## OpenCv-Python 最小外接圆、最小外接矩形、椭圆拟合、直线拟合

-牧野- 2020-11-13 08:02:37
Python OpenCV 最小 opencv-python 外接圆

``````#coding: utf-8
import cv2
import numpy as np
import imutils
im = cv2.imread('./5121.png')
imgray = cv2.cvtColor(im,cv2.COLOR_BGR2GRAY)
ret,thresh = cv2.threshold(imgray,0,255,cv2.THRESH_BINARY+cv2.THRESH_OTSU) # 大津阈值
contours = cv2.findContours(thresh,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_NONE) #cv2.RETR_EXTERNAL 定义只检测外围轮廓
cnts = contours[0] if imutils.is_cv2() else contours[1] #用imutils来判断是opencv是2还是2+
for cnt in cnts:
# 外接矩形框，没有方向角
x, y, w, h = cv2.boundingRect(cnt)
cv2.rectangle(im, (x, y), (x + w, y + h), (0, 255, 0), 2)
# 最小外接矩形框，有方向角
rect = cv2.minAreaRect(cnt)
box = cv2.cv.Boxpoints() if imutils.is_cv2()else cv2.boxPoints(rect)
box = np.int0(box)
cv2.drawContours(im, [box], 0, (0, 0, 255), 2)
# 最小外接圆
(x, y), radius = cv2.minEnclosingCircle(cnt)
center = (int(x), int(y))
radius = int(radius)
cv2.circle(im, center, radius, (255, 0, 0), 2)
# 椭圆拟合
ellipse = cv2.fitEllipse(cnt)
cv2.ellipse(im, ellipse, (255, 255, 0), 2)
# 直线拟合
rows, cols = im.shape[:2]
[vx, vy, x, y] = cv2.fitLine(cnt, cv2.DIST_L2, 0, 0.01, 0.01)
lefty = int((-x * vy / vx) + y)
righty = int(((cols - x) * vy / vx) + y)
im = cv2.line(im, (cols - 1, righty), (0, lefty), (0, 255, 255), 2)
cv2.imshow('a',im)
cv2.imwrite('./result.jpg',im)
cv2.waitKey(0)``````

https://blog.csdn.net/dcrmg/article/details/89927816