Get TIFF tag value (including non-ASCII characters) from TIFF images in Java 11 - utf-8

Question

I am trying to read different tag values (like tags 259 (Compression), 33432 (Copyright), 306 (DateTime), 315 (Artist) etc.) from a TIFF image in Java. Can anyone suggest what is best way to get those values in Java 11 ?
i tried to get those values using tiffinfo commands (like "tiffinfo -c myfile.tif"). But i did not find any specific command in tiffinfo (libtiff) or any Java library which will give me the specific tag values (e.g. DateTime) of a TIFF image.
Update:
As haraldK suggested, i tried with ImageIO like following
try (ImageInputStream input = ImageIO.createImageInputStream(tiffFile)) {
ImageReader reader = ImageIO.getImageReaders(input).next(); // TODO: Handle reader not found
reader.setInput(input);
IIOMetadata metadata = reader.getImageMetadata(0);
TIFFDirectory ifd = TIFFDirectory.createFromMetadata​(metadata);
TIFFField dateTime = ifd.get​TIFFField(306);
String dateString = dateTime.getAsString(0);
}
But it does not give exact value of the tag. In case of non-ASCII value (ö, ü, ä etc), question marks replace the real values.
Can anyone tell me how to get the exact value (including non-ASCII) of the tag from TIFFField ?

Answer 1

You can use standard ImageIO, read the TIFF image metadata and get the requested values from it, like this by using some extra support classes in the JDK, starting from Java 9:
try (ImageInputStream input = ImageIO.createImageInputStream(tiffFile)) {
ImageReader reader = ImageIO.getImageReaders(input).next(); // TODO: Handle reader not found
reader.setInput(input);
IIOMetadata metadata = reader.getImageMetadata(0); // 0 is the index of first image
TIFFDirectory ifd = TIFFDirectory.createFromMetadata​(metadata);
TIFFField dateTime = ifd.get​TIFFField(306); // Yes, that's 3 F's...
String dateString = dateTime.getAsString(0); // TIFF dates are strings...
}
tiffFile must be a valid (existing, readable) java.io.File, java.io.RandomAccessFile or java.io.InputStream (or other supported input, this is plugin-based, really). If not, input will be null, and the code will fail.
You can use similar, but a lot more verbose version, that will work in older versions of Java, as long as you have a TIFF plugin:
try (ImageInputStream input = ImageIO.createImageInputStream(tiffFile)) {
ImageReader reader = ImageIO.getImageReaders(input).next(); // TODO: Handle reader not found
reader.setInput(input);
IIOMetadata metadata = reader.getImageMetadata(0); // 0 is the index of first image
// Get "native" TIFF metadata for first IFD
IIOMetadataNode root = metadata.getAsTree("com_sun_media_imageio_plugins_tiff_image_1.0");
Node ifd = root.getFirstChild();
NodeList fields = ifd.getElementsByTagName("TIFFField"); // Yes, that's 3 F's...
for (int i = 0; i < fields.getLength(); i++) {
Element field = (Element) fields.item(i);
if ("306".equals(field.getAttribute("number"))) {
// This is your DateTime (306) tag,
// now do something with it 😀
// ...
}
}
}
Hardly elegant code, though... The Java 9+ approach is much cleaner and easier to reason about.