Normalize a grayscale image with Min-Max scaling to a range of [0.1, 0.9]

normalize_grayscale.py

def normalize_grayscale(image_data):
    """
    Normalize the image data with Min-Max scaling to a range of [0.1, 0.9]
    :param image_data: The image data to be normalized
    :return: Normalized image data
    """
    # Implement Min-Max scaling for grayscale image data
    a = 0.1
    b = 0.9
    grayscale_min = 0
    grayscale_max = 255
    return a + ( ( (image_data - grayscale_min)*(b - a) )/( grayscale_max - grayscale_min ) )