Bug 104986 Backgound image uses an absolute path
Currently Chart uses an absolute path to indicate a backgournd image, that may cause the design unusable on other environments. Expected the background image can be definded in multiple ways like in report designer. e.g. URI(absolute path), File(relative path), Embedded Image(Encoded Image Data).
chart/org.eclipse.birt.chart.device.extension/src/org/eclipse/birt/chart/device/swing/SwingRendererImpl.java
return;
		}
		
		final Bounds bo = ore.getBounds( );
		final Ellipse2D.Double e2d = new Ellipse2D.Double( bo.getLeft( ),
				bo.getTop( ),
				bo.getWidth( ),
				bo.getHeight( ) );
		Stroke sPrevious = null;
		Stroke sCurrent = getCachedStroke( lia );
		if ( sCurrent != null ) 
		{
			sPrevious = _g2d.getStroke( );
			_g2d.setStroke( sCurrent );
		}
		_g2d.setColor( cFG );
		_g2d.draw( e2d );
		if ( sPrevious != null ) 
		{
			_g2d.setStroke( sPrevious );
		}
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.chart.event.IPrimitiveRenderListener#fillOval(org.eclipse.birt.chart.event.OvalRenderEvent)
	 */
	public void fillOval( OvalRenderEvent ore ) throws ChartException
	{
		final Fill flBackground = ore.getBackground( );