Question

我有以下代码：

private synchronized void produceSignatureImage(java.awt.event.ActionEvent evt, final String envStrFileName) {
    final String es = envStrFileName;
    java.awt.EventQueue.invokeLater(new Runnable() {
        @Override
        public void run() {
            try {
                BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
                bufferedImage.createGraphics().drawImage(img, 0, 0, TrusteeSignature.this);
                String filename = sdf.format(new Timestamp(System.currentTimeMillis())) + ".jpg";
                File outputfile = new File(IMAGE_FILE_PATH + filename);
                String fullPath = outputfile.getAbsolutePath();
                if (isNotesLocal()) {
                    NotesThread.sinitThread();
                }
                s = openSession();
                s.setEnvironmentVar(envStrFileName, fullPath);
                ImageIO.write(bufferedImage, "jpg", outputfile);
                Button b = (Button) evt.getSource();
                b.setEnabled(false);
                clear();
            } catch (Exception ex) {
                ex.printStackTrace();
            } finally {
                try {
                    if (s != null) {
                        TrusteeSignature.this.closeSession(s);
                    }
                } catch (NotesException e) {
                    e.printStackTrace();
                }
                if (isNotesLocal()) {
                    NotesThread.stermThread();
                }
            }
        }
    });

这很好，但是我想将图像尺寸从固定的500x250减小到200x150，减少60％。

我不需要我们要写入文件系统的原始大小的图像，并且很乐意在写入文件之前减小文件的大小。我在此站点的其他地方找到了以下代码。

   /**
 * we want the x and o to be resized when the JFrame is resized
 *
 * @param originalImage an x or an o. Use cross or oh fields.
 *
 * @param biggerWidth
 * @param biggerHeight
 */
private Image resizeToBig(Image originalImage, int biggerWidth, int biggerHeight) {
    int type = BufferedImage.TYPE_INT_ARGB;

    BufferedImage resizedImage = new BufferedImage(biggerWidth, biggerHeight, type);
    Graphics2D g = resizedImage.createGraphics();

    g.setComposite(AlphaComposite.Src);
    g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
    g.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
    g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

    g.drawImage(originalImage, 0, 0, biggerWidth, biggerHeight, this);
    g.dispose();

    return resizedImage;
}

我看到图像正在变大。我假设将60％的调整大小数字设置为变量后，也可以通过以下两行代码来减少图像的大小：

BufferedImage resizedImage = new BufferedImage(biggerWidth, biggerHeight, type);
Graphics2D g = resizedImage.createGraphics();

我不确定的是：因为我只想将40％大小的图像写入OS，所以在将JPG文件写入OS之前，我应该在代码的哪个位置进行大小调整？

是的，我是Java新手！

Answer 1

在您的try块的开头尝试以下操作：

Image resizedImage = img.getScaledInstance(newWidth, newHeight, Image.SCALE_DEFAULT);
BufferedImage bufferedImage = new BufferedImage(newWidth, newHeight, BufferedImage.TYPE_INT_RGB);
bufferedImage.createGraphics().drawImage(resizedImage, 0, 0, TrusteeSignature.this);

...其中newWidth和newHeight等于您希望的调整尺寸，例如200和150。

文档：https://docs.oracle.com/javase/8/docs/api/java/awt/Image.html#getScaledInstance-int-int-int-

我想将用户创建的图像尺寸减少60％

1 个答案: