* @param ar a 2D array of a primitive numeric type (doubles not supported yet)
*/
public FITSImage(final Object ar) throws IOException, FitsException {
ImageData data = new ImageData(ar);
Header header = new Header(data);
ImageHDU hdu = new ImageHDU(header, data);
_fits = new Fits();
_fits.addHDU(hdu);
// Default to the primary HDU
setHDU(0);