Bug 212291 SWT Chart render engine always uses 96 DPI(Display) resolution
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/device/IDisplayServer.java
* @param url
	 *            The URL associated with the image location
	 * 
	 * @return An instance of an image associated with the specified URL
	 * 
	 * @throws ImageLoadingException
	 */
	Object loadImage( URL url ) throws ChartException;
	/**
	 * Returns the size(width, height) of the device specific image that was
	 * previously loaded by the <code>loadImage(URL)</code> method
	 * 
	 * @param oImage
	 *            The image for which the size is being requested
	 * 
	 * @return The size of the image
	 */
	Size getSize( Object oImage );
	/**
	 * An observer is typically associated with certain device types to aid in
	 * image loading and image metadata retrieval.
	 * 
	 * @return An image observer associated with a specific device renderer
	 */
	Object getObserver( );
	/**
	 * An instance of a text metrics computation class capable of providing text
	 * metric information associated with a given Label to aid in typically
	 * computing the size of rendered text
	 *