Question

Complete this in simple python code.

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)

.............................................................................

Write a function to convert an image to sepia tone. Remember that rgb values must be integers between 0 and 255...

Answer 1

Image conversion code according to above formula is
CODE 1 :
from PIL import Image     #using Image from pillow library

def sepia(img_path:str)->Image:
    img = Image.open(img_path)
    width, height = img.size

    pixels = img.load()       #creating the pixel map

    for y in range(height):
     for x in range(width):
         r, g, b = img.getpixel((x, y))

         new_r = int(0.393 * r + 0.769 * g + 0.189 * b)
         new_g = int(0.349 * r + 0.686 * g + 0.168 * b)
         new_b = int(0.272 * r + 0.534 * g + 0.131 * b)

         if new_r > 255:       #r,g,b should not exceed 255
             new_r = 255

         if new_g > 255:
             new_g = 255

         if new_b > 255:
             new_b = 255

         pixels[x, y] = (new_r,new_g,new_b)

    return img

You can also use this simple formula instead for conversion (it is simple and effective).

CODE 2 :

from PIL import Image     #using Image from pillow library

def sepia(img_path:str)->Image:
    img = Image.open(img_path)
    width, height = img.size

    pixels = img.load()        #creating the pixel map

    for y in range(height):
     for x in range(width):
         r, g, b = img.getpixel((x, y))

         new_val = (0.3 * r + 0.59 * g + 0.11 * b)
         

         new_r = int(new_val * 2)
         if new_r > 255:       #r,g,b should not exceed 255
             new_r = 255

         new_g = int(new_val * 1.5)
         if new_g > 255:
             new_g = 255

         new_b = int(new_val)
         if new_b > 255:
             new_b = 255

         pixels[x, y] = (new_r,new_g,new_b)

    return img