Java2D图形消除锯齿 [英] Java2D Graphics anti-aliased

问题描述

我是Java新手，尝试使用Java2D Graphics创建图像。但是输出结果是反锯齿的。我尝试了很多方法来纠正它，但不起作用。

  public BufferedImage createNameOnButton（String label）{
 int messageWidth = 0; 
 Font font = new Font（Arial，Font.PLAIN，11）; 
 
 BufferedImage bi = new BufferedImage（
 10，10，BufferedImage.TYPE_INT_RGB）; 
 
 Graphics2D g2d =（Graphics2D）bi.getGraphics（）; 
 g2d.setRenderingHint（
 RenderingHints.KEY_ANTIALIASING，
 RenderingHints.VALUE_ANTIALIAS_ON）; 
 g2d.setRenderingHint（
 RenderingHints.KEY_TEXT_ANTIALIASING，
 RenderingHints.VALUE_TEXT_ANTIALIAS_ON）; 
 g2d.setRenderingHint（
 RenderingHints.KEY_FRACTIONALMETRICS，
 RenderingHints.VALUE_FRACTIONALMETRICS_ON）; 
 g2d.setFont（font）; 
 
 bi = g2d.getDeviceConfiguration（）
 .createCompatibleImage（500，30，Transparency.BITMASK）; 
 FontMetrics fm = bi.getGraphics（）。getFontMetrics（font）; 
 int messageHeight = fm.getHeight（） -  fm.getDescent（）; 
 for（char ch：label.toCharArray（））{
 messageWidth + = fm.charWidth（ch）; 
} 
 
 bi = bi.getSubimage（50，0，messageWidth + 10，fm.getHeight（））; 
图形g = bi.getGraphics（）; 
 g.setColor（Color.black）; 
 AttributedString as = new AttributedString（label）; 
 as.addAttribute（TextAttribute.FONT，font）; 
 g.drawString（as.getIterator（），5，messageHeight）; 
 g2d.dispose（）; 
 g.dispose（）; 
返回bi; 
} 
  

任何人都可以帮我解决错误吗？

解决方案

假设您确实需要平滑（无别名）文本， TextLayout 可能会使这更简单。 FontRenderContext code> 构造函数可以管理反锯齿和小数指标设置。

附录：使用 g2d.setColor（Color .blue）似乎产生了预期的效果。

附录：在Mac OS X上， Pixie / Developer / Applications / Graphics Tools / 中的c $ c>应用程序可以方便地检查anti-alias像素。在其他平台上，可以使用 Zoom 。

< pre $ / ** @see https://stackoverflow.com/questions/4285464 * /
public class BITest extends JPanel {

private BufferedImage image = createNameOnButton（Sample）;

public BITest（）{
this.setPreferredSize（new Dimension（
image.getWidth（），image.getHeight（）））;


@Override
protected void paintComponent（Graphics g）{
super.paintComponent（g）;
g.drawImage（image，0，0，null）;
}

public BufferedImage createNameOnButton（String label）{
Font font = new Font（Arial，Font.PLAIN，64）;
FontRenderContext frc = new FontRenderContext（null，true，true）;
TextLayout layout = new TextLayout（label，font，frc）;
Rectangle r = layout.getPixelBounds（null，0，0）;
System.out.println（r）;
BufferedImage bi = new BufferedImage（
r.width + 1，r.height + 1，
BufferedImage.TYPE_INT_ARGB）;
Graphics2D g2d =（Graphics2D）bi.getGraphics（）;
g2d.setColor（Color.blue）;
layout.draw（g2d，0，-r.y）;
g2d.dispose（）;
返回bi;


private void display（）{
JFrame f = new JFrame（BITest）;
f.setDefaultCloseOperation（JFrame.EXIT_ON_CLOSE）;
f.setUndecorated（true）;
f.add（this）;
f.pack（）;
f.setLocationRelativeTo（null）;
f.setVisible（true）;


public static void main（String [] args）{
EventQueue.invokeLater（new Runnable（）{
$ b $ @Override
public void run（）{
new BITest（）。display（）;
}
}）;
}
}


I am new to Java and trying to use Java2D Graphics to create a Image. But the output is coming as anti-aliased. I tried many ways to rectify it but doesn't work. The characters are getting distorted or jagged.

public BufferedImage createNameOnButton(String label) {
    int messageWidth = 0;
    Font font = new Font("Arial", Font.PLAIN, 11);

    BufferedImage bi = new BufferedImage(
        10, 10, BufferedImage.TYPE_INT_RGB);

    Graphics2D g2d = (Graphics2D) bi.getGraphics();
    g2d.setRenderingHint(
        RenderingHints.KEY_ANTIALIASING,
        RenderingHints.VALUE_ANTIALIAS_ON);
    g2d.setRenderingHint(
        RenderingHints.KEY_TEXT_ANTIALIASING,
        RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
    g2d.setRenderingHint(
        RenderingHints.KEY_FRACTIONALMETRICS,
        RenderingHints.VALUE_FRACTIONALMETRICS_ON);
    g2d.setFont(font);

    bi = g2d.getDeviceConfiguration()
        .createCompatibleImage(500, 30, Transparency.BITMASK);
    FontMetrics fm = bi.getGraphics().getFontMetrics(font);
    int messageHeight = fm.getHeight() - fm.getDescent();
    for (char ch : label.toCharArray()) {
        messageWidth += fm.charWidth(ch);
    }

    bi = bi.getSubimage(50, 0, messageWidth + 10, fm.getHeight());
    Graphics g = bi.getGraphics();
    g.setColor(Color.black);
    AttributedString as = new AttributedString(label);
    as.addAttribute(TextAttribute.FONT, font);
    g.drawString(as.getIterator(), 5, messageHeight);
    g2d.dispose();
    g.dispose();
    return bi;
}

Can anyone please help me to rectify the error?

解决方案

Assuming you actually want smooth (non-aliased) text, TextLayout may make this easier. The FontRenderContext constructor can manage the anti-aliasing and fractional metrics settings.

Addendum: Using g2d.setColor(Color.blue) seems to produce the expected effect.

Addendum: On Mac OS X, the Pixie application in /Developer/Applications/Graphics Tools/ is convenient for examining the anti-alias pixels. On other platforms, Zoom may be used.

/** @see https://stackoverflow.com/questions/4285464 */
public class BITest extends JPanel {

    private BufferedImage image = createNameOnButton("Sample");

    public BITest() {
        this.setPreferredSize(new Dimension(
            image.getWidth(), image.getHeight()));
    }

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        g.drawImage(image, 0, 0, null);
    }

    public BufferedImage createNameOnButton(String label) {
        Font font = new Font("Arial", Font.PLAIN, 64);
        FontRenderContext frc = new FontRenderContext(null, true, true);
        TextLayout layout = new TextLayout(label, font, frc);
        Rectangle r = layout.getPixelBounds(null, 0, 0);
        System.out.println(r);
        BufferedImage bi = new BufferedImage(
            r.width + 1, r.height + 1,
            BufferedImage.TYPE_INT_ARGB);
        Graphics2D g2d = (Graphics2D) bi.getGraphics();
        g2d.setColor(Color.blue);
        layout.draw(g2d, 0, -r.y);
        g2d.dispose();
        return bi;
    }

    private void display() {
        JFrame f = new JFrame("BITest");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setUndecorated(true);
        f.add(this);
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                new BITest().display();
            }
        });
    }
}

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