resizing a ImageIcon in a JButton

I would try to override the getIcon() method of JButton, and resize the super.getIcon(). (Or, redefining the lnf for that button.)

   Image img = icon.getImage() ;  
   Image newimg = img.getScaledInstance( NEW_WIDTH, NEW_HEIGHT,  java.awt.Image.SCALE_SMOOTH ) ;  
   icon = new ImageIcon( newimg );

from http://www.coderanch.com/t/331731/GUI/java/Resize-ImageIcon