Resizing several images

[Lenou]

Hello! Do someone know if it is possible to resize multiple images with a script even through they have different sizes?

[Abambo]

Yes, it is possible. But you need to define the criteria. How will the final size be determined?

[D Fosse · Accepted solution]

If the goal is a standard size, File > Automate > Fit Image is what you want for this. It can be used in actions, a script is not necessary.

It will work on both portrait and landscape, resizing the longest side. It can either enlarge if applicable, or not.

[Lenou]

Thank you very much! It seems to work well!

[DDmUSA]

I need to process a bunch of images and based on which dimension is larger, the width or the height, I need to resize the larger dimension to 800 pixels and have the other dimension auto-calculate to some number.  How is this achieved?  I looked at the File...Automate....Fit Image, and I see the contrain within boxes.  If I specify 80o pixles in both boxes, will this process only set the larger dimension to 800?  I guess I can give it a try while I wait for your response.

[DDmUSA]

I tried creating an action to Fit the Image within 800 x 800 pixels and then get the canvas size to 800 x 800 pixels and then save as PNG.  When I look at the output folder, the images are not being saved as 800 x 800.  I suspect the canvas size is not working.

[Stephen Marsh]

I tried creating an action to Fit the Image within 800 x 800 pixels and then get the canvas size to 800 x 800 pixels and then save as PNG.  When I look at the output folder, the images are not being saved as 800 x 800.  I suspect the canvas size is not working.

By @DDmUSA

When set to 800x800px, the longest edge will be resized to 800px, with the shortest edge proportionally smaller.

What size is the original? What is the size after fit image?

[Ayla_6644]

1. Python Solution (PIL - Pillow)

You can use the Pillow (PIL) library to resize multiple images in a folder, regardless of their original sizes.

Example: Resize all images to 500x500 pixels

python

from PIL import Image import os input_folder = "images/" # Folder containing images output_folder = "resized_images/" # Output folder # Create output directory if it doesn't exist os.makedirs(output_folder, exist_ok=True) # Loop through all images in the input folder for filename in os.listdir(input_folder): if filename.endswith((".jpg", ".jpeg", ".png", ".bmp", ".gif")): img_path = os.path.join(input_folder, filename) img = Image.open(img_path) # Resize the image while maintaining aspect ratio img_resized = img.resize((500, 500), Image.ANTIALIAS) # Save the resized image img_resized.save(os.path.join(output_folder, filename)) print("Batch image resizing completed!")

✔ This script resizes all images in the images/ folder and saves them to resized_images/.

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2. Python Solution (OpenCV)

If you prefer OpenCV, use the following script:

python

import cv2 import os input_folder = "images/" output_folder = "resized_images/" os.makedirs(output_folder, exist_ok=True) for filename in os.listdir(input_folder): if filename.endswith((".jpg", ".jpeg", ".png")): img_path = os.path.join(input_folder, filename) img = cv2.imread(img_path) # Resize image while keeping aspect ratio img_resized = cv2.resize(img, (500, 500)) cv2.imwrite(os.path.join(output_folder, filename), img_resized) print("Images resized successfully!")

3. Using ImageMagick (Command Line)

If you prefer a command-line approach, ImageMagick can resize all images in a folder:

bash

magick mogrify -path resized_images -resize 500x500 images/*.jpg

✔ This command resizes all .jpg images in the images/ folder and saves them to resized_images/.

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Which One Should You Use?

• :white_heavy_check_mark: Python (PIL or OpenCV) – Best for automation in scripts or web applications.

• :white_heavy_check_mark: ImageMagick – Fastest for bulk resizing via command line