How to find the coordinates of the missing parts in a image compared to the original complete image?

[nissansz]

Complete image is below

Image with grey missing part is below

Want to find the coordinates of the grey missing part.

[radarhere]

At first, I wanted to suggest

from PIL import Image, ImageChops
with Image.open("complete.png") as complete:
    with Image.open("missing.jpg") as missing:
        delta = ImageChops.subtract_modulo(complete.convert("RGB"), missing)
        print(delta.getbbox())

However, while your first image is a PNG, your second image is a JPEG. Because JPEG is a lossy format, when your image was saved as a JPEG file, subtle changes would have been created, meaning that a simple comparison cannot be made.

Instead, the comparison needs to include a threshold.

from PIL import Image, ImageChops
with Image.open("complete.png") as complete:
    with Image.open("missing.jpg") as missing:
        complete_l = complete.convert("L")
        missing_l = missing.convert("L")
        def check(x, y):
        	return abs(complete_l.getpixel((x, y)) - missing_l.getpixel((x, y))) > 3
        
        coords = []
        for x in range(complete.width):
            for y in range(complete.height):
                if check(x, y):
                    coords.append(x)
                    break
            if len(coords) == 1:
                break
        for y in range(complete.height):
            for x in range(complete.width):
                if check(x, y):
                    coords.append(y)
                    break
            if len(coords) == 2:
                break
        for x in reversed(range(complete.width)):
            for y in range(complete.height):
                if check(x, y):
                    coords.append(x)
                    break
            if len(coords) == 3:
                break
        for y in reversed(range(complete.height)):
            for x in range(complete.width):
                if check(x, y):
                    coords.append(y)
                    break
            if len(coords) == 4:
                break
        print(coords)

This code prints [500, 56, 623, 159]

[nissansz]

Thank you.