Python图像处理实现画板

Python图像处理实现画板：

Python图像处理也是依赖opencv的Python接口实现的，Python语言简单易懂，简洁明了。本次实现画板涂鸦，一个是在里面画矩形，还有画线。其他也都可以扩展，本案例只做例程，思路是对鼠标事件的处理，以及滚动条调节颜色处理。鼠标事件就包含有左键按下，以及释放事件的处理。

import cv2

import numpy as np

# null function

def nothing(x):

    pass

Drawing = False

Mode = True

IX,IY = -1,-1

def drawCircle(Event,X,Y,Flags,Param):

    R = cv2.getTrackbarPos('R','Image')

    G = cv2.getTrackbarPos('G','Image')

    B = cv2.getTrackbarPos('B','Image')

#get color value

    Color = (B,G,R);

    global IX,IY,Drawing,Mode

    if Event == cv2.EVENT_LBUTTONDOWN:

        Drawing = True

        IX,IY = X,Y

    elif Event == cv2.EVENT_MOUSEMOVE and Flags == cv2.EVENT_FLAG_LBUTTON:

        if Drawing == True:

            if Mode == True:

                cv2.rectangle(Img,(IX,IY),(X,Y),Color,-1)

            else:

                cv2.circle(Img,(X,Y),3,Color,-1);

                

    elif Event == cv2.EVENT_LBUTTONUP:

        Drawing = False

#create image with 3 chanels        

Img = np.zeros((660,660,3),np.uint8)

#create window

cv2.namedWindow('Image')

#create track bar, range for 0~255

cv2.createTrackbar('R','Image',0,255,nothing)

cv2.createTrackbar('G','Image',0,255,nothing)

cv2.createTrackbar('B','Image',0,255,nothing)

#set mouse ack 

cv2.setMouseCallback('Image',drawCircle)

while(1):

    cv2.imshow('Image',Img)

    k = cv2.waitKey(10)&0xFF

   #switch draw mode

    if k == ord('m'):   

        Mode = not Mode

    elif k == 27:

        break

#you must destroy all of sources

cv2.destroyAllWindows()

最后的效果图如下