PIL对上传到Django的图片进行处理并保存的实例

pic = request.FILES["picture"]
# pic是 <class 'django.core.files.uploadedfile.InMemoryUploadedFile'> 类型的数据

# 而pillow的Image.open("./xxx.jpg") 则是：

<class 'PIL.JpegImagePlugin.JpegImageFile'> 类型的数据

# 问题是如何把InMemoryUploadedFile转化为PIL类型，并且处理之后再转回InMemoryUploadedFile，并save

from PIL import Image

pic = request.FILES["picture"]
im_pic = Image.open(pic)
# 这样就把InMemoryUploadedFile转化为了PIL类型数据，pic是InMemoryUploadedFile，im_pic是PIL类型

w, h = im_pic.size
if w >= h:
  w_start = (w-h)*0.618
  box = (w_start, 0, w_start+h, h)
  region = im_pic.crop(box)
else:
  h_start = (h-w)*0.618
  box = (0, h_start, w, h_start+w)
  region = im_pic.crop(box)

# region就是PIL处理后的正方形了

from io import BytesIO
from django.core.files.uploadedfile import InMemoryUploadedFile

// 先保存到磁盘io
pic_io = BytesIO()
region.save(pic_io, im_pic.format)
// 再转化为InMemoryUploadedFile数据
pic_file = InMemoryUploadedFile(
  file=pic_io,
  field_name=None,
  name=pic.name,
  content_type=pic.content_type,
  size=pic.size,
  charset=None
)

from ./models import Picture

p = Picture(picture=pic_file)
p.save()