pythontesseractpython-tesseract

Pytesseract not recognize text from image in Python

I am working with a Django application, there for some purpose i need to solve captcha i am already saving temporary captcha file but when i try to read captcha using pytesseract it return nothing empty string.

enter image description here

enter image description here

Solution

  • tesseract sometimes may have problem when text is too small or too big. It may have other problems. See documentation: Improving the quality of the output | tessdoc

    If I resize your image 200% then tesseract can get text.

    I used external program ImageMagick for this but you may use python module pillow
    (or Wand which also uses Imagemagick)

    $ convert captcha.png -scale 200% captcha-200p.png

    Command file can show some information about files

    $ file ca*

captcha-200p.png: PNG image data, 300 x 60, 8-bit grayscale, non-interlaced
captcha.png:      PNG image data, 150 x 30, 8-bit/color RGBA, non-interlaced

    Strange is that you don't get any error message because when I run tesseract only with input image then it shows message how to use it

    $ tesseract captcha-200p.png

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.

    It needs output name without extension (and it adds .txt) to write result in file

    $ tesseract captcha-200p.png output

Estimating resolution as 308

$ cat ouput.txt

81+20=?

    or it needs - to set ouput to stdout and show it on screen or redirect to other program

    $ tesseract captcha-200p.png -

Estimating resolution as 308
81+20=?

    Tested on: Linux Mint 22 (based on Ubuntu 24.02), tesseract 5.3.4 (leptonica-1.82.0)