Create a GeoRaster object from a file

def from_file(filename, **kwargs):
    """
    Create a GeoRaster object from a file
    """
    ndv, xsize, ysize, geot, projection, datatype = get_geo_info(filename, **kwargs)
    data = gdalnumeric.LoadFile(filename, **kwargs)
    data = np.ma.masked_array(data, mask=data == ndv, fill_value=ndv)
    return GeoRaster(data, geot, nodata_value=ndv, projection=projection, datatype=datatype)