如何使用 Python 中的枕头以 1:1 的纵横比裁剪图像？

Question

I am trying to crop the image into 1:1 aspect ratio with the following code.

from PIL import Image

def crop_image(image):
    width, height = image.size
    print(width, height)
    aspect_ratio = width/float(height)

    if aspect_ratio < 1:
        bottom_offset = height/2 - width/2
        top = height - bottom_offset
        bottom = top + width
        left = 0
        right = left+width
        print((top, bottom, left, right))
        new_image = image.crop((left,top, right, bottom))
        print(new_image.size)
        new_image.save("new.jpg")

image = Image.open('test.jpg')
crop_image(image)

but it is not giving me the right output. I am using the following image: input

and it gives me the following output: output

it gives me the right dimensions but not the right output.

Answer 1

Just compare width and height to find which side should be sliced. The crop offset of two side border equals to the difference divided by 2.

Numpy

from PIL import Image
import numpy as np
def crop_image(img):
    width, height = image.size
    if width == height:
        return img
    img = np.array(img)
    offset  = int(abs(height-width)/2)
    if width>height:
        img = img[:,offset:(width-offset),:]
    else:
        img = img[offset:(height-offset),:,:]
    return Image.fromarray(img)

image = Image.open(r"test.jpg")
crop_image(image)

PIL

from PIL import Image
image = Image.open(r"test.jpg")
def crop_image(image):
    width, height = image.size
    if width == height:
        return image
    offset  = int(abs(height-width)/2)
    if width>height:
        image = image.crop([offset,0,width-offset,height])
    else:
        image = image.crop([0,offset,width,height-offset])
    return image
image = Image.open(r"test.jpg")
crop_image(image)