How To Obtain An Image's Single Colour Channel Without Using The Split Function In Opencv Python?

I'd like to highlight a hand for real-time gesture recognition. I observed that the image of a hand gets highlighted differently for different colour channels using the cv2.imsplit

Solution 1:

You can use numpy's slice:

import cv2
import numpy as np

## read image as np.ndarray in BGR order
img = cv2.imread("test.png")


## use OpenCV function to split channels
b, g, r = cv2.split(img)

## use numpy slice to extract special channel
b = img[...,0]
g = img[...,1]
r = img[...,2]

Solution 2:

import cv2
import numpy as np
from PIL import Image

img_file = "sample.jpg"
image = cv2.imread(img_file)

# USING NUMPY SLICE
red = image[:,:,2]
green = image[:,:,1]
blue = image[:,:,0]

# USING OPENCV SPLIT FUNCTION
b,g,r=cv2.split(image)

# USING NUMPY dsplit
[b,g,r]=np.dsplit(image,image.shape[-1])

# USING PIL 
image = Image.open("image.jpg")
r,g,b = image.split()