Java实现将彩色PDF转为灰度PDF的示例代码

<repositories>
    <repository>
        <id>com.e-iceblue</id>
            <url>https://repo.e-iceblue.cn/repository/maven-public/</url>
        </repository>
    </repositories>
<dependencies>
    <dependency>
        <groupId> e-iceblue </groupId>
        <artifactId>spire.pdf</artifactId>
        <version>5.3.1</version>
    </dependency>
</dependencies>

import com.spire.pdf.conversion.*;

public class ToGrayPDF {
    public static void main(String[] args) {
        //创建一个PdfGrayConverter实例并加载PDF文档
        PdfGrayConverter converter = new PdfGrayConverter("Booklet.pdf");

        //将彩色PDF转换为灰度
        converter.toGrayPdf("ToGray.pdf");
        converter.dispose();
    }
}

   //计算像素点的灰度
    public static int getGray(Color pixel) {
        return (pixel.getRed()*30+pixel.getGreen()*60+pixel.getBlue()*10)/100;
    }

    JFileChooser jChooser = new JFileChooser();
    //设置默认的打开目录,如果不设的话按照window的默认目录(我的文档)
    jChooser.setCurrentDirectory(new File("f:/"));
    //打开一个对话框
    int index = jChooser.showDialog(null, "打开文件");
    if (index == JFileChooser.APPROVE_OPTION) {
     path=jChooser.getSelectedFile().getAbsolutePath();
    }
    Image img = new ImageIcon(path).getImage();
    BufferedImage bfi = new BufferedImage(img.getWidth(null),img.getHeight(null),BufferedImage.TYPE_INT_RGB);
    bfi.getGraphics().drawImage(img, 0, 0,null);
    for(int y=0;y<bfi.getHeight();y++) 
        for(int x=0;x<bfi.getWidth();x++) {
            Color pixel = new Color(bfi.getRGB(x, y));
            bfi.setRGB(x, y,new Color(getGray(pixel),getGray(pixel),getGray(pixel)).getRGB());
        }
    ImageIO.write(bfi, "JPEG", new File("1.jpg"));