How can I view images stored with a .npy extension and save my own files in that format?
Advertisement
Answer
.npy is the file extension for numpy arrays – you can read them using numpy.load:
import numpy as np
img_array = np.load('filename.npy')
One of the easiest ways to view them is using matplotlib’s imshow function:
from matplotlib import pyplot as plt plt.imshow(img_array, cmap='gray') plt.show()
You could also use PIL or pillow:
from PIL import Image im = Image.fromarray(img_array) # this might fail if `img_array` contains a data type that is not supported by PIL, # in which case you could try casting it to a different dtype e.g.: # im = Image.fromarray(img_array.astype(np.uint8)) im.show()
These functions aren’t part of the Python standard library, so you may need to install matplotlib and/or PIL/pillow if you haven’t already. I’m also assuming that the files are either 2D [rows, cols] (black and white) or 3D [rows, cols, rgb(a)] (color) arrays of pixel values.
