PYTHON

Select right color to threshold and image with opencv

import numpy as np 
import cv2

# load image
img = cv2.imread("Eding.png")
# convert to HSV
hsv = cv2.cvtColor(img, cv2.COLOR_BGR2HSV) 
# set lower and upper color limits
lower_val = np.array([50,100,170])
upper_val = np.array([70,255,255])
# Threshold the HSV image to get only green colors
mask = cv2.inRange(hsv, lower_val, upper_val)
# apply mask to original image - this shows the green with black blackground
only_green = cv2.bitwise_and(img,img, mask= mask)

# create a black image with the dimensions of the input image
background = np.zeros(img.shape, img.dtype)
# invert to create a white image
background = cv2.bitwise_not(background)
# invert the mask that blocks everything except green -
# so now it only blocks the green area's
mask_inv = cv2.bitwise_not(mask)
# apply the inverted mask to the white image,
# so it now has black where the original image had green
masked_bg = cv2.bitwise_and(background,background, mask= mask_inv)
# add the 2 images together. It adds all the pixel values, 
# so the result is white background and the the green from the first image
final = cv2.add(only_green, masked_bg)

#show image
cv2.imshow("img", final)
cv2.waitKey(0)
cv2.destroyAllWindows()