'Returns the following information for all public, available images:
* id -- The opaque image identifier
* name -- The name of the image
* disk_format -- The disk image format
* container_format -- The "container" format of the image
* checksum -- MD5 checksum of the image data
* size -- Size of image data in bytes
:param req: The WSGI/Webob Request object
:returns: The response body is a mapping of the following form
{\'images\': [
{\'id\': <ID>,
\'name\': <NAME>,
\'disk_format\': <DISK_FORMAT>,
\'container_format\': <DISK_FORMAT>,
\'checksum\': <CHECKSUM>,
\'size\': <SIZE>}, {...}]'

def index(self, req):

    self._enforce(req, 'get_images')
    params = self._get_query_params(req)
    try:
        images = registry.get_images_list(req.context, **params)
    except exception.Invalid as e:
        raise HTTPBadRequest(explanation=e.msg, request=req)
    return dict(images=images)
