这似乎是一个非常容易的问题,但我无法弄清楚这里发生了什么。 基本上,我想要做的是在Django模型上从一个图像创建两个不同的缩略图。最终发生的事情是,它似乎是循环并重新创建相同的图像(每次向它附加一个下划线),直到它抛出一个文件名大的错误。所以,你最终得到的结果是:
OSError: [Errno 36] File name too long: 'someimg________________etc.jpg'
以下是代码(保存方法在Artist模型上):
def save(self, *args, **kwargs):
if self.image:
iname = os.path.split(self.image.name)[-1]
fname, ext = os.path.splitext(iname)
tlname, tsname = fname + '_thumb_l' + ext, fname + '_thumb_s' + ext
self.thumb_large.save(tlname, make_thumb(self.image, size=(250,250)))
self.thumb_small.save(tsname, make_thumb(self.image, size=(100,100)))
super(Artist, self).save(*args, **kwargs)
def make_thumb(infile, size=(100,100)):
infile.seek(0)
image = Image.open(infile)
if image.mode not in ('L', 'RGB'):
image.convert('RGB')
image.thumbnail(size, Image.ANTIALIAS)
temp = StringIO()
image.save(temp, 'png')
return ContentFile(temp.getvalue())
为了简洁起见,我没有展示进口产品。假设Artist模型上有两个ImageField:thumb_large和thumb_small。
我测试的方式是否有效,在shell中:
artist = Artist.objects.get(id=1)
artist.save()
#error here after a little wait (until I assume it generates enough images that the OSError gets raised)
如果这不是正确的方法,我会很感激任何反馈。谢谢!
答案 0 :(得分:3)
通常我喜欢尽可能为模板作者提供缩略图功能。这样他们就可以调整模板中的东西大小。而将其构建到业务逻辑层则更加固定。你可能有理由。
此模板过滤器应在首次加载时生成文件,然后在将来加载时加载文件。虽然我认为我添加了中心裁剪功能,但它很久以前就借鉴了一些博客。其他人很可能拥有更多功能。
{% load thumbnailer %}
...
<img src="{{someimage|thumbnail_crop:'200x200'}}" />
file appname / templatetags / thumbnailer.py
import os
import Image
from django.template import Library
register.filter(thumbnail)
from settings import MEDIA_ROOT, MEDIA_URL
def thumbnail_crop(file, size='104x104', noimage=''):
# defining the size
x, y = [int(x) for x in size.split('x')]
# defining the filename and the miniature filename
try:
filehead, filetail = os.path.split(file.path)
except:
return '' # '/media/img/noimage.jpg'
basename, format = os.path.splitext(filetail)
#quick fix for format
if format.lower() =='.gif':
return (filehead + '/' + filetail).replace(MEDIA_ROOT, MEDIA_URL)
miniature = basename + '_' + size + format
filename = file.path
miniature_filename = os.path.join(filehead, miniature)
filehead, filetail = os.path.split(file.url)
miniature_url = filehead + '/' + miniature
if os.path.exists(miniature_filename) and os.path.getmtime(filename)>os.path.getmtime(miniature_filename):
os.unlink(miniature_filename)
# if the image wasn't already resized, resize it
if not os.path.exists(miniature_filename):
try:
image = Image.open(filename)
except:
return noimage
src_width, src_height = image.size
src_ratio = float(src_width) / float(src_height)
dst_width, dst_height = x, y
dst_ratio = float(dst_width) / float(dst_height)
if dst_ratio < src_ratio:
crop_height = src_height
crop_width = crop_height * dst_ratio
x_offset = float(src_width - crop_width) / 2
y_offset = 0
else:
crop_width = src_width
crop_height = crop_width / dst_ratio
x_offset = 0
y_offset = float(src_height - crop_height) / 3
image = image.crop((x_offset, y_offset, x_offset+int(crop_width), y_offset+int(crop_height)))
image = image.resize((dst_width, dst_height), Image.ANTIALIAS)
try:
image.save(miniature_filename, image.format, quality=90, optimize=1)
except:
try:
image.save(miniature_filename, image.format, quality=90)
except:
return '' #'/media/img/noimage.jpg'
return miniature_url
register.filter(thumbnail_crop)