Question

Very stuck on creating a python program for the below question:

Write a program that has three functions: sepia(), remove_all_red(), and gray_scale() to process the image. Plot all four images. No global variables are allowed. Each function needs parameter(s) in order to manipulate and draw the image.

Sepia Tone images are those brownish colored images that may remind you of times past. The formula for creating a sepia tone is as follows:

newR = (R × 0.393 + G × 0.769 + B × 0.189)

newG = (R × 0.349 + G × 0.686 + B × 0.168)

newB = (R × 0.272 + G × 0.534 + B × 0.131)

Red removal from an image:

Simply set the R component to 0.

Gray scale conversion:

                        newR = (R × 0.289 + G × 0.587 + B × 0.114)

newG = (R × 0.289 + G × 0.587 + B × 0.114)

newB = (R × 0.289 + G × 0.587 + B × 0.114)

where R, G, and B are the original image pixel red, green and blue values.

Hint: Remember that RGB values must be integers between 0 and 255.

Answer 1

#for uploading files into Google colab online
from google.colab import files
f = files.upload()

import numpy
#PIL library for imagee processing
from PIL import Image
#IPython library for showing images in google colab
from IPython import display

#function for grayscale conversion of image ;input:image ; output:grayscale image
def gray_scale():
#Open the image using PIL library Image.open
img = Image.open('p_1_4_a.jpg')
#convert the image into a numpy array
rgb = numpy.array(img)

#Iterate through all rows
for i in range(len(rgb)):
#Iterate through all columns
for j in range(len(rgb[1])):
temp = []
#apply given formula
newR = (0.289*rgb[i][j][0])+(0.587*rgb[i][j][1])+(0.114*rgb[i][j][2])
newG = (0.289*rgb[i][j][0])+(0.587*rgb[i][j][1])+(0.114*rgb[i][j][2])
newB = (0.289*rgb[i][j][0])+(0.587*rgb[i][j][1])+(0.114*rgb[i][j][2])
#assign the value to the duplicate array
temp.append(newR)
temp.append(newG)
temp.append(newB)   
rgb[i][j] = temp
#set the values into uint8 form and convert it into numpy array
rgb = numpy.asarray(rgb.astype('uint8'))
#make an image from array
gray = Image.fromarray(rgb)
print("Input Image")
#Displaying the input rgb image
display.display(img)
print("Grayscale Image")
#Displaying the output Grayscale image
display.display(gray)
return

  
  
#Function call for Grayscale Image
gray_scale()

#function for sepia conversion of image ;input:image ; output:sepia image
def sepia():
#Open the image using PIL library Image.open
img = Image.open('p_1_4_a.jpg')
#convert the image into a numpy array
rgb = numpy.array(img)

#Iterate through all rows
for i in range(len(rgb)):
#Iterate through all columns
for j in range(len(rgb[1])):
temp = []
#apply given formula
newR = (0.393*rgb[i][j][0])+(0.769*rgb[i][j][1])+(0.189*rgb[i][j][2])
newG = (0.349*rgb[i][j][0])+(0.686*rgb[i][j][1])+(0.168*rgb[i][j][2])
newB = (0.272*rgb[i][j][0])+(0.534*rgb[i][j][1])+(0.131*rgb[i][j][2])
#assign the value to the duplicate array
temp.append(newR)
temp.append(newG)
temp.append(newB)   
rgb[i][j] = temp
#set the values into uint8 form and convert it into numpy array
rgb = numpy.asarray(rgb.astype('uint8'))
#make an image from array
gray = Image.fromarray(rgb)
print("Input Image")
#Displaying the input rgb image
display.display(img)
print("sepia Image")
#Displaying the output sepia image
display.display(gray)
return   

sepia()

#function for all red removal of image ;input:image ; output:red removed image
def remove_all_red():
#Open the image using PIL library Image.open
img = Image.open('p_1_4_a.jpg')
#convert the image into a numpy array
rgb = numpy.array(img)

#Iterate through all rows
for i in range(len(rgb)):
#Iterate through all columns
for j in range(len(rgb[1])):
temp = []
#apply given formula
newR = 0.0
newG = (0.349*rgb[i][j][0])+(0.686*rgb[i][j][1])+(0.168*rgb[i][j][2])
newB = (0.272*rgb[i][j][0])+(0.534*rgb[i][j][1])+(0.131*rgb[i][j][2])
#assign the value to the duplicate array
temp.append(newR)
temp.append(newG)
temp.append(newB)   
rgb[i][j] = temp
#set the values into uint8 form and convert it into numpy array
rgb = numpy.asarray(rgb.astype('uint8'))
#make an image from array
gray = Image.fromarray(rgb)
print("Input Image")
#Displaying the input rgb image
display.display(img)
print("sepia Image")
#Displaying the output image
display.display(gray)
return   

remove_all_red()

#outputs: