If you encounter any error after thoroughly following these steps, feel free to contact us via `OpenCV4Android <https://groups.google.com/group/android-opencv/>`_ discussion group or OpenCV `Q&A forum <http://answers.opencv.org>`_. We'll do our best to help you out.
*:file:`sdk/native` folder contains OpenCV C++ headers (for JNI code) and native Android libraries (\*\.so and \*\.a) for ARM-v5, ARM-v7a and x86 architectures;
*:file:`sdk/etc` folder contains Haar and LBP cascades distributed with OpenCV.
*:file:`apk` folder contains Android packages that should be installed on the target Android device to enable OpenCV library access via OpenCV Manager API (see details below).
On production devices that have access to Google Play Market (and internet) these packages will be installed from Market on the first start of an application using OpenCV Manager API.
But dev kits without Market or internet require this packages to be installed manually.
(Install the `Manager.apk` and the corresponding `binary_pack.apk` depending on the device CPU, the Manager GUI provides this info).
Starting version 2.4.3 `OpenCV4Android SDK` uses `OpenCV Manager` API for library initialization. `OpenCV Manager` is an Android service based solution providing the following benefits for OpenCV applications developers:
You may have used `Tegra Android Development Pack <http://developer.nvidia.com/tegra-android-development-pack>`_
(**TADP**) released by **NVIDIA** for Android development environment setup.
Beside Android development tools the TADP 2.0 includes OpenCV4Android SDK 2.4.2, so it can be already installed in your system and you can skip to running the ``face-detection`` sample.
More details regarding TADP can be found in the :ref:`android_dev_intro` guide.
Manual OpenCV4Android SDK setup
===============================
Get the OpenCV4Android SDK
--------------------------
#. Go to the `OpenCV dowload page on SourceForge <http://sourceforge.net/projects/opencvlibrary/files/opencv-android/>`_ and download the latest available version. Currently it's |opencv_android_bin_pack_url|_
#. Create a new folder for Android with OpenCV development. For this tutorial I have unpacked OpenCV to the :file:`C:\\Work\\OpenCV4Android\\` directory.
#. Start *Eclipse* and choose your workspace location.
We recommend to start working with OpenCV for Android from a new clean workspace. A new Eclipse workspace can for example be created in the folder where you have unpacked OpenCV4Android SDK package:
..image:: images/eclipse_1_choose_workspace.png
:alt:Choosing C:\Work\android-opencv\ as workspace location
:align:center
#. Import OpenCV library 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 the |opencv_android_bin_pack| is a regular Android project that already references OpenCV library.
Follow the steps below to import OpenCV and samples into the 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:
At this point you should be able to build and run the samples. Keep in mind, that ``face-detection``, ``Tutorial 3`` and ``Tutorial 4`` include some native code and require Android NDK and CDT plugin for Eclipse to build working applications.
* Select project you want to start in :guilabel:`Package Explorer` and just press :kbd:`Ctrl + F11` or select option :menuselection:`Run --> Run` from the 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 about the running mode for 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.
Chances are that on the first launch you will not have the `OpenCV Manager <https://docs.google.com/a/itseez.com/presentation/d/1EO_1kijgBg_BsjNp2ymk-aarg-0K279_1VZRcPplSuk/present#slide=id.p>`_ package installed.
To get rid of the message you will need to install `OpenCV Manager` and the appropriate `OpenCV binary pack`.
Simply tap :menuselection:`Yes` if you have *Google Play Market* installed on your device/emulator. It will redirect you to the corresponding page on *Google Play Market*.
If you have no access to the *Market*, which is often the case with emulators - you will need to install the packages from OpenCV4Android SDK folder manually. Open the console/terminal and type in the following two commands:
Now, when you have your instance of OpenCV4Adroid SDK set up and configured, you may want to proceed to using OpenCV in your own application. You can learn how to do that in a separate :ref:`dev_with_OCV_on_Android` tutorial.
