Get image's width and height faster

Hi,
I have problem how to get image's width and height (represented by file.jpg) faster.
Using BufferedImage's getWidth() or getHeight() methods is very slow cause I have to read the whole image via ImageIO.read().

Is there a way how to get image's height and width much faster ?

Thank you for your advices.

I hope this helps:

Toolkit tk=Toolkit.getDefaultToolkit();
IMG=tk.getImage(".\\background.jpg");

MediaTracker mt = new MediaTracker(this);
mt.addImage(IMG,0);
try{
mt.waitForAll();
}catch(InterruptedException e)
{System.out.println(e.getMessage());};

//now IMG.getWidth, IMG.getHeight see documentation of java.awt.Image class