How PIL imports image data: a useful reference for checking stellar.py intensitySAAW() and tools.py converter()

How our image data imported via PIL and converted to numpy array is stored

Our test image, img_2617.tif, is 1810x606 (WxH). Each element in the big list is a row, of which there are 606. Each element in the row list is a column list. Each column list has 1810 columns. Each element in the column list is a 3-element list. This three element list contains the R,G,B raw image data.

@brunston



In [2]:

    
import numpy as np
from PIL import Image



In [3]:

    
img = Image.open("IMG_2617.tif")
img_data = np.array(img)
img_data









    Out[3]:





array([[[1, 0, 0],
        [1, 0, 1],
        [1, 0, 1],
        ..., 
        [1, 0, 0],
        [3, 2, 2],
        [0, 0, 0]],

       [[1, 0, 1],
        [0, 0, 0],
        [1, 1, 1],
        ..., 
        [1, 0, 1],
        [1, 1, 1],
        [0, 0, 0]],

       [[0, 0, 0],
        [1, 0, 0],
        [1, 0, 1],
        ..., 
        [1, 0, 0],
        [0, 0, 0],
        [1, 1, 1]],

       ..., 
       [[1, 0, 1],
        [0, 0, 0],
        [0, 0, 0],
        ..., 
        [0, 0, 0],
        [0, 0, 0],
        [0, 0, 0]],

       [[2, 1, 2],
        [1, 1, 1],
        [0, 0, 0],
        ..., 
        [1, 0, 0],
        [1, 1, 1],
        [0, 0, 0]],

       [[1, 0, 0],
        [1, 0, 0],
        [1, 1, 1],
        ..., 
        [0, 0, 0],
        [0, 0, 0],
        [0, 0, 0]]], dtype=uint8)



In [4]:

    
len(img_data)









    Out[4]:





606



In [5]:

    
len(img_data[0])









    Out[5]:





1810



In [6]:

    
len(img_data[0][1])









    Out[6]:





3



In [7]:

    
np.fliplr(img_data)









    Out[7]:





array([[[0, 0, 0],
        [3, 2, 2],
        [1, 0, 0],
        ..., 
        [1, 0, 1],
        [1, 0, 1],
        [1, 0, 0]],

       [[0, 0, 0],
        [1, 1, 1],
        [1, 0, 1],
        ..., 
        [1, 1, 1],
        [0, 0, 0],
        [1, 0, 1]],

       [[1, 1, 1],
        [0, 0, 0],
        [1, 0, 0],
        ..., 
        [1, 0, 1],
        [1, 0, 0],
        [0, 0, 0]],

       ..., 
       [[0, 0, 0],
        [0, 0, 0],
        [0, 0, 0],
        ..., 
        [0, 0, 0],
        [0, 0, 0],
        [1, 0, 1]],

       [[0, 0, 0],
        [1, 1, 1],
        [1, 0, 0],
        ..., 
        [0, 0, 0],
        [1, 1, 1],
        [2, 1, 2]],

       [[0, 0, 0],
        [0, 0, 0],
        [0, 0, 0],
        ..., 
        [1, 1, 1],
        [1, 0, 0],
        [1, 0, 0]]], dtype=uint8)



In [ ]: