如何将枕头图像对象保存到Django ImageField？
如何将枕头图像对象保存到Django ImageField？
提问于 2015-10-05 17:33:06
缩略图的Django模型如下：
class Thumb(models.Model):
thumb = models.ImageField(upload_to='uploads/thumb/', null=True, default=None)视图使用pillow包生成一个缩略图，并应使用如下代码将其保存在Thumb实例中：
image.thumbnail((50, 50))
inst.thumb.save('thumb.jpg', ???)为???上的inst.thumb.save制作image数据的正确方法是什么
我能够让下面的代码正常工作：
thumb_temp = NamedTemporaryFile()
image.save(thumb_temp, 'JPEG', quality=80)
thumb_temp.flush()
inst.thumb.save('thumb.jpg', File(thumb_temp))
thumb_temp.close() # Probably required to ensure temp file delete at close但是，仅仅为了将内部数据传递给inst.thumb.save而编写临时文件似乎相当笨拙，所以我想知道是否有更好的方法来做到这一点。Django class NamedTemporaryFile的文档。
回答 3
Stack Overflow用户
发布于 2017-08-28 01:43:27
下面是一个可用的示例(Python3，django 1.11)，它从Model.ImageField中获取图像，使用PIL (枕头)对其执行调整大小操作，然后将结果文件保存到相同的ImageField中。希望这应该很容易适应你必须对模型图像进行的任何处理。
from io import BytesIO
from django.core.files.uploadedfile import InMemoryUploadedFile
from django.core.files.base import ContentFile
from PIL import Image
IMAGE_WIDTH = 100
IMAGE_HEIGHT = 100
def resize_image(image_field, width=IMAGE_WIDTH, height=IMAGE_HEIGHT, name=None):
"""
Resizes an image from a Model.ImageField and returns a new image as a ContentFile
"""
img = Image.open(image_field)
if img.size[0] > width or img.size[1] > height:
new_img = img.resize((width, height))
buffer = BytesIO()
new_img.save(fp=buffer, format='JPEG')
return ContentFile(buffer.getvalue())
#assuming your Model instance is called `instance`
image_field = instance.image_field
img_name = 'my_image.jpg'
img_path = settings.MEDIA_ROOT + img_name
pillow_image = resize_image(
image_field,
width=IMAGE_WIDTH,
height=IMAGE_HEIGHT,
name=img_path)
image_field.save(img_name, InMemoryUploadedFile(
pillow_image, # file
None, # field_name
img_name, # file name
'image/jpeg', # content_type
pillow_image.tell, # size
None) # content_type_extra
)Stack Overflow用户
发布于 2018-10-23 03:41:49
您可以为您的型号创建pre_save receiver：
from io import BytesIO
from functools import partial
from django.db import models
from django.core.files.uploadedfile import InMemoryUploadedFile
from PIL import Image
class Article(models.Model):
title = models.CharField(max_length=120)
slug = models.SlugField(max_length=120, unique=True)
image = models.ImageField(
upload_to=upload_image_location
)
thumbnail_image = models.ImageField(
upload_to=partial(upload_image_location, thumbnail=True),
editable=False, blank=True
)
def create_thumbnail(self):
image = Image.open(self.image.file.file)
image.thumbnail(size=(310, 230))
image_file = BytesIO()
image.save(image_file, image.format)
self.thumbnail_image.save(
self.image.name,
InMemoryUploadedFile(
image_file,
None, '',
self.image.file.content_type,
image.size,
self.image.file.charset,
),
save=False
)
@receiver(models.signals.pre_save, sender=Article)
def prepare_images(sender, instance, **kwargs):
if instance.pk:
try:
article = Article.objects.get(pk=instance.pk)
old_image = article.image
old_thumbnail_image = article.thumbnail_image
except Article.DoesNotExist:
return
else:
new_image_extension = os.path.splitext(instance.image.name)[1]
if old_image and not old_image.name.endswith(new_image_extension):
old_image.delete(save=False)
old_thumbnail_image.delete(save=False)
if not instance.thumbnail_image or not instance.image._committed:
instance.create_thumbnail()图像缩略图是使用Pillow在create_thumbnail方法中创建的。这种方法可以很好地与django-storages一起使用，并将缩略图保存在自定义存储中，名称类似于“文章_slug_thumbnail.jpeg”。
我的upload_image_location方法：
def upload_image_location(instance, filename, thumbnail=False):
_, ext = os.path.splitext(filename)
return f'articles/{instance.slug}{f"_thumbnail" if thumbnail else ""}{ext}'Stack Overflow用户
发布于 2021-05-19 17:52:30
class Profile(models.Model):
user = models.OneToOneField(User,on_delete=models.CASCADE)
image = models.ImageField(default = 'default.jpg',upload_to='profile_pics')
def __str__(self):
return f'{self.user.username} Profile'
def save(self):
super().save()
img = Image.open(self.image.path)
if img.height >300 or img.width >300:
oputput_size = (300,300)
img.thumbnail(oputput_size)
img.save(self.image.path)页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/32945292
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