此次学习了如何用OpenCV建立一个色调盘。其中会用到cv2.getTrackbarPos(), cv2.createTrackbar()函数。
code:
import cv2
import numpy as np
def nothing(x):
pass
#Create a black image, a window
img = np.zeros((300,512,3),np.uint8)
cv2.namedWindow('image')
#create trackbars for color change
cv2.createTrackbar('R','image',0,255,nothing) #建立一个调节红色的横条
cv2.createTrackbar('G','image',0,255,nothing)
cv2.createTrackbar('B','image',0,255,nothing)
#create switch for ON/OFF functionality
switch = '0 : OFF \n1 : ON'
cv2.createTrackbar(switch, 'image',0,1,nothing)
while(1):
cv2.imshow('image',img)
k = cv2.waitKey(1) & 0xFF
if k == 27:
break
#get current positions of four trackbars
r = cv2.getTrackbarPos('R','image') #记录当前红色条的数据
g = cv2.getTrackbarPos('G', 'image')
b = cv2.getTrackbarPos('B', 'image')
s = cv2.getTrackbarPos(switch, 'image')
if s == 0:
img[:] = 0
else:
img[:] = [b,g,r]
cv2.destroyAllWindows()
Code结果展示:
![初识OpenCV-Python - 004: Trackbar as the color palette_第1张图片](http://img.e-com-net.com/image/info8/f54548adbd5e4012b8828ebf91ec7d66.png)