Django表格ImageField验证一定宽度和高度

Question

我正在尝试以表单级别验证图像维度，并在提交的照片不符合图像尺寸1080x1920的要求上向用户显示一条消息。我不想将宽度和高度大小存储在数据库中。我尝试使用ImageField宽度和高度属性。但这是行不通的。

class Adv(models.Model):
    image = models.ImageField(upload_to=r'photos/%Y/%m/',
        width_field = ?,
        height_field = ?,
        help_text='Image size: Width=1080 pixel. Height=1920 pixel',

Answer 1

您可以通过两种方式进行

1. 模型中的验证

   来自django.core.corpeptions导入验证

   def validate_image(image):
       max_height = 1920
       max_width = 1080
       height = image.file.height 
       width = image.file.width
       if width > max_width or height > max_height:
           raise ValidationError("Height or Width is larger than what is allowed")
   class Photo(models.Model):
       image = models.ImageField('Image', upload_to=image_upload_path, validators=[validate_image])
   

2. 以形式清洁

           def clean_image(self):
               image = self.cleaned_data.get('image', False)
               if image:
                   if image._height > 1920 or image._width > 1080:
                       raise ValidationError("Height or Width is larger than what is allowed")
                   return image
               else:
                   raise ValidationError("No image found")
   

Answer 2

我们需要一个图像处理库（例如pi）来检测图像维度，这是正确的解决方案：

# Custom validator to validate the maximum size of images
def maximum_size(width=None, height=None):
    from PIL import Image
    def validator(image):
        img = Image.open(image)
        fw, fh = img.size
        if fw > width or fh > height:
            raise ValidationError(
            "Height or Width is larger than what is allowed")
     return validator

然后在模型中：

class Photo(models.Model):
    image = models.ImageField('Image', upload_to=image_upload_path, validators=[maximum_size(128,128)])