def METHOD_NAME(self, global_opts: RCOptions, opts: 'CLIOptions', args: ArgsType) -> PayloadType:
    if len(args) != 1:
        self.fatal('Must specify path to exactly one PNG image')
    path = os.path.expanduser(args[0])
    import secrets
    ret = {
        'match': opts.match,
        'self': opts.self,
        'alpha': opts.alpha,
        'position': opts.position,
        'stream_id': secrets.token_urlsafe(),
    }
    if path.lower() == 'none':
        ret['data'] = '-'
        return ret
    if not is_png(path):
        self.fatal(f'{path} is not a PNG image')
    def file_pipe(path: str) -> CmdGenerator:
        with open(path, 'rb') as f:
            while True:
                data = f.read(512)
                if not data:
                    break
                ret['data'] = standard_b64encode(data).decode('ascii')
                yield ret
        ret['data'] = ''
        yield ret
    return file_pipe(path)