import os

def get_subdirectories(root_dir, max_depth=2):
    directories = []
    for root, dirs, _ in sorted(os.walk(root_dir)):
        if root == root_dir:
            continue  # Skip the root directory itself
        depth = root[len(root_dir):].count(os.sep)
        if depth < max_depth:
            directories.append(root)
        else:
            del dirs[:]  # Stop descending further
    return directories

def load_files(ad):
    valid_extensions = {"tiff", "tif", "png", "jpg", "jpeg", "bmp", "gif", "webp"}  # Common image formats
    FileNames = []
    for file in sorted(os.listdir(ad)):
        try:
            if file.split(".")[-1].lower() in valid_extensions:
                FileNames.append(file)
        except IndexError:
            pass
    return sorted(FileNames)