HocrHeaderFixer.cs

using System.Text;
using System.Text.RegularExpressions;
using System.Xml;
using System.Xml.Linq;

class HocrHeaderFixer : IHocrXmlProcessor
{
    public void Init()
    {
        Console.WriteLine("Fixing hOCR file headers...");
    }

    public void Process(string hocrFile, XDocument hocrXml)
    {
        XNamespace ns = "http://www.w3.org/1999/xhtml";
        var head = hocrXml.Element(ns + "html").Element(ns + "head");
        head.Element(ns + "title").Value = "Image: " + Regex.Replace(Path.GetFileName(hocrFile), "_HOCR.shtml$", "_JP2.jpg");
        head.Add(new XElement(ns + "meta", new XAttribute("name", "ocr-system"), new XAttribute("content", "Transkribus")));
        var writer = XmlWriter.Create(File.Open(hocrFile, FileMode.Truncate), new XmlWriterSettings 
        {
            // need to specify false here to stop it from emitting a byte order mark
            Encoding = new UTF8Encoding(false), 
            Indent = true
        });
        hocrXml.Save(writer);
        writer.Close();
    }
}