class Image(models.Model):
	name      = models.CharField(max_length=100,verbose_name=u'Имя картинки') 
	pos_img = models.TextField(max_length=1000,verbose_name=u'Позиция картинки')#Сдесь нужен список позиций изображения вида [[X1, Y1], [X2, Y2], ... ,[Xn, Yn]]

[[X1, Y1], [X2, Y2], ... ,[Xn, Yn]]

>>> myList = [1,2,3,4,5,'hello']
>>> import simplejson as json
>>> myJsonList = json.dumps(myList)
>>> myJsonList
'[1, 2, 3, 4, 5, "hello"]'
>>> myJsonList.__class__
<type 'str'>
>>> jsonDec = json.decoder.JSONDecoder()
>>> myPythonList = jsonDec.decode(myJsonList)
>>> myPythonList
[1, 2, 3, 4, 5, u'hello']
>>> myPythonList.__class__
<type 'list'>