gistfile1.py

from sorl.thumbnail import get_thumbnail
from django.http import HttpResponseRedirect

def responsive_image(request):
    image_path = request.GET.get('image_path')
    width = int(request.GET.get('width'))
    height = int(request.GET.get('height'))
    is_retina = bool(request.GET.get('is_retina', False))
    if is_retina:
        width *= 2
        height *= 2
    if not image_path or not width or not height:
        return HttpResponse(content='missing get parameters', status=404)
    path_ = 'http://'+request.META['HTTP_HOST'] + image_path
    thumb = get_thumbnail(path_, '%dx%d' % (width, height))
    return HttpResponseRedirect(thumb.url)