Python: 如何使用 PIL 模块调整图像大小

Python: How to resize an image using PIL module

我正在尝试将图像的大小调整为 500x500 像素,但出现此错误:

File "C:\Python27\lib\site-packages\PIL\Image.py", line 1681, in save
     save_handler = SAVE[format.upper()] KeyError: 'JPG'

这是代码:

from PIL import Image
img = Image.open('car.jpg')
new_img = img.resize((500,500))
new_img.save('car_resized','jpg')

您需要在调用保存函数时将格式参数设置为'JPEG':

from PIL import Image
img = Image.open('car.jpg')
new_img = img.resize((500,500))
new_img.save("car_resized.jpg", "JPEG", optimize=True)

解决方法如下:

from PIL import Image
img = Image.open('car.jpg')
new_img = img.resize((500,500), Image.ANTIALIAS)
quality_val = 90 ##you can vary it considering the tradeoff for quality vs performance
new_img.save("car_resized.jpg", "JPEG", quality=quality_val)

PIL 中有重采样技术列表,如 ANTIALIASBICUBICBILINEARCUBICANTIALIAS 被认为是缩小规模的最佳选择。