title: How to calculate the mean for each pixel value?
body: <p>I want to calculate the mean for each pixel value and how to show them separatly.for example: 
  Mean 124.34(red),124.44(green),124.67(blue),123.56(gray)
  I try like this...</p>
  
  <pre><code> import numpy as np
   import math 
   img = Image.open('cameraman.jpg')
   h,w=img.size 
   #print(h,w)
   arr = np.array(img)
   total = 0 
  for i in range(arr.shape[0]):
        for j in range(arr.shape[1]):
              total+=arr[(i,j)]
    a=h*w
  mean=(total)/a
  print("Mean Value is: ",np.mean)
  </code></pre>