read dynamic number of images of same shape into Python NumPy array

Question

I have this code:

image_list = []
for filename in glob.glob('C:\\Users\\Utilizador\\Desktop\\menu\\*.jpg'): 
    im=cv2.imread(filename)
    image_list.append(im)

This creates me a list of images, but I need it to be in an array form with shape (num_of_images, width, height, 3)

All images have the same shape Any ideas? Thanks

Answer 1

Since all images have same shape, we can create an empty array and then read each image into that.

In [103]: file_path = 'C:\\Users\\Utilizador\\Desktop\\menu\\*.jpg'
In [104]: num_imgs = len(glob.glob(file_path))
In [105]: width, height, channels = 512, 512, 3

In [106]: batch_arr = np.empty((num_imgs, width, height, channels), dtype=np.uint8)

In [107]: for idx, filename in enumerate(glob.glob(file_path)):
              img = cv2.imread(filename)
              # if img is of different width and height than defined above
              # do some resize and then insert in the array.
              batch_arr[idx] = img