*cv2.arcLength(contours[i],True)#计算轮廓长度
approx=cv2.approxPolyDP(contours[i],epsilon,True)#计算逼近多边形
adp=cv2.drawContours(adp,[approx],0,(0,0,255),2)#绘制图像轮廓
cv2.imshow("result0.055",adp)
adp=o.copy()
epsilon=0.05*cv2.arcLength(contours[i],True)#计算轮廓长度
approx = cv2.approxPolyDP(contours[i],epsilon, True)#计算逼近多边形
adp=cv2.drawContours(adp, [approx],0,(0,0,255),2)#绘制图像轮廓
cv2.imshow("result0.05",adp)
adp=o.copy()
epsilon=0.02*cv2.arcLength(contours[i],True)#计算轮廓长度
approx=cv2.approxPolyDP(contours[i],epsilon,True)#计算逼近多边形
adp=cv2.drawContours(adp,[approx],0,(0,0,255),2)#绘制图像轮廓
cv2.imshow("result0.02",adp)
cv2.waitKey()
cv2.destroyAllWindows()