trouble with python script to sort image based on image_difference and SSIM

Question

I keep running into "IndexError: list index out of range" but I can't seem to squash it. It's a simple program, but chasing issues in VSCode kind of causes more issues than it solves and I'm too new to coding to parse what's happening.

I have a folder of 50 similar png's that I have reduced to 512x512 and I want them to be sorted by sequentially finding the next unsorted image with image_difference's min_diff and building a new list of images based on that before renaming all files based on their order in the new list.

What is causing the indexerror? I've tried a few things from forums, but I can't tell the good from bad and it's all run together at this point.

This is what I've got so far: `

`import os
import cv2
import numpy as np
from skimage.metrics import structural_similarity as ssim
from tqdm import tqdm
from itertools import islice
from itertools import count

# path to the folder containing the images
folder_path = "D:\\resized"

# list all the images in the folder
images = [f for f in os.listdir(folder_path) if f.endswith(".jpg") or f.endswith(".png")]

# sort the images in lexicographic order
images.sort()

# function to calculate the difference between two images
def image_difference(img1, img2):
    diff = cv2.absdiff(img1, img2)
    return np.sum(diff)

# function to calculate the SSIM between two images
def image_ssim(img1, img2):
    return ssim(img1, img2, win_size = 7, channel_axis=2)

# function to find the index of the image that has the smallest difference with the current image
def find_min_diff_index(current_image, images, folder_path):
    min_diff = float('inf')
    min_diff_index = -1
    for j in count():
        try:
            diff = image_difference(cv2.imread(folder_path + "/" + current_image), cv2.imread(folder_path + "/" + images[j]))
            if diff < min_diff:
                min_diff = diff
                min_diff_index = j
        except IndexError:
            break
    return min_diff_index

# initialize the new list of images
new_images = []

# add the first image to the new list
new_images.append(images[0])


# loop through the remaining images
for i in tqdm(range(len(images))):
    min_diff_index = find_min_diff_index(images[i], islice(images, i+1, len(images)),folder_path)
    # check if the SSIM between current image and the next image is greater than a threshold
    if min_diff_index !=-1 and image_ssim(cv2.imread(folder_path + "/" + new_images[-1]), cv2.imread(folder_path + "/" + images[min_diff_index]))> 0.8:
        # add the next image with the smallest difference to the new list
        new_images.append(images[min_diff_index])
        # remove the added image from the list
        images.pop(min_diff_index)
        i -= 1
    else:
        # remove the current image from the list
        images.pop(i)
        i -= 1

# rename the images i the new order
for i in range(len(new_images)):
    if new_images[i].endswith(".png"):
        os.rename(folder_path + "/" + new_images[i], folder_path + "/" + str(i) + ".png")
    else:
        os.rename(folder_path + "/" + new_images[i], folder_path + "/" + str(i) + ".jpg")`