def apply_brightness_contrast(input_img, brightness=0, contrast=0):
    if brightness != 0:
        if brightness > 0:
            shadow = brightness
            highlight = 255
        else:
            shadow = 0
            highlight = 255 + brightness
        alpha_b = (highlight - shadow) / 255
        gamma_b = shadow

        buf = cv.addWeighted(input_img, alpha_b, input_img, 0, gamma_b)
    else:
        buf = input_img.copy()

    if contrast != 0:
        f = 131 * (contrast + 127) / (127 * (131 - contrast))
        alpha_c = f
        gamma_c = 127 * (1 - f)

        buf = cv.addWeighted(buf, alpha_c, buf, 0, gamma_c)

    return buf