问题
I found way to convert RGB to HSV, but still I am unable to find the upper and lower value of color. How to do i calculate that?
I have to take out the pickachu from the image
and this my code till now
import cv2
import numpy as np
cap = cv2.VideoCapture(0)
while True:
_, frame = cap.read()
hsv = cv2.cvtColor(frame, cv2.COLOR_BGR2HSV)
lower_red = np.array([30,50,50])
upper_red = np.array([255,255,180]) #it is trial and error
mask = cv2.inRange(frame, lower_red, upper_red)
res = cv2.bitwise_and(frame, frame, mask= mask)
cv2.imshow('frame',frame)
cv2.imshow('mask',mask)
cv2.imshow('res',res)
k = cv2.waitKey(5) & 0xFF
if k == 27:
break
cv2.destroyAllWindows()
cap.release()
please help me
回答1:
you can use the following program to find the upper and lower hue values for the pixel by clicking on it(i.e. the pixel you want).
import cv2
import numpy as np
image_hsv = None # global ;(
pixel = (20,60,80) # some stupid default
# mouse callback function
def pick_color(event,x,y,flags,param):
if event == cv2.EVENT_LBUTTONDOWN:
pixel = image_hsv[y,x]
#you might want to adjust the ranges(+-10, etc):
upper = np.array([pixel[0] + 10, pixel[1] + 10, pixel[2] + 40])
lower = np.array([pixel[0] - 10, pixel[1] - 10, pixel[2] - 40])
print(pixel, lower, upper)
image_mask = cv2.inRange(image_hsv,lower,upper)
cv2.imshow("mask",image_mask)
def main():
import sys
global image_hsv, pixel # so we can use it in mouse callback
image_src = cv2.imread(sys.argv[1]) # pick.py my.png
if image_src is None:
print ("the image read is None............")
return
cv2.imshow("bgr",image_src)
## NEW ##
cv2.namedWindow('hsv')
cv2.setMouseCallback('hsv', pick_color)
# now click into the hsv img , and look at values:
image_hsv = cv2.cvtColor(image_src,cv2.COLOR_BGR2HSV)
cv2.imshow("hsv",image_hsv)
cv2.waitKey(0)
cv2.destroyAllWindows()
if __name__=='__main__':
main()
来源:https://stackoverflow.com/questions/53258628/how-to-i-specify-the-upper-and-the-lower-value-of-a-color-in-hsv-opencv-python