An image, in any acceptable form (see asNifti).

A character string containing a file name.

An optional template object to derive NIfTI-1 properties from. Passed to asNifti if image is an array.

The NIfTI datatype to use when writing the data out. The default, "auto" uses the R type or, for internal images, the original datatype. Other possibilities are "float", "int16", etc., which may be preferred to reduce file size. However, no checks are done to ensure that the coercion maintains precision.

An integer (1 or 2) giving the NIfTI file format version to use. Version 2 is usually only needed for very large images or where metadata needs to be stored with high precision. The types available for storing the pixel data are the same in both cases.