Question

因此，我正在处理的程序接收图像，压缩它并将其发送到JPEG。我的程序运行正常，我只是想让它看起来不错。我是通过Java Swing做的，我是一个完全新手。

这是我的主要内容：

import java.awt.image.BufferedImage;
import java.awt.image.RenderedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import javax.imageio.IIOImage;
import javax.imageio.ImageIO;
import javax.imageio.ImageWriteParam;    
import javax.imageio.ImageWriter;
import javax.imageio.stream.FileImageOutputStream;
import javax.imageio.stream.ImageOutputStream;
import javax.swing.JFrame;
import javax.swing.JFileChooser;

import com.sun.media.jai.widget.DisplayJAI;


public class JPEGCompression {

public static void main(String[] args) throws IOException {

    JFileChooser chooser = new JFileChooser();
    chooser.setCurrentDirectory(new File("./tmp"));

    chooser.setFileFilter(new javax.swing.filechooser.FileFilter() {
        public boolean accept(File f) {
            return f.getName().toLowerCase().endsWith(".png")
                    || f.isDirectory();
        }

        public String getDescription() {
            return "PNG Images";
        }
    });

    int r = chooser.showOpenDialog(new JFrame());
    if (r == JFileChooser.APPROVE_OPTION) {
        BufferedImage n = ImageIO.read(chooser.getSelectedFile());
        showOriginalImage("Original Image", n);
        compressAndShow(n, 0.7f);

    }

}

public static void compressAndShow(BufferedImage image, float quality)
        throws IOException {

    Iterator<ImageWriter> writers = ImageIO.getImageWritersBySuffix("jpeg");
    if (!writers.hasNext())
        throw new IllegalStateException("No writers found");
    ImageWriter writer = (ImageWriter) writers.next();

    ImageWriteParam param = writer.getDefaultWriteParam();
    param.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
    param.setCompressionQuality(quality);

    ByteArrayOutputStream bos = new ByteArrayOutputStream(); 
    ImageOutputStream ios = ImageIO.createImageOutputStream(bos);
    writer.setOutput(ios);
    writer.write(null, new IIOImage(image, null, null), param);
    ios.flush();

    ByteArrayInputStream in = new ByteArrayInputStream(bos.toByteArray());
    RenderedImage out = ImageIO.read(in);
    int size = bos.toByteArray().length;
    showCompressedImage("Compressed to " + quality + ": " + size + " bytes", out);

    File file = new File("compressed. " + quality + ".jpeg");
    FileImageOutputStream output = new FileImageOutputStream(file);
    writer.setOutput(output);
    writer.write(null, new IIOImage(image, null, null), param);

}

private static void showOriginalImage(String title, RenderedImage img) {


    JFrame frame = new JFrame(title);
    frame.getContentPane().add(new DisplayJAI(img));
    frame.pack();
    frame.setVisible(true);

    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

private static void showCompressedImage(String title, RenderedImage img) {

    JFrame frame = new JFrame(title);
    frame.getContentPane().add(new DisplayJAI(img));
    frame.pack();
    frame.setVisible(true);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

}

目前两种展示图像方法完全相同。我想要的是showOriginalImage（）在框架的顶部有一个文本字段，用户可以在其中输入压缩质量（目前硬编码为0.7f），其值介于0-1之间。然后，一旦他们选择了质量，compressAndShow（）就会运行。

我将非常感谢任何关于如何做到这一点的建议/帮助，感谢。

Answer 1

您应该创建一个JPanel并向其添加DisplayJAI和JTextField。然后将此面板添加到内容窗格。可能是默认面板布局（FlowLayout）不适合您的需要。在这种情况下，请尝试使用BorderLayout或BoxLayout。

我在JPanel上显示BufferedImage和文本字段时遇到问题

1 个答案: