提取和打印文本位置

1 回答

• 2

  正如评论中所讨论的，这是DrawPrintTextLocations工具的1.8版本，它是2.0版本的示例集合的一部分，它基于更为人熟知的PrintTextLocations示例 . 与2.0版本不同，此版本不显示字体边界框，仅显示文本提取大小，即大小字形（a，e等）的高度 . 它用作文本提取的启发式工具 . 这就是“我得到的文字位置是半身”效果的原因 . 如果你需要边框，最好使用2.0（可能太大了） . 要获得精确的大小，您必须计算每个字形的路径并获得该字形的边界，同样，您需要该版本的2.0版本 .

  public class DrawPrintTextLocations extends PDFTextStripper
  {
      private BufferedImage image;
      private final String filename;
      static final int SCALE = 4;
      private Graphics2D g2d;
      private final PDDocument document;
  
      /**
       * Instantiate a new PDFTextStripper object.
       *
       * @param document
       * @param filename
       * @throws IOException If there is an error loading the properties.
       */
      public DrawPrintTextLocations(PDDocument document, String filename) throws IOException
      {
          this.document = document;
          this.filename = filename;
      }
  
      /**
       * This will print the documents data.
       *
       * @param args The command line arguments.
       *
       * @throws IOException If there is an error parsing the document.
       */
      public static void main(String[] args) throws IOException
      {
          if (args.length != 1)
          {
              usage();
          }
          else
          {
              PDDocument document = null;
              try
              {
                  document = PDDocument.load(new File(args[0]));
  
                  DrawPrintTextLocations stripper = new DrawPrintTextLocations(document, args[0]);
                  stripper.setSortByPosition(true);
  
                  for (int page = 0; page < document.getNumberOfPages(); ++page)
                  {
                      stripper.stripPage(page);
                  }
              }
              finally
              {
                  if (document != null)
                  {
                      document.close();
                  }
              }
          }
      }
  
      private void stripPage(int page) throws IOException
      {
          PDPage pdPage = (PDPage) document.getDocumentCatalog().getAllPages().get(page);
          image = pdPage.convertToImage(BufferedImage.TYPE_INT_RGB, 72 * SCALE);
          PDRectangle cropBox = pdPage.getCropBox();
  
          g2d = image.createGraphics();
          g2d.setStroke(new BasicStroke(0.1f));
          g2d.scale(SCALE, SCALE);
  
          setStartPage(page + 1);
          setEndPage(page + 1);
  
          Writer dummy = new OutputStreamWriter(new ByteArrayOutputStream());
          writeText(document, dummy);
  
          // beads in green
          g2d.setStroke(new BasicStroke(0.4f));
          List<PDThreadBead> pageArticles = pdPage.getThreadBeads();
          for (PDThreadBead bead : pageArticles)
          {
              PDRectangle r = bead.getRectangle();
              GeneralPath p = transform(r, Matrix.getTranslatingInstance(-cropBox.getLowerLeftX(), cropBox.getLowerLeftY()));
              AffineTransform flip = new AffineTransform();
              flip.translate(0, pdPage.findCropBox().getHeight());
              flip.scale(1, -1);
              Shape s = flip.createTransformedShape(p);
              g2d.setColor(Color.green);
              g2d.draw(s);
          }
  
          g2d.dispose();
  
          String imageFilename = filename;
          int pt = imageFilename.lastIndexOf('.');
          imageFilename = imageFilename.substring(0, pt) + "-marked-" + (page + 1) + ".png";
          ImageIO.write(image, "png", new File(imageFilename));
      }
  
      /**
       * Override the default functionality of PDFTextStripper.
       */
      @Override
      protected void writeString(String string, List<TextPosition> textPositions) throws IOException
      {
          for (TextPosition text : textPositions)
          {
              System.out.println("String[" + text.getXDirAdj() + ","
                      + text.getYDirAdj() + " fs=" + text.getFontSize() + " xscale="
                      + text.getXScale() + " height=" + text.getHeightDir() + " space="
                      + text.getWidthOfSpace() + " width="
                      + text.getWidthDirAdj() + "]" + text.getCharacter());
  
              // in red:
              // show rectangles with the "height" (not a real height, but used for text extraction 
              // heuristics, it is 1/2 of the bounding box height and starts at y=0)
              Rectangle2D.Float rect = new Rectangle2D.Float(
                      text.getXDirAdj(),
                      (text.getYDirAdj() - text.getHeightDir()),
                      text.getWidthDirAdj(),
                      text.getHeightDir());
              g2d.setColor(Color.red);
              g2d.draw(rect);
          }
      }
  
      /**
       * This will print the usage for this document.
       */
      private static void usage()
      {
          System.err.println("Usage: java " + DrawPrintTextLocations.class.getName() + " <input-pdf>");
      }
  
  
      /**
       * Transforms the given point by this matrix.
       *
       * @param x x-coordinate
       * @param y y-coordinate
       */
      private Point2D.Float transformPoint(Matrix m, float x, float y)
      {
          float[][] values = m.getValues();
          float a = values[0][0];
          float b = values[0][1];
          float c = values[1][0];
          float d = values[1][1];
          float e = values[2][0];
          float f = values[2][2];
          return new Point2D.Float(x * a + y * c + e, x * b + y * d + f);
      }
  
      /**
       * Returns a path which represents this rectangle having been transformed by the given matrix.
       * Note that the resulting path need not be rectangular.
       */
      private GeneralPath transform(PDRectangle r, Matrix matrix)
      {
          float x1 = r.getLowerLeftX();
          float y1 = r.getLowerLeftY();
          float x2 = r.getUpperRightX();
          float y2 = r.getUpperRightY();
  
          Point2D.Float p0 = transformPoint(matrix, x1, y1);
          Point2D.Float p1 = transformPoint(matrix, x2, y1);
          Point2D.Float p2 = transformPoint(matrix, x2, y2);
          Point2D.Float p3 = transformPoint(matrix, x1, y2);
  
          GeneralPath path = new GeneralPath();
          path.moveTo((float) p0.getX(), (float) p0.getY());
          path.lineTo((float) p1.getX(), (float) p1.getY());
          path.lineTo((float) p2.getX(), (float) p2.getY());
          path.lineTo((float) p3.getX(), (float) p3.getY());
          path.closePath();
          return path;
      }
  
  }
  

  回复于 2024-05-03T05:00:58+08:00