Here is the snippet i use in https://web.facebook.com/notes/khairul-imam/rgb-color-channel-quick-glance/519312241608587. No need to create a new file, you can use IPython just to test the code. Make sure you have numpy, scipy, matplotlib installed in your virtualenvironment or computer

rgb_color_channel.py

import cv2 as cv
from matplotlib import pyplot as plt

#load image
rgb_image = cv.imread('images/bebek_imut.jpg')

#see the output
rgb_image

#print rgb_image's shape
rgb_image.shape

#split rgb_image into individual color in b,g,r order
split_rgb = cv.split(rgb_image)

#print splitted color
split_rgb

#create a histogram for each color channel
colors = ('b','g','r')
plt.figure()
plt.title('RGB Channel Histogram ')
plt.xlabel('Grayscale value')
plt.ylabel('frequency')

#loop over channels
for color, channel in zip(colors, split_rgb): 
    histogram = cv.calcHist([channel], [0], None, [256], [0, 256])
    plt.plot(histogram, color=color)
    plt.xlim([0, 256])
    
#show the histogram
plt.show()

Hey I am having trouble with running this script in djnago. Can you help me out.