You need to get it from the classpath instead of from the local disk file system.
Assuming that images is actually a package and that this package is inside the same JAR as the current class, then do so:
BufferedImage myPicture = null;
try {
myPicture = ImageIO.read(getClass().getResource("/images/Report.png"));
} catch (IOException e1) {
e1.printStackTrace();
}
JLabel headerImage = new JLabel(new ImageIcon(myPicture));