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

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

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()

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

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 5

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 6

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)