在django中上传到s3之前如何压缩图像? [英] how to compress the image before uploading to s3 in django?

问题描述

我正在开发一个用户可以上传图像的应用程序.我想将图像大小减小200-500kb. 这是我的models.py文件

I am working on an application where a user can upload an image. I want to reduce the size of the image in 200-500kb. This is my models.py file

class Report_item(models.Model):
    owner = models.ForeignKey(settings.AUTH_USER_MODEL)
    title = models.CharField(max_length=255, help_text='*Title for the post e.g. item identity')
    image = models.ImageField(default="add Item image",
                          upload_to=get_uplaod_file_name)


    def __str__(self):
        return self.title + "      " + str(self.publish)

这是我的views.py文件

And this is my views.py file

class ReportCreate(generic.CreateView):
model = Report_item
fields = ['title','image']

def get_form(self, form_class=None):
    if form_class is None:
        form_class = self.get_form_class()
    form = super(ReportCreate, self).get_form(form_class)
    form.fields['title'].widget = TextInput(
        attrs={'placeholder': '*Enter UID e.g. CBSE Marksheet Roll nunber 0506***'})
    return form

def form_valid(self, form):
    self.object = form.save(commit=False)
    self.object.owner = self.request.user
    self.object.save()
    return FormMixin.form_valid(self, form)

我正在使用Django 1.11和S3存储.请在上传到s3之前帮助我压缩图像.

I am using Django 1.11 and S3 storage. Kindly help me to compress the image before uploading to s3.

推荐答案

因此，我们需要在模型中定义一个save方法，以便在保存之前压缩图像.以下代码可以帮助我解决问题.

So we need to define a save method in models in order to compress the image before save. Following code help me what I want to achieve for my problem.

class Report_item(models.Model):
    owner = models.ForeignKey(settings.AUTH_USER_MODEL)
    title = models.CharField(max_length=255, help_text='*Title for the post e.g. item identity')
    
    image = models.ImageField(default="add Item image",
                              upload_to=get_uplaod_file_name)

    def save(self):
        # Opening the uploaded image
        im = Image.open(self.image)

        output = BytesIO()

        # Resize/modify the image
        im = im.resize((100, 100))

        # after modifications, save it to the output
        im.save(output, format='JPEG', quality=90)
        output.seek(0)

        # change the imagefield value to be the newley modifed image value
        self.image = InMemoryUploadedFile(output, 'ImageField', "%s.jpg" % self.image.name.split('.')[0], 'image/jpeg',
                                        sys.getsizeof(output), None)

        super(Report_item, self).save()

借助此5 Mb图像，压缩到大约4 kb.

WIth the help of this 5 Mb image compress to 4 kb approx.

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