这是我的form .py:
class UploadImageForm(forms.ModelForm):
class Meta:
model = UserImages
fields = ['photo']
这是我的models.py:
class UserImages(models.Model):
user = models.ForeignKey(User)
photo = models.ImageField(upload_to=get_file_path)
，这是我的观点:
def uploadImageView(request):
if request.method == 'POST':
form = UploadImageForm(request.POST, request.FILES)
if form.is_valid():
instance = form.save(commit=False)
instance.user = request.user
instance.save()
return redirect('/')
else:
form = UploadImageForm()
return render(request, 'uploadImagePage.html', {'uploadImageForm': form})
但是这只保存正在上传的图像。我如何保存图像的缩略图版本以及与图像的缩略图版本具有完全相同的名称，除了后面的单词"缩略图"?
我读的教程说我能做到
im = Image.open(infile)
im.thumbnail(size, Image.ANTIALIAS)
来获取缩略图，但在我的情况下，图像甚至还没有保存
根据xjtian的回答。这适用于Python 3:
import os.path
from PIL import Image
from io import BytesIO
from django.core.files.base import ContentFile
from .my_app_settings import THUMB_SIZE
class Photo(models.Model):
photo = models.ImageField(upload_to='photos')
thumbnail = models.ImageField(upload_to='thumbs', editable=False)
def save(self, *args, **kwargs):
if not self.make_thumbnail():
# set to a default thumbnail
raise Exception('Could not create thumbnail - is the file type valid?')
super(Photo, self).save(*args, **kwargs)
def make_thumbnail(self):
image = Image.open(self.photo)
image.thumbnail(THUMB_SIZE, Image.ANTIALIAS)
thumb_name, thumb_extension = os.path.splitext(self.photo.name)
thumb_extension = thumb_extension.lower()
thumb_filename = thumb_name + '_thumb' + thumb_extension
if thumb_extension in ['.jpg', '.jpeg']:
FTYPE = 'JPEG'
elif thumb_extension == '.gif':
FTYPE = 'GIF'
elif thumb_extension == '.png':
FTYPE = 'PNG'
else:
return False # Unrecognized file type
# Save thumbnail to in-memory file as StringIO
temp_thumb = BytesIO()
image.save(temp_thumb, FTYPE)
temp_thumb.seek(0)
# set save=False, otherwise it will run in an infinite loop
self.thumbnail.save(thumb_filename, ContentFile(temp_thumb.read()), save=False)
temp_thumb.close()
return True
要做到这一点，你应该添加一个新的ImageField到你当前的UserImages模型来保存缩略图，然后覆盖你的save方法来创建和保存完整的图像保存后的缩略图。
我从我的一个项目中改编了下面的代码片段，我很确定它会做你需要做的事情:
from cStringIO import StringIO
import os
from django.db import models
from django.core.files.base import ContentFile
from django.core.files.storage import default_storage as storage
from PIL import Image
# Thumbnail size tuple defined in an app-specific settings module - e.g. (400, 400)
from app.settings import THUMB_SIZE
class Photo(models.Model):
"""
Photo model with automatically generated thumbnail.
"""
photo = models.ImageField(upload_to='photos')
thumbnail = models.ImageField(upload_to='thumbs', editable=False)
def save(self, *args, **kwargs):
"""
Make and save the thumbnail for the photo here.
"""
super(Photo, self).save(*args, **kwargs)
if not self.make_thumbnail():
raise Exception('Could not create thumbnail - is the file type valid?')
def make_thumbnail(self):
"""
Create and save the thumbnail for the photo (simple resize with PIL).
"""
fh = storage.open(self.photo.name, 'r')
try:
image = Image.open(fh)
except:
return False
image.thumbnail(THUMB_SIZE, Image.ANTIALIAS)
fh.close()
# Path to save to, name, and extension
thumb_name, thumb_extension = os.path.splitext(self.photo.name)
thumb_extension = thumb_extension.lower()
thumb_filename = thumb_name + '_thumb' + thumb_extension
if thumb_extension in ['.jpg', '.jpeg']:
FTYPE = 'JPEG'
elif thumb_extension == '.gif':
FTYPE = 'GIF'
elif thumb_extension == '.png':
FTYPE = 'PNG'
else:
return False # Unrecognized file type
# Save thumbnail to in-memory file as StringIO
temp_thumb = StringIO()
image.save(temp_thumb, FTYPE)
temp_thumb.seek(0)
# Load a ContentFile into the thumbnail field so it gets saved
self.thumbnail.save(thumb_filename, ContentFile(temp_thumb.read()), save=True)
temp_thumb.close()
return True
我是根据ziiiro的回答写的。它可以在Django2.2.1中正常工作。需要保存图像字段路径的进程。
models.py
from django.db import models
from my.images import make_thumbnail
class Image(models.Model):
image = models.ImageField(upload_to='')
thumbnail = models.ImageField(upload_to='', editable=False)
icon = models.ImageField(upload_to='', editable=False)
def save(self, *args, **kwargs):
# save for image
super(Image, self).save(*args, **kwargs)
make_thumbnail(self.thumbnail, self.image, (200, 200), 'thumb')
make_thumbnail(self.icon, self.image, (100, 100), 'icon')
# save for thumbnail and icon
super(Image, self).save(*args, **kwargs)
my.images.py
from django.core.files.base import ContentFile
import os.path
from PIL import Image
from io import BytesIO
def make_thumbnail(dst_image_field, src_image_field, size, name_suffix, sep='_'):
"""
make thumbnail image and field from source image field
@example
thumbnail(self.thumbnail, self.image, (200, 200), 'thumb')
"""
# create thumbnail image
image = Image.open(src_image_field)
image.thumbnail(size, Image.ANTIALIAS)
# build file name for dst
dst_path, dst_ext = os.path.splitext(src_image_field.name)
dst_ext = dst_ext.lower()
dst_fname = dst_path + sep + name_suffix + dst_ext
# check extension
if dst_ext in ['.jpg', '.jpeg']:
filetype = 'JPEG'
elif dst_ext == '.gif':
filetype = 'GIF'
elif dst_ext == '.png':
filetype = 'PNG'
else:
raise RuntimeError('unrecognized file type of "%s"' % dst_ext)
# Save thumbnail to in-memory file as StringIO
dst_bytes = BytesIO()
image.save(dst_bytes, filetype)
dst_bytes.seek(0)
# set save=False, otherwise it will run in an infinite loop
dst_image_field.save(dst_fname, ContentFile(dst_bytes.read()), save=False)
dst_bytes.close()
另一个解决方案是正确的，但当实现为个人资料图片时失败。可以肯定的是，个人资料将不仅仅是一张图片和一个缩略图。如果任何其他字段更新了，而个人资料图片没有更新，您可能会遇到一些不同的问题。为了避免这种情况，您必须实现原始文件名与更新时返回的文件名的比较。如果个人资料图片未更新，则不希望保存缩略图。设置一个类字符串为None，并在运行make_thumbnail之前进行比较。
import os.path
from PIL import Image
from io import BytesIO
from django.core.files.base import ContentFile
from .my_app_settings import THUMB_SIZE
class Photo(models.Model):
photo = models.ImageField(upload_to='photos')
thumbnail = models.ImageField(upload_to='thumbs', editable=False)
# Class string added to store original name of photo
original_photo_name = None
# When the form is initialized save the original photo name
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.original_photo_name = self.photo.name
def save(self, *args, **kwargs):
# This checks if the photo was updated or not before saving a thumbnail
if self.original_photo_name != self.photo.name:
if not self.make_thumbnail():
# set to a default thumbnail
raise Exception('Could not create thumbnail - is the file type valid?')
super(Photo, self).save(*args, **kwargs)
def make_thumbnail(self):
image = Image.open(self.photo)
image.thumbnail(THUMB_SIZE, Image.ANTIALIAS)
thumb_name, thumb_extension = os.path.splitext(self.photo.name)
thumb_extension = thumb_extension.lower()
thumb_filename = thumb_name + '_thumb' + thumb_extension
if thumb_extension in ['.jpg', '.jpeg']:
FTYPE = 'JPEG'
elif thumb_extension == '.gif':
FTYPE = 'GIF'
elif thumb_extension == '.png':
FTYPE = 'PNG'
else:
return False # Unrecognized file type
# Save thumbnail to in-memory file as StringIO
temp_thumb = BytesIO()
image.save(temp_thumb, FTYPE)
temp_thumb.seek(0)
# set save=False, otherwise it will run in an infinite loop
self.thumbnail.save(thumb_filename, ContentFile(temp_thumb.read()), save=False)
temp_thumb.close()
return True
如果你不想从头开始实现解决方案，我建议你使用一个名为sorl-thumbnail的django应用
您可能忘记保存文件了:
im.save(file + ".thumbnail", "JPEG")
看到http://effbot.org/imagingbook/image.htm示例
有一个超级简单的方法，
在模型:def upload_thumb_dir(self, filename):
path = f'path_to_thumb.jpg'
return path
thumb = ProcessedImageField(upload_to=upload_thumb_dir,
processors=[ResizeToFill(192, 108)],
max_length= 255,
format='JPEG',
default='preview.jpg',
options={'quality': 80},
null=True, blank=True
)
# ...
def save(self, *args, **kwargs):
self.thumb = self.rawfile.file
super(VersionPreviews, self).save(*args, **kwargs)