// pop up a window to choose the HDU to view
if (_fitsHDUChooser != null) {
_fitsHDUChooser.updateDisplay(fitsImage);
} else {
_fitsHDUChooserFrame = new FITSHDUChooserFrame(this, fitsImage);
_fitsHDUChooser = _fitsHDUChooserFrame.getFitsHDUChooser();
}
if (skipEmptyPrimary) {
_fitsHDUChooser.selectImage(1);