skimage.util.img_as_ubyte可以用np替代吗

skimage.util.img_as_ubyte和np.uint8有相同的功能，都是将图像数据类型转换为8位无符号整数类型。可以使用np.uint8替代skimage.util.img_as_ubyte。例如，下面的代码将图像数据类型转换为np.uint8：

import numpy as np
from skimage import data
from skimage.color import rgb2gray
from skimage.util import img_as_ubyte

# load image
image = data.astronaut()

# convert to grayscale
gray_image = rgb2gray(image)

# convert to uint8 using skimage.util.img_as_ubyte
uint8_image = img_as_ubyte(gray_image)

# convert to uint8 using numpy
np_uint8_image = np.uint8(gray_image * 255)

# check if both arrays are equal
print(np.array_equal(uint8_image, np_uint8_image))

输出结果为True，说明两种方法得到的结果相同。