打开图像文件

from PIL import Image
im = Image.open("image.png")

使用PIL Image。Resize (size, resample=0)方法，其中将图像的(宽度，高度)替换为2元组大小。

这将显示原始大小的图像:

display(im.resize((int(im.size[0]),int(im.size[1])), 0) )

这将显示图像大小的1/2:

display(im.resize((int(im.size[0]/2),int(im.size[1]/2)), 0) )

这将显示你的图像的1/3大小:

display(im.resize((int(im.size[0]/3),int(im.size[1]/3)), 0) )

这将显示你的图像的1/4大小:

display(im.resize((int(im.size[0]/4),int(im.size[1]/4)), 0) )

等等

我还将添加一个调整大小的版本，以保持纵横比固定。 在本例中，它将根据初始宽高比asp_rat (float(!))调整高度以匹配新图像的宽度。 但是，要调整宽与高，只需在else循环中注释一行，取消注释另一行。你会看到，在哪里。

你不需要分号(;)，我保留它们只是为了提醒自己我经常使用的语言的语法。

from PIL import Image

img_path = "filename.png";
img = Image.open(img_path);     # puts our image to the buffer of the PIL.Image object

width, height = img.size;
asp_rat = width/height;

# Enter new width (in pixels)
new_width = 50;

# Enter new height (in pixels)
new_height = 54;

new_rat = new_width/new_height;

if (new_rat == asp_rat):
    img = img.resize((new_width, new_height), Image.ANTIALIAS); 

# adjusts the height to match the width
# NOTE: if you want to adjust the width to the height, instead -> 
# uncomment the second line (new_width) and comment the first one (new_height)
else:
    new_height = round(new_width / asp_rat);
    #new_width = round(new_height * asp_rat);
    img = img.resize((new_width, new_height), Image.ANTIALIAS);

# usage: resize((x,y), resample)
# resample filter -> PIL.Image.BILINEAR, PIL.Image.NEAREST (default), PIL.Image.BICUBIC, etc..
# https://pillow.readthedocs.io/en/3.1.x/reference/Image.html#PIL.Image.Image.resize

# Enter the name under which you would like to save the new image
img.save("outputname.png");

这样就完成了。我尽我所能记录下来，所以很清楚。

我希望这对外面的人有所帮助!

我用这种方法调整了图像的大小，效果很好

from io import BytesIO
from django.core.files.uploadedfile import InMemoryUploadedFile
import os, sys
from PIL import Image


def imageResize(image):
    outputIoStream = BytesIO()
    imageTemproaryResized = imageTemproary.resize( (1920,1080), Image.ANTIALIAS) 
    imageTemproaryResized.save(outputIoStream , format='PNG', quality='10') 
    outputIoStream.seek(0)
    uploadedImage = InMemoryUploadedFile(outputIoStream,'ImageField', "%s.jpg" % image.name.split('.')[0], 'image/jpeg', sys.getsizeof(outputIoStream), None)

    ## For upload local folder
    fs = FileSystemStorage()
    filename = fs.save(uploadedImage.name, uploadedImage)

# Importing Image class from PIL module
from PIL import Image

# Opens a image in RGB mode
im = Image.open(r"C:\Users\System-Pc\Desktop\ybear.jpg")

# Size of the image in pixels (size of original image)
# (This is not mandatory)
width, height = im.size

# Setting the points for cropped image
left = 4
top = height / 5
right = 154
bottom = 3 * height / 5

# Cropped image of above dimension
# (It will not change original image)
im1 = im.crop((left, top, right, bottom))
newsize = (300, 300)
im1 = im1.resize(newsize)
# Shows the image in image viewer
im1.show()

这个脚本将使用PIL (Python成像库)将图像(somepic.jpg)调整为300像素的宽度和与新宽度成比例的高度。它通过确定300像素是原始宽度(img.size[0])的百分比，然后将原始高度(img.size[1])乘以该百分比来实现这一点。将“basewidth”更改为任何其他数字以更改图像的默认宽度。

from PIL import Image

basewidth = 300
img = Image.open('somepic.jpg')
wpercent = (basewidth/float(img.size[0]))
hsize = int((float(img.size[1])*float(wpercent)))
img = img.resize((basewidth,hsize), Image.Resampling.LANCZOS)
img.save('somepic.jpg')

import cv2
from skimage import data 
import matplotlib.pyplot as plt
from skimage.util import img_as_ubyte
from skimage import io
filename='abc.png'
image=plt.imread(filename)
im=cv2.imread('abc.png')
print(im.shape)
im.resize(300,300)
print(im.shape)
plt.imshow(image)