In this section we will explain how to make some existing application to use OpenCV. Starting from 2.4.2 release on Android so-called "OpenCV Manager" is used for providing applications with the best version of OpenCV. You can get more information here: :ref:`Android_OpenCV_Manager`.
In this section we will explain how to make some existing application to use OpenCV.
Starting from 2.4.2 release on Android so-called "OpenCV Manager" is used for providing applications with the best version of OpenCV.
You can get more information here: :ref:`Android_OpenCV_Manager`.
Application development with async initialization
-------------------------------------------------
Using async initialization is a preferred way for application development. It uses OpenCV Manager Android service to get OpenCV libraries.
Using async initialization is a preferred way for application development. It uses the OpenCV Manager for access to OpenCV libraries.
#. Add OpenCV library project to your workspace. Go to :guilabel:`File –> Import –> Existing project in your workspace`, push Browse button and select OpenCV SDK path.
#. Add OpenCV library project to your workspace. Use menu :guilabel:`File –> Import –> Existing project in your workspace`,
push :guilabel:`Browse` button and select OpenCV SDK path (:file:`OpenCV-2.4.2-android-sdk/sdk`).
..image:: images/eclipse_opencv_dependency0.png
:alt:Add dependency from OpenCV library
:align:center
#. In application project add reference to OpenCV Java SDK in :guilabel:`Project –> Properties –> Android –> Library –> Add` select ``OpenCV Library - 2.4.2``;
#. In application project add a reference to the OpenCV Java SDK in :guilabel:`Project –> Properties –> Android –> Library –> Add` select ``OpenCV Library - 2.4.2``.
..image:: images/eclipse_opencv_dependency1.png
:alt:Add dependency from OpenCV library
:align:center
If you want to use OpenCV Manager-based approach you need to install packages with the Service and OpenCV package for you platform. You can do it using Google Play service or manually with adb tool:
To use OpenCV Manager-based approach you need to install packages with the `Manager` and `OpenCV binary package` for you platform.
You can do it using Google Play Market or manually with ``adb`` tool:
..code-block:: sh
:linenos:
@ -341,7 +345,7 @@ If you want to use OpenCV Manager-based approach you need to install packages wi
There is a very base code snippet for Async init. It shows only basis principles of library Initiation. See the "15-puzzle" OpenCV sample for details.
There is a very base code snippet implementing the async initialization. It shows basic principles. See the "15-puzzle" OpenCV sample for details.
..code-block:: java
:linenos:
@ -354,14 +358,14 @@ There is a very base code snippet for Async init. It shows only basis principles
switch (status) {
case LoaderCallbackInterface.SUCCESS:
{
Log.i(TAG, "OpenCV loaded successfully");
// Create and set View
mView = new puzzle15View(mAppContext);
setContentView(mView);
Log.i(TAG, "OpenCV loaded successfully");
// Create and set View
mView = new puzzle15View(mAppContext);
setContentView(mView);
} break;
default:
{
super.onManagerConnected(status);
super.onManagerConnected(status);
} break;
}
}
@ -385,55 +389,82 @@ There is a very base code snippet for Async init. It shows only basis principles
}
It this case application works with OpenCV Manager in asynchronous fashion. ``OnManagerConnected`` callback will be called in UI thread, when initialization finishes.
Please note, that it is not allowed to use OpenCV calls or load OpenCV-dependent native libs before invoking this callback. Load your own native libraries after OpenCV initialization.
Please note, that it is not allowed to use OpenCV calls or load OpenCV-dependent native libs before invoking this callback.
Load your own native libraries that depend on OpenCV after the successful OpenCV initialization.
Application development with static initialization
According to this approach all OpenCV binaries are linked and put to your application package. It is designed mostly for development purposes.
This way is deprecated for the production code, release package should communicate with OpenCV Manager, use the async initialization described above.
According to this approach all OpenCV binaries are included into your application package. It is designed mostly for development purposes.
This approach is deprecated for the production code, release package is recommended to communicate with OpenCV Manager via the async initialization described above.
#. Add OpenCV library project to your workspace. Go to :guilabel:`File –> Import –> Existing project in your workspace`, push :guilabel:`Browse` button and select OpenCV SDK path.
#. Add the OpenCV library project to your workspace the same way as for the async initialization above.
Use menu :guilabel:`File –> Import –> Existing project in your workspace`, push :guilabel:`Browse` button and select OpenCV SDK path (:file:`OpenCV-2.4.2-android-sdk/sdk`).
..image:: images/eclipse_opencv_dependency0.png
:alt:Add dependency from OpenCV library
:align:center
#. In application project add reference to OpenCV Java SDK in :guilabel:`Project –> Properties –> Android –> Library –> Add` select ``OpenCV Library - 2.4.2``;
#. In the application project add a reference to the OpenCV Java SDK in :guilabel:`Project –> Properties –> Android –> Library –> Add` select ``OpenCV Library - 2.4.2``;
..image:: images/eclipse_opencv_dependency1.png
:alt:Add dependency from OpenCV library
:align:center
#. Copy native libs to your project directory to folder :file:`libs/target_arch/`.
#. If your application project **doesn't have a JNI part**, just copy the OpenCV native libs to your project directory to folder :file:`libs/target_arch/`.
In case of the application project **with a JNI part**, instead of manual libraries copying you need to modify your ``Android.mk`` file:
add the following two code lines after the ``"include $(CLEAR_VARS)"`` and before ``"include path_to_OpenCV-2.4.2-android-sdk/sdk/native/jni/OpenCV.mk"``
After adding depedency from OpenCV library project, Eclipse will automatically copy all needed libraries to the application package.
To use OpenCV functionality you need to add OpenCV library initialization code before using any OpenCV specific code, for example, to the static section of ``Activity`` class.
..code-block:: make
:linenos:
..code-block:: java
:linenos:
OPENCV_CAMERA_MODULES:=on
OPENCV_INSTALL_MODULES:=on
The result should look like the following:
..code-block:: make
:linenos:
include $(CLEAR_VARS)
# OpenCV
OPENCV_CAMERA_MODULES:=on
OPENCV_INSTALL_MODULES:=on
include ../../sdk/native/jni/OpenCV.mk
After that the OpenCV libraries will be copied to your application :file:`libs` folder during the JNI part build.
Eclipse will automatically include all the libraries from the :file:`libs` folder to the application package (APK).
static {
if (!OpenCVLoader.initDebug()) {
// Report initialization error
#. The last step of enabling OpenCV in your application is Java initialization code before call to OpenCV API.
It can be done, for example, in the static section of the ``Activity`` class:
..code-block:: java
:linenos:
static {
if (!OpenCVLoader.initDebug()) {
// Handle initialization error
}
}
}
If you application includes other OpenCV-dependent native libraries you need to init OpenCV before them.
If you application includes other OpenCV-dependent native libraries you should load them **after** OpenCV initialization:
..code-block:: java
:linenos:
..code-block:: java
:linenos:
static {
if (OpenCVLoader.initDebug()) {
System.loadLibrary("my_super_lib1");
System.loadLibrary("my_super_lib2");
} else {
// Report initialization error
static {
if (!OpenCVLoader.initDebug()) {
// Handle initialization error
} else {
System.loadLibrary("my_jni_lib1");
System.loadLibrary("my_jni_lib2");
}
}
}
Whats next?
===========
What's next?
============
Read the :ref:`Android_Binary_Package_with_NDK` tutorial to learn how to add native OpenCV code to your Android project.
@ -162,8 +162,12 @@ then paste the CDT 8.0 repository URL http://download.eclipse.org/tools/cdt/rele
#. Define the ``NDKROOT`` environment variable containing the path to Android NDK in your system (e.g. **"X:\\Apps\\android-ndk-r8"** or **"/opt/android-ndk-r8"**).
#. CDT Builder is configured for Windows hosts, on Linux or MacOS open `Project Properties` of the projects having JNI part (`face-detection`, `Tutorial 3` and `Tutorial 4`), select :guilabel:`C/C++ Build` in the left pane, remove **".cmd"** and leave ``"${NDKROOT}/ndk-build"`` in the :guilabel:`Build command` edit box and click :guilabel:`OK`.
#. | CDT Builder is already configured for **Windows** hosts,
| on **Linux** or **MacOS** a small modification is required:
Open `Project Properties` of the projects having JNI part (`face-detection`, `Tutorial 3` and `Tutorial 4`),
select :guilabel:`C/C++ Build` in the left pane,
remove **".cmd"** and leave ``"${NDKROOT}/ndk-build"`` in the :guilabel:`Build command` edit box and click :guilabel:`OK`.
..image:: images/eclipse_cdt_cfg4.png
:alt:Configure CDT
@ -242,13 +246,15 @@ To build your own Android application, which uses OpenCV from native part, the f
include C:\Work\android-opencv\OpenCV-2.4.0\share\OpenCV\OpenCV.mk
should be inserted into the :file:`jni/Android.mk` file right after the line
should be inserted into the :file:`jni/Android.mk` file **after** the line
..code-block:: make
include $(CLEAR_VARS)
Several variables can be used to customize OpenCV stuff, they should be set **before** the ``"include ...\OpenCV.mk"`` line:
#. Several variables can be used to customize OpenCV stuff, but you **don't need** to use them when your application uses the `async initialization` via the `OpenCV Manager` API.
Note: these variables should be set **before** the ``"include .../OpenCV.mk"`` line:
@ -407,11 +407,11 @@ Decomposes a projection matrix into a rotation matrix and a camera matrix.
:param rotMatrZ:Optional 3x3 rotation matrix around z-axis.
:param eulerAngles:Optional three-element vector containing three Euler angles of rotation.
:param eulerAngles:Optional three-element vector containing three Euler angles of rotation in degrees.
The function computes a decomposition of a projection matrix into a calibration and a rotation matrix and the position of a camera.
It optionally returns three rotation matrices, one for each axis, and three Euler angles that could be used in OpenGL.
It optionally returns three rotation matrices, one for each axis, and three Euler angles that could be used in OpenGL. Note, there is always more than one sequence of rotations about the three principle axes that results in the same orientation of an object, eg. see [Slabaugh]_. Returned tree rotation matrices and corresponding three Euler angules are only one of the possible solutions.
The function is based on
:ocv:func:`RQDecomp3x3` .
@ -999,9 +999,7 @@ Computes an RQ decomposition of 3x3 matrices.
The function computes a RQ decomposition using the given rotations. This function is used in
:ocv:func:`decomposeProjectionMatrix` to decompose the left 3x3 submatrix of a projection matrix into a camera and a rotation matrix.
It optionally returns three rotation matrices, one for each axis, and the three Euler angles
(as the return value)
that could be used in OpenGL.
It optionally returns three rotation matrices, one for each axis, and the three Euler angles in degrees (as the return value) that could be used in OpenGL. Note, there is always more than one sequence of rotations about the three principle axes that results in the same orientation of an object, eg. see [Slabaugh]_. Returned tree rotation matrices and corresponding three Euler angules are only one of the possible solutions.
@ -1479,4 +1477,6 @@ The function reconstructs 3-dimensional points (in homogeneous coordinates) by u
..[HH08] Hirschmuller, H. Stereo Processing by Semiglobal Matching and Mutual Information, PAMI(30), No. 2, February 2008, pp. 328-341.
..[Slabaugh] Slabaugh, G.G. Computing Euler angles from a rotation matrix. http://gregslabaugh.name/publications/euler.pdf
..[Zhang2000] Z. Zhang. A Flexible New Technique for Camera Calibration. IEEE Transactions on Pattern Analysis and Machine Intelligence, 22(11):1330-1334, 2000.
Marina Kolpakova
13 years ago
