Question

我只希望图像在各自的位置，如pdf中的确切布局，但我不希望文本在其中呈现有没有办法做到目前我正在以这种方式工作但文本也在这里那么有没有办法满足这个要求

             File sourceFile=new File(pdfFile);
             String fileName = sourceFile.getName().replace(".pdf", "");             
             int pageNumber = 1;
             for (PDPage page : li) 
             {
                 BufferedImage image = page.convertToImage();
                 File outputfile = new File(imgDes + fileName +"_"+ pageNumber +".png");
                 System.out.println("Image Created -> "+ outputfile.getName());
                 ImageIO.write(image, "png", outputfile);
                 pageNumber++;
             }

Answer 1

从PageDrawer派生一个类，并覆盖所有不处理空图像的方法，然后调用drawPage（）。我只是覆盖了processTextPosition（），并没有打扰线条，形状等，但我认为我的意思很清楚。

public class MyPageDrawer extends PageDrawer
{

    public MyPageDrawer() throws IOException
    {
    }

    @Override
    protected void processTextPosition(TextPosition text)
    {
    }

    // taken from PDPage.convertToImage, with extra parameter and one modification
    static BufferedImage convertToImage(PDPage page, int imageType, int resolution) throws IOException
    {
        final Color TRANSPARENT_WHITE = new Color(255, 255, 255, 0);
        final int DEFAULT_USER_SPACE_UNIT_DPI = 72;

        PDRectangle cropBox = page.findCropBox();
        float widthPt = cropBox.getWidth();
        float heightPt = cropBox.getHeight();
        float scaling = resolution / (float) DEFAULT_USER_SPACE_UNIT_DPI;
        int widthPx = Math.round(widthPt * scaling);
        int heightPx = Math.round(heightPt * scaling);
        Dimension pageDimension = new Dimension((int) widthPt, (int) heightPt);
        int rotationAngle = page.findRotation();
        // normalize the rotation angle
        if (rotationAngle < 0)
        {
            rotationAngle += 360;
        }
        else if (rotationAngle >= 360)
        {
            rotationAngle -= 360;
        }
        // swap width and height
        BufferedImage retval;
        if (rotationAngle == 90 || rotationAngle == 270)
        {
            retval = new BufferedImage(heightPx, widthPx, imageType);
        }
        else
        {
            retval = new BufferedImage(widthPx, heightPx, imageType);
        }
        Graphics2D graphics = (Graphics2D) retval.getGraphics();
        graphics.setBackground(TRANSPARENT_WHITE);
        graphics.clearRect(0, 0, retval.getWidth(), retval.getHeight());
        if (rotationAngle != 0)
        {
            int translateX = 0;
            int translateY = 0;
            switch (rotationAngle)
            {
                case 90:
                    translateX = retval.getWidth();
                    break;
                case 270:
                    translateY = retval.getHeight();
                    break;
                case 180:
                    translateX = retval.getWidth();
                    translateY = retval.getHeight();
                    break;
                default:
                    break;
            }
            graphics.translate(translateX, translateY);
            graphics.rotate((float) Math.toRadians(rotationAngle));
        }
        graphics.scale(scaling, scaling);
        PageDrawer drawer = new MyPageDrawer(); // MyPageDrawer instead of PageDrawer
        drawer.drawPage(graphics, page, pageDimension);
        drawer.dispose();
        graphics.dispose();
        return retval;
    }

    public static void main(String[] args) throws IOException
    {
        String filename = "......./blah.pdf";

        // open the document
        PDDocument doc = PDDocument.loadNonSeq(new File(filename), null);
        List<PDPage> pages = doc.getDocumentCatalog().getAllPages();
        for (int p = 0; p < pages.size(); ++p)
        {
            PDPage page = pages.get(p);
            BufferedImage bim = convertToImage(page, BufferedImage.TYPE_INT_RGB, 300);

            boolean b = ImageIOUtil.writeImage(bim, "page-" + (p + 1) + ".png", 300);
            if (!b)
            {
                // error handling
            }
        }
        doc.close();
    }

}

使用pdfbox库java从PDF中提取图像

1 个答案: