def topng(self, path, prefix='image', overwrite=False):
        """
        Write 2d images as PNG files.

        Files will be written into a newly-created directory.
        Three-dimensional data will be treated as RGB channels.

        Parameters
        ----------
        path : string
            Path to output directory, must be one level below an existing directory.

        prefix : string
            String to prepend to filenames.

        overwrite : bool
            If true, the directory given by path will first be deleted if it exists.
        """
        from thunder.images.writers import topng
        # TODO add back colormap and vmin/vmax
        topng(self, path, prefix=prefix, overwrite=overwrite)
Write 2d images as PNG files.

        Files will be written into a newly-created directory.
        Three-dimensional data will be treated as RGB channels.

        Parameters
        ----------
        path : string
            Path to output directory, must be one level below an existing directory.

        prefix : string
            String to prepend to filenames.

        overwrite : bool
            If true, the directory given by path will first be deleted if it exists.