ImageIO, TIFF, and metadata problems

Question

I'm trying to set some metadata parameters for output of a TIFF image. The problem I had was, the API returns a W3C DOM Node, and since the DOM API is so disgusting, I didn't want to use it directly.
And naturally, since XPath is supposed to work over a DOM, I thought I could use it as a shortcut.
Sample program:
import java.awt.image.BufferedImage;
import java.awt.image.RenderedImage;
import javax.imageio.metadata.IIOMetadata;
import javax.imageio.ImageIO;
import javax.imageio.ImageTypeSpecifier;
import javax.imageio.ImageWriteParam;
import javax.imageio.ImageWriter;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathFactory;
import org.w3c.dom.Node;
public class TiffMetadataBug {
    public static void main(String[] args) throws Exception {
        // Test image
        RenderedImage image = new BufferedImage(8, 8, BufferedImage.TYPE_INT_ARGB);
        // Get the default metadata for this kind of image
        ImageWriter imageWriter = ImageIO.getImageWritersByFormatName("TIFF").next();
        ImageWriteParam writeParam = imageWriter.getDefaultWriteParam();
        IIOMetadata metadata = imageWriter.getDefaultImageMetadata(new ImageTypeSpecifier(image), writeParam);
        // The root metadata node is...
        Node metadataRoot = metadata.getAsTree(metadata.getNativeMetadataFormatName());
        // Output the metadata DOM as XML.
        Transformer identity = TransformerFactory.newInstance().newTransformer();
        System.out.print("XML:");
        identity.transform(new DOMSource(metadataRoot), new StreamResult(System.out));
        System.out.println();
        // Try to match a path into the DOM.
        XPath xPath = XPathFactory.newInstance().newXPath();
        Object result = xPath.evaluate("//TIFFField[@number='282']/TIFFRationals/TIFFRational", metadataRoot, XPathConstants.NODE);
        System.out.println("Result of XPath evaluation: " + result);
}The first bit of the output was done to see what XPath to use. It contains XML like this:
    <TIFFField number="282" name="XResolution">
        <TIFFRationals>
            <TIFFRational value="1/1"/>
        </TIFFRationals>
    </TIFFField>So my XPath:
//TIFFField[@number='282']/TIFFRationals/TIFFRationalshould work fine.
I wonder if this is a bug in the ImageIO metadata code, or if I'm actually doing something wrong here.

Answer 1

Hi!
I try to get tiff tags together with their data out of a TIFF-file with the use of DOM. I get problems reading the metadata. How can I read metadata so I can output it like above?
thanks in advanced.
Errors I get:
Exception in thread "main" javax.imageio.IIOException: I/O error reading image metadata!
at com.sun.media.imageioimpl.plugins.tiff.TIFFImageReader.readMetadata(Unknown Source)
at com.sun.media.imageioimpl.plugins.tiff.TIFFImageReader.seekToImage(Unknown Source)
at com.sun.media.imageioimpl.plugins.tiff.TIFFImageReader.getImageMetadata(Unknown Source)
at tiffmetadatabug.Main.main(Main.java:96)
Caused by: java.io.EOFException
at javax.imageio.stream.ImageInputStreamImpl.readShort(ImageInputStreamImpl.java:211)
at javax.imageio.stream.ImageInputStreamImpl.readUnsignedShort(ImageInputStreamImpl.java:222)
at com.sun.media.imageioimpl.plugins.tiff.TIFFIFD.initialize(Unknown Source)
at com.sun.media.imageioimpl.plugins.tiff.TIFFIFD.initialize(Unknown Source)
at com.sun.media.imageioimpl.plugins.tiff.TIFFImageMetadata.initializeFromStream(Unknown Source)
... 4 more
Java Result: 1