使用FileInputStream和FileOutputStream实现图片反色

import java.io.BufferedInputStream;import java.io.DataInputStream;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;public class HomeWork {public static void main(String[]args) throws IOException{String filename="src/changeColor.bmp";DataInputStream in=new DataInputStream(new BufferedInputStream(new FileInputStream(filename)));String filename1="src/changeColor1.bmp";FileOutputStream fos=new FileOutputStream(filename1);int b=0;byte[] buf=new byte[54];    in.read(buf);    fos.write(buf);    //in.skip(54);while((b=in.read())!=-1){fos.write(255-b);}fos.close();in.close();}}