本文实例讲述了Python基于opencv实现的简单画板功能。分享给大家供大家参考，具体如下：

import cv2import numpy as npdrawing = False # true if mouse is pressedix,iy = -1,-1def nothing(x): pass# mouse callback functiondef draw_circle(event,x,y,flags,param): global ix,iy,drawing g = param[0] b = param[1] r = param[2] shape = param[3] if event == cv2.EVENT_LBUTTONDOWN: drawing = True ix,iy = x,y elif event == cv2.EVENT_MOUSEMOVE: if drawing == True: if shape == 0: cv2.rectangle(img,(ix,iy),(x,y),(g,b,r),-1) else: cv2.circle(img,(x,y),5,(g,b,r),-1) elif event == cv2.EVENT_LBUTTONUP: drawing = False if shape == 0: cv2.rectangle(img,(ix,iy),(x,y),(g,b,r),-1) else: cv2.circle(img,(x,y),5,(g,b,r),-1)# Create a black image, a windowimg = np.zeros((300,512,3), np.uint8)cv2.namedWindow('image')# create trackbars for color changecv2.createTrackbar('R','image',0,255,nothing)cv2.createTrackbar('G','image',0,255,nothing)cv2.createTrackbar('B','image',0,255,nothing)# create switch for ON/OFF functionalityswitch1 = '0 : OFF \n1 : ON'switch2 = '0: Rectangle \n1: Line 'cv2.createTrackbar(switch1, 'image',0,1,nothing)cv2.createTrackbar(switch2, 'image',0,1,nothing)while(1): cv2.imshow('image',img) k = cv2.waitKey(1) & 0xFF # get current positions of four trackbars if k == 27: break r = cv2.getTrackbarPos('R','image') g = cv2.getTrackbarPos('G','image') b = cv2.getTrackbarPos('B','image') shape = cv2.getTrackbarPos(switch2,'image') s = cv2.getTrackbarPos(switch1,'image') if s == 0: img[:] = 0 else: if k == 27: break cv2.setMouseCallback('image',draw_circle,(b,g,r,shape))cv2.destroyAllWindows()

运行效果：

更多关于Python相关内容感兴趣的读者可查看本站专题：《Python数学运算技巧总结》、《Python数据结构与算法教程》、《Python函数使用技巧总结》、《Python字符串操作技巧汇总》、《Python入门与进阶经典教程》、《Python文件与目录操作技巧汇总》及《Python图片操作技巧总结》

希望本文所述对大家Python程序设计有所帮助。