PIL: Thumbnail and end up with a square image

Question

Calling

image = Image.open(data)
image.thumbnail((36,36), Image.NEAREST)

will maintain the aspect ratio. But I need to end up displaying the image like this:

<img src="/media/image.png" style="height:36px; width:36px" />

Can I have a letterbox style with either transparent or white around the image?

Edris

Answer 1

Paste the image into a transparent image with the right size as a background

from PIL import Image
size = (36, 36)
image = Image.open(data)
image.thumbnail(size, Image.LANCZOS)
background = Image.new('RGBA', size, (255, 255, 255, 0))
background.paste(
    image, (int((size[0] - image.size[0]) / 2), int((size[1] - image.size[1]) / 2))
)
background.save("output.png")

EDIT: fixed syntax error

Ninnyhammer

UPDATE: use Image.ANTIALIAS instead of Image.NEAREST to get more quality and compressed image. – Cap

NOTE: Be sure to use background.save() and not image.save() – Letti

For Python 3 replace "/" with "//" – Javelin

@Babu: Image.ANTIALIAS was deprecated in favor of Image.LANCZOS (#76616542). I updated the answers but cannot edit your comment. – Ung

Answer 2

PIL already has a function to do exactly that:

from PIL import Image, ImageOps
thumb = ImageOps.fit(image, size, Image.LANCZOS)

Kylstra

It was 2 years later... ;) This is a good answer for the question, the older answer is good to have too, in case you want to do something similar but not quite the same – Navigate

Sorry for the double post. For the sake of completeness: the first line above should read "from PIL import Image, ImageOps". (Assuming no other relevant imports elsewhere in the code.) – Navigate

This method somehow cropping my image to fit into the resolution. – Cap

That method does not apply transparency in my case. Is there any way to fix this? – Generous

Using this method does NOT produce a square image with transparent padding. – Letti

Why so many upvotes? This doesn't answer the question at all. – Squamosal

it gets lots of upvotes because this question comes up high in a Google search for python pil resize and crop and this is an elegant solution for that, its irrelevance to the OP notwithstanding. – Endosmosis

Or python PIL center image square, but this seem to crop it, indeed. – Parasiticide

Answer 3

from PIL import Image

import StringIO

def thumbnail_image():
    image = Image.open("image.png")
    image.thumbnail((300, 200))
    thumb_buffer = StringIO.StringIO()
    image.save(thumb_buffer, format=image.format)
    fp = open("thumbnail.png", "w")
    fp.write(thumb_buffer.getvalue())
    fp.close()

Musil

thumbnail won't force a square image. And what is the point of using StringIO? – Whereas

Answer 4

Update of Cesar Canassa's answer.

This will create a thumbnail of image.jpg as image_thumb.jpg:

from PIL import Image, ImageOps
fname = 'image.jpg'
size = (48,48)
thumb = ImageOps.fit(Image.open(fname), size, Image.LANCZOS)
thumb.save('{}_thumb.jpg'.format(fname[:fname.rfind('.')]), "JPEG")

Elwira

Answer 5

Or this, maybe... (forgive spaghetti)

from PIL import Image

def process_image(image, size):
    if image.size[0] > size[0] or image.size[1] > size[1]:
        #preserve original
        thumb = image.copy()
        thumb.thumbnail(size,Image.LANCZOS)
        img = thumb.copy()
    img_padded = Image.new("RGBA",size)
    img_padded.paste(image,(int((size[0]-image.size[0])/2),int((size[1]-image.size[1])/2)))
    return img_padded

Extremist

Answer 6

you can wrap Nadia's answer in this function, which gives you control over size and background.

def make_square(im, min_size=36, fill_color=(255, 255, 255, 0)):
    x, y = im.size
    size = min(min_size, x, y)
    new_im = Image.new('RGBA', (size, size), fill_color)
    im.thumbnail((256, 256))
    new_im.paste(im, (int((x - size) / 2), int((y -size) / 2))
    return new_im

Bevel

Answer 7

Why not simply use the resize method ?

from PIL import Image
image = Image.open('/path/to/img.png')
image = image.resize((36,36), Image.LANCZOS)

See recommendations for image resizing in this release note: https://pillow.readthedocs.io/en/stable/releasenotes/5.3.0.html

Subtangent

Because it squishes the image. – Whereas