Django Dateiuploads mit ImageField Validierung

from django import forms
from django.core.exceptions import ValidationError
import magic
 
class ProfilePictureForm(forms.Form):
    picture = forms.ImageField()
    
    def clean_picture(self):
        image = self.cleaned_data['picture']
        # Validate file type using magic bytes
        mime_type = magic.from_buffer(image.read(1024), mime=True)
        image.seek(0)  # Reset file pointer after reading
        allowed_types = ['image/jpeg', 'image/png', 'image/webp']
        if mime_type not in allowed_types:
            raise ValidationError('Unsupported file format')
        # Validate file size (max 5MB)
        if image.size > 5 * 1024 * 1024:
            raise ValidationError('Image size cannot exceed 5MB')
        # Validate dimensions
        img = Image.open(image)
        if img.width < 200 or img.height < 200:
            raise ValidationError('Image must be at least 200x200 pixels')
        return image