Python/PIL Resize all images in a folder

Question

I have the following code that I thought would resize the images in the specified path But when I run it, nothing works and yet python doesn't throw any error so I don't know what to do. Please advise. Thanks.

from PIL import Image
import os, sys

path = ('C:\Users\Maxxie\color\complete')

def resize():
for item in os.listdir(path):
    if os.path.isfile(item):
        im = Image.open(item)
        f, e = os.path.splitext(item)
        imResize = im.resize((200,200), Image.ANTIALIAS)
        imResize.save(f + ' resized.jpg', 'JPEG', quality=90)

resize()

Answer 1

#!/usr/bin/python
from PIL import Image
import os, sys

path = "/root/Desktop/python/images/"
dirs = os.listdir( path )

def resize():
    for item in dirs:
        if os.path.isfile(path+item):
            im = Image.open(path+item)
            f, e = os.path.splitext(path+item)
            imResize = im.resize((200,200), Image.ANTIALIAS)
            imResize.save(f + ' resized.jpg', 'JPEG', quality=90)

resize()

Your mistake is belong to full path of the files. Instead of item must be path+item

Answer 2

In case you want to keep the same aspect ratio of the image you can use this script.

from PIL import Image
import os, sys

path = "/path/images/"
dirs = os.listdir( path )
final_size = 244;

def resize_aspect_fit():
    for item in dirs:
         if item == '.DS_Store':
             continue
         if os.path.isfile(path+item):
             im = Image.open(path+item)
             f, e = os.path.splitext(path+item)
             size = im.size
             ratio = float(final_size) / max(size)
             new_image_size = tuple([int(x*ratio) for x in size])
             im = im.resize(new_image_size, Image.ANTIALIAS)
             new_im = Image.new("RGB", (final_size, final_size))
             new_im.paste(im, ((final_size-new_image_size[0])//2, (final_size-new_image_size[1])//2))
             new_im.save(f + 'resized.jpg', 'JPEG', quality=90)
resize_aspect_fit()

Answer 3

John Ottenlips's solution created pictures with black borders on top/bottom i think because he used

  Image.new("RGB", (final_size, final_size))

which creates a square new image with the final_size as dimension, even if the original picture was not a square.

This fixes the problem and, in my opinion, makes the solution a bit clearer:

from PIL import Image
import os

path = "C:/path/needs/to/end/with/a/"
resize_ratio = 0.5  # where 0.5 is half size, 2 is double size

def resize_aspect_fit():
    dirs = os.listdir(path)
    for item in dirs:
        if item == '.jpg':
            continue
        if os.path.isfile(path+item):
            image = Image.open(path+item)
            file_path, extension = os.path.splitext(path+item)

            new_image_height = int(image.size[0] / (1/resize_ratio))
            new_image_length = int(image.size[1] / (1/resize_ratio))

            image = image.resize((new_image_height, new_image_length), Image.ANTIALIAS)
            image.save(file_path + "_small" + extension, 'JPEG', quality=90)


resize_aspect_fit()

Answer 4

Expanding on the great solution of @Sanjar Stone

for including subfolders and also avoid DS warnings you can use the glob library:

from PIL import Image
import os, sys
import glob

root_dir = "/.../.../.../"


for filename in glob.iglob(root_dir + '**/*.jpg', recursive=True):
    print(filename)
    im = Image.open(filename)
    imResize = im.resize((28,28), Image.ANTIALIAS)
    imResize.save(filename , 'JPEG', quality=90)

Answer 5

For those that are on Windows:

from PIL import Image
import glob

image_list = []
resized_images = []

for filename in glob.glob('YOURPATH\\*.jpg'):
    print(filename)
    img = Image.open(filename)
    image_list.append(img)

for image in image_list:
    image = image.resize((224, 224))
    resized_images.append(image)

for (i, new) in enumerate(resized_images):
    new.save('{}{}{}'.format('YOURPATH\\', i+1, '.jpg'))

Answer 6

This code just worked for me to resize images..

from PIL import Image
import glob
import os

# new folder path (may need to alter for Windows OS)
# change path to your path
path = 'yourpath/Resized_Shapes' #the path where to save resized images
# create new folder
if not os.path.exists(path):
    os.makedirs(path)

# loop over existing images and resize
# change path to your path
for filename in glob.glob('your_path/*.jpg'): #path of raw images
    img = Image.open(filename).resize((306,306))
    # save resized images to new folder with existing filename
    img.save('{}{}{}'.format(path,'/',os.path.split(filename)[1]))

Answer 7

Heavily borrowed the code from @Sanjar Stone. This code work well in Windows OS. Can be used to bulky resize the images and assembly back to its corresponding subdirectory.

Original folder with it subdir:
..\DATA\ORI-DIR
├─Apolo
├─Bailey
├─Bandit
├─Bella

New folder with its subdir:

..\DATA\NEW-RESIZED-DIR
├─Apolo
├─Bailey
├─Bandit
├─Bella

Gist link: https://gist.github.com/justudin/2c1075cc4fd4424cb8ba703a2527958b

from PIL import Image
import glob
import os

# new folder path (may need to alter for Windows OS)
# change path to your path
ORI_PATH = '..\DATA\ORI-DIR'
NEW_SIZE = 224
PATH = '..\DATA\NEW-RESIZED-DIR' #the path where to save resized images

# create new folder
if not os.path.exists(PATH):
    os.makedirs(PATH)

# loop over existing images and resize
# change path to your path
for filename in glob.glob(ORI_PATH+'**/*.jpg'): #path of raw images with is subdirectory
    img = Image.open(filename).resize((NEW_SIZE,NEW_SIZE))
    
    # get the original location and find its subdir
    loc = os.path.split(filename)[0]
    subdir = loc.split('\\')[1]
    
    # assembly with its full new directory
    fullnew_subdir = PATH+"/"+subdir
    name = os.path.split(filename)[1]
    
    # check if the subdir is already created or not
    if not os.path.exists(fullnew_subdir):
        os.makedirs(fullnew_subdir)
    
    # save resized images to new folder with existing filename
    img.save('{}{}{}'.format(fullnew_subdir,'/',name))

Answer 8

Expanded the answer of Andrei M. In order to only change the height of the picture and automatically size the width.

from PIL import Image
import os

path = "D:/.../.../.../resized/"
dirs = os.listdir(path)

def resize():
    for item in dirs:
        if item == '.jpg':
            continue
        if os.path.isfile(path+item):
            image = Image.open(path+item)
            file_path, extension = os.path.splitext(path+item)
            size = image.size

            new_image_height = 190
            new_image_width = int(size[1] / size[0] * new_image_height)

            image = image.resize((new_image_height, new_image_width), Image.ANTIALIAS)
            image.save(file_path + "_small" + extension, 'JPEG', quality=90)


resize()