Question

我有一个应用程序，用于存储上传的文件（图像，zip，视频..等）。我使用模型FileField来处理上传。问题是上传图像时我想调整图像大小并将其保存在模型中的另一个字段（拇指）中。

这是我的models.py

class Files(models.Model):
    file = models.FileField(upload_to=upload_path())
    thumb =  models.CharField(max_length=255,default=None,blank=True , null=True)
    user = models.ForeignKey(User, null=True,blank=True)
    date =  models.DateTimeField('date added',blank=True, null=True)

文件用于存储原始文件网址， thumb 用于存储缩略图网址。

我知道我们可以使用PIL进行调整大小，但我是python的新手，我不知道如何使用它并将其保存在应用程序中。

Answer 1

这是我为我的烧瓶应用程序网站编写的模块，但您可以为Django应用程序更改它并使用它。它创建缩略图和裁剪图像。对我来说非常有用：

"""
usage: <img src="{{ thumbnail('files/'+media.path, '150x150') }}" alt="" />
"""

# python imports
import os
import errno
import traceback

try:
    from PIL import Image, ImageOps
except ImportError:
    raise RuntimeError('Image module of PIL needs to be installed')


class Thumbnail(object):

    def __init__(self, app=None):
        if app is not None:
            self.init_app(self.app)
        else:
            self.app = None

    def init_app(self, app):
        self.app = app

        if not self.app.config.get('MEDIA_FOLDER', None):
            raise RuntimeError('You\'re using the flask-thumbnail app '
                               'without having set the required MEDIA_FOLDER setting.')

        if not self.app.config.get('THUMBNAIL_FOLDER', None):
            raise RuntimeError(
                'You didn\'t set THUMBNAIL_FOLDER setting.')

        app.config.setdefault('THUMBNAIL_FOLDER', os.path.join(self.app.config['MEDIA_FOLDER'], 'thumbnail'))
        app.config.setdefault('MEDIA_URL', '/media/')
        app.config.setdefault('THUMBNAIL_URL', os.path.join(self.app.config['MEDIA_URL'], 'thumbnail'))

        app.jinja_env.globals['thumbnail'] = self.thumbnail

    def thumbnail(self, img_url, size, crop=None, bg=None, quality=92):
        """

        :param img_url: url img - '/assets/media/summer.jpg'
        :param size: size return thumb - '100x100'
        :param crop: crop return thumb - 'fit' or None
        :param bg: tuple color or None - (255, 255, 255, 0)
        :param quality: JPEG quality 1-100
        :return: :thumb_url:
        """
        try:
            width, height = [int(x) for x in size.split('x')]
            url_path, img_name = os.path.split(img_url)
            name, fm = os.path.splitext(img_name)

            miniature = self._get_name(name, fm, size, crop, bg, quality)

            original_filename = os.path.join(
                self.app.config['MEDIA_FOLDER'],
                url_path,
                img_name)
            thumb_filename = os.path.join(
                self.app.config['THUMBNAIL_FOLDER'],
                miniature)

            # create folders
            self._get_path(thumb_filename)

            thumb_url = os.path.join(
                self.app.config['THUMBNAIL_URL'],
                miniature)

            if os.path.exists(thumb_filename):
                return thumb_url

            elif not os.path.exists(thumb_filename):
                thumb_size = (width, height)
                try:
                    image = Image.open(original_filename)
                except IOError:
                    return None

                if crop == 'fit':
                    img = ImageOps.fit(image, thumb_size, Image.ANTIALIAS)
                else:
                    img = image.copy()
                    img.thumbnail((width, height), Image.ANTIALIAS)

                if bg:
                    img = self._bg_square(img, bg)

                img.save(thumb_filename, image.format, quality=quality)

                return thumb_url
        except Exception, e:
            traceback.print_exc()
            print(e.message)

    @staticmethod
    def _bg_square(img, color=0xff):
        size = (max(img.size),) * 2
        layer = Image.new('L', size, color)
        layer.paste(
            img, tuple(map(lambda x: (x[0] - x[1]) / 2, zip(size, img.size))))
        return layer

    @staticmethod
    def _get_path(full_path):
        directory = os.path.dirname(full_path)

        try:
            if not os.path.exists(full_path):
                os.makedirs(directory)
        except OSError as e:
            if e.errno != errno.EEXIST:
                raise

    @staticmethod
    def _get_name(name, fm, *args):
        for v in args:
            if v:
                name += '_%s' % v
        name += fm

        return name

Answer 2

这就是我的工作方式。

from django.core.files.uploadedfile import InMemoryUploadedFile

def create_thumbnail(obj, ext=None):
    imaged, imgformat = resize_and_crop(obj.file, (150, 150),crop_type='middle' )
    thumb_io = BytesIO()
    imaged.save(thumb_io,  format=imgformat, quality=92)
    new_file_name = u'thumb-' + str(obj.file.name)
    thumbfile = InMemoryUploadedFile(thumb_io,
                            u"thumb", # important to specify field name here
                            new_file_name,
                            ext,
                            thumb_io,
                            None)
    return thumbfile

class Files(models.Model):
    file = models.FileField(upload_to=upload_path())
    thumb =  models.FileField(max_length=255,default=None,blank=True , null=True)
    user = models.ForeignKey(User, null=True,blank=True)
    date =  models.DateTimeField('date added',blank=True, null=True)

    def save(self, *args, **kwargs):
        self.url = create_thumbnail(self, ext)       
        return super(MediaUpload, self).save(*args, **kwargs)

resize_and_crop（）引用此excellent script。

此处的重点是使用InMemoryUploadedFile将文件保存在内存中并将其传递给FileField以完成剩余的工作。

如何调整图像大小并保存 - django

2 个答案: