如何将4D Numpy数组保存到图像

Question

I want to create an image date_set which includes 176 small images (128*128*3) from one big image (1408, 2048, 3). I do the following thing: step 1. Load the big image and convert it to numpy array. (1408, 2048, 3) 3d array step 2. cut it into 176 pieces: (176, 128, 128, 3) 4d array step 3. I don't know how to save 176 images from 4d array in this step. Does anyone could help me to solve this problem? Thanks very much!

from astropy.io import fits
from astropy.utils.data import download_file
image_file = download_file('https://data.sdss.org/sas/dr12/boss/photoObj/frames/301/1035/3/frame-irg-001035-3-0011.jpg', cache=True )
image = imread(image_file)


def blockshaped(arr, nrows, ncols, c):
"""
Return an array of shape (n, nrows, ncols) where
n * nrows * ncols = arr.size

If arr is a 2D array, the returned array should look like n subblocks with
each subblock preserving the "physical" layout of arr.
"""
h, w = arr.shape[:2]
return (arr.reshape(h//nrows, nrows, -1, ncols, c)
           .swapaxes(1,2)
           .reshape(-1, nrows, ncols, c))

a= image[:1408, :]
b= blockshaped(a, 128, 128, 3)
b.shape

b.shape = (176, 128, 128, 3)

Answer 1

Here's a possible way to do it.

import numpy as np
import scipy.misc

images = np.zeros((176,128,128,3)) 
for i in range(len(images)):
    scipy.misc.imsave('date_set_' + str(i) + '.jpg', images[i,:,:,:])