Java returning incorrect values for width and height of a Tiff image

Question

I have some TIFF images (sorry, I cannot post them b/c of there confidential nature) that are returning the incorrect values for the width and height. I am using Image.getWidth(null) and have tried the relevant methods from BufferedImage. When I open the same files in external viewers (Irfanview, MS Office Document Imaging) they look fine and report the "correct" dimensions. When I re-save the files, my code works fine. Obviously, there is something wrong with the files, but why would the Java code fail and not the external viewers? Is there some way I can detect file problems?
Here is the code, the relevant section is in the print() routine.
* ImagePrinter.java
* Created on Feb 27, 2008
* Created by tso1207
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.print.PageFormat;
import java.awt.print.PrinterException;
import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import javax.imageio.ImageIO;
import javax.imageio.ImageReader;
import javax.imageio.stream.FileImageInputStream;
import javax.imageio.stream.ImageInputStream;
import com.shelter.io.FileTypeIdentifier;
public class ImagePrinter extends FilePrintable
   private final ImageReader _reader;
   private final int _pageCount;
   private final boolean _isTiff;
   //for speed we will hold current page info in memory
   private Image _image = null;
   private int _imgWidth = 0;
   private int _imgHeight = 0;
   private int _currentPage = -1;
   public ImagePrinter(File imageFile) throws IOException
      super(imageFile);
      ImageInputStream fis = new FileImageInputStream(getFile());
      Iterator readerIter = ImageIO.getImageReaders(fis);
      ImageReader reader = null;
      while (readerIter.hasNext())
         reader = (ImageReader) readerIter.next();
      reader.setInput(fis);
      _reader = reader;
      int pageCount = 1;
      String mimeType = FileTypeIdentifier.getMimeType(imageFile, true);
      if (mimeType.equalsIgnoreCase("image/tiff"))
         _isTiff = true;
         pageCount = reader.getNumImages(true);
      else
         _isTiff = false;
      _pageCount = pageCount;
   public int print(java.awt.Graphics g, java.awt.print.PageFormat pf, int pageIndex)
      throws java.awt.print.PrinterException
      int drawX = 0, drawY = 0;
      double scaleRatio = 1;
      if (getCurrentPage() != (pageIndex - getPageOffset()))
         try
            setCurrentPage(pageIndex - getPageOffset());
            setImage(_reader.read(getCurrentPage()));
            setImgWidth(getImage().getWidth(null));
            setImgHeight(getImage().getHeight(null));
         catch (IndexOutOfBoundsException e)
            return NO_SUCH_PAGE;
         catch (IOException e)
            throw new PrinterException(e.getLocalizedMessage());
         if (!_isTiff && getImgWidth() > getImgHeight())
            pf.setOrientation(PageFormat.LANDSCAPE);
         else
            pf.setOrientation(PageFormat.PORTRAIT);
      Graphics2D g2 = (Graphics2D) g;
      g2.translate(pf.getImageableX(), pf.getImageableY());
      g2.setClip(0, 0, (int) pf.getImageableWidth(), (int) pf.getImageableHeight());
      scaleRatio =
         (double) ((getImgWidth() > getImgHeight())
            ? (pf.getImageableWidth() / getImgWidth())
            : (pf.getImageableHeight() / getImgHeight()));
      //check the scale ratio to make sure that we will not write something off the page
      if ((getImgWidth() * scaleRatio) > pf.getImageableWidth())
         scaleRatio = (pf.getImageableWidth() / getImgWidth());
      else if ((getImgHeight() * scaleRatio) > pf.getImageableHeight())
         scaleRatio = (pf.getImageableHeight() / getImgHeight());
      int drawWidth = getImgWidth();
      int drawHeight = getImgHeight();
      //center image
      if (scaleRatio < 1)
         drawX = (int) ((pf.getImageableWidth() - (getImgWidth() * scaleRatio)) / 2);
         drawY = (int) ((pf.getImageableHeight() - (getImgHeight() * scaleRatio)) / 2);
         drawWidth = (int) (getImgWidth() * scaleRatio);
         drawHeight = (int) (getImgHeight() * scaleRatio);
      else
         drawX = (int) (pf.getImageableWidth() - getImgWidth()) / 2;
         drawY = (int) (pf.getImageableHeight() - getImgHeight()) / 2;
      g2.drawImage(getImage(), drawX, drawY, drawWidth, drawHeight, null);
      g2.dispose();
      return PAGE_EXISTS;
    * <br><br>
    * Created By: TSO1207 - John Loyd
    * @since version XXX
    * @return
   public int getPageCount()
      return _pageCount;
   public void destroy()
      setImage(null);
      try
         _reader.reset();
         _reader.dispose();
      catch (Exception e)
      System.gc();
    * <br><br>
    * Created By: TSO1207 - John Loyd
    * @since Mar 25, 2008
    * @return
   public Image getImage()
      return _image;
    * <br><br>
    * Created By: TSO1207 - John Loyd
    * @since Mar 25, 2008
    * @return
   public int getImgHeight()
      return _imgHeight;
    * <br><br>
    * Created By: TSO1207 - John Loyd
    * @since Mar 25, 2008
    * @return
   public int getImgWidth()
      return _imgWidth;
    * <br><br>
    * Created By: TSO1207 - John Loyd
    * @since Mar 25, 2008
    * @param image
   public void setImage(Image image)
      _image = image;
    * <br><br>
    * Created By: TSO1207 - John Loyd
    * @since Mar 25, 2008
    * @param i
   public void setImgHeight(int i)
      _imgHeight = i;
    * <br><br>
    * Created By: TSO1207 - John Loyd
    * @since Mar 25, 2008
    * @param i
   public void setImgWidth(int i)
      _imgWidth = i;
    * <br><br>
    * Created By: TSO1207 - John Loyd
    * @since Mar 25, 2008
    * @return
   public int getCurrentPage()
      return _currentPage;
    * <br><br>
    * Created By: TSO1207 - John Loyd
    * @since Mar 25, 2008
    * @param i
   public void setCurrentPage(int i)
      _currentPage = i;
}Edited by: jloyd01 on Jul 3, 2008 8:26 AM

Answer 1

Figured it out. The files have a different vertical and horizontal resolutions. In this case the horizontal resolution is 200 DPI and the vertical is 100 DPI. The imgage width and height values are based on those resolution values. I wrote a section of code to take care of the problem (at least for TIFF 6.0)
   private void setPageSize(int pageNum) throws IOException
      IIOMetadata imageMetadata = _reader.getImageMetadata(pageNum);
      //Get the IFD (Image File Directory) which is the root of all the tags
      //for this image. From here we can get all the tags in the image.
      TIFFDirectory ifd = TIFFDirectory.createFromMetadata(imageMetadata);
      double xPixles = ifd.getTIFFField(256).getAsDouble(0);
      double yPixles = ifd.getTIFFField(257).getAsDouble(0);
      double xRes = ifd.getTIFFField(282).getAsDouble(0);
      double yres = ifd.getTIFFField(283).getAsDouble(0);
      int resUnits = ifd.getTIFFField(296).getAsInt(0);
      double imageWidth = xPixles / xRes;
      double imageHeight = yPixles / yres;
      //if units are in CM convert ot inches
      if (resUnits == 3)
         imageWidth = imageWidth * 0.3937;
         imageHeight = imageHeight * 0.3937;
      //convert to pixles in 72 DPI
      imageWidth = imageWidth * 72;
      imageHeight = imageHeight * 72;
      setImgWidth((int) Math.round(imageWidth));
      setImgHeight((int) Math.round(imageHeight));
      setImgAspectRatio(imageWidth / imageHeight);
   }