Old characters in gothic texts

dneumann81Discussions, OCR evaluation/quality control

I am trying evaluate OCR texts produced by Abbyy Recognition Server. The original texts have some old characters which don’t exist anymore. For example, the “long s”: http://en.wikipedia.org/wiki/Long_s. The server recognizes it as a normal s. However, our ground truth files have the correct “long s” in them. Do you have any tips for me how to treat such characters? I am not aware of a switch in the Abbyy Server to produce those old characters.