tesseract-for-android

This repository provides cross compile instructions and compiled binaries of tesseract for Android. The official repository of tesseract can be found here. The repository with android compilation support can be found here and its port which this repository uses can be found here.

Contents

• Compatibility
• Dependencies
• Downloads
• Install Instructions For Termux In Android
• tesseract Usage
• Cross Compile Instructions for Android Using NDK
• Current Features
• Planned Features
• Issues
• Worthy Of Note
• FAQs And FUQs
• Changelog
• Contributions

Compatibility

• Android for armeabi-v7a x86 arm64-v8a x86_64 archs. Users may want to run tesseract commands using Termux App.

Dependencies

-

Downloads

• GitHub releases.

Install Instructions For Termux In Android:

The tesseract file should be placed in termux bin directory /data/data/com.termux/files/usr/bin and it should have termux uid:gid ownership and have executable 700 permission before it can be run in the termux terminal without specifying its path.

1. Copy the file to termux bin directory: Either cd to the download/extraction directory and run following commands

   cat tesseract > /data/data/com.termux/files/usr/bin/tesseract
   

   Or use a file browser like root explorer to copy the file to the termux bin directory.

2. Set correct ownership and permission: Either run following commands to set them automatically, requires su binary to be in $PATH.

   export termux_bin_path="/data/data/com.termux/files/usr/bin"; export owner="$(stat -c "%u" "$termux_bin_path")"; for f in tesseract; do if [ -f "$termux_bin_path/$f" ]; then su -c "chown $owner:$owner \"$termux_bin_path/$f\" && chmod 700 \"$termux_bin_path/$f\""; fi; done;
   

   Or manually set them with your file browser. You can find termux uid and gid by running the command id -u in a non root shell in termux or by checking the properties of the termux bin directory from your file browser.

3. Download trained language data file for your language and 4.1 from here. For english the file is eng.traineddata.

4. Then create /data/data/com.termux/files/home/image_text_searcher/tessdata directory and place the trained language data file eng.traineddata in it or whatever trained language data file you downloaded. The tessdata directory is created inside the image_text_searcher directory to provide consistency with the [Image Text Searcher] project's default values.

tesseract Usage

• Test OCR on a test jpg with following commands.

  To print output text to stdout

   tesseract --tessdata-dir image_text_searcher/tessdata test.jpg stdout
  

  To print output text to a file

   tesseract --tessdata-dir image_text_searcher/tessdata test.jpg test.txt
  

Cross Compile Instructions for Android Using NDK

• Download Android NDK r20 from latest releases or old releases and extract to $HOME/Android/ndk/android-ndk-r20

• Get tesseract and leptonica source code

  Either clone this repository

   https://github.com/agnostic-apollo/tesseract-for-android
  

  Or clone tess-two repository by alexcohn which may be updated with latest versions.

   git clone https://github.com/alexcohn/tess-two
   git clone --branch 4.1 https://github.com/alexcohn/tesseract tess-two/tesseract
   git clone https://github.com/alexcohn/leptonica tess-two/leptonica
  

• Add NDK path to $PATH

   PATH="$PATH:$HOME/Android/ndk/android-ndk-r20"
  

• Compile With NDK

  Compile tesseract static binary for arm64-v8a

   ndk-build -C tess-two/tess-two tesseract APP_ABI=arm64-v8a
  

  Compile tesseract static binary for all APP_ABIs

   ndk-build -C tess-two/tess-two tesseract APP_ABI="armeabi-v7a x86 arm64-v8a x86_64"
  

• tesseract static binary should be compiled at tess-two/tess-two/obj/local/<APP_ABI>

• Extract and zip compiled tesseract binaries to tesseract-out directory with the format tesseract-<APP_ABI>. This step is optional.

   bash tesseract_extractor.sh
  

• Check if a compiled binary is the correct ABI

   file tesseract-out/tesseract-<APP_ABI>
  

Current Features

-

Planned Features

-

Issues

-

Worthy Of Note

-

FAQs And FUQs

Check FAQs_And_FUQs.md file for the Frequently Asked Questions(FAQs) and Frequently Unasked Questions(FUQs).

Changelog

Check CHANGELOG.md file for the Changelog.

Contributions

-