fix: Edge cases in filters.

import numpy as np

from numpy.typing import ArrayLike

# Expects an array with dtype=float

def linear_stretch(array: ArrayLike) -> ArrayLike:

    frames, height, width = array.shape

    max_val, min_val = np.max(array), np.min(array)

    if max_val - min_val == 0:

        print("Error: Cannot apply linear stretch filter on constant images, "

              "which would cause a division by 0 error! Ignoring filter.")

        return array

    factor = 1.0 / (max_val - min_val)

    for n in range(frames):

        array[n] = array[n] - min_val

def logarithm_stretch(array: ArrayLike, factor=10.0) -> ArrayLike:

    if array.min() < 0:

        # Shifting if the array contains negative numbers.

        array += abs(array.min())

    return factor * np.log(array + 1.0)