ocr

Create a config file (e.g “letters”) in tessdata/configs directory – usually /usr/share/tesseract/tessdata/configs or /usr/share/tesseract-ocr/tessdata/configs And add this line to the config file: tessedit_char_whitelist abcdefghijklmnopqrstuvwxyz …or maybe [a-z] works. I don’t know. Then call tesseract similar to this: tesseract input.tif output nobatch letters That will limit tesseract to recognize only the wanted characters.