opencv学习——画线、圆、文字

import cv2import numpy as np# creat a black imageimg = np.zeros((512,512,3), np.uint8)# draw a diagonal blue line with thickness of 5 pxcv2.line(img, (0,0),(511,511),(255,0,0),5)# draw a rectanglecv2.rectangle(img, (384,0),(510,128),(0,255,0),3)# draw a circle, -1:fill the circlecv2.circle(img, (447,63),63,(0,0,255),-1)# draw a ellipsecv2.ellipse(img,(256,256),(100,50),0,0,180,(255,0,255),-1)#draw a polygonpts = np.array([[10,5],[20,30],[70,20],[50,10]], np.int32)pts = pts.reshape((-1,1,2))# if the third argument is Flase, you will get a polylines joining all the points, not a closed shape.cv2.polylines(img,[pts],True,(0,255,255))# add textfont = cv2.FONT_HERSHEY_SIMPLEXcv2.putText(img,'opencv',(10,500),font,4,(255,255,255),7,cv2.LINE_AA)cv2.imshow('image', img)cv2.waitKey(0)cv2.destroyAllWindows()cv2.waitKey(1)cv2.waitKey(1)cv2.waitKey(1)cv2.waitKey(1)