Python实现Opencv图片画rectangle

今天配置了下Eclipse下的Python，做了个Opencv在图片上画rectangle的小程序：

Python还不太熟悉，感觉变量用的还是不适应，之后看下有没有更好点的方式

最开始用的cv2实现的，但是没找到类似cvCopy的函数，非常囧，后来改成用cv实现

import cv2.cv as cv
 
global startPointx 
global startPointy 
global flagDraw 
startPointx = 0
startPointy = 0
flagDraw = False

if __name__ == '__main__':

    image = cv.LoadImage("E:/lena.jpg",cv.CV_LOAD_IMAGE_COLOR)

    imgc = cv.CreateImage((image.width,image.height), 8, 3)
    cv.Copy(image, imgc)
      
    def onMouseEvent(event,x,y,flags,param):
        global startPointx 
        global startPointy 
        global flagDraw
        #鼠标左键按下响应 
        if(event==1):
            print "Position is: %d,%d" ,x,y 
            startPointx = x
            startPointy = y
            flagDraw = True
        #鼠标移动响应 
        if(event==0):
            if(flagDraw==True):
                cv.Rectangle(imgc, (startPointx,startPointy), (x,y), (255,0,0),3)
                
                cv.ShowImage('rectangle', imgc)
                cv.Copy(image, imgc)
                print "EndPosition is: %d,%d" ,x,y
        #鼠标左键抬起响应
        if(event==4):
            if(flagDraw==True):
                cv.Rectangle(image, (startPointx,startPointy), (x,y), (255,0,0),3)
                cv.ShowImage('rectangle', image)
                flagDraw = False
            
            
    cv.ShowImage('rectangle', imgc)
    while True:
        cv.SetMouseCallback('rectangle', onMouseEvent)
        c = cv.WaitKey()
        if c == 27 or c == ord('q'):
            break
    cv.DestroyAllWindows()