I am creating a django-cms site for a client. I would like to do something like:
You are on the right track, once that's there when all you need is the plugin which in this case you can use filer. And to make it better you can use the CMS_PLACEHOLDER_CONF setting to only allow that one plugin to be placeholder inside the background-image placeholder, like so:
CMS_PLACEHOLDER_CONF = {
'background-image': {
"plugins": ('YourImagePlugin', ),
'name':"Background Image",
'limits': {
'global': 1,
},
},
}