Blacklist and whitelist unsupported with LSTM (4.0)

Blacklist and whitelist no longer work in 4.00alpha. They used to work in 3.04.

https://groups.google.com/forum/#!topic/tesseract-ocr/cpcJHTE2xMo

Same problem for me with 4.00alpha, I tried to set tessedit_char_whitelist by using:

cli with option -c tessedit_char_whitelist=abcdefghijklmnopqrstuvwxyz
cli with config file
tesserocr python module

But I keep getting non letter results

I can provide Dockerfile + python script + images if needed

Same problem for me. Still getting symbols and alphabets despite setting tessedit_char_whitelist="0123456789".

I encountered the same issue today when using --oem 1,2,3. It works fine for --oem 0 (Original Tesseract).

I am encountering the same issue, is there a solution for this issue yet?.

I am encountering the same issue, is there a solution for this issue yet?.

No.

I am facing the same issue. Is it really a bug or is it just not supported for LSTM?

It's currently not supported for LSTM.

People, please do not add another "I have the same issue" comment.

Are there plans to support whitelisting on LSTM in the future?

I also have this problem when using Tesseract 4 from C++

tess->SetVariable("tessedit_char_whitelist", "01234567890abcdefg");

has no effect on the output. The same with blacklist.

Tesseract returns not only ascii + language-specific characters but also some strange other characters from UTF-8.

Is there a way to get a full list of all possible characters, specific for a language or not? Basing on such list one could make a workaround to map such wrong characters to best fitting ones that are expected (like EM DASH to plain ASCII dash etc.) and remove those without any sensible fit. It would be useful for me in current circumstances and maybe it could be useful for others in need of whitelisting.

@theraysmith

@theraysmith Are there plans to support this for LSTM?

In response to https://groups.google.com/forum/#!topic/tesseract-ocr/-oeCTcojYfw

You can try the plus-minus type of training if you just want a digits type of traineddata.

Your training_text can contain numbers in the format you need and you can train with a font matching your images.

For proof of concept you can try my experimental version at

https://github.com/Shreeshrii/tessdata_shreetest

@Shreeshrii

I would like to exclude everything except letters and digits from the result. I started from eng.traineddata and trained my font from graphical images (@Shreeshrii: thanks!!)) . Is there a way to get rid of all the other symbols, especially !"=)() ... ?

I am using --oem 1.

Thank you very much,
Ernst

has this been resolved or anyone found a workaround?

has this been resolved

No.

Has anyone tested the 4.1 Version? It's supposed to be fixed now? release notes

Really excited ！ It works!

@nguyenq

@nguyenq, can we close this issue?

Didn't realize I'd opened this issue. It's been so long ago. :)

https://github.com/tesseract-ocr/tesseract/wiki#tesseract-4-packages-with-lstm-engine-and-related-traineddata Install from Alex's ppa

…

On Fri, 30 Aug 2019, 21:18 OllieD3711, ***@***.***> wrote: This appears to be working for me, just upgraded my 4.0 version to 4.1. FINALLY! lol been waiting on this. @kev2316 <https://github.com/kev2316> I'm having trouble upgrading to 4.1.0. I'm sure I'm doing something stupid (using sudo apt-upgrade, and also tried sudo apt install), but when I try upgrade, I'm told I already have the latest version, 4.00~git2288-10f4998a-2. How can I upgrade to 4.1.0? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#751?email_source=notifications&email_token=ABG37I5ILLDA745L7XWIC6TQHE6LLA5CNFSM4DC3C6RKYY3PNVWWK3TUL52HS4DFVREXG43VMVBW63LNMVXHJKTDN5WW2ZLOORPWSZGOD5SBBTI#issuecomment-526651597>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABG37I6G7RJ7R3ZNMOFTPKLQHE6LLANCNFSM4DC3C6RA> .

stbt.ocr docstring: Note that LSTM engine ignores char_whitelist

Just to conclude and in addition:

To solve the black- and whitlist problem in version 4.0, two solutions have already been mentioned:

Update Tesseract to version 4.1 (the future-oriented approach)
Use the legacy mode with --oem flag

The Ubuntu package sources only contains tesseract version 4.0.0-beta.1. If you can't upgrade and don't want to use the legacy mode, try to build a simple black- or whitelist function if you are using tesseract with a wrapper in another programming language. One example with PyTesserocr can be found in this blog article: return2 – Python Tesseract 4.0 OCR: Recognize only numbers / digits and exclude all other characters.

Alex's ppa can be used on Ubuntu for the latest versions.
Please see https://github.com/tesseract-ocr/tesseract/wiki

Just to conclude and in addition:

To solve the black- and whitlist problem in version 4.0, two solutions have already been mentioned:

Update Tesseract to version 4.1 (the future-oriented approach)

Use the legacy mode with --oem flag

The Ubuntu package sources only contains tesseract version 4.0.0-beta.1. If you can't upgrade and don't want to use the legacy mode, try to build a simple black- or whitelist function if you are using tesseract with a wrapper in another programming language. One example with PyTesserocr can be found in this blog article: return2 – Python Tesseract 4.0 OCR: Recognize only numbers / digits and exclude all other characters.

Is your method 3 a joke? It is not detection of numbers only , it is filtering out text AFTER being detected.

Fix cross-panel OCR garbling, remove no-op whitelist, loosen density …

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Blacklist and whitelist unsupported with LSTM (4.0) #751

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Blacklist and whitelist unsupported with LSTM (4.0) #751

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