Java ImageIO异常缓慢

Question

我正在制作一个程序，将客户端屏幕发送到服务器并显示它，但是速度非常慢。一帧需要2-3秒，上传/下载速度也不成问题。我做错了什么/可以更改以加快此速度的任何事情？

服务器：

import java.awt.BorderLayout;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.zip.GZIPInputStream;

import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;

public class Server {

    public static void main(String[] args) {
        try {
            JPanel panel = new JPanel();
            panel.setLayout(new BorderLayout());

            JLabel label = new JLabel();
            label.setSize(800, 600);
            label.setVisible(true);

            JScrollPane scroll = new JScrollPane();
            scroll.getViewport().add(label);
            panel.add(scroll, BorderLayout.CENTER);

            JFrame frame = new JFrame();
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            frame.getContentPane().add(panel);
            frame.setSize(800, 600);
            frame.setVisible(true);

            ServerSocket serverSocket = new ServerSocket(25565);
            Socket socket = serverSocket.accept();
            GZIPInputStream in = new GZIPInputStream(socket.getInputStream());
            BufferedImage image = null;
            while(socket.isConnected()) {
                image = ImageIO.read(in);
                if(image != null) {
                    label.setIcon(new ImageIcon(image));
                    label.repaint();

                }
            }
            in.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

客户：

import java.awt.AWTException;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.Toolkit;
import java.io.IOException;
import java.net.Socket;
import java.util.zip.GZIPOutputStream;

import javax.imageio.ImageIO;

public class Client {

    public static void main(String[] args) {
        try {
            Robot robot = new Robot();
            Toolkit toolkit = Toolkit.getDefaultToolkit();
            Rectangle screen = new Rectangle((int) toolkit.getScreenSize().getWidth(), (int) toolkit.getScreenSize().getHeight());
            Socket socket = new Socket("127.0.0.1", 25565);
            GZIPOutputStream out = new GZIPOutputStream(socket.getOutputStream());

            while(socket.isConnected()) {
                ImageIO.write(robot.createScreenCapture(screen), "png", out);
            }
            out.close();
        } catch (AWTException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Answer 1

如果您png以GZIPStream的形式发送图像，则可能是个坏主意。您将无法获得显着的压缩增益，因为png已经具有良好的压缩率。根据图像的种类，您还可以考虑jpeg实现更好的压缩。

但可能最重要的是用BufferedOuputStream包装输出流：

BufferedOutputStream out = new BufferedOutputStream(socket.getOutputStream());

您可以在输入流中执行相同的操作。