Create Preprocessing.md

docs/Preprocessing.md

@@ -0,0 +1,10 @@
+# Preprocessing
+
+The preprocessing pipeline that is developed at the 
+[Berlin State Library](http://staatsbibliothek-berlin.de/) 
+comprises the following steps:
+- textline extraction @[sbb_pixelwise_segmentation](https://github.com/qurator-spk/pixelwise_segmentation_SBB)
+- word segmentation @[ocrd_tesserocr](https://github.com/OCR-D/ocrd_tesserocr)
+- OCR @[ocrd_calamari](https://github.com/qurator-spk/ocrd_calamari)
+- Tokenization
+- Pretagging @[sbb_ner](https://github.com/qurator-spk/sbb_ner)