Android RakNet 系列之五 视频通讯 OpenCV4Android

浏览数：178 / 时间：2015年06月11日

简介

引入OpenCV4Android的目标是在Raknet框架下解决视频通讯的问题，目前在ubuntu下已成功实现，现在把它引用到Android平台下。

OpenCV是一个基于开源发行的跨平台计算机视觉库，可以在 Windows, Android, Maemo,FreeBSD, OpenBSD, iOS,Linux 和Mac OS等平台上运行。它轻量级而且高效——由一系列 C 函数和少量 C++ 类构成，同时提供了Python、Ruby、MATLAB等语言的接口，实现了图像处理和计算机视觉方面的很多通用算法。OpenCV致力于真实世界的实时应用，通过优化的C代码的编写对其执行速度带来了可观的提升，并且可以通过购买Intel的IPP高性能多媒体函数库(Integrated Performance Primitives)得到更快的处理速度。

相关网站

http://sourceforge.net/projects/opencvlibrary/files/opencv-android/ 最新版项目源码下载
http://www.opencv.org.cn/   OpenCV中文论坛
http://opencv.org/?s=+android&x=0&y=0  OpenCV 官网
http://www.code.opencv.org/projects/opencv/issues OpenCV 官网下解决方案
http://docs.opencv.org/platforms/android/service/doc/index.html 或  http://docs.opencv.org/trunk/     OpenCV 官网下介绍文档

http://www.jayrambhia.com/android/ 相关博客

详情

项目介绍

官方提供了一个库项目（OpenCV Library - 2.4.10）和九个Demo项目（OpenCV Manager - 2.4.10、OpenCV Tutorial 1 - Camera Preview、OpenCV Tutorial 2 - Mixed Processing、OpenCV Tutorial 3 - Camera Control、OpenCV Sample - 4 puzzle、OpenCV Sample - camera-calibration、OpenCV Sample - color-blob-detection、OpenCV Sample - face-detection、OpenCV Sample - image-manipulations、OpenCV Sample - native-activity、OpenCV Library - 2.4.10），再加上OpenCV Manager项目共计11个项目，项目如图：




OpenCV Manager - 2.4.10

官方提供的Demo运行需要OpenCV Manager项目的支持，该项目负责匹配手机加载库文件，通过服务绑定进行通讯。

如果未安装它，并运行Demo会出现提示框：OpenCV Manager package was not found! Try to install it?  当然如果直接使用它的库运行是不会出现此情况的。原因就是该项目只是做加载库的工作。


项目如图：



官方给出解释：




加载库的代码如下：

public class BinderConnector {
	private static boolean mIsReady = false;
	private MarketConnector mMarket;

	static {
		try {
			System.loadLibrary("OpenCVEngine");
			System.loadLibrary("OpenCVEngine_jni");
			mIsReady = true;
		} catch (UnsatisfiedLinkError localUnsatisfiedLinkError) {
			mIsReady = false;
			localUnsatisfiedLinkError.printStackTrace();
		}
	}

	public BinderConnector(MarketConnector paramMarketConnector) {
		this.mMarket = paramMarketConnector;
	}

	private native void Final();

	private native boolean Init(MarketConnector paramMarketConnector);

	public native IBinder Connect();

	public boolean Disconnect() {
		if (mIsReady)
			Final();
		return mIsReady;
	}

	public boolean Init() {
		boolean bool = false;
		if (mIsReady)
			bool = Init(this.mMarket);
		return bool;
	}
}
public class HardwareDetector { //硬件匹配
	public static final int ARCH_ARMv5 = 0x4000000;
	public static final int ARCH_ARMv6 = 0x8000000;
	public static final int ARCH_ARMv7 = 0x10000000;
	public static final int ARCH_ARMv8 = 0x20000000;
	public static final int ARCH_MIPS = 0x40000000;
	public static final int ARCH_UNKNOWN = -1;
	public static final int ARCH_X64 = 0x2000000;
	public static final int ARCH_X86 = 0x1000000;
	public static final int FEATURES_HAS_GPU = 65536;
	public static final int FEATURES_HAS_NEON = 8;
	public static final int FEATURES_HAS_NEON2 = 22;
	public static final int FEATURES_HAS_SSE = 1;
	public static final int FEATURES_HAS_SSE2 = 2;
	public static final int FEATURES_HAS_SSE3 = 4;
	public static final int FEATURES_HAS_VFPv3 = 2;
	public static final int FEATURES_HAS_VFPv3d16 = 1;
	public static final int FEATURES_HAS_VFPv4 = 4;
	public static final int PLATFORM_TEGRA = 1;
	public static final int PLATFORM_TEGRA2 = 2;
	public static final int PLATFORM_TEGRA3 = 3;
	public static final int PLATFORM_TEGRA4 = 5;
	public static final int PLATFORM_TEGRA4i = 4;
	public static final int PLATFORM_TEGRA5 = 6;
	public static final int PLATFORM_UNKNOWN = -1;
	public static boolean mIsReady = false;

	static {
		try {
			System.loadLibrary("OpenCVEngine");
			System.loadLibrary("OpenCVEngine_jni");
			mIsReady = true;
		} catch (UnsatisfiedLinkError localUnsatisfiedLinkError) {
			mIsReady = false;
			localUnsatisfiedLinkError.printStackTrace();
		}
	}

	public static native int DetectKnownPlatforms();

	public static native int GetCpuID();

	public static native String GetPlatformName();

	public static native int GetProcessorCount();
}
public class OpenCVLibraryInfo {
	private String mLibraryList;
	private long mNativeObj;
	private String mPackageName;
	private String mVersionName;

	public OpenCVLibraryInfo(String paramString) {
		mNativeObj = open(paramString + "/libopencv_info.so");

		if (this.mNativeObj == 0L)
			return;
		this.mPackageName = getPackageName(this.mNativeObj);
		this.mLibraryList = getLibraryList(this.mNativeObj);
		this.mVersionName = getVersionName(this.mNativeObj);
		close(this.mNativeObj);
	}

	private native void close(long paramLong);

	private native String getLibraryList(long paramLong);

	private native String getPackageName(long paramLong);

	private native String getVersionName(long paramLong);

	private native long open(String paramString);

	public String libraryList() {
		return this.mLibraryList;
	}

	public String packageName() {
		return this.mPackageName;
	}

	public boolean status() {
		if (mNativeObj == 0L || mLibraryList.length() == 0)
			return false;

		return true;
	}

	public String versionName() {
		return this.mVersionName;
	}
}
//关键服务  demo中绑定的服务就该服务 该服务就是匹配手机加载库
public class OpenCVEngineService extends Service {
	private static final String TAG = "OpenCVEngine/Service";
	private IBinder mEngineInterface = null;
	private MarketConnector mMarket;
	private BinderConnector mNativeBinder;

	public void OnDestroy() {
		Log.i("OpenCVEngine/Service", "OpenCV Engine service destruction");
		this.mNativeBinder.Disconnect();
	}

	public IBinder onBind(Intent paramIntent) {
		Log.i("OpenCVEngine/Service", "Service onBind called for intent "
				+ paramIntent.toString());
		return this.mEngineInterface;
	}

	public void onCreate() {
		Log.i("OpenCVEngine/Service", "Service starting");
		super.onCreate();
		Log.i("OpenCVEngine/Service", "Engine binder component creating");
		this.mMarket = new MarketConnector(getBaseContext());
		this.mNativeBinder = new BinderConnector(this.mMarket);
		if (this.mNativeBinder.Init()) {
			this.mEngineInterface = this.mNativeBinder.Connect();
			Log.i("OpenCVEngine/Service", "Service started successfully");
		}
		else {
			 Log.e("OpenCVEngine/Service",
			 "Cannot initialize native part of OpenCV Manager!");
			 Log.e("OpenCVEngine/Service", "Using stub instead");
			return;
		}
		
		this.mEngineInterface = new OpenCVEngineInterface(this);
	}

	public boolean onUnbind(Intent paramIntent) {
		Log.i("OpenCVEngine/Service", "Service onUnbind called for intent "
				+ paramIntent.toString());
		return true;
	}
}
它的AndroidManifest.xml 如下：

<?xml version="1.0" encoding="utf-8"?>
<manifest android:versionCode="2191" android:versionName="2.19" package="org.opencv.engine"
  xmlns:android="http://schemas.android.com/apk/res/android">
    <uses-feature android:name="android.hardware.touchscreen" android:required="false" />
    <application android:label="@string/app_name" android:icon="@drawable/icon">
        <service android:name="OpenCVEngineService" android:exported="true" android:process=":OpenCVEngineProcess">
            <intent-filter>
                <action android:name="org.opencv.engine.BIND" />
            </intent-filter>
        </service>
        <activity android:label="@string/app_name" android:name="org.opencv.engine.manager.ManagerActivity" android:screenOrientation="portrait">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest>


OpenCV Tutorial 1 - Camera Preview

Demo就一个文件，使用摄像机预览，Demo中提供了两种方法，一种是Java层调用，一种是Native层调用。

如图：


关键控件如下：

    <org.opencv.android.JavaCameraView
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:visibility="gone"
        android:id="@+id/tutorial1_activity_java_surface_view"
        opencv:show_fps="true"
        opencv:camera_id="any" />

    <org.opencv.android.NativeCameraView
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:visibility="gone"
        android:id="@+id/tutorial1_activity_native_surface_view"
        opencv:show_fps="true"
        opencv:camera_id="any" />


OpenCV Tutorial 2 - Mixed Processing

该Demo就一个Java文件和一个C++文件，实现4中混合处理。

如图：


本地代码如下：

JNIEXPORT void JNICALL Java_org_opencv_samples_tutorial2_Tutorial2Activity_FindFeatures(JNIEnv*, jobject, jlong addrGray, jlong addrRgba)
{
    Mat& mGr  = *(Mat*)addrGray;
    Mat& mRgb = *(Mat*)addrRgba;
    vector<KeyPoint> v;

    FastFeatureDetector detector(50);
    detector.detect(mGr, v);
    for( unsigned int i = 0; i < v.size(); i++ )
    {
        const KeyPoint& kp = v[i];
        circle(mRgb, Point(kp.pt.x, kp.pt.y), 10, Scalar(255,0,0,255));
    }
}

使用的控件如下：

    <org.opencv.android.JavaCameraView
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:id="@+id/tutorial2_activity_surface_view" />


OpenCV Tutorial 3 - Camera Control

该Demo就2个Java文件，摄像头控制，控制颜色显示、摄像分辨率。

效果如图：


关键代码：

使用的控件

    <org.opencv.samples.tutorial3.Tutorial3View
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:visibility="gone"
        android:id="@+id/tutorial3_activity_java_surface_view" />
public class Tutorial3View extends JavaCameraView implements PictureCallback {

    private static final String TAG = "Sample::Tutorial3View";
    private String mPictureFileName;

    public Tutorial3View(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public List<String> getEffectList() {
        return mCamera.getParameters().getSupportedColorEffects();
    }

    public boolean isEffectSupported() {
        return (mCamera.getParameters().getColorEffect() != null);
    }

    public String getEffect() {
        return mCamera.getParameters().getColorEffect();
    }

    public void setEffect(String effect) {
        Camera.Parameters params = mCamera.getParameters();
        params.setColorEffect(effect);
        mCamera.setParameters(params);
    }

    public List<Size> getResolutionList() {
        return mCamera.getParameters().getSupportedPreviewSizes();
    }

    public void setResolution(Size resolution) {
        disconnectCamera();
        mMaxHeight = resolution.height;
        mMaxWidth = resolution.width;
        connectCamera(getWidth(), getHeight());
    }

    public Size getResolution() {
        return mCamera.getParameters().getPreviewSize();
    }

    public void takePicture(final String fileName) {
        Log.i(TAG, "Taking picture");
        this.mPictureFileName = fileName;
        // Postview and jpeg are sent in the same buffers if the queue is not empty when performing a capture.
        // Clear up buffers to avoid mCamera.takePicture to be stuck because of a memory issue
        mCamera.setPreviewCallback(null);

        // PictureCallback is implemented by the current class
        mCamera.takePicture(null, null, this);
    }

    @Override
    public void onPictureTaken(byte[] data, Camera camera) {
        Log.i(TAG, "Saving a bitmap to file");
        // The camera preview was automatically stopped. Start it again.
        mCamera.startPreview();
        mCamera.setPreviewCallback(this);

        // Write the image in a file (in jpeg format)
        try {
            FileOutputStream fos = new FileOutputStream(mPictureFileName);

            fos.write(data);
            fos.close();

        } catch (java.io.IOException e) {
            Log.e("PictureDemo", "Exception in photoCallback", e);
        }

    }
}


OpenCV Sample - 4 puzzle

该Demo就两个Java文件，实现摄像格式错乱输出。

效果如图：


主要代码如下：

public class Puzzle15Processor { //摄像图片转换

    private static final int GRID_SIZE = 4;
    private static final int GRID_AREA = GRID_SIZE * GRID_SIZE;
    private static final int GRID_EMPTY_INDEX = GRID_AREA - 1;
    private static final String TAG = "Puzzle15Processor";
    private static final Scalar GRID_EMPTY_COLOR = new Scalar(0x33, 0x33, 0x33, 0xFF);

    private int[]   mIndexes;
    private int[]   mTextWidths;
    private int[]   mTextHeights;

    private Mat mRgba15;
    private Mat[] mCells15;
    private boolean mShowTileNumbers = true;

    public Puzzle15Processor() {
        mTextWidths = new int[GRID_AREA];
        mTextHeights = new int[GRID_AREA];

        mIndexes = new int [GRID_AREA];

        for (int i = 0; i < GRID_AREA; i++)
            mIndexes[i] = i;
    }

    /* this method is intended to make processor prepared for a new game */
    public synchronized void prepareNewGame() {
        do {
            shuffle(mIndexes);
        } while (!isPuzzleSolvable());
    }

    /* This method is to make the processor know the size of the frames that
     * will be delivered via puzzleFrame.
     * If the frames will be different size - then the result is unpredictable
     */
    public synchronized void prepareGameSize(int width, int height) {
        mRgba15 = new Mat(height, width, CvType.CV_8UC4);
        mCells15 = new Mat[GRID_AREA];

        for (int i = 0; i < GRID_SIZE; i++) {
            for (int j = 0; j < GRID_SIZE; j++) {
                int k = i * GRID_SIZE + j;
                mCells15[k] = mRgba15.submat(i * height / GRID_SIZE, (i + 1) * height / GRID_SIZE, j * width / GRID_SIZE, (j + 1) * width / GRID_SIZE);
            }
        }

        for (int i = 0; i < GRID_AREA; i++) {
            Size s = Core.getTextSize(Integer.toString(i + 1), 3/* CV_FONT_HERSHEY_COMPLEX */, 1, 2, null);
            mTextHeights[i] = (int) s.height;
            mTextWidths[i] = (int) s.width;
        }
    }

    /* this method to be called from the outside. it processes the frame and shuffles
     * the tiles as specified by mIndexes array
     */
    public synchronized Mat puzzleFrame(Mat inputPicture) {
        Mat[] cells = new Mat[GRID_AREA];
        int rows = inputPicture.rows();
        int cols = inputPicture.cols();

        rows = rows - rows%4;
        cols = cols - cols%4;

        for (int i = 0; i < GRID_SIZE; i++) {
            for (int j = 0; j < GRID_SIZE; j++) {
                int k = i * GRID_SIZE + j;
                cells[k] = inputPicture.submat(i * inputPicture.rows() / GRID_SIZE, (i + 1) * inputPicture.rows() / GRID_SIZE, j * inputPicture.cols()/ GRID_SIZE, (j + 1) * inputPicture.cols() / GRID_SIZE);
            }
        }

        rows = rows - rows%4;
        cols = cols - cols%4;

        // copy shuffled tiles
        for (int i = 0; i < GRID_AREA; i++) {
            int idx = mIndexes[i];
            if (idx == GRID_EMPTY_INDEX)
                mCells15[i].setTo(GRID_EMPTY_COLOR);
            else {
                cells[idx].copyTo(mCells15[i]);
                if (mShowTileNumbers) {
                    Core.putText(mCells15[i], Integer.toString(1 + idx), new Point((cols / GRID_SIZE - mTextWidths[idx]) / 2,
                            (rows / GRID_SIZE + mTextHeights[idx]) / 2), 3/* CV_FONT_HERSHEY_COMPLEX */, 1, new Scalar(255, 0, 0, 255), 2);
                }
            }
        }

        for (int i = 0; i < GRID_AREA; i++)
            cells[i].release();

        drawGrid(cols, rows, mRgba15);

        return mRgba15;
    }

    public void toggleTileNumbers() {
        mShowTileNumbers = !mShowTileNumbers;
    }

    public void deliverTouchEvent(int x, int y) {
        int rows = mRgba15.rows();
        int cols = mRgba15.cols();

        int row = (int) Math.floor(y * GRID_SIZE / rows);
        int col = (int) Math.floor(x * GRID_SIZE / cols);

        if (row < 0 || row >= GRID_SIZE || col < 0 || col >= GRID_SIZE) {
            Log.e(TAG, "It is not expected to get touch event outside of picture");
            return ;
        }

        int idx = row * GRID_SIZE + col;
        int idxtoswap = -1;

        // left
        if (idxtoswap < 0 && col > 0)
            if (mIndexes[idx - 1] == GRID_EMPTY_INDEX)
                idxtoswap = idx - 1;
        // right
        if (idxtoswap < 0 && col < GRID_SIZE - 1)
            if (mIndexes[idx + 1] == GRID_EMPTY_INDEX)
                idxtoswap = idx + 1;
        // top
        if (idxtoswap < 0 && row > 0)
            if (mIndexes[idx - GRID_SIZE] == GRID_EMPTY_INDEX)
                idxtoswap = idx - GRID_SIZE;
        // bottom
        if (idxtoswap < 0 && row < GRID_SIZE - 1)
            if (mIndexes[idx + GRID_SIZE] == GRID_EMPTY_INDEX)
                idxtoswap = idx + GRID_SIZE;

        // swap
        if (idxtoswap >= 0) {
            synchronized (this) {
                int touched = mIndexes[idx];
                mIndexes[idx] = mIndexes[idxtoswap];
                mIndexes[idxtoswap] = touched;
            }
        }
    }

    private void drawGrid(int cols, int rows, Mat drawMat) {
        for (int i = 1; i < GRID_SIZE; i++) {
            Core.line(drawMat, new Point(0, i * rows / GRID_SIZE), new Point(cols, i * rows / GRID_SIZE), new Scalar(0, 255, 0, 255), 3);
            Core.line(drawMat, new Point(i * cols / GRID_SIZE, 0), new Point(i * cols / GRID_SIZE, rows), new Scalar(0, 255, 0, 255), 3);
        }
    }

    private static void shuffle(int[] array) {
        for (int i = array.length; i > 1; i--) {
            int temp = array[i - 1];
            int randIx = (int) (Math.random() * i);
            array[i - 1] = array[randIx];
            array[randIx] = temp;
        }
    }

    private boolean isPuzzleSolvable() {

        int sum = 0;
        for (int i = 0; i < GRID_AREA; i++) {
            if (mIndexes[i] == GRID_EMPTY_INDEX)
                sum += (i / GRID_SIZE) + 1;
            else {
                int smaller = 0;
                for (int j = i + 1; j < GRID_AREA; j++) {
                    if (mIndexes[j] < mIndexes[i])
                        smaller++;
                }
                sum += smaller;
            }
        }
        return sum % 2 == 0;
    }
}


OpenCV Sample - camera-calibration

该Demo就4个Java文件，实现摄像校准。

效果如图：



使用的控件：

    <org.opencv.android.JavaCameraView
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:id="@+id/camera_calibration_java_surface_view" />


OpenCV Sample - color-blob-detection
该Demo就两个Java文件，实现色斑检测。

效果如图：



使用的控件：

    <org.opencv.android.JavaCameraView
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:id="@+id/color_blob_detection_activity_surface_view" />

public class ColorBlobDetector { //匹配
    // Lower and Upper bounds for range checking in HSV color space
    private Scalar mLowerBound = new Scalar(0);
    private Scalar mUpperBound = new Scalar(0);
    // Minimum contour area in percent for contours filtering
    private static double mMinContourArea = 0.1;
    // Color radius for range checking in HSV color space
    private Scalar mColorRadius = new Scalar(25,50,50,0);
    private Mat mSpectrum = new Mat();
    private List<MatOfPoint> mContours = new ArrayList<MatOfPoint>();

    // Cache
    Mat mPyrDownMat = new Mat();
    Mat mHsvMat = new Mat();
    Mat mMask = new Mat();
    Mat mDilatedMask = new Mat();
    Mat mHierarchy = new Mat();

    public void setColorRadius(Scalar radius) {
        mColorRadius = radius;
    }

    public void setHsvColor(Scalar hsvColor) {
        double minH = (hsvColor.val[0] >= mColorRadius.val[0]) ? hsvColor.val[0]-mColorRadius.val[0] : 0;
        double maxH = (hsvColor.val[0]+mColorRadius.val[0] <= 255) ? hsvColor.val[0]+mColorRadius.val[0] : 255;

        mLowerBound.val[0] = minH;
        mUpperBound.val[0] = maxH;

        mLowerBound.val[1] = hsvColor.val[1] - mColorRadius.val[1];
        mUpperBound.val[1] = hsvColor.val[1] + mColorRadius.val[1];

        mLowerBound.val[2] = hsvColor.val[2] - mColorRadius.val[2];
        mUpperBound.val[2] = hsvColor.val[2] + mColorRadius.val[2];

        mLowerBound.val[3] = 0;
        mUpperBound.val[3] = 255;

        Mat spectrumHsv = new Mat(1, (int)(maxH-minH), CvType.CV_8UC3);

        for (int j = 0; j < maxH-minH; j++) {
            byte[] tmp = {(byte)(minH+j), (byte)255, (byte)255};
            spectrumHsv.put(0, j, tmp);
        }

        Imgproc.cvtColor(spectrumHsv, mSpectrum, Imgproc.COLOR_HSV2RGB_FULL, 4);
    }

    public Mat getSpectrum() {
        return mSpectrum;
    }

    public void setMinContourArea(double area) {
        mMinContourArea = area;
    }

    public void process(Mat rgbaImage) {
        Imgproc.pyrDown(rgbaImage, mPyrDownMat);
        Imgproc.pyrDown(mPyrDownMat, mPyrDownMat);

        Imgproc.cvtColor(mPyrDownMat, mHsvMat, Imgproc.COLOR_RGB2HSV_FULL);

        Core.inRange(mHsvMat, mLowerBound, mUpperBound, mMask);
        Imgproc.dilate(mMask, mDilatedMask, new Mat());

        List<MatOfPoint> contours = new ArrayList<MatOfPoint>();

        Imgproc.findContours(mDilatedMask, contours, mHierarchy, Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE);

        // Find max contour area
        double maxArea = 0;
        Iterator<MatOfPoint> each = contours.iterator();
        while (each.hasNext()) {
            MatOfPoint wrapper = each.next();
            double area = Imgproc.contourArea(wrapper);
            if (area > maxArea)
                maxArea = area;
        }

        // Filter contours by area and resize to fit the original image size
        mContours.clear();
        each = contours.iterator();
        while (each.hasNext()) {
            MatOfPoint contour = each.next();
            if (Imgproc.contourArea(contour) > mMinContourArea*maxArea) {
                Core.multiply(contour, new Scalar(4,4), contour);
                mContours.add(contour);
            }
        }
    }

    public List<MatOfPoint> getContours() {
        return mContours;
    }
}


OpenCV Sample - face-detection
该Demo就两个Java文件和两个C++文件，实现匹配脸。

效果如图：


使用的控件：

    <org.opencv.android.JavaCameraView
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:id="@+id/fd_activity_surface_view" />
public class DetectionBasedTracker
{
    public DetectionBasedTracker(String cascadeName, int minFaceSize) {
        mNativeObj = nativeCreateObject(cascadeName, minFaceSize);
    }

    public void start() {
        nativeStart(mNativeObj);
    }

    public void stop() {
        nativeStop(mNativeObj);
    }

    public void setMinFaceSize(int size) {
        nativeSetFaceSize(mNativeObj, size);
    }

    public void detect(Mat imageGray, MatOfRect faces) {
        nativeDetect(mNativeObj, imageGray.getNativeObjAddr(), faces.getNativeObjAddr());
    }

    public void release() {
        nativeDestroyObject(mNativeObj);
        mNativeObj = 0;
    }

    private long mNativeObj = 0;

    private static native long nativeCreateObject(String cascadeName, int minFaceSize);
    private static native void nativeDestroyObject(long thiz);
    private static native void nativeStart(long thiz);
    private static native void nativeStop(long thiz);
    private static native void nativeSetFaceSize(long thiz, int size);
    private static native void nativeDetect(long thiz, long inputImage, long faces);
}

OpenCV Sample - image-manipulations
该Demo就一个Java文件，实现图片操作。

效果如图：


使用的控件：

    <org.opencv.android.JavaCameraView
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:id="@+id/image_manipulations_activity_surface_view" />
实现CvCameraViewListener2接口，从而操作图片。

OpenCV Sample - native-activity

该Demo就一个Java文件和一个C++文件，实现本地界面显示图片。

效果如图：


本地代码如下：

struct Engine
{
    android_app* app;
    cv::Ptr<cv::VideoCapture> capture;
};

static cv::Size calc_optimal_camera_resolution(const char* supported, int width, int height)
{
    int frame_width = 0;
    int frame_height = 0;

    size_t prev_idx = 0;
    size_t idx = 0;
    float min_diff = FLT_MAX;

    do
    {
        int tmp_width;
        int tmp_height;

        prev_idx = idx;
        while ((supported[idx] != ‘\0‘) && (supported[idx] != ‘,‘))
            idx++;

        sscanf(&supported[prev_idx], "%dx%d", &tmp_width, &tmp_height);

        int w_diff = width - tmp_width;
        int h_diff = height - tmp_height;
        if ((h_diff >= 0) && (w_diff >= 0))
        {
            if ((h_diff <= min_diff) && (tmp_height <= 720))
            {
                frame_width = tmp_width;
                frame_height = tmp_height;
                min_diff = h_diff;
            }
        }

        idx++; // to skip comma symbol

    } while(supported[idx-1] != ‘\0‘);

    return cv::Size(frame_width, frame_height);
}

static void engine_draw_frame(Engine* engine, const cv::Mat& frame)
{
    if (engine->app->window == NULL)
        return; // No window.

    ANativeWindow_Buffer buffer;
    if (ANativeWindow_lock(engine->app->window, &buffer, NULL) < 0)
    {
        LOGW("Unable to lock window buffer");
        return;
    }

    int32_t* pixels = (int32_t*)buffer.bits;

    int left_indent = (buffer.width-frame.cols)/2;
    int top_indent = (buffer.height-frame.rows)/2;

    if (top_indent > 0)
    {
        memset(pixels, 0, top_indent*buffer.stride*sizeof(int32_t));
        pixels += top_indent*buffer.stride;
    }

    for (int yy = 0; yy < frame.rows; yy++)
    {
        if (left_indent > 0)
        {
            memset(pixels, 0, left_indent*sizeof(int32_t));
            memset(pixels+left_indent+frame.cols, 0, (buffer.stride-frame.cols-left_indent)*sizeof(int32_t));
        }
        int32_t* line = pixels + left_indent;
        size_t line_size = frame.cols*4*sizeof(unsigned char);
        memcpy(line, frame.ptr<unsigned char>(yy), line_size);
        // go to next line
        pixels += buffer.stride;
    }
    ANativeWindow_unlockAndPost(engine->app->window);
}

static void engine_handle_cmd(android_app* app, int32_t cmd)
{
    Engine* engine = (Engine*)app->userData;
    switch (cmd)
    {
        case APP_CMD_INIT_WINDOW:
            if (app->window != NULL)
            {
                LOGI("APP_CMD_INIT_WINDOW");

                engine->capture = new cv::VideoCapture(0);

                union {double prop; const char* name;} u;
                u.prop = engine->capture->get(CV_CAP_PROP_SUPPORTED_PREVIEW_SIZES_STRING);

                int view_width = ANativeWindow_getWidth(app->window);
                int view_height = ANativeWindow_getHeight(app->window);

                cv::Size camera_resolution;
                if (u.name)
                    camera_resolution = calc_optimal_camera_resolution(u.name, 640, 480);
                else
                {
                    LOGE("Cannot get supported camera camera_resolutions");
                    camera_resolution = cv::Size(ANativeWindow_getWidth(app->window),
                                          ANativeWindow_getHeight(app->window));
                }

                if ((camera_resolution.width != 0) && (camera_resolution.height != 0))
                {
                    engine->capture->set(CV_CAP_PROP_FRAME_WIDTH, camera_resolution.width);
                    engine->capture->set(CV_CAP_PROP_FRAME_HEIGHT, camera_resolution.height);
                }

                float scale = std::min((float)view_width/camera_resolution.width,
                                       (float)view_height/camera_resolution.height);

                if (ANativeWindow_setBuffersGeometry(app->window, (int)(view_width/scale),
                    int(view_height/scale), WINDOW_FORMAT_RGBA_8888) < 0)
                {
                    LOGE("Cannot set pixel format!");
                    return;
                }

                LOGI("Camera initialized at resolution %dx%d", camera_resolution.width, camera_resolution.height);
            }
            break;
        case APP_CMD_TERM_WINDOW:
            LOGI("APP_CMD_TERM_WINDOW");

            engine->capture->release();
            break;
    }
}

void android_main(android_app* app)
{
    Engine engine;

    // Make sure glue isn‘t stripped.
    app_dummy();

    size_t engine_size = sizeof(engine); // for Eclipse CDT parser
    memset((void*)&engine, 0, engine_size);
    app->userData = &engine;
    app->onAppCmd = engine_handle_cmd;
    engine.app = app;

    float fps = 0;
    cv::Mat drawing_frame;
    std::queue<int64> time_queue;

    // loop waiting for stuff to do.
    while (1)
    {
        // Read all pending events.
        int ident;
        int events;
        android_poll_source* source;

        // Process system events
        while ((ident=ALooper_pollAll(0, NULL, &events, (void**)&source)) >= 0)
        {
            // Process this event.
            if (source != NULL)
            {
                source->process(app, source);
            }

            // Check if we are exiting.
            if (app->destroyRequested != 0)
            {
                LOGI("Engine thread destroy requested!");
                return;
            }
        }

        int64 then;
        int64 now = cv::getTickCount();
        time_queue.push(now);

        // Capture frame from camera and draw it
        if (!engine.capture.empty())
        {
            if (engine.capture->grab())
                engine.capture->retrieve(drawing_frame, CV_CAP_ANDROID_COLOR_FRAME_RGBA);

             char buffer[256];
             sprintf(buffer, "Display performance: %dx%d @ %.3f", drawing_frame.cols, drawing_frame.rows, fps);
             cv::putText(drawing_frame, std::string(buffer), cv::Point(8,64),
                         cv::FONT_HERSHEY_COMPLEX_SMALL, 1, cv::Scalar(0,255,0,255));
             engine_draw_frame(&engine, drawing_frame);
        }

        if (time_queue.size() >= 2)
            then = time_queue.front();
        else
            then = 0;

        if (time_queue.size() >= 25)
            time_queue.pop();

        fps = time_queue.size() * (float)cv::getTickFrequency() / (now-then);
    }
}

OpenCV Library - 2.4.10
该项目是OpenCV Java SDK，实现Java下操作OpenCV。

如图：


概括如下：

包 描述
org.opencv.android

对应：
libopencv_androidcamera.a		AsyncServiceHelper：辅助工具：绑定服务、解开服务、加载库。
BaseLoaderCallback：实现加载回调。
CameraBridgeViewBase：摄像控件基类，继承SurfaceView。
FpsMeter：帧统计。
InstallCallbackInterface：初始化回调接口。
JavaCameraView：java层实现摄像。
LoaderCallbackInterface：加载回调接口。
NativeCameraView：本地摄像控件。
OpenCVLoader：根据版本加载OpenCV库。
StaticHelper：辅助OpenCVLoader。
Utils：其他功能辅助。
org.opencv.calib3d

对应：
libopencv_calib3d.a		3D实现库，还包括了BM块匹配算法类StereoBM、SGBM块匹配算法类StereoSGBM类。
org.opencv.contrib

对应：
libopencv_contrib.a		Contrib：
FaceRecognizer：
StereoVar：
org.opencv.core


对应：
libopencv_core.a		核心库 定义了图像的新容器。
Algorithm：
Core：
CvException：
CvType：
Mat：
MatOfByte：
MatOfDMatch：
MatOfFloat：
MatOfDouble：
MatOfFloat4：
MatOfFloat6：
MatOfInt：
MatOfInt4：
MatOfKeyPoint：
MatOfPoint：
MatOfPoint2f：
MatOfPoint3：
MatOfPoint3f：
MatOfRect：
Point：
Point3：
Range：
Rect：
RotatedRect：
Scalar：
Size：
TermCriteria：
org.opencv.engineOpenCVEngineInterface.aidl：
org.opencv.features2d


对应：
libopencv_features2d.a		DescriptorExtractor：
DescriptorMatcher：
FeatureDetector：
DMatch：
Features2d：
GenericDescriptorMatcher：
KeyPoint：
org.opencv.gpu

对应：
libopencv_ocl.a		DeviceInfo：
Gpu：
TargetArchs：
org.opencv.highgui

对应：
libopencv_highgui.a		Highgui：
VideoCapture：
org.opencv.imgproc

对应：
libopencv_imgproc.a		CLAHE：
Imgproc：
Moments：
Subdiv2D：
org.opencv.ml


对应：
libopencv_ml.a		CvANN_MLP_TrainParams：
CvANN_MLP：
CvBoost：
CvBoostParams：
CvDTree：
CvDTreeParams：
CvERTrees：
CvGBTrees：
CvGBTreesParams：
CvKNearest：
CvNormalBayesClassifier：
CvParamGrid：
CvRTParams：
CvRTrees：
CvStatModel：
CvSVM：
CvSVMParams：
EM：
Ml：
org.opencv.objdetect

对应：
libopencv_objdetect.a		CascadeClassifier：
HOGDescriptor：
Objdetect：
org.opencv.photo

对应：
libopencv_photo.a		Photo：
org.opencv.utilsConverters：
org.opencv.video

对应：
libopencv_video.a
libopencv_videostab.a		BackgroundSubtractor：
BackgroundSubtractorMOG：
BackgroundSubtractorMOG2：
KalmanFilter：
Video：

其他模块：

libopencv_flann.a     //特征匹配算法实现 
libopencv_legacy.a
libopencv_stitching.a  //图像拼接
libopencv_superres.a
libopencv_ts.a

OpenCV.mk

 

#编译前 需定义 NDK_USE_CYGPATH=1
USER_LOCAL_PATH:=$(LOCAL_PATH)	#路径


USER_LOCAL_C_INCLUDES:=$(LOCAL_C_INCLUDES)	#定义变量
USER_LOCAL_CFLAGS:=$(LOCAL_CFLAGS)
USER_LOCAL_STATIC_LIBRARIES:=$(LOCAL_STATIC_LIBRARIES)
USER_LOCAL_SHARED_LIBRARIES:=$(LOCAL_SHARED_LIBRARIES)
USER_LOCAL_LDLIBS:=$(LOCAL_LDLIBS)


LOCAL_PATH:=$(subst ?,,$(firstword ?$(subst \, ,$(subst /, ,$(call my-dir))))) #本地路径


OPENCV_TARGET_ARCH_ABI:=$(TARGET_ARCH_ABI)	#目标版本
OPENCV_THIS_DIR:=$(patsubst $(LOCAL_PATH)\\%,%,$(patsubst $(LOCAL_PATH)/%,%,$(call my-dir)))	#本目录
OPENCV_MK_DIR:=$(dir $(lastword $(MAKEFILE_LIST)))	#所有的mk目录
OPENCV_LIBS_DIR:=$(OPENCV_THIS_DIR)/libs/opencv/$(OPENCV_TARGET_ARCH_ABI)	#对应库目录
OPENCV_3RDPARTY_LIBS_DIR:=$(OPENCV_THIS_DIR)/libs/3rdparty/$(OPENCV_TARGET_ARCH_ABI)	#3d库目录
OPENCV_BASEDIR:=		#基目录
OPENCV_LOCAL_C_INCLUDES:="$(LOCAL_PATH)/$(OPENCV_THIS_DIR)/include/opencv" "$(LOCAL_PATH)/$(OPENCV_THIS_DIR)/include" #本地包含目录
OPENCV_MODULES:=contrib legacy stitching superres ocl objdetect ml ts videostab video photo calib3d features2d highgui imgproc flann androidcamera core #对应的库文件
OPENCV_LIB_TYPE:=STATIC	#静态库


OPENCV_HAVE_GPU_MODULE:=off  #是否具备gpu
OPENCV_USE_GPU_MODULE:=on	#是否开启


ifeq ($(TARGET_ARCH_ABI),armeabi-v7a)  #与v7a相等
    ifeq ($(OPENCV_HAVE_GPU_MODULE),on)	#开启gpu
        ifneq ($(CUDA_TOOLKIT_DIR),)
            OPENCV_USE_GPU_MODULE:=on
        endif
    endif
    OPENCV_DYNAMICUDA_MODULE:=
else
    OPENCV_DYNAMICUDA_MODULE:=
endif


CUDA_RUNTIME_LIBS:=


ifeq ($(OPENCV_LIB_TYPE),)	#未表明使用库类型则使用动态
    OPENCV_LIB_TYPE:=SHARED
endif


ifeq ($(OPENCV_LIB_TYPE),SHARED)
    OPENCV_LIBS:=java
    OPENCV_LIB_TYPE:=SHARED
else
    OPENCV_LIBS:=$(OPENCV_MODULES)
    OPENCV_LIB_TYPE:=STATIC
endif


ifeq ($(OPENCV_LIB_TYPE),SHARED) #引入3D库
    OPENCV_3RDPARTY_COMPONENTS:=
    OPENCV_EXTRA_COMPONENTS:=
else
    ifeq ($(TARGET_ARCH_ABI),armeabi-v7a)
        OPENCV_3RDPARTY_COMPONENTS:=tbb libjpeg libpng libtiff libjasper IlmImf
        OPENCV_EXTRA_COMPONENTS:=c log m dl z
    endif
    ifeq ($(TARGET_ARCH_ABI),x86)
        OPENCV_3RDPARTY_COMPONENTS:=tbb libjpeg libpng libtiff libjasper IlmImf
        OPENCV_EXTRA_COMPONENTS:=c log m dl z
    endif
    ifeq ($(TARGET_ARCH_ABI),armeabi)
        OPENCV_3RDPARTY_COMPONENTS:= libjpeg libpng libtiff libjasper IlmImf
        OPENCV_EXTRA_COMPONENTS:=c log m dl z
    endif
    ifeq ($(TARGET_ARCH_ABI),mips)
        OPENCV_3RDPARTY_COMPONENTS:=tbb libjpeg libpng libtiff libjasper IlmImf
        OPENCV_EXTRA_COMPONENTS:=c log m dl z
    endif
endif


ifeq ($(OPENCV_CAMERA_MODULES),on) #引入相机库（只有动态库）
    ifeq ($(TARGET_ARCH_ABI),armeabi)
        OPENCV_CAMERA_MODULES:= native_camera_r2.2.0 native_camera_r2.3.3 native_camera_r3.0.1 native_camera_r4.0.0 native_camera_r4.0.3 native_camera_r4.1.1 native_camera_r4.2.0 native_camera_r4.3.0 native_camera_r4.4.0
    endif
    ifeq ($(TARGET_ARCH_ABI),armeabi-v7a)
        OPENCV_CAMERA_MODULES:= native_camera_r2.2.0 native_camera_r2.3.3 native_camera_r3.0.1 native_camera_r4.0.0 native_camera_r4.0.3 native_camera_r4.1.1 native_camera_r4.2.0 native_camera_r4.3.0 native_camera_r4.4.0
    endif
    ifeq ($(TARGET_ARCH_ABI),x86)
        OPENCV_CAMERA_MODULES:= native_camera_r2.3.3 native_camera_r3.0.1 native_camera_r4.0.3 native_camera_r4.1.1 native_camera_r4.2.0 native_camera_r4.3.0 native_camera_r4.4.0
    endif
    ifeq ($(TARGET_ARCH_ABI),mips)
        OPENCV_CAMERA_MODULES:= native_camera_r4.0.3 native_camera_r4.1.1 native_camera_r4.2.0 native_camera_r4.3.0 native_camera_r4.4.0
    endif
else
    OPENCV_CAMERA_MODULES:=
endif


ifeq ($(OPENCV_LIB_TYPE),SHARED)
    OPENCV_LIB_SUFFIX:=so
else
    OPENCV_LIB_SUFFIX:=a
    OPENCV_INSTALL_MODULES:=on
endif


define add_opencv_module #添加opencv库
    include $(CLEAR_VARS)
    LOCAL_MODULE:=opencv_$1
    LOCAL_SRC_FILES:=$(OPENCV_LIBS_DIR)/libopencv_$1.$(OPENCV_LIB_SUFFIX)
    include $(PREBUILT_$(OPENCV_LIB_TYPE)_LIBRARY)
endef


define add_cuda_module	#添加cuda库
    include $(CLEAR_VARS)
    LOCAL_MODULE:=$1
    LOCAL_SRC_FILES:=$(CUDA_TOOLKIT_DIR)/targets/armv7-linux-androideabi/lib/lib$1.so
    include $(PREBUILT_SHARED_LIBRARY)
endef


define add_opencv_3rdparty_component #添加3D库
    include $(CLEAR_VARS)
    LOCAL_MODULE:=$1
    LOCAL_SRC_FILES:=$(OPENCV_3RDPARTY_LIBS_DIR)/lib$1.a
    include $(PREBUILT_STATIC_LIBRARY)
endef


define add_opencv_camera_module #添加相机库
    include $(CLEAR_VARS)
    LOCAL_MODULE:=$1
    LOCAL_SRC_FILES:=$(OPENCV_LIBS_DIR)/lib$1.so
    include $(PREBUILT_SHARED_LIBRARY)
endef


ifeq ($(OPENCV_MK_$(OPENCV_TARGET_ARCH_ABI)_ALREADY_INCLUDED),)  #未包含则添加
    ifeq ($(OPENCV_INSTALL_MODULES),on)
        $(foreach module,$(OPENCV_LIBS),$(eval $(call add_opencv_module,$(module))))
        ifneq ($(OPENCV_DYNAMICUDA_MODULE),)
            ifeq ($(OPENCV_LIB_TYPE),SHARED)
              $(eval $(call add_opencv_module,$(OPENCV_DYNAMICUDA_MODULE)))
            endif
        endif
    endif


    ifeq ($(OPENCV_USE_GPU_MODULE),on)
        ifeq ($(INSTALL_CUDA_LIBRARIES),on)
            $(foreach module,$(CUDA_RUNTIME_LIBS),$(eval $(call add_cuda_module,$(module))))
        endif
    endif


    $(foreach module,$(OPENCV_3RDPARTY_COMPONENTS),$(eval $(call add_opencv_3rdparty_component,$(module))))
    $(foreach module,$(OPENCV_CAMERA_MODULES),$(eval $(call add_opencv_camera_module,$(module))))


    ifneq ($(OPENCV_BASEDIR),)
        OPENCV_LOCAL_C_INCLUDES += $(foreach mod, $(OPENCV_MODULES), $(OPENCV_BASEDIR)/modules/$(mod)/include)
        ifeq ($(OPENCV_USE_GPU_MODULE),on)
            OPENCV_LOCAL_C_INCLUDES += $(OPENCV_BASEDIR)/modules/gpu/include
        endif
    endif


    #turn off module installation to prevent their redefinition
    OPENCV_MK_$(OPENCV_TARGET_ARCH_ABI)_ALREADY_INCLUDED:=on
endif


ifeq ($(OPENCV_MK_$(OPENCV_TARGET_ARCH_ABI)_GPU_ALREADY_INCLUDED),) #未包含则添加
    ifeq ($(OPENCV_USE_GPU_MODULE),on)
        include $(CLEAR_VARS)
        LOCAL_MODULE:=opencv_gpu
        LOCAL_SRC_FILES:=$(OPENCV_LIBS_DIR)/libopencv_gpu.a
        include $(PREBUILT_STATIC_LIBRARY)
    endif
    OPENCV_MK_$(OPENCV_TARGET_ARCH_ABI)_GPU_ALREADY_INCLUDED:=on
endif


ifeq ($(OPENCV_LOCAL_CFLAGS),)	#标识
    OPENCV_LOCAL_CFLAGS := -fPIC -DANDROID -fsigned-char
endif


include $(CLEAR_VARS)


LOCAL_C_INCLUDES:=$(USER_LOCAL_C_INCLUDES)  #包含路径
LOCAL_CFLAGS:=$(USER_LOCAL_CFLAGS)	#标识
LOCAL_STATIC_LIBRARIES:=$(USER_LOCAL_STATIC_LIBRARIES)  #静态库
LOCAL_SHARED_LIBRARIES:=$(USER_LOCAL_SHARED_LIBRARIES)  #动态库
LOCAL_LDLIBS:=$(USER_LOCAL_LDLIBS)		#静态目录


LOCAL_C_INCLUDES += $(OPENCV_LOCAL_C_INCLUDES)  #追加包含路径
LOCAL_CFLAGS     += $(OPENCV_LOCAL_CFLAGS)	#追加标识


ifeq ($(OPENCV_USE_GPU_MODULE),on)	#使用gpu则添加cuda路径
    LOCAL_C_INCLUDES += $(CUDA_TOOLKIT_DIR)/include
endif


ifeq ($(OPENCV_INSTALL_MODULES),on) #
    LOCAL_$(OPENCV_LIB_TYPE)_LIBRARIES += $(foreach mod, $(OPENCV_LIBS), opencv_$(mod))
    ifeq ($(OPENCV_LIB_TYPE),SHARED)
        ifneq ($(OPENCV_DYNAMICUDA_MODULE),)
            LOCAL_$(OPENCV_LIB_TYPE)_LIBRARIES += $(OPENCV_DYNAMICUDA_MODULE)
        endif
    endif
else
    LOCAL_LDLIBS += -L$(call host-path,$(LOCAL_PATH)/$(OPENCV_LIBS_DIR)) $(foreach lib, $(OPENCV_LIBS), -lopencv_$(lib)) #追加目录
endif


ifeq ($(OPENCV_LIB_TYPE),STATIC) #静态 追加3D库
    LOCAL_STATIC_LIBRARIES += $(OPENCV_3RDPARTY_COMPONENTS)
endif


LOCAL_LDLIBS += $(foreach lib,$(OPENCV_EXTRA_COMPONENTS), -l$(lib)) #静态目录


ifeq ($(OPENCV_USE_GPU_MODULE),on)
    ifeq ($(INSTALL_CUDA_LIBRARIES),on)
        LOCAL_SHARED_LIBRARIES += $(foreach mod, $(CUDA_RUNTIME_LIBS), $(mod))
    else
        LOCAL_LDLIBS += -L$(CUDA_TOOLKIT_DIR)/targets/armv7-linux-androideabi/lib $(foreach lib, $(CUDA_RUNTIME_LIBS), -l$(lib))
    endif
    LOCAL_STATIC_LIBRARIES+=libopencv_gpu
endif


LOCAL_PATH:=$(USER_LOCAL_PATH) #恢复原路径



结束

OpenCV在Android上的应用，使图片、相机操作变得简单了，接下来掌握OpenCV直接使用技巧。

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