.. code-block:: java
:linenos:
- public class MyActivity extends Activity implements HelperCallbackInterface
- {
- private BaseLoaderCallback mOpenCVCallBack = new BaseLoaderCallback(this) {
- @Override
- public void onManagerConnected(int status) {
- switch (status) {
- case LoaderCallbackInterface.SUCCESS:
- {
- Log.i(TAG, "OpenCV loaded successfully");
- // Create and set View
- mView = new puzzle15View(mAppContext);
- setContentView(mView);
- } break;
- default:
- {
- super.onManagerConnected(status);
- } break;
- }
- }
- };
-
- /** Call on every application resume **/
- @Override
- protected void onResume()
- {
- Log.i(TAG, "called onResume");
- super.onResume();
-
- Log.i(TAG, "Trying to load OpenCV library");
- if (!OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_2, this, mOpenCVCallBack))
+ public class Sample1Java extends Activity implements CvCameraViewListener {
+
+ private BaseLoaderCallback mLoaderCallback = new BaseLoaderCallback(this) {
+ @Override
+ public void onManagerConnected(int status) {
+ switch (status) {
+ case LoaderCallbackInterface.SUCCESS:
+ {
+ Log.i(TAG, "OpenCV loaded successfully");
+ mOpenCvCameraView.enableView();
+ } break;
+ default:
+ {
+ super.onManagerConnected(status);
+ } break;
+ }
+ }
+ };
+
+ @Override
+ public void onResume()
{
- Log.e(TAG, "Cannot connect to OpenCV Manager");
+ super.onResume();
+ OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_3, this, mLoaderCallback);
}
+
+ ...
}
It this case application works with OpenCV Manager in asynchronous fashion. ``OnManagerConnected``
result.
#. Open Eclipse IDE, create a new clean workspace, create a new Android project
- :menuselection:`File --> New --> Android Project`.
-
-#. Set name, target, package and ``minSDKVersion`` accordingly.
-
-#. Create a new class :menuselection:`File -> New -> Class`. Name it for example:
- *HelloOpenCVView*.
-
- .. image:: images/dev_OCV_new_class.png
- :alt: Add a new class.
- :align: center
+ :menuselection:`File --> New --> Android Project`
- * It should extend ``SurfaceView`` class.
- * It also should implement ``SurfaceHolder.Callback``, ``Runnable``.
+#. Set name, target, package and ``minSDKVersion`` accordingly. The minimal SDK version for build
+ with OpenCV4Android SDK is 11. Minimal device API Level (for application manifest) is 8.
-#. Edit ``HelloOpenCVView`` class.
+#. Allow Eclipse to create default activity. Lets name the activity ``HelloOpenCvActivity``.
- * Add an ``import`` line for ``android.content.context``.
+#. Choose Blank Activity with full screen layout. Lets name the layout ``HelloOpenCvLayout``.
- * Modify autogenerated stubs: ``HelloOpenCVView``, ``surfaceCreated``, ``surfaceDestroyed`` and
- ``surfaceChanged``.
-
- .. code-block:: java
- :linenos:
-
- package com.hello.opencv.test;
-
- import android.content.Context;
-
- public class HelloOpenCVView extends SurfaceView implements Callback, Runnable {
-
- public HelloOpenCVView(Context context) {
- super(context);
- getHolder().addCallback(this);
- }
-
- public void surfaceCreated(SurfaceHolder holder) {
- (new Thread(this)).start();
- }
+#. Import OpenCV library project to your workspace.
- public void surfaceDestroyed(SurfaceHolder holder) {
- cameraRelease();
- }
-
- public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
- cameraSetup(width, height);
- }
+#. Reference OpenCV library within your project properties.
- * Add ``cameraOpen``, ``cameraRelease`` and ``cameraSetup`` voids as shown below.
+ .. image:: images/dev_OCV_reference.png
+ :alt: Reference OpenCV library.
+ :align: center
- * Also, don't forget to add the public void ``run()`` as follows:
+#. Edit your layout file as xml file and pass the following layout there:
- .. code-block:: java
+ .. code-block:: xml
:linenos:
- public void run() {
- // TODO: loop { getFrame(), processFrame(), drawFrame() }
- }
+ <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+ xmlns:tools="http://schemas.android.com/tools"
+ xmlns:opencv="http://schemas.android.com/apk/res-auto"
+ android:layout_width="match_parent"
+ android:layout_height="match_parent" >
- public boolean cameraOpen() {
- return false; //TODO: open camera
- }
+ <org.opencv.android.JavaCameraView
+ android:layout_width="fill_parent"
+ android:layout_height="fill_parent"
+ android:visibility="gone"
+ android:id="@+id/HelloOpenCvView"
+ opencv:show_fps="true"
+ opencv:camera_id="any" />
- private void cameraRelease() {
- // TODO release camera
- }
-
- private void cameraSetup(int width, int height) {
- // TODO setup camera
- }
+ </LinearLayout>
-#. Create a new ``Activity`` :menuselection:`New -> Other -> Android -> Android Activity` and name
- it, for example: *HelloOpenCVActivity*. For this activity define ``onCreate``, ``onResume`` and
- ``onPause`` voids.
+#. Add the following permissions to the :file:`AndroidManifest.xml` file:
- .. code-block:: java
+ .. code-block:: xml
:linenos:
- public void onCreate (Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- mView = new HelloOpenCVView(this);
- setContentView (mView);
- }
+ </application>
- protected void onPause() {
- super.onPause();
- mView.cameraRelease();
- }
+ <uses-permission android:name="android.permission.CAMERA"/>
- protected void onResume() {
- super.onResume();
- if( !mView.cameraOpen() ) {
- // MessageBox and exit app
- AlertDialog ad = new AlertDialog.Builder(this).create();
- ad.setCancelable(false); // This blocks the "BACK" button
- ad.setMessage("Fatal error: can't open camera!");
- ad.setButton("OK", new DialogInterface.OnClickListener() {
- public void onClick(DialogInterface dialog, int which) {
- dialog.dismiss();
- finish();
- }
- });
- ad.show();
- }
- }
+ <uses-feature android:name="android.hardware.camera" android:required="false"/>
+ <uses-feature android:name="android.hardware.camera.autofocus" android:required="false"/>
+ <uses-feature android:name="android.hardware.camera.front" android:required="false"/>
+ <uses-feature android:name="android.hardware.camera.front.autofocus" android:required="false"/>
-#. Add the following permissions to the :file:`AndroidManifest.xml` file:
+#. Set application theme in AndroidManifest.xml to hide title and system buttons.
.. code-block:: xml
:linenos:
- </application>
+ <application
+ android:icon="@drawable/icon"
+ android:label="@string/app_name"
+ android:theme="@android:style/Theme.NoTitleBar.Fullscreen" >
+
+#. Add OpenCV library initialization to your activity. Fix errors by adding requited imports.
+
+ .. code-block:: java
+ :linenos:
+
+ private BaseLoaderCallback mLoaderCallback = new BaseLoaderCallback(this) {
+ @Override
+ public void onManagerConnected(int status) {
+ switch (status) {
+ case LoaderCallbackInterface.SUCCESS:
+ {
+ Log.i(TAG, "OpenCV loaded successfully");
+ mOpenCvCameraView.enableView();
+ } break;
+ default:
+ {
+ super.onManagerConnected(status);
+ } break;
+ }
+ }
+ };
- <uses-permission android:name="android.permission.CAMERA" />
- <uses-feature android:name="android.hardware.camera" />
- <uses-feature android:name="android.hardware.camera.autofocus" />
-
-#. Reference OpenCV library within your project properties.
-
- .. image:: images/dev_OCV_reference.png
- :alt: Reference OpenCV library.
- :align: center
+ @Override
+ public void onResume()
+ {
+ super.onResume();
+ OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_3, this, mLoaderCallback);
+ }
-#. We now need some code to handle the camera. Update the ``HelloOpenCVView`` class as follows:
+#. Defines that your activity implements CvViewFrameListener interface and fix activity related
+ errors by defining missed methods. For this activity define ``onCreate``, ``onDestroy`` and
+ ``onPause`` and implement them according code snippet bellow. Fix errors by adding requited
+ imports.
.. code-block:: java
:linenos:
- private VideoCapture mCamera;
-
- public boolean cameraOpen() {
- synchronized (this) {
- cameraRelease();
- mCamera = new VideoCapture(Highgui.CV_CAP_ANDROID);
- if (!mCamera.isOpened()) {
- mCamera.release();
- mCamera = null;
- Log.e("HelloOpenCVView", "Failed to open native camera");
- return false;
- }
- }
- return true;
- }
+ private CameraBridgeViewBase mOpenCvCameraView;
- public void cameraRelease() {
- synchronized(this) {
- if (mCamera != null) {
- mCamera.release();
- mCamera = null;
- }
- }
- }
+ @Override
+ public void onCreate(Bundle savedInstanceState) {
+ Log.i(TAG, "called onCreate");
+ super.onCreate(savedInstanceState);
+ getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
+ setContentView(R.layout.HelloOpenCvLayout);
+ mOpenCvCameraView = (CameraBridgeViewBase) findViewById(R.id.HelloOpenCvView);
+ mOpenCvCameraView.setVisibility(SurfaceView.VISIBLE);
+ mOpenCvCameraView.setCvCameraViewListener(this);
+ }
- private void cameraSetup(int width, int height) {
- synchronized (this) {
- if (mCamera != null && mCamera.isOpened()) {
- List<Size> sizes = mCamera.getSupportedPreviewSizes();
- int mFrameWidth = width;
- int mFrameHeight = height;
- { // selecting optimal camera preview size
- double minDiff = Double.MAX_VALUE;
- for (Size size : sizes) {
- if (Math.abs(size.height - height) < minDiff) {
- mFrameWidth = (int) size.width;
- mFrameHeight = (int) size.height;
- minDiff = Math.abs(size.height - height);
- }
- }
- }
- mCamera.set(Highgui.CV_CAP_PROP_FRAME_WIDTH, mFrameWidth);
- mCamera.set(Highgui.CV_CAP_PROP_FRAME_HEIGHT, mFrameHeight);
- }
- }
- }
+ @Override
+ public void onPause()
+ {
+ super.onPause();
+ if (mOpenCvCameraView != null)
+ mOpenCvCameraView.disableView();
+ }
-#. The last step would be to update the ``run()`` void in ``HelloOpenCVView`` class as follows:
+ public void onDestroy() {
+ super.onDestroy();
+ if (mOpenCvCameraView != null)
+ mOpenCvCameraView.disableView();
+ }
- .. code-block:: java
- :linenos:
+ public void onCameraViewStarted(int width, int height) {
+ }
- public void run() {
- while (true) {
- Bitmap bmp = null;
- synchronized (this) {
- if (mCamera == null)
- break;
- if (!mCamera.grab())
- break;
-
- bmp = processFrame(mCamera);
- }
- if (bmp != null) {
- Canvas canvas = getHolder().lockCanvas();
- if (canvas != null) {
- canvas.drawBitmap(bmp, (canvas.getWidth() - bmp.getWidth()) / 2,
- (canvas.getHeight() - bmp.getHeight()) / 2, null);
- getHolder().unlockCanvasAndPost(canvas);
-
- }
- bmp.recycle();
- }
- }
- }
+ public void onCameraViewStopped() {
+ }
- protected Bitmap processFrame(VideoCapture capture) {
- Mat mRgba = new Mat();
- capture.retrieve(mRgba, Highgui.CV_CAP_ANDROID_COLOR_FRAME_RGBA);
- //process mRgba
- Bitmap bmp = Bitmap.createBitmap(mRgba.cols(), mRgba.rows(), Bitmap.Config.ARGB_8888);
- try {
- Utils.matToBitmap(mRgba, bmp);
- } catch(Exception e) {
- Log.e("processFrame", "Utils.matToBitmap() throws an exception: " + e.getMessage());
- bmp.recycle();
- bmp = null;
- }
- return bmp;
- }
+ public Mat onCameraFrame(Mat inputFrame) {
+ return inputFrame;
+ }
+
+#. Run your application on device or emulator.
+
+Lets discuss some most important steps. Every Android application with UI must implement Activity
+and View. By the first steps we create blank activity and default view layout. The simplest
+OpenCV-centric application must implement OpenCV initialization, create its own view to show
+preview from camera and implements ``CvViewFrameListener`` interface to get frames from camera and
+process it.
+
+First of all we create our application view using xml layout. Our layout consists of the only
+one full screen component of class ``org.opencv.android.JavaCameraView``. This class is
+implemented inside OpenCV library. It is inherited from ``CameraBridgeViewBase``, that extends
+``SurfaceView`` and uses standard Android camera API. Alternatively you can use
+``org.opencv.android.NativeCameraView`` class, that implements the same interface, but uses
+``VideoCapture`` class as camera access back-end. ``opencv:show_fps="true"`` and
+``opencv:camera_id="any"`` options enable FPS message and allow to use any camera on device.
+Application tries to use back camera first.
+
+After creating layout we need to implement ``Activity`` class. OpenCV initialization process has
+been already discussed above. In this sample we use asynchronous initialization. Implementation of
+``CvCameraViewListener`` interface allows you to add processing steps after frame grabbing from
+camera and before its rendering on screen. The most important function is ``onCameraFrame``. It is
+callback function and it is called on retrieving frame from camera. The callback input is frame
+from camera. RGBA format is used by default. You can change this behavior by ``SetCaptureFormat``
+method of ``View`` class. ``Highgui.CV_CAP_ANDROID_COLOR_FRAME_RGBA`` and
+``Highgui.CV_CAP_ANDROID_GREY_FRAME`` are supported. It expects that function returns RGBA frame
+that will be drawn on the screen.
projects / profile / ivi / opencv.git / commitdiff