用Java显示图像

Question

我想显示图像,但不知道该怎么做.我是否必须安装一些库文件或者只是它可以完成我不知道.实际上我想做图像处理,但首先我必须采取图像输入和显示图像然后我可以得到图像处理的效果作为输出,并决定它(算法)是否正确.我只安装了日食.我也在谷歌搜索,但无论他们建议什么都不好.要么我必须安装或不安装.我试过以下代码:

import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Image;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;
import javax.swing.JComponent;
import javax.swing.JFrame;

public class ImageTest {
    public static void main(String[] args){
        EventQueue.invokeLater(new Runnable()
        {
            public void run(){
                ImageFrame frame = new ImageFrame();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setVisible(true);


            }
        }
        );
    }
}

class ImageFrame extends JFrame{

    public ImageFrame(){
        setTitle("ImageTest");
        setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

        ImageComponent component = new ImageComponent();
        add(component);

    }

    public static final int DEFAULT_WIDTH = 300;
    public static final int DEFAULT_HEIGHT = 200;
}


class ImageComponent extends JComponent{
    /**
     * 
     */
    private static final long serialVersionUID = 1L;
    private Image image;
    public ImageComponent(){
        try{
            File image2 = new File("bishnu.jpg");
            image = ImageIO.read(image2);

        }
        catch (IOException e){
            e.printStackTrace();
        }
    }
    public void paintComponent (Graphics g){
        if(image == null) return;
        int imageWidth = image.getWidth(this);
        int imageHeight = image.getHeight(this);

        g.drawImage(image, 50, 50, this);

        for (int i = 0; i*imageWidth <= getWidth(); i++)
            for(int j = 0; j*imageHeight <= getHeight();j++)
                if(i+j>0) g.copyArea(0, 0, imageWidth, imageHeight, i*imageWidth, j*imageHeight);
    }

}

它只是显示一个图形窗口,但无法显示图像"bishnu.jpg"

我应该在eclipse中安装任何东西吗？但我认为没有什么需要安装.

Answer 1

import java.awt.FlowLayout;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

public class DisplayImage {

    public static void main(String avg[]) throws IOException
    {
        DisplayImage abc=new DisplayImage();
    }

    public DisplayImage() throws IOException
    {
        BufferedImage img=ImageIO.read(new File("f://images.jpg"));
        ImageIcon icon=new ImageIcon(img);
        JFrame frame=new JFrame();
        frame.setLayout(new FlowLayout());
        frame.setSize(200,300);
        JLabel lbl=new JLabel();
        lbl.setIcon(icon);
        frame.add(lbl);
        frame.setVisible(true);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}

Answer 2

调整路径后,运行代码会为我显示图像.你能验证你的图像路径是否正确,例如尝试绝对路径？

Answer 3

如果您想加载/处理/显示图像，我建议您使用图像处理框架。例如，使用Marvin ，您只需几行源代码即可轻松完成此操作。

源代码：

public class Example extends JFrame{

    MarvinImagePlugin prewitt           = MarvinPluginLoader.loadImagePlugin("org.marvinproject.image.edge.prewitt");
    MarvinImagePlugin errorDiffusion    = MarvinPluginLoader.loadImagePlugin("org.marvinproject.image.halftone.errorDiffusion");
    MarvinImagePlugin emboss            = MarvinPluginLoader.loadImagePlugin("org.marvinproject.image.color.emboss");

    public Example(){
        super("Example");

        // Layout
        setLayout(new GridLayout(2,2));

        // Load images
        MarvinImage img1 = MarvinImageIO.loadImage("./res/car.jpg");
        MarvinImage img2 = new MarvinImage(img1.getWidth(), img1.getHeight());
        MarvinImage img3 = new MarvinImage(img1.getWidth(), img1.getHeight());
        MarvinImage img4 = new MarvinImage(img1.getWidth(), img1.getHeight());

        // Image Processing plug-ins
        errorDiffusion.process(img1, img2);
        prewitt.process(img1, img3);
        emboss.process(img1, img4);

        // Set panels
        addPanel(img1);
        addPanel(img2);
        addPanel(img3);
        addPanel(img4);

        setSize(560,380);
        setVisible(true);
    }

    public void addPanel(MarvinImage image){
        MarvinImagePanel imagePanel = new MarvinImagePanel();
        imagePanel.setImage(image);
        add(imagePanel);
    }

    public static void main(String[] args) {
        new Example().setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}

输出：