Tesseract OCR tips — useful commands on usage CL tool

Here is my second post on OCR using Tesseract. This time I would like to share some commands I found useful when using Tesseract command line tool.

First of all main help on Tesseract command line can be displayed using arguments “ — help” and “ — help-extra”. “ — help” will show breif wersion of user manual:

Usage:
  tesseract --help | --help-extra | --version
  tesseract --list-langs
  tesseract imagename outputbase [options...] [configfile...]
OCR options:
  -l LANG[+LANG]        Specify language(s) used for OCR.
NOTE: These options must occur before any configfile.
Single options:
  --help                Show this help message.
  --help-extra          Show extra help for advanced users.
  --version             Show version information.
  --list-langs          List available languages for tesseract engine.

“ — help-extra” will show more detailed version:

Usage:
  tesseract --help | --help-extra | --help-psm | --help-oem | --version
  tesseract --list-langs [--tessdata-dir PATH]
  tesseract --print-parameters [options...] [configfile...]
  tesseract imagename|imagelist|stdin outputbase|stdout [options...] [configfile...]
OCR options:
  --tessdata-dir PATH   Specify the location of tessdata path.
  --user-words PATH     Specify the location of user words file.
  --user-patterns PATH  Specify the location of user patterns file.
  -l LANG[+LANG]        Specify language(s) used for OCR.
  -c VAR=VALUE          Set value for config variables.
                        Multiple -c arguments are allowed.
  --psm NUM             Specify page segmentation mode.
  --oem NUM             Specify OCR Engine mode.
NOTE: These options must occur before any configfile.
Page segmentation modes:
...
OCR Engine modes: (see https://github.com/tesseract-ocr/tesseract/wiki#linux)
...
Single options:
  -h, --help            Show minimal help message.
  --help-extra          Show extra help for advanced users.
  --help-psm            Show page segmentation modes.
  --help-oem            Show OCR Engine modes.
  -v, --version         Show version information.
  --list-langs          List available languages for tesseract engine.
  --print-parameters    Print tesseract parameters.

I have skipped some sections to save space.

You can specify special parameters when using Tesseract OCR on image. There is an argument to show all the available parameters in Tesseract. This argument is “ — print-parameters”. Nice thing in this option is that the output displays default values for all parameters

Tesseract parameters:
editor_image_xpos 590 Editor image X Pos
editor_image_ypos 10 Editor image Y Pos
editor_image_menuheight 50 Add to image height for menu bar
editor_image_word_bb_color 7 Word bounding box colour
editor_image_blob_bb_color 4 Blob bounding box colour

That’s all for this time. Enjoy the OCR using Tesseract and see you soon.