How to solve: IndexError: image index out of range

Question

I'm newbee in python and trying to get every 80th pixel in 80th row, here is my code:

from PIL import Image


im = Image.open("UIC.bmp")
size = (list(im.size))  #  size is 1200x800
pixel_row = []
for y in range(0,1200, 80):
    print(y)

    for x in range(0, 800, 80):
        print(x)
        cordinate = x, y
        pixel_row.append(im.getpixel(cordinate))


print(pixel_row)

After it's done, I decode text using the code:

print(pixel_list)

decode_list = []
for i in range(len(pixel_list)):
    decode_list.append(chr(pixel_list[i] - 100))

decode_text = ''.join(decode_list)

print(decode_text)

It gives an error:

Traceback (most recent call last):
  File "/Users/apple/Desktop/projects/BariySatarov/test.py", line 13, in <module>
    pixel_row.append(im.getpixel(cordinate)[2])
  File "/Users/apple/Desktop/projects/BariySatarov/venv/lib/python3.8/site-packages/PIL/Image.py", line 1358, in getpixel
    return self.im.getpixel(xy)
IndexError: image index out of range

Don't understand how to figure it out, because I get the same range as the range of the picture.

PS Tried to put range(0,1199, 80) and range(0, 799, 80), it doesn't work

Answer 1

You can use numpy and array indexing for this:

from PIL import Image
import numpy as np


im = Image.open("UIC.bmp")
arr = np.array(im)
pixel_row = arr[::80,::80].flatten()

Answer 2

You have to change between x and y.

x means column, not row.