
.. _Android_Binary_Package:


Using Android binary package with Eclipse
*****************************************

This tutorial was tested using Ubuntu 10.04 and Windows 7 SP1 operating systems. Nevertheless, it should also work on any other **OS**\ es supported by Android SDK (including Mac OS X). If you encounter errors after following the steps described here, feel free to contact us via *android-opencv* discussion group https://groups.google.com/group/android-opencv/ and we will try to help you.

Quick environment setup for Android development
===============================================

If you are making a clean environment installation then you can try **T**\ egra **A**\ ndroid **D**\ evelopment **P**\ ack (*TADP*) released by *NVIDIA*:

  http://developer.nvidia.com/tegra-android-development-pack

It will cover all of the environment set up automatically and you can go to the next step :ref:`Get_the_OpenCV_package_for_Android_development` right after automatic setup.

If you are a beginner in Android development then we recommentd you to start with TADP.

.. note:: *NVIDIA*\ 's Tegra Android Development Pack includes some special features for |Nvidia_Tegra_Platform|_ but it is not just for *Tegra* devices
  
   + You need at least *1.6 Gb* free disk space for installation.

   + TADP will download Android SDK platforms and Android NDK from Google's server, so you need an Internet connection for the installation.

   + TADP can ask you to flash your development kit at the end of installation process. Just skip this step if you have no |Tegra_Ventana_Development_Kit|_\ .

   + (``UNIX``) TADP will ask you for a *root* in the middle of installation, so you need to be a member of *sudo* group.

     ..


.. |Nvidia_Tegra_Platform| replace:: *NVIDIA*\ ’s Tegra platform
.. _Nvidia_Tegra_Platform: http://developer.nvidia.com/node/19071
.. |Tegra_Ventana_Development_Kit| replace:: Tegra Ventana Development Kit
.. _Tegra_Ventana_Development_Kit: http://developer.nvidia.com/tegra-ventana-development-kit

.. _Android_Environment_Setup_Lite: 

Manual environment setup for Android Development
================================================

You need the following tools to be installed:

#. **Sun JDK 6**

   Visit http://www.oracle.com/technetwork/java/javase/downloads/index.html and download installer for your OS.

   Here is a detailed :abbr:`JDK (Java Development Kit)` installation guide for Ubuntu and Mac OS: http://source.android.com/source/initializing.html#installing-the-jdk (only JDK sections are applicable for OpenCV)

   .. note:: OpenJDK is not usable for Android development because Android SDK supports only Sun JDK.
        If you use Ubuntu, after installation of Sun JDK you should run the following command to set Sun java environment:

        .. code-block:: bash

           sudo update-java-alternatives --set java-6-sun

#. **Android SDK**

   Get the latest Android SDK from http://developer.android.com/sdk/index.html

   Here is Google's install guide for SDK http://developer.android.com/sdk/installing.html

   .. note:: If you choose SDK packed into Windows installer, then you should have 32-bit JRE installed. It is not needed for Android development, but installer is x86 application and requires 32-bit Java runtime.

   .. note:: If you are running x64 version of Ubuntu Linux, then you need ia32 shared libraries for use on amd64 and ia64 systems to be installed. You can install them with the following command:

      .. code-block:: bash

         sudo apt-get install ia32-libs

      For Red Hat based systems the following command might be helpful:

      .. code-block:: bash

         sudo yum install libXtst.i386 

#. **Android SDK components**

   You need the following SDK components to be installed:

   * *Android SDK Tools, revision12* or newer

     Older revisions should also work, but they are not recommended.

   * *SDK Platform Android 2.2, API 8, revision 2* (also known as  *android-8*)

     This is minimal platform supported by OpenCV Java API. And it is set as default for OpenCV distribution. It is possible to use newer platform with OpenCV package, but it requires to edit OpenCV project settings.

     .. image:: images/android_sdk_and_avd_manager.png
        :height: 400px 
        :alt: Android SDK and AVD manager
        :align: center
     
     See `Adding SDK Components
     <http://developer.android.com/sdk/adding-components.html>`_ for help with installing/updating SDK components.

#. **Eclipse IDE**

   Check the `Android SDK System Requirements
   <http://developer.android.com/sdk/requirements.html>`_ document for a list of Eclipse versions that are compatible with the Android SDK. 
   For OpenCV 2.3.1 we recommend Eclipse 3.7 (Indigo) or Eclipse 3.6 (Helios). They work well for OpenCV under both Windows and Linux.
   
   If you have no Eclipse installed, you can download it from this location:
    
      http://www.eclipse.org/downloads/ 
      
#. **ADT plugin for Eclipse**

   This instruction is copied from http://developer.android.com/sdk/eclipse-adt.html#downloading
   . Please, visit that page if you have any troubles with ADT plugin installation.

   Assuming that you have Eclipse IDE installed, as described above, follow these steps to download and install the ADT plugin:

   #. Start Eclipse, then select :menuselection:`Help --> Install New Software...`
   #. Click :guilabel:`Add` (in the top-right corner).
   #. In the :guilabel:`Add Repository` dialog that appears, enter "ADT Plugin" for the Name and the following URL for the Location:

      https://dl-ssl.google.com/android/eclipse/

   #. Click :guilabel:`OK`

      .. note:: If you have trouble acquiring the plugin, try using "http" in the Location URL, instead of "https" (https is preferred for security reasons).
   
   #. In the :guilabel:`Available Software` dialog, select the checkbox next to :guilabel:`Developer Tools` and click :guilabel:`Next`.
   #. In the next window, you'll see a list of the tools to be downloaded. Click :guilabel:`Next`.
   #. Read and accept the license agreements, then click :guilabel:`Finish`.

      .. note:: If you get a security warning saying that the authenticity or validity of the software can't be established, click :guilabel:`OK`.
   
   #. When the installation completes, restart Eclipse. 

.. _Get_the_OpenCV_package_for_Android_development:

Get the OpenCV package for Android development
==============================================

#. Go to the http://sourceforge.net/projects/opencvlibrary/files/opencv-android/ and download the latest available version. Currently it is |opencv_android_bin_pack_url|_

#. Create new folder for Android+OpenCV development.

      .. note:: Better to use a path without spaces in it. Otherwise you will probably have problems with :command:`ndk-build`.

#. Unpack the OpenCV package into that dir.

   You can unpack it using any popular archiver (for example with |seven_zip|_):

   .. image:: images/android_package_7zip.png
      :alt: Exploring OpenCV package with 7-Zip
      :align: center

   On Unix you can also use the following command:
   
   .. code-block:: bash

      tar -jxvf ~/Downloads/OpenCV-2.3.1-android-bin.tar.bz2
      
   For this tutorial I have unpacked OpenCV to the :file:`C:\\Work\\android-opencv\\` directory.

.. |opencv_android_bin_pack| replace:: OpenCV-2.3.1-android-bin.tar.bz2
.. _opencv_android_bin_pack_url: http://sourceforge.net/projects/opencvlibrary/files/opencv-android/2.3.1/OpenCV-2.3.1-android-bin.tar.bz2/download
.. |opencv_android_bin_pack_url| replace:: |opencv_android_bin_pack|
.. |seven_zip| replace:: 7-Zip
.. _seven_zip: http://www.7-zip.org/

Open OpenCV library and samples in Eclipse
==========================================

#. Start the *Eclipse* and choose your workspace location.

   I recommend to start familiarizing yourself with OpenCV for Android from a new clean workspace. So I have chosen my OpenCV package directory for the new workspace:

      .. image:: images/eclipse_1_choose_workspace.png
         :alt: Choosing C:\Work\android-opencv\ as workspace location
         :align: center

#. Configure your ADT plugin

   .. important:: ADT plugin settings are workspace-dependent. So you have to repeat this step each time when you create a new workspace.

   Once you have created a new workspace, you have to point the ADT plugin to the Android SDK directory. This setting is stored in workspace metadata, as result this step is required each time when you are creating new workspace for Android development. See `Configuring the ADT Plugin
   <http://developer.android.com/sdk/eclipse-adt.html#configuring>`_ document for the original instructions from *Google*.
   
   * Select :menuselection:`Window --> Preferences...` to open the Preferences panel (Mac OS X: :menuselection:`Eclipse --> Preferences`):

      .. image:: images/eclipse_2_window_preferences.png
         :height: 400px 
         :alt: Select Window > Preferences...
         :align: center
   
   * Select :guilabel:`Android` from the left panel.

    You may see a dialog asking whether you want to send usage statistics to *Google*. If so, make your choice and click :guilabel:`Proceed`. You cannot continue with this procedure until you click :guilabel:`Proceed`.

      .. image:: images/eclipse_3_preferences_android.png
         :alt: Select Android from the left panel
         :align: center

   * For the SDK Location in the main panel, click :guilabel:`Browse...` and locate your Android SDK directory. 

   * Click :guilabel:`Apply` button at the bottom right corner of main panel:

      .. image:: images/eclipse_4_locate_sdk.png
         :alt: Locate Android SDK
         :align: center

   * Click :guilabel:`OK` to close preferences dialog.
   
#. Import OpenCV and samples into workspace.

   OpenCV library is packed as a ready-for-use `Android Library Project
   <http://developer.android.com/guide/developing/projects/index.html#LibraryProjects>`_. You can simply reference it in your projects.
   
   Each sample included into |opencv_android_bin_pack| is a regular Android project that already references OpenCV library.
   Follow next steps to import OpenCV and samples into workspace:
   
   * Right click on the :guilabel:`Package Explorer` window and choose :guilabel:`Import...` option from the context menu:

      .. image:: images/eclipse_5_import_command.png
         :alt: Select Import... from context menu
         :align: center

   * In the main panel select :menuselection:`General --> Existing Projects into Workspace` and press :guilabel:`Next` button:

      .. image:: images/eclipse_6_import_existing_projects.png
         :alt: General > Existing Projects into Workspace
         :align: center

   * For the :guilabel:`Select root directory` in the main panel locate your OpenCV package folder. (If you have created workspace in the package directory, then just click :guilabel:`Browse...` button and instantly close directory choosing dialog with :guilabel:`OK` button!) Eclipse should automatically locate OpenCV library and samples:

      .. image:: images/eclipse_7_select_projects.png
         :alt: Locate OpenCV library and samples
         :align: center

   * Click :guilabel:`Finish` button to complete the import operation.
   
   After clicking :guilabel:`Finish` button Eclipse will load all selected projects into workspace. And... will indicate numerous errors:

      .. image:: images/eclipse_8_false_alarm.png
         :alt: Confusing Eclipse screen with numerous errors
         :align: center

   However **all these errors are only false-alarms**!
   
   To help Eclipse to understand that there are no any errors choose OpenCV library in :guilabel:`Package Explorer` (left mouse click) and press :kbd:`F5` button on your keyboard. Then choose any sample (except first samples in *Tutorial Base* and *Tutorial Advanced*) and also press :kbd:`F5`.
   
   After this manipulation Eclipse will rebuild your workspace and error icons will disappear one after another:

      .. image:: images/eclipse_9_errors_dissapearing.png
         :alt: After small help Eclipse removes error icons!
         :align: center

   Once Eclipse completes build you will have the clean workspace without any build errors:

      .. image:: images/eclipse_10_crystal_clean.png
         :alt: OpenCV package imported into Eclipse
         :align: center

   .. note:: If you are importing only OpenCV library without samples then instead of second refresh command (:kbd:`F5`) you might need to make :menuselection:`Android Tools --> Fix Project Properties` from project context menu.
   
Running OpenCV Samples
======================

At this point you should be able to build and run all samples except two from Advanced tutorial (these samples require Android NDK to build working applications, see the next tutorial :ref:`Android_Binary_Package_with_NDK` to learn how to compile them).

Also I want to note that only ``Tutorial 1 Basic - 0. Android Camera`` and ``Tutorial 1 Basic - 1. Add OpenCV`` samples are able to run on Emulator from Android SDK. Other samples are using OpenCV Native Camera which does not work with emulator.

.. note:: Latest *Android SDK tools, revision 12* can run ARM v7 OS images but *Google* does not provide such images with SDK.

Well, running samples from Eclipse is very simple:

* Connect your device with :command:`adb` tool from Android SDK or create Emulator with camera support.

   * See `Managing Virtual Devices
     <http://developer.android.com/guide/developing/devices/index.html>`_ document for help with Android Emulator.
   * See `Using Hardware Devices
     <http://developer.android.com/guide/developing/device.html>`_ for help with real devices (not emulators).


* Select project you want to start in :guilabel:`Package Explorer:guilabel:` and just press :kbd:`Ctrl + F11` or select option :menuselection:`Run --> Run` from main menu, or click :guilabel:`Run` button on the toolbar.

  .. note:: Android Emulator can take several minutes to start. So, please, be patient.

* On the first run Eclipse will ask you how to run your application:

  .. image:: images/eclipse_11_run_as.png
     :alt: Run sample as Android Application
     :align: center

* Select the :guilabel:`Android Application` option and click :guilabel:`OK` button. Eclipse will install and run the sample.
  
  Here is ``Tutorial 1 Basic - 1. Add OpenCV`` sample detecting edges using Canny algorithm from OpenCV:

  .. image:: images/emulator_canny.png
     :height: 600px 
     :alt: Tutorial 1 Basic - 1. Add OpenCV - running Canny
     :align: center



How to use OpenCV library project in your application
=====================================================

If you already have an Android application, you can add a reference to OpenCV and import all its functionality. 

#. First of all you need to have both projects (your app and OpenCV) in a single workspace. 
   So, open workspace with your application and import the OpenCV project into your workspace as stated above. 

#. Add a reference to OpenCV project.

   Do the right mouse click on your app in Package Explorer, go to :menuselection:`Properties --> Android --> Library --> Add`
   and choose the OpenCV library project. 

Whats next?
===========

Read the :ref:`Android_Binary_Package_with_NDK` tutorial to learn how add native OpenCV code to your Android project.

