Python Pillow trying to change resolution of photo while same proportion-CodePudding

I'm trying to create something with Pillow. The Problem is the following. I have a photo like with a resolution of 612 * 563.

I would like to change the height of this photo while the Proportion stays like in picture one. If I try to change the resolution for instance to 612 * 500 the tire gets wider.

That's not how I want it. Is there a way in pillow how I can change the resolution (height) of the photo while keeping the original proportions?

I have now added the following code, which was given by Kris. Unfortunately it still does not seem to work.

Code Sample Python

Python does not say that theres a mistake but it does not save a file at all. The new picture should be saved under the name "ReifenTest1" or am I wrong?

CodePudding user response：

Well, you need to resize maintaining aspect ratio. Then it will be ok. See an example here.

def auto_resize(image_im: Image.Image, max_height):
    if image_im:
        width, height = image_im.size # get the current size
        if height > max_height:
            aspect = width / height # find the aspect ratio
            r_height = max_height # Set your needed height
            r_width = int(r_height * aspect) #Calcualte the width for lock on proportions
            image_im = image_im.resize((r_width, r_height)) # resize then!
    return image_im

CodePudding user response：

You can just use the thumbnail method from PIL to obtain a resized image that keeps the original aspect ratio.

from PIL import Image

target_width = 612
target_height = 500
maxsize = (target_width, target_height)
path_to_the_image = /path/to/the/image
image = Image.open(path_to_the_image)
image.thumbnail(maxsize, Image.ANTIALIAS)
image.save("resized-image.*") # change the * for png/jpeg/etc