def get_mosaic_image_part(image, mosaic_ix):
    """ Splits a mosaic image generated from combine_images, using indexes as follows:
        0 1
        2 3 
        Only the image portion at the specified index is returned.
    """
    split_image_part = []
    height = int(image.shape[0] / 2)
    width = int(image.shape[1] / 2)
    if mosaic_ix == 0:
        split_image_part = image[0:height,0:width]
    elif mosaic_ix == 1:
        split_image_part = image[0:height,width:]
    elif mosaic_ix == 2:
        split_image_part = image[height:,0:width]
    else:
        split_image_part = image[height:,width:]

    return split_image_part