Common Fraktur OCR errors

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Some of the most common OCR text errors are listed below. You will find yourself getting better proofing results if you keep these in mind while you work. Double-checking for these common errors can make a BIG difference!


The Fraktur alphabet

Fraktur alphabet.gif

Similar characters

Some characters have a very similar appearance:

  • f | ſ (long s) (yes, there are two different characters for 's'!)
  • a | u | n
  • c | e | o
  • t | k
  • i | l
  • d | ck (Ligature)
  • w | sch (too many vertical lines?)
  • M | W
  • A | U
  • R | K
  • E | G
  • h | y

See also this site for a discussion of similar letters in Fraktur.

'long s' vs. 'f'

The 'normal' s is used at the end of a syllable, the long 's' (ſ) elsewhere. If in doubt, this may help you to proof the correct word: aus vs. auf, ausſteigen vs. aufſteigen etc.

For long s in general: Proofing_old_texts#Long_s|"Proofing Old Texts" page

very seldom correctly recognized characters

x

Numbers

Sometimes numbers are unreadable in a fraktur-font. The numbers are recognized as dirt and do not appear.

strange (=older) writings

Especially in German texts: the OCR software often uses a spellchecker with a modern dictionary, so words that have changed in spelling may be OCRed with the modern spellings instead of what is on the page:

  • words earlier written with 'th', now are written only with 't' (e.g. eigenthümlich -> eigentümlich, roth -> rot). The OCR results miss the 'h's.
  • The same with umlaut-dots: kömmt -> kommt

Be sure to proof it according to the image, not modern spelling.

Proper Names

  • People and Place-names are often spelled in unexpected ways.
  • Double-check all proper names to be certain that what got OCR'd as "Banks" isn't really "Bariks" ("ri" / "n" is a really common OCR error).

Fixing common OCR errors in Preprocessing when Providing Content

Even with hand-trained patterns, OCR programs have their problems with fraktur font. In order to fix the most common errors, frakprep should be used.

External links

  • Fraktur tool: like DP's Greek transliteration tool, but for the fraktur alphabet
  • Script Teacher: a site for learning fraktur (and other) fonts. Select the first checkbox in the "Font Face" options to practice fraktur (as opposed to other blackletter fonts).