/tess-two

Fork of Tesseract Tools for Android.

Primary LanguageCApache License 2.0Apache-2.0

#tess-two

A fork of Tesseract Tools for Android (tesseract-android-tools) that adds some additional functions. Tesseract Tools for Android is a set of Android APIs and build files for the Tesseract OCR and Leptonica image processing libraries.

This project works with Tesseract v3.02. The required source code for Tesseract 3.02 and Leptonica 1.68 is included within the tess-two/jni folder.

The tess-two subdirectory contains tools for compiling the Tesseract and Leptonica libraries for use on the Android platform. It contains an Eclipse Android library project that provides a Java API for accessing natively-compiled Tesseract and Leptonica APIs.

This project adds the following methods on top of tesseract-android-tools to enable retrieving bounding boxes for words and characters recognized using OCR:

  • TessBaseAPI::GetRegions()
  • TessBaseAPI::GetTextlines()
  • TessBaseAPI::GetStrips()
  • TessBaseAPI::GetWords()
  • TessBaseAPI::GetCharacters()

Note: GetTextlines(), GetStrips(), GetWords() and GetCharacters() work well, but I have not gotten good results from Tesseract when calling GetRegions().

Requires

  • Android 2.2 or higher
  • A trained data file for a language - available here. Data files must be extracted to a subdirectory named "tessdata".

eyes-two

The eyes-two subdirectory contains a second, separate library project with additional image processing code copied from the eyes-free project without modifications. It includes native functions for text detection, blurriness detection, optical flow detection, and thresholding. Building eyes-two is not necessary for using the Tesseract API.

While I haven't tested all the Eyes-two code, I've bundled it in this project alongside tess-two for convenience due to its dependency on Leptonica.

Build

This project is set up to build on Android SDK Tools r19 and Android NDK r7c. The build works on 64-bit Ubuntu 11.04. It's been reported to not work on Ubuntu 11.10 (Issue 6).

On 64-bit Ubuntu, you may need to install the "ia32-libs" 32-bit compatibility library.

To build tess-two, run the following commands in the terminal:

git clone git://github.com/rmtheis/tess-two tess
cd tess/tess-two
ndk-build
android update project --path .
ant release

To build eyes-two, additionally run the following:

cd ../eyes-two
ndk-build
android update project --path .
ant release

After building, the tess-two and eyes-two projects can be imported into Eclipse using File->Import->Existing Projects into Workspace.

License

This project is licensed under the Apache License, Version 2.0

/*
 * Copyright 2011 Robert Theis
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

This project contains third party software within "tess-two/jni" with separate license agreements:

  • Tesseract 3.02 (Modified to add TessBaseAPI::GetCharacters())
  • Leptonica 1.68 (Unmodified)