初识OpenCV-Python - 004: Trackbar as the color palette

The use OpenCV learn how to set up a tonal disk. Which will be used cv2.getTrackbarPos (), cv2.createTrackbar () function.

code:

CV2 Import 
Import numpy AS NP 

DEF Nothing ( X): 
 Pass 

#Create Black Image A, A window 
IMG np.zeros = (( 300 , 512 , . 3) , np.uint8) 
cv2.namedWindow ( 'Image') 

#create trackbars Color Change for 
cv2.createTrackbar ( 'R & lt' , 'Image' , 0 , 255 , Nothing) # establish a red bar adjustment 
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 the else: IMG [:] = [B , G , R & lt] cv2.destroyAllWindows () Code Results display: