For converting an image to a gif, first get a copy of the GifEncoder class from Acme.com--
http://www.acme.com/java/software/Acme.JPM.Encoders.GifEncoder.html

Here is some code that I used to create an image using the GifEncoder class.

try {
        	// Create an unshown frame
      		frame = new Frame();
      		frame.addNotify();

      		// Get a graphics region, using the Frame
      		Image image = frame.createImage(1100, 1600);
      		g = image.getGraphics();

        // Draw "Hello World!" to the off screen graphics context
      		g.setFont(new Font("Serif", Font.ITALIC, 48));
      		g.drawString("Hello World!", 10, 50);	
      		GifEncoder encoder = new GifEncoder(image, outputFile);
      		encoder.encode();
} finally {
      		// Clean up resources
      		if (g != null) g.dispose();
      		if (frame != null) frame.removeNotify();
}