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.engine | OpenCVEngineInterface.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.utils | Converters： |
| 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.alibopencv_stitching.a //图像拼接libopencv_superres.alibopencv_ts.a
OpenCV.mk
#编译前 需定义 NDK_USE_CYGPATH=1USER_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)/$(OPENCV_THIS_DIR)/include" #本地包含目录OPENCV_MODULES:=contrib legacy stitching superres ocl objdetect ml ts videostab video photo calib3d features2d highgui imgproc flann androidcamera core #对应的库文件OPENCV_LIB_TYPE:=STATIC #静态库OPENCV_HAVE_GPU_MODULE:=off #是否具备gpuOPENCV_USE_GPU_MODULE:=on #是否开启ifeq ($(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:=endifCUDA_RUNTIME_LIBS:=ifeq ($(OPENCV_LIB_TYPE),) #未表明使用库类型则使用动态 OPENCV_LIB_TYPE:=SHAREDendififeq ($(OPENCV_LIB_TYPE),SHARED) OPENCV_LIBS:=java OPENCV_LIB_TYPE:=SHAREDelse OPENCV_LIBS:=$(OPENCV_MODULES) OPENCV_LIB_TYPE:=STATICendififeq ($(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 endifendififeq ($(OPENCV_CAMERA_MODULES),on) #引入相机库（只有动态库） ifeq ($(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 ($(TARGET_ARCH_ABI),mips) OPENCV_CAMERA_MODULES:= native_camera_r4.0.3 native_camera_r4.1.1 native_camera_r4.2.0 native_camera_r4.3.0 native_camera_r4.4.0 endifelse OPENCV_CAMERA_MODULES:=endififeq ($(OPENCV_LIB_TYPE),SHARED) OPENCV_LIB_SUFFIX:=soelse OPENCV_LIB_SUFFIX:=a OPENCV_INSTALL_MODULES:=onendifdefine 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)endefdefine 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)endefdefine 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)endefdefine 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 $(PREBUILT_SHARED_LIBRARY)endefifeq ($(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:=onendififeq ($(OPENCV_MK_$(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:=onendififeq ($(OPENCV_LOCAL_CFLAGS),) #标识 OPENCV_LOCAL_CFLAGS := -fPIC -DANDROID -fsigned-charendifinclude $(CLEAR_VARS)LOCAL_C_INCLUDES:=$(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 += $(CUDA_TOOLKIT_DIR)/includeendififeq ($(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 += $(OPENCV_DYNAMICUDA_MODULE) endif endifelse LOCAL_LDLIBS += -L$(call host-path,$(LOCAL_PATH)/$(OPENCV_LIBS_DIR)) $(foreach lib, $(OPENCV_LIBS), -lopencv_$(lib)) #追加目录endififeq ($(OPENCV_LIB_TYPE),STATIC) #静态 追加3D库 LOCAL_STATIC_LIBRARIES += $(OPENCV_3RDPARTY_COMPONENTS)endifLOCAL_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_gpuendifLOCAL_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。