opencv_python学习笔记六

8使用滑动条作调色板

cv2.getTrackbarPos()

cv2.createTrackbar()

函数原型
def getTrackbarPos(trackbarname, #滚动条名字

winname)#放置窗口的名字

def createTrackbar(trackbarName,
                   windowName,
                   value,
                   count,
                   onChange)

使用三个滚动条设置RGB

示例代码如下

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# @Time    : 2016/11/14 10:17
# @Author  : Retacn
# @Site    : 使用滑动条作调色板
# @File    : trackbarTest.py
# @Software: PyCharm

import cv2
import numpy as np

def nothing(x):
    pass

#创建图像
img=np.zeros((300,512,3),np.uint8)
cv2.namedWindow("Trackbar")

cv2.createTrackbar("R","Trackbar",0,255,nothing)
cv2.createTrackbar("G","Trackbar",0,255,nothing)
cv2.createTrackbar("B","Trackbar",0,255,nothing)

switch='0:OFF 1:ON'
cv2.createTrackbar(switch,'Trackbar',0,1,nothing)

while(1):
    cv2.imshow('Trackbar',img)
    k=cv2.waitKey(1)&0xFF
    if k==27:
        break

    r=cv2.getTrackbarPos('R','Trackbar')
    g=cv2.getTrackbarPos('G','Trackbar')
    b=cv2.getTrackbarPos('B','Trackbar')
    s=cv2.getTrackbarPos(switch,'Trackbar')

    if s==0:
        img[:]=0
    else:
        img[:]=[b,g,r]
cv2.destroyAllWindows()