Openalpr: tessdata not located during the alpr install test

Created on 20 Mar 2018 · 7Comments · Source: openalpr/openalpr

Following the instruction for OS X at:

https://github.com/openalpr/openalpr/wiki/Compilation-instructions-(OS-X)

The last step before testing the install asks to copy the runtime_data directory

# copy runtime_data
mkdir /usr/local/share/openalpr
cp -r ../../runtime_data /usr/local/share/openalpr/

Running the install test after that gives the following error

wget http://i.imgur.com/pjukRD0.jpg -O lp.jpg
alpr lp.jpg

Error opening data file /usr/local/share/openalpr/runtime_data/ocr/lus.traineddata
Please make sure the TESSDATA_PREFIX environment variable is set to your "tessdata" directory.
Failed loading language 'lus'
Tesseract couldn't load any languages!
[1]    44280 segmentation fault  alpr lp.jpg

The error comes from the fact that the tesseract files are looked up in /usr/local/share/openalpr/runtime_data/ocr/ instead of /usr/local/share/openalpr/runtime_data/ocr/tessdata.

I tried exporting the TESSDATA_PREFIX as indicated by the error message and the following issue in the tesseract repo

https://github.com/tesseract-ocr/tesseract/issues/221

export TESSDATA_PREFIX=/usr/local/share/openalpr/runtime_data/ocr

Still no luck. I also tried the following variants with the same result

export TESSDATA_PREFIX=/usr/local/share/openalpr/runtime_data/ocr
export TESSDATA_PREFIX=tessdata

Looking at this part of the error

Error opening data file /usr/local/share/openalpr/runtime_data/ocr/lus.traineddata

I tried to move the file to /usr/local/share/openalpr/runtime_data/ocr which makes alpr happy

alpr lp.jpg
plate0: 10 results
    - 6RUX251    confidence: 95.1969
    - 6RUXZ51    confidence: 87.8443
    - 6RUX2S1    confidence: 85.4606
    - 6RUX25I    confidence: 85.4057
    - 6ROX251    confidence: 85.3351
    - 6RDX251    confidence: 84.7451
    - 6R0X251    confidence: 84.7044
    - 6RQX251    confidence: 82.9933
    - 6RUXZS1    confidence: 78.1079
    - 6RUXZ5I    confidence: 78.053

From what I see in the code

//openalpr/config/openalpr.conf.defaults
runtime_dir = ${CMAKE_INSTALL_PREFIX}/share/openalpr/runtime_data

//openalpr/src/openalpr/config.cpp
  void Config::loadCommonValues(string configFile)
  {
...
    runtimeBaseDir = getString(ini,defaultIni, "", "runtime_dir", DEFAULT_RUNTIME_DATA_DIR);
...
}
  string Config::getTessdataPrefix()
  {
    return this->runtimeBaseDir + "/ocr/";
  }
//openalpr/src/openalpr/ocr/tesseract_ocr.cpp
   // Tesseract requires the prefix directory to be set as an env variable
    tesseract.Init(config->getTessdataPrefix().c_str(), config->ocrLanguage.c_str()     );

Although the comment above tesseract.Init seems to indicate TESSDATA_PREFIX should be taken into account in practice I see exactly the getTessdataPrefix concatenated with ocrLanguage being used.

Let me know if I overlooked something

My environement

tesseract 4.0.0-beta.1
 leptonica-1.75.3
  libjpeg 9c : libpng 1.6.34 : libtiff 4.0.9 : zlib 1.2.11

 Found AVX2
 Found AVX
 Found SSE

opencv-2.4.13.6

alpr --version

alpr  version: 2.3.0

OS X 10.13.3

Source

amchoukir

👍3

Most helpful comment

sudo cp -a /usr/share/openalpr/runtime_data/ocr/tessdata/*.traineddata /usr/share/openalpr/runtime_data/ocr/

It works for me :)

karthick965938 on 24 Jan 2020

👍10 🎉4 ❤2 🚀1

All 7 comments

I have the same issue. Tried to export the TESSDATA_PREFIX to the correct path and it changed nothing when i reran tesseract. It's not taking the environment variable into account at all.
I'm on Ubuntu 16.04 and I compiled from source and now have the following:

tesseract 4.0.0-beta.1-53-g3fcb
 leptonica-1.76.0
  libjpeg 8d (libjpeg-turbo 1.4.2) : libpng 1.2.54 : libtiff 4.0.6 : zlib 1.2.8
 Found AVX2
 Found AVX
 Found SSE

EnergyFusion on 26 Mar 2018

Unable to fix the issue by the methods described, I copied /usr/share/openalpr/runtime_data/ocr/tessdata/*.traineddata into /usr/share/openalpr/runtime_data/ocr/ and it seems to have corrected the problem. This is probably not recommended, and YMMV.

weasel5i2 on 14 May 2018

👍7 😄1

I have the same problem in Kubuntu 18.04

After following the official instructions for installing the package on an Ubuntu machine (Easy Way), running the install test, I've get this error

alpr lp.jpg 
Error opening data file /usr/share/openalpr/runtime_data/ocr/lus.traineddata
Please make sure the TESSDATA_PREFIX environment variable is set to your "tessdata" directory.
Failed loading language 'lus'
Tesseract couldn't load any languages!
Segmentation fault (core dumped)

After the penultimate line it takes a long time (aprox 10 seconds) and Ubuntu crashes:

Sorry, Ubuntu 18.04 has experienced an internal error.
If you notice further problems, try restarting the computer

The log can be seen here or:
alpr_crash_apport_log.txt

Tesseract version:

tesseract 4.0.0-beta.1
 leptonica-1.75.3
  libgif 5.1.4 : libjpeg 8d (libjpeg-turbo 1.5.2) : libpng 1.6.34 : libtiff 4.0.9 : zlib 1.2.11 : libwebp 0.6.1 : libopenjp2 2.3.0

 Found AVX2
 Found AVX
 Found SSE