Parse manifest file to build up the collection of images.
        
        :param fpath: path to the manifest file

def parse_manifest(self, fpath):
        """Parse manifest file to build up the collection of images.
        
        :param fpath: path to the manifest file
        """
        with open(fpath, 'r') as fh:
            for entry in json.load(fh):

                # Every entry of a manifest file needs to have a "filename"
                # attribute. It is the only requirement so we check for it in a
                # strict fashion.
                if "filename" not in entry:
                    raise(RuntimeError(
                        'Entries in {} need to have "filename"'.format(fpath)))

                filename = entry.pop("filename")

                proxy_image = None
                if isinstance(self, MicroscopyCollection):
                    proxy_image = MicroscopyImage(filename, entry)
                else:
                    proxy_image = ProxyImage(filename, entry)
                self.append(proxy_image)