Android RakNet 系列之五 视频通讯 OpenCV4Android
栏目：综合技术时间：2014-12-16 08:37:39
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，现在把它援用到Android平台下。
OpenCV是1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1系列 C 函数和少许 C++ 类构成，同时提供了Python、Ruby、MATLAB等语言的接口，实现了图象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利用，通过优化的C代码的编写对其履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。
相干网站
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/ 相干博客
详情
项目介绍
官方提供了1个库项目（OpenCV Library - 2.4.10）和9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项目总计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? 固然如果直接使用它的库运行是不会出现此情况的。缘由就是该项目只是做加载库的工作。
项目如图：
官方给出解释：
加载库的代码以下：
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 = ⑴;
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 = ⑴;
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 以下：<?xml version="1.0" encoding="utf⑻"?>
<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1个文件，使用摄像机预览，Demo中提供了两种方法，1种是Java层调用，1种是Native层调用。
如图：
关键控件以下：
<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1个Java文件和1个C++文件，实现4中混合处理。
如图：
本地代码以下：
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));
}
}
使用的控件以下：
<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，控制色彩显示、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：
主要代码以下：
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 = ⑴;
// 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1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1个Java文件和1个C++文件，实现本地界面显示图片。
效果如图：
本地代码以下：
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] != ' ') && (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[idx⑴] != ' ');
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：
概括以下：
| 包 | 描写 |
| 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 定义了图象的新容器。 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 //特点匹配算法实现
libopencv_legacy.a
libopencv_stitching.a //图象拼接
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)/$(OPENCV_THIS_DIR)/include" #本地包括目录
OPENCV_MODULES:=contrib legacy stitching superres ocl objdetect ml ts videostab video photo calib3d features2d highgui imgproc flann androidcamera core #对应的库文件
OPENCV_LIB_TYPE:=STATIC #静态库
OPENCV_HAVE_GPU_MODULE:=off #是不是具有gpu
OPENCV_USE_GPU_MODULE:=on #是不是开启
ifeq ($(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_$(OPENCV_TARGET_ARCH_ABI)_ALREADY_INCLUDED),) #未包括则添加
ifeq ($(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),) #未包括则添加
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) #包括路径
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) #追加包括路径
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上的利用，使图片、相机操作变得简单了，接下来掌握OpenCV直接使用技能。
------分隔线----------------------------
------分隔线----------------------------