Resizing images on Google Colab using Python Pillow

Question

I've my ipynb and a folder named PRimage (with 100+ images) in my google drive and my drive is already mounted at /content/drive. My images are arranged in sequence eg. 1_1.jpg, 1_2.jpg and so on. I'm trying to use a for loop to resize all images, like this:

from google.colab import drive
drive.mount('/content/drive')

from os import listdir
from matplotlib import image
from PIL import Image

loaded_images = list()
for filename in listdir('/content/drive/My Drive/PRimage'):
  img_data = image.imread('/content/drive/My Drive/PRimage/'+ filename)
  loaded_images.append(img_data)
  print('> loaded %s %s' % (filename, img_data.shape))

def resize():
    files = listdir('/content/drive/My Drive/PRimage')
    for item in files:
            image = Image.open(item)
            image.thumbnail((64,64))
            print(image.size)

resize()

However, I get this error message:

Answer 1

Insert a new code cell and use pwd to check your present working directory. Make sure it is at /content/drive/My Drive/PRimage. Use cd /content/drive/My\ Drive/PRimage to change dirs. Your FileNotFoundError is the cause of your unknown pwd. Always look for your root working dirs in such cases. Your code executes from pwd and expects the similar dir structure within it.

Helper function to resize image

def resize_image(src_img, size=(64,64), bg_color="white"): 
    from PIL import Image

    # rescale the image so the longest edge is the right size
    src_img.thumbnail(size, Image.ANTIALIAS)

    # Create a new image of the right shape
    new_image = Image.new("RGB", size, bg_color)

    # Paste the rescaled image onto the new centered background
    new_image.paste(src_img, (int((size[0] - src_img.size[0]) / 2), int((size[1] - src_img.size[1]) / 2)))

    # return the resized image
    return new_image


# get the list of test image files
test_folder = '/content/drive/My Drive/PRimage'
test_image_files = os.listdir(test_folder)

# Empty array on which to store the images
image_arrays = []
size = (64,64)
background_color="white"

# Get the images
for file_idx in range(len(test_image_files)):
    img = Image.open(os.path.join(test_folder, test_image_files[file_idx]))

    # resize the image
    resized_img = np.array(resize_image(img, size, background_color))

    # Add the image to the array of images
    image_arrays.append(resized_img)