python 單通道轉3通道

import numpy as np

with tf.Session():
	image, label = sess.run(next_batch)	# batch_size=1
	print(image.shape)	# [224, 224, 1]
	image = np.concatenate((image, image, image), axis=-1)
	print(image.shape)	# [224, 224, 3]
	# image有三個通道，每個通道都是原始的單通道的複製