CODEWITHSUNDEEP
javatagsmetadatajpegkeyword
Shirux
Shirux

Reputation: 153

Modifying or adding new tags to a jpg (Metadata) with iim4j

I am trying to modify or add new tags with the iim4j library, but its documentation is poor. I've been searching for examples on the internet and didn't found anything so far. I only got the examples the library offers. There's one example about reading the Metadata and I can get the title, description and tags of the image (the ones I care). I know the library manage these info as DataSet and DataSetInfo so I tried to create new instances of these objects for the info I want to add but I have no results so far.

This is the code for reading the IPTC section of a jpeg file:

    public static void dump(File file) throws Exception {

    System.out.println("IPTC segment for " + file);
    IIMFile iimFile = new IIMFile();

    IIMReader reader = new IIMReader(new JPEGIIMInputStream(new FileIIMInputStream(file)), new IIMDataSetInfoFactory());
    iimFile.readFrom(reader, 20);

    for (Iterator i = iimFile.getDataSets().iterator(); i.hasNext();) {
        DataSet ds = (DataSet) i.next();            
        Object value = ds.getValue();
        if (value instanceof byte[]) {
            value = "<bytes " + ((byte[]) value).length + ">";
        }
        DataSetInfo info = ds.getInfo();
        if (info instanceof DefaultDataSetInfo)
        {
            System.out.println("-----------");
            System.out.println("Number : " + info.getDataSetNumber());
            System.out.println("Name :" + info.getName());
            Serializer serializador=info.getSerializer();
            if(serializador instanceof StringSerializer)
                System.out.println("Serializer :" + serializador.toString());
            System.out.println("Repeat : " + info.isRepeatable());
            System.out.println("----------");
        }

        System.out.println(info.toString() + " " + info.getName() + ": " + value);

    }
    reader.close();
}

I can obtain all the info I need and also I know that kind of objects I must use to add new info on another files. So i tried this one to add a new tag:

    String tagToAdd="Tag to add";
    int size= tagToAdd.length();
    DefaultDataSetInfo valueTag=new DefaultDataSetInfo(537,"Keywords", new StringSerializer(size+ ""),true);
    DefaultDataSet dataSet=new DefaultDataSet(valueTag, tagToAdd.getBytes());
    iimFile.add(dataSet);

and tried this one to write a new file with a tag:

    String tagToAdd="Tag to add";
    int size= tagToAdd.length();
    DefaultDataSetInfo valueTag=new DefaultDataSetInfo(537,"Keywords", new StringSerializer(size+ ""),true);
    DefaultDataSet dataSet=new DefaultDataSet(valueTag, tagToAdd.getBytes());

    IIMWriter escritor= new IIMWriter(new DefaultIIMOutputStream(file));
    escritor.write(dataSet);
    escritor.close();

Tags weren't add. I need some help with this library and its use. Thanks

Upvotes: 3

Views: 811

Answers (1)

R&#233;gis Jean-Gilles
R&#233;gis Jean-Gilles

Reputation: 32719

From my own testing, it seems that IIMWriter is only intended to be used to write the IPTC metadata to a file, and nothing else. Needless to say, that does not make for a valid JPEG file. What you want is to take an existing JPEG file, and generate a new file with the same data, except for the IPTC metadata that should be removed (if any) and replaced with the content of your IIMFile.

That's exactly what JPEGUtil.insertIIMIntoJPEG is for. What you need to do is something like this (where newFile is a File insatnce pointing to where you want to save the modified JPEG):

// 1. Read original IIM
IIMReader reader = new IIMReader(new JPEGIIMInputStream(new FileIIMInputStream(file)), new IIMDataSetInfoFactory());
iimFile.readFrom(reader, 20);

// 2. Add dataset
DataSet dataSet = ... // Whatever you want
iimFile.add(dataSet);

// 3. Create new copy of JPEG file new IIM
try (
  InpuStream in = new BufferedInputStream(new FileInputStream(file));
  OutputStream out = new BufferedOutputStream(new FileOutputStream(newFile))
) {
  JPEGUtil.insertIIMIntoJPEG(out, iimFile, in)
}

Upvotes: 1

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