public void prepareWriteSequence(IIOMetadata streamMetadata) throws IOException {
ImageOutputStream out = (ImageOutputStream) getOutput();
out.setByteOrder(ByteOrder.LITTLE_ENDIAN);
out.writeShort(0x00004949); // 0: II = intel = little endian
out.writeShort(42); // 2: version, magic value
ifdptr = out.getStreamPosition(); // save position (4): write here later the offset to first ifd
// (ifd linked list)
out.writeInt(0); // 4: offset first Image File Directory
// 8: header size
}
