使用pdfbox将pdf转换为图像时只有一半图像

Question

我正在使用pdfbox将pdf转换为图像，但我只获得原始图像的一半。有人可以帮忙吗

String sourceDir = "D:/pdffiles/Sample_93.pdf"; // Pdf files are read from this folder
String destinationDir = "D:/images/png/"; // converted images from pdf document are saved here

File sourceFile = new File(sourceDir);
File destinationFile = new File(destinationDir);
if (!destinationFile.exists()) {
    destinationFile.mkdir();
    System.out.println("Folder Created -> "+ destinationFile.getAbsolutePath());
}
if (sourceFile.exists()) {
    PDDocument document = PDDocument.loadNonSeq(new File(sourceDir), null);
    List<PDPage> pdPages = document.getDocumentCatalog().getAllPages();
    int page = 0;
    for (PDPage pdPage : pdPages){ 
        ++page;
        BufferedImage bim = pdPage.convertToImage(BufferedImage.TYPE_INT_RGB, 300);
        ImageIOUtil.writeImage(bim, "Report" + "-" + page + ".png", 300);
    }
    document.close();
}

下面是半张图片

incomplete image

修改1：

第1页内容正确显示第2页，图像（扫描为pdf图像）仅出现一半。

修改2

尝试使用以下代码，其中图像变为黑色区域，白色区域变为黑色

Total Black Image

public class ImageMain {
public static void setup() throws IOException {
    // load a pdf from a byte buffer
    File file = new File("D:/odimages/selection.pdf");
    RandomAccessFile raf = new RandomAccessFile(file, "r");
    FileChannel channel = raf.getChannel();
    ByteBuffer buf = channel.map(FileChannel.MapMode.READ_ONLY, 0, channel.size());
    PDFFile pdffile = new PDFFile(buf);
    int numPgs = pdffile.getNumPages();
    for (int i = 0; i < numPgs; i++) {
        // draw the first page to an image
        PDFPage page = pdffile.getPage(i);
        // get the width and height for the doc at the default zoom
        Rectangle rect = new Rectangle(0, 0, (int) page.getBBox().getWidth(), (int) page.getBBox().getHeight());
        // generate the image
        Image img = page.getImage(rect.width, rect.height, // width & height
                rect, // clip rect
                null, // null for the ImageObserver
                true, // fill background with white
                true // block until drawing is done
                );
        // save it as a file
        BufferedImage bImg = toBufferedImage(img);
        File yourImageFile = new File("D:/odimages/png/page_" + i + ".png");
        ImageIO.write(bImg, "png", yourImageFile);
    }
}

// This method returns a buffered image with the contents of an image
public static BufferedImage toBufferedImage(Image image) {
    if (image instanceof BufferedImage) {
        return (BufferedImage) image;
    }
    // This code ensures that all the pixels in the image are loaded
    image = new ImageIcon(image).getImage();
    // Determine if the image has transparent pixels; for this method's
    // implementation, see e661 Determining If an Image Has Transparent
    // Pixels
    boolean hasAlpha = hasAlpha(image);
    // Create a buffered image with a format that's compatible with the
    // screen
    BufferedImage bimage = null;
    GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
    try {
        // Determine the type of transparency of the new buffered image
        int transparency = Transparency.OPAQUE;
        if (hasAlpha) {
            transparency = Transparency.BITMASK;
        }
        // Create the buffered image
        GraphicsDevice gs = ge.getDefaultScreenDevice();
        GraphicsConfiguration gc = gs.getDefaultConfiguration();
        bimage = gc.createCompatibleImage(image.getWidth(null), image.getHeight(null), transparency);
    } catch (HeadlessException e) {
        // The system does not have a screen
    }
    if (bimage == null) {
        // Create a buffered image using the default color model
        int type = BufferedImage.TYPE_INT_RGB;
        if (hasAlpha) {
            type = BufferedImage.TYPE_INT_ARGB;
        }
        bimage = new BufferedImage(image.getWidth(null), image.getHeight(null), type);
    }
    // Copy image to buffered image
    Graphics g = bimage.createGraphics();
    // Paint the image onto the buffered image
    g.drawImage(image, 0, 0, null);
    g.dispose();
    return bimage;
}

public static boolean hasAlpha(Image image) {
    // If buffered image, the color model is readily available
    if (image instanceof BufferedImage) {
        BufferedImage bimage = (BufferedImage) image;
        return bimage.getColorModel().hasAlpha();
    }
    // Use a pixel grabber to retrieve the image's color model;
    // grabbing a single pixel is usually sufficient
    PixelGrabber pg = new PixelGrabber(image, 0, 0, 1, 1, false);
    try {
        pg.grabPixels();
    } catch (InterruptedException e) {
    }
    // Get the image's color model
    ColorModel cm = pg.getColorModel();
    return cm.hasAlpha();
}

public static void main(final String[] args) {
    SwingUtilities.invokeLater(new Runnable() {
        public void run() {
            try {
                ImageMain.setup();
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
    });
}
}