Tesseract does not recognise these numbers

[Juanjo Gómez Navarro]

I have this simple image with a date:

Tesseract produces the output: 

$ tesseract test.png -

Estimating resolution as 233

03:41 pm

In similar images, I have the problem that it misunderstands 1's for 7's and the other way around. How can I help Tesseract to recognise these characters?

My version of Tesseract is:

$ tesseract -v

tesseract 5.0.0-alpha-20210401-130-g7a308

 leptonica-1.79.0

  libgif 5.1.4 : libjpeg 8d (libjpeg-turbo 2.0.3) : libpng 1.6.37 : libtiff 4.1.0 : zlib 1.2.11 : libwebp 0.6.1 : libopenjp2 2.3.1

 Found AVX2

 Found AVX

 Found FMA

 Found SSE4.1

 Found OpenMP 201511

[Zdenko Podobny]

With tessdata from  [1]  and oem 0 you can get:

tesseract unnamed.png - --psm 7 --oem 0
09:41 Dm

Otherwise:

tesseract unnamed.png - --psm 7

0%:41 pm

With small preprocessing (blur and resize, so letter have high around 30 points) you can get :

tesseract time.png - --psm 7
09:41 pm

[1] https://github.com/tesseract-ocr/tessdata

Zdenko

št 17. 6. 2021 o 15:51 Juanjo Gómez Navarro <juanjo.go...@gmail.com> napísal(a):

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[Juanjo Gómez Navarro]

Thanks for the hint. A little bit of blur and resizing indeed helped.