如何使用python连接图像的灰度和RGB通道

Question

I have following code:

import cv2
import numpy as np

img = cv2.imread('a.jpg')
gray = cv2.imread('b.jpg')
gray = cv2.cvtColor(gray, cv2.COLOR_BGR2GRAY)

print('a shape:', img.shape)  # a shape: (50,50,3)
print('b shape:', img.shape)  # b shape: (50,50)

result = np.concatenate((img, gray), axis=2)
print('result: ', result.shape)  # hope result shape: (50, 50, 4) 

I get a exception as following :

ValueError: all the input arrays must have same number of dimensions

I want to get result.shape = (50, 50, 4), 4 channels . How to revise my code?

Answer 1

我相信你正在寻找np.dstack ：

result = np.dstack((img, gray))