java.lang.ClassLoader.loadClass中的错误(未知来源)

对于我的论文,我试图用图片处理一些事情,完成它的一个步骤是找到图片中的角落.经过一些冲浪,我发现它可以用Moravec的角点检测算法实现.幸运的是,我发现Moravec的算法已经由JFeatureLib在此链接上实现： https://code.google.com/p/jfeaturelib/source/browse/src/main/java/de/lmu/ifi/dbs/jfeaturelib/pointDetector/Moravec.java?r=8d96a8fa9a43a0ec7e7084b40169be56bddd6f36

(当然我在Eclipse的构建路径中导入了JFeatureLib提供的jar文件)
所以我在项目的链接中使用了代码,并编写了一些代码来调用它.这是我创建一个Frame的代码,打开图片并在该链接上调用Moravec算法：

import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;




public class Compare{
    public Compare(){
        JFrame frame = new JFrame("Find corners in picture");
        frame.setDefaultCloSEOperation(JFrame.EXIT_ON_CLOSE);
        JPanel panel = (JPanel)frame.getContentPane();
        JLabel label = new JLabel();
        label.setIcon(new ImageIcon("house.jpg"));
        panel.add(label);
        frame.setLocationRelativeTo(null);
        frame.pack();
        frame.setVisible(true);
    }
    public static void main (String[] args){
        SwingUtilities.invokeLater(new Runnable(){
            public void run(){
                new Compare();
            }
        });
        Moravec picture = new Moravec();
    }
}

关键是它在线上返回一个错误

Moravec picture = new Moravec();

这个错误是这样的：

Exception in thread "main" java.lang.UnsupportedClassVersionError: de/lmu/ifi/dbs/jfeaturelib/pointDetector/PointDetector : Unsupported major.minor version 51.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(Unknown Source)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.access$000(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(Unknown Source)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.access$000(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at Compare.main(Compare.java:32)

你能给我一些建议吗？
非常感谢！