import java.awt.Color;import java.awt.image.BufferedImage;import java.io.File;import java.io.IOException;import javax.imageio.ImageIO;public class ConvertImageFile {  public static void main(String[] args) {    BufferedImage bufferedImage;    try {      // read image file      bufferedImage = ImageIO.read(new File("c://java.png"));      // create a blank, RGB, same width and height, and a white      // background      BufferedImage newBufferedImage = new BufferedImage(          bufferedImage.getWidth(), bufferedImage.getHeight(),          BufferedImage.TYPE_INT_RGB);      // TYPE_INT_RGB:創建一個RBG圖像，24位深度，成功將32位圖轉化成24位      newBufferedImage.createGraphics().drawImage(bufferedImage, 0, 0,          Color.WHITE, null);      // write to jpeg file      ImageIO.write(newBufferedImage, "jpg", new File("c://java.jpg"));      System.out.println("Done");    } catch (IOException e) {      e.printStackTrace();    }  }}