深入OpenCV Android应用开发 中文版 – 第五章代码更新

发布于 作者： John Hany 3,365次阅读

本书中文版购书链接：京东  当当

英文原版购书链接：亚马逊《Mastering OpenCV Android Application Programming》

        原书所给代码以章为单位，针对的Android版本从API 19到API 21不等，同时使用的OpenCV库版本也有2.4.9和2.4.10两种。本文给出的代码是在原书代码的基础上，针对Android 7.0（API 24）与OpenCV 3.2进行了修改，适当地增加了一些预处理等操作，以使代码整体上更合理。

        原书的完整代码可以在这里获取：https://www.packtpub.com/lcode_download/22299。

        更新后的代码托管在GitHub：https://github.com/johnhany/MOAAP/tree/master/MOAAP-Chp5-r3。

        关于在Android Studio上配置OpenCV开发环境的方法，请参考《在Android Studio上进行OpenCV 3.1开发》。

        本章介绍如何在Android Studio 2上通过OpenCV使用常见的目标追踪算法，涉及的算法有光流法，图像金字塔以及KTL追踪器。关于以上各算法的原理可以参考《深入OpenCV Android应用开发》第五章。

开发环境

        Windows 10 x64

        Android Studio 2.3.3（Gradle 3.3，Android Plugin 2.3.3）

        Android 7.0（API 24）

        JDK 8u141

        OpenCV 3.2.0 Android SDK

代码及简略解释

        1. 创建Android Studio项目，包命名为net.johnhany.moaap_chp5。导入OpenCV-android-sdk\sdk\java到项目中，并为app模块加载模块依赖。

        2. 将app\src\main\java\net\johnhany\moaap_chp5\MainActivity.java文件修改为如下内容： 

package net.johnhany.moaap_chp5;

import android.Manifest;
import android.content.pm.PackageManager;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.WindowManager;

import org.opencv.android.BaseLoaderCallback;
import org.opencv.android.CameraBridgeViewBase;
import org.opencv.android.CameraBridgeViewBase.CvCameraViewFrame;
import org.opencv.android.CameraBridgeViewBase.CvCameraViewListener2;
import org.opencv.android.LoaderCallbackInterface;
import org.opencv.android.OpenCVLoader;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.core.MatOfByte;
import org.opencv.core.MatOfFloat;
import org.opencv.core.MatOfPoint;
import org.opencv.core.MatOfPoint2f;
import org.opencv.core.Point;
import org.opencv.core.Scalar;
import org.opencv.imgproc.Imgproc;
import org.opencv.video.Video;

import java.util.List;

public class MainActivity extends AppCompatActivity implements CvCameraViewListener2 {
    private static final String    TAG = "MOAAP_CHP5";

    private static final int       VIEW_MODE_KLT_TRACKER = 0;
    private static final int       VIEW_MODE_OPTICAL_FLOW = 1;

    static int                      REQUEST_CAMERA = 0;
    static boolean                  camera_granted = false;

    private int                    mViewMode;
    private Mat                    mRgba;
    private Mat                    mIntermediateMat;
    private Mat                    mGray;
    private Mat                    mPrevGray;

    MatOfPoint2f prevFeatures, nextFeatures;
    MatOfPoint features;

    MatOfByte status;
    MatOfFloat err;

    private MenuItem               mItemPreviewOpticalFlow, mItemPreviewKLT;

    private CameraBridgeViewBase   mOpenCvCameraView;

    private BaseLoaderCallback  mLoaderCallback = new BaseLoaderCallback(this) {
        @Override
        public void onManagerConnected(int status) {
            switch (status) {
                case LoaderCallbackInterface.SUCCESS:
                {
                    Log.i(TAG, "OpenCV loaded successfully");

                    mOpenCvCameraView.enableView();
                } break;
                default:
                {
                    super.onManagerConnected(status);
                } break;
            }
        }
    };

    @Override
    public void onCreate(Bundle savedInstanceState) {
        Log.i(TAG, "called onCreate");
        super.onCreate(savedInstanceState);
        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);

        setContentView(R.layout.activity_main);

        if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.CAMERA)
                != PackageManager.PERMISSION_GRANTED) {
            Log.i("permission", "request READ_EXTERNAL_STORAGE");
            ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.CAMERA}, REQUEST_CAMERA);
        }else {
            Log.i("permission", "READ_EXTERNAL_STORAGE already granted");
            camera_granted = true;
        }

        mOpenCvCameraView = (CameraBridgeViewBase) findViewById(R.id.main_activity_surface_view);
        mOpenCvCameraView.setCvCameraViewListener(this);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        Log.i(TAG, "called onCreateOptionsMenu");
        mItemPreviewKLT = menu.add("KLT Tracker");
        mItemPreviewOpticalFlow = menu.add("Optical Flow");
        return true;
    }

    @Override
    public void onPause()
    {
        super.onPause();
        if (mOpenCvCameraView != null)
            mOpenCvCameraView.disableView();
    }

    @Override
    public void onResume()
    {
        super.onResume();
        OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_3_2_0, this, mLoaderCallback);
    }

    public void onDestroy() {
        super.onDestroy();
        if (mOpenCvCameraView != null)
            mOpenCvCameraView.disableView();
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String permissions[], @NonNull int[] grantResults) {
        if (requestCode == REQUEST_CAMERA) {
            // If request is cancelled, the result arrays are empty.
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                // permission was granted
                Log.i("permission", "CAMERA granted");
                camera_granted = true;
            } else {
                // permission denied
                Log.i("permission", "CAMERA denied");
            }
        }
    }

    public void onCameraViewStarted(int width, int height) {
        mRgba = new Mat(height, width, CvType.CV_8UC4);
        mIntermediateMat = new Mat(height, width, CvType.CV_8UC4);
        mGray = new Mat(height, width, CvType.CV_8UC1);
//        Log.d(TAG, "\nRows: "+height+"\nCols: "+width+"\n");
        resetVars();
    }

    public void onCameraViewStopped() {
        mRgba.release();
        mGray.release();
        mIntermediateMat.release();
    }

    public Mat onCameraFrame(CvCameraViewFrame inputFrame) {
        final int viewMode = mViewMode;
        switch (viewMode) {
            case VIEW_MODE_OPTICAL_FLOW:
                mGray = inputFrame.gray();
                if(features.toArray().length==0){
                    int rowStep = 50, colStep = 100;
                    int nRows = mGray.rows()/rowStep, nCols = mGray.cols()/colStep;

//                    Log.d(TAG, "\nRows: "+nRows+"\nCols: "+nCols+"\n");

                    Point points[] = new Point[nRows*nCols];
                    for(int i=0; i<nRows; i++){
                        for(int j=0; j<nCols; j++){
                            points[i*nCols+j]=new Point(j*colStep, i*rowStep);
//                            Log.d(TAG, "\nRow: "+i*rowStep+"\nCol: "+j*colStep+"\n: ");
                        }
                    }

                    features.fromArray(points);

                    prevFeatures.fromList(features.toList());
                    mPrevGray = mGray.clone();
                    break;
                }

                nextFeatures.fromArray(prevFeatures.toArray());
                Video.calcOpticalFlowPyrLK(mPrevGray, mGray, prevFeatures, nextFeatures, status, err);

                List<Point> prevList=features.toList(), nextList=nextFeatures.toList();
                Scalar color = new Scalar(255);

                for(int i = 0; i<prevList.size(); i++){
//                    Core.circle(mGray, prevList.get(i), 5, color);
                    Imgproc.line(mGray, prevList.get(i), nextList.get(i), color);
                }

                mPrevGray = mGray.clone();
                break;
            case VIEW_MODE_KLT_TRACKER:
                mGray = inputFrame.gray();

                if(features.toArray().length==0){
                    Imgproc.goodFeaturesToTrack(mGray, features, 10, 0.01, 10);
                    Log.d(TAG, features.toList().size()+"");
                    prevFeatures.fromList(features.toList());
                    mPrevGray = mGray.clone();
//                    prevFeatures.fromList(nextFeatures.toList());
                    break;
                }

//                OpticalFlow(mPrevGray.getNativeObjAddr(), mGray.getNativeObjAddr(), prevFeatures.getNativeObjAddr(), nextFeatures.getNativeObjAddr());
                Video.calcOpticalFlowPyrLK(mPrevGray, mGray, prevFeatures, nextFeatures, status, err);
                List<Point> drawFeature = nextFeatures.toList();
//                Log.d(TAG, drawFeature.size()+"");
                for(int i = 0; i<drawFeature.size(); i++){
                    Point p = drawFeature.get(i);
                    Imgproc.circle(mGray, p, 5, new Scalar(255));
                }
                mPrevGray = mGray.clone();
                prevFeatures.fromList(nextFeatures.toList());
                break;
            default: mViewMode = VIEW_MODE_KLT_TRACKER;
        }

        return mGray;
    }

    public boolean onOptionsItemSelected(MenuItem item) {
        Log.i(TAG, "called onOptionsItemSelected; selected item: " + item);

        if (item == mItemPreviewOpticalFlow) {
            mViewMode = VIEW_MODE_OPTICAL_FLOW;
            resetVars();
        } else if (item == mItemPreviewKLT){
            mViewMode = VIEW_MODE_KLT_TRACKER;
            resetVars();
        }
        return true;
    }

    private void resetVars(){
        mPrevGray = new Mat(mGray.rows(), mGray.cols(), CvType.CV_8UC1);
        features = new MatOfPoint();
        prevFeatures = new MatOfPoint2f();
        nextFeatures = new MatOfPoint2f();
        status = new MatOfByte();
        err = new MatOfFloat();
    }
}

        3. 修改app\src\main\res\layout\activity_main.xml文件： 

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal"
    tools:context="net.johnhany.moaap_chp5.MainActivity">

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

</LinearLayout>

        4. 在app\src\main\java\net\johnhany\moaap_chp5下新建一个HomeActivity.java文件，其内容为： 

package net.johnhany.moaap_chp5;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class HomeActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_home);
        Button bPyramids, bOptFlowKLT;
        bPyramids = (Button) findViewById(R.id.bPyramids);
        bOptFlowKLT = (Button) findViewById(R.id.bOptFlowKLT);
        bOptFlowKLT.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent i = new Intent(getApplicationContext(), MainActivity.class);
                startActivity(i);
            }
        });
        bPyramids.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent i = new Intent(getApplicationContext(), PyramidActivity.class);
                startActivity(i);
            }
        });
    }
}

        5. 在app\src\main\res\layout下新建一个activity_home.xml文件，其内容为： 

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >
    <LinearLayout
        android:layout_height="wrap_content"
        android:layout_width="match_parent"
        android:orientation="vertical" >

        <Button
            android:id="@+id/bPyramids"
            android:layout_height="wrap_content"
            android:layout_width="wrap_content"
            android:text="@string/home_button_1" />

        <Button
            android:id="@+id/bOptFlowKLT"
            android:layout_height="wrap_content"
            android:layout_width="wrap_content"
            android:text="@string/home_button_2" />

    </LinearLayout>

</ScrollView>

        6. 在app\src\main\java\net\johnhany\moaap_chp5下新建一个PyramidActivity.java文件，文件内容为： 

package net.johnhany.moaap_chp5;

import android.Manifest;
import android.support.v7.app.AppCompatActivity;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Environment;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;

import org.opencv.android.BaseLoaderCallback;
import org.opencv.android.LoaderCallbackInterface;
import org.opencv.android.OpenCVLoader;
import org.opencv.android.Utils;
import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;

public class PyramidActivity extends AppCompatActivity {

    private final int SELECT_PHOTO = 1;
    private ImageView ivImage;
    Mat src;
    static int ACTION_MODE = 0;
    static final int MODE_NONE = 0, MODE_GAUSSIAN_PYR_UP = 1, MODE_GAUSSIAN_PYR_DOWN = 2, MODE_LAPLACIAN_PYR = 3;
    private boolean srcSelected = false;
    static int REQUEST_READ_EXTERNAL_STORAGE = 0;
    static boolean read_external_storage_granted = false;
    Button bGaussianPyrUp, bGaussianPyrDown, bLaplacianPyr;

    private BaseLoaderCallback mOpenCVCallBack = new BaseLoaderCallback(this) {
        @Override
        public void onManagerConnected(int status) {
            switch (status) {
                case LoaderCallbackInterface.SUCCESS:
                    //DO YOUR WORK/STUFF HERE
                    break;
                default:
                    super.onManagerConnected(status);
                    break;
            }
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_pyramid);
        if (getActionBar() != null) {
            getActionBar().setDisplayHomeAsUpEnabled(true);
        }
        ivImage = (ImageView)findViewById(R.id.ivImage);
        bGaussianPyrUp = (Button) findViewById(R.id.bGaussianPyrUp);
        bGaussianPyrDown = (Button) findViewById(R.id.bGaussianPyrDown);
        bLaplacianPyr = (Button) findViewById(R.id.bLaplacianPyr);

        if (ContextCompat.checkSelfPermission(PyramidActivity.this, Manifest.permission.READ_EXTERNAL_STORAGE)
                != PackageManager.PERMISSION_GRANTED) {
            Log.i("permission", "request READ_EXTERNAL_STORAGE");
            ActivityCompat.requestPermissions(PyramidActivity.this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},
                    REQUEST_READ_EXTERNAL_STORAGE);
        }else {
            Log.i("permission", "READ_EXTERNAL_STORAGE already granted");
            read_external_storage_granted = true;
        }

        bGaussianPyrUp.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                ACTION_MODE = MODE_GAUSSIAN_PYR_UP;
                executeTask();
            }
        });

        bGaussianPyrDown.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                ACTION_MODE = MODE_GAUSSIAN_PYR_DOWN;
                executeTask();
            }
        });

        bLaplacianPyr.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                ACTION_MODE = MODE_LAPLACIAN_PYR;
                executeTask();
            }
        });

        if(!srcSelected){
            bGaussianPyrDown.setEnabled(false);
            bGaussianPyrUp.setEnabled(false);
            bLaplacianPyr.setEnabled(false);
        }

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu_pyramid, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        int id = item.getItemId();

        if (id == R.id.action_load_first_image) {
            Intent photoPickerIntent = new Intent(Intent.ACTION_PICK);
            photoPickerIntent.setType("image/*");
            startActivityForResult(photoPickerIntent, SELECT_PHOTO);
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent imageReturnedIntent) {
        super.onActivityResult(requestCode, resultCode, imageReturnedIntent);

        switch(requestCode) {
            case SELECT_PHOTO:
                if(resultCode == RESULT_OK){
                    try {
                        final Uri imageUri = imageReturnedIntent.getData();
                        final InputStream imageStream = getContentResolver().openInputStream(imageUri);
                        final Bitmap selectedImage = BitmapFactory.decodeStream(imageStream);
                        src = new Mat(selectedImage.getHeight(), selectedImage.getWidth(), CvType.CV_8UC4);
                        Utils.bitmapToMat(selectedImage, src);
                        srcSelected = true;
                        bGaussianPyrUp.setEnabled(true);
                        bGaussianPyrDown.setEnabled(true);
                        bLaplacianPyr.setEnabled(true);
                    } catch (FileNotFoundException e) {
                        e.printStackTrace();
                    }
                }
                break;
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String permissions[], @NonNull int[] grantResults) {
        if (requestCode == REQUEST_READ_EXTERNAL_STORAGE) {
            // If request is cancelled, the result arrays are empty.
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                // permission was granted
                Log.i("permission", "READ_EXTERNAL_STORAGE granted");
                read_external_storage_granted = true;
            } else {
                // permission denied
                Log.i("permission", "READ_EXTERNAL_STORAGE denied");
            }
        }
    }

    private void executeTask(){
        if(srcSelected){

            new AsyncTask<Void, Void, Bitmap>() {
                @Override
                protected void onPreExecute() {
                    super.onPreExecute();
                }

                @Override
                protected Bitmap doInBackground(Void... params) {
                    Mat srcRes = new Mat();
                    switch (ACTION_MODE){
                        case MODE_GAUSSIAN_PYR_UP:
                            Imgproc.pyrUp(src, srcRes);
                            break;
                        case MODE_GAUSSIAN_PYR_DOWN:
                            Imgproc.pyrDown(src, srcRes);
                            break;
                        case MODE_LAPLACIAN_PYR:
                            Imgproc.pyrDown(src, srcRes);
                            Imgproc.pyrUp(srcRes, srcRes);
                            Core.absdiff(srcRes, src, srcRes);
                            break;
                    }

                    if(ACTION_MODE != MODE_NONE) {
                        Bitmap image = Bitmap.createBitmap(srcRes.cols(), srcRes.rows(), Bitmap.Config.ARGB_8888);
                        Utils.matToBitmap(srcRes, image);
                        FileOutputStream out = null;
                        try {
                            out = new FileOutputStream(Environment.getExternalStorageDirectory() + "/Download/MOAAP/Chapter5/" + ACTION_MODE + ".png");
                            image.compress(Bitmap.CompressFormat.PNG, 100, out); // bmp is your Bitmap instance
//                            image = BitmapFactory.decodeFile(Environment.getExternalStorageDirectory() + "/Download/MOAAP/Chapter5/" + ACTION_MODE + ".png");
                        } catch (Exception e) {
                            e.printStackTrace();
                        } finally {
                            try {
                                if (out != null) {
                                    out.close();
                                }
                            } catch (IOException e) {
                                e.printStackTrace();
                            }
                        }

                        Imgcodecs.imwrite(Environment.getExternalStorageDirectory() + "/Download/MOAAP/Chapter5/" + ACTION_MODE + "-imwrite.png", srcRes);

                        Mat src1 = new Mat();
                        Imgproc.cvtColor(srcRes, src1, Imgproc.COLOR_BGR2BGRA);
                        Imgcodecs.imwrite(Environment.getExternalStorageDirectory() + "/Download/MOAAP/Chapter5/" + ACTION_MODE + "-imwriteBGRA.png", src1);

                        Imgproc.cvtColor(srcRes, src1, Imgproc.COLOR_BGR2RGBA);
                        Imgcodecs.imwrite(Environment.getExternalStorageDirectory() + "/Download/MOAAP/Chapter5/" + ACTION_MODE + "-imwriteRGBA.png", src1);

//                        Utils.matToBitmap(src1, image);
                        return image;
                    }
                    return null;
                }

                @Override
                protected void onPostExecute(Bitmap bitmap) {
                    super.onPostExecute(bitmap);
                    if(bitmap!=null) {
                        ivImage.setImageBitmap(bitmap);
                    }
                }
            }.execute();
        }
    }

    @Override
    protected void onResume() {
        super.onResume();
        OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_3_2_0, this, mOpenCVCallBack);
    }
}

        7. 在app\src\main\res\layout下新建一个activity_pyramid.xml文件，文件内容为： 

<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >
    <LinearLayout android:orientation="vertical" android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <ImageView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:contentDescription="@string/pyramid_img_descrip"
            android:visibility="visible"
            android:id="@+id/ivImage" />
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal">
            <Button
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_weight="0.5"
                android:id="@+id/bGaussianPyrUp"
                style="?android:attr/borderlessButtonStyle"
                android:text="@string/pyramid_button_1"/>
            <Button
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_weight="0.5"
                android:id="@+id/bGaussianPyrDown"
                style="?android:attr/borderlessButtonStyle"
                android:text="@string/pyramid_button_2"/>
        </LinearLayout>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal">
            <Button
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:id="@+id/bLaplacianPyr"
                android:text="@string/pyramid_button_3"/>
        </LinearLayout>
    </LinearLayout>
</ScrollView>

        8. 在app\src\main\res目录下创建一个名为menu的Andorid resource directory，再在res\menu中创建一个menu_main.xml文件： 

<?xml version="1.0" encoding="utf-8"?>
<menu>

</menu>

        9. 在app\src\main\res\menu目录下新建一个名为menu_pyramid.xml的文件，其内容为： 

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <item android:id="@+id/action_load_first_image"
        android:title="@string/action_load_first_image"
        android:orderInCategory="1"
        app:showAsAction="never" />
</menu>

        10. 修改app\src\main\res\AndroidManifest.xml文件为如下内容： 

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="net.johnhany.moaap_chp5">

    <uses-permission android:name="android.permission.CAMERA" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

    <uses-feature android:name="android.hardware.camera" android:required="false" />
    <uses-feature android:name="android.hardware.camera.autofocus" android:required="false" />
    <uses-feature android:name="android.hardware.camera.front" android:required="false" />
    <uses-feature android:name="android.hardware.camera.front.autofocus" android:required="false" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true">
        <activity
            android:name=".MainActivity"
            android:screenOrientation="landscape"
            android:theme="@style/CamTheme"
            android:label="@string/title_activity_main"
            android:parentActivityName=".HomeActivity" >
            <!-- Parent activity meta-data to support 4.0 and lower -->
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value=".HomeActivity" />
        </activity>

        <activity android:name=".HomeActivity"
            android:theme="@style/AppTheme"
            android:label="@string/title_activity_home">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <activity
            android:name=".PyramidActivity"
            android:label="@string/title_activity_pyramid"
            android:theme="@style/AppTheme"
            android:parentActivityName=".HomeActivity" >
            <!-- Parent activity meta-data to support 4.0 and lower -->
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value=".HomeActivity" />
        </activity>
    </application>

</manifest>

        11. 修改app\src\main\res\values\strings.xml文件： 

<resources>
    <string name="app_name">第五章 - 深入OpenCV Android应用开发</string>
    <string name="home_button_1">Image Pyramids</string>
    <string name="home_button_2">Optical Flow and KLT Tracker</string>
    <string name="pyramid_img_descrip">Image View</string>
    <string name="pyramid_button_1">Gaussian Pyramid Up</string>
    <string name="pyramid_button_2">Gaussian Pyramid Down</string>
    <string name="pyramid_button_3">Laplacian Pyramid</string>
    <string name="action_load_first_image">Load Image</string>
    <string name="title_activity_main">第五章 - 深入OpenCV Android应用开发</string>
    <string name="title_activity_pyramid">第五章 - 深入OpenCV Android应用开发</string>
    <string name="title_activity_home">第五章 - 深入OpenCV Android应用开发</string>
</resources>

        12. 修改app\src\main\res\values\styles.xml文件： 

<resources>

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <!-- Customize your theme here. -->
        <item name="android:windowActionBar">true</item>
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
    </style>

    <style name="CamTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <!-- Customize your theme here. -->
        <item name="android:windowNoTitle">true</item>
        <item name="android:windowActionBar">true</item>
        <item name="android:windowFullscreen">true</item>
        <item name="android:windowContentOverlay">@null</item>
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
    </style>

</resources>

        13. app\build.gradle文件修改为： 

apply plugin: 'com.android.application'

android {
    compileSdkVersion 24
    buildToolsVersion "26.0.1"
    defaultConfig {
        applicationId "net.johnhany.moaap_chp5"
        minSdkVersion 16
        targetSdkVersion 24
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:24.2.1'
    compile 'com.android.support.constraint:constraint-layout:1.0.2'
    testCompile 'junit:junit:4.12'
    compile project(':openCVLibrary320')
}

        14. openCVLibrary320\build.gradle文件修改为： 

apply plugin: 'com.android.library'

android {
    compileSdkVersion 24
    buildToolsVersion "26.0.1"

    defaultConfig {
        minSdkVersion 16
        targetSdkVersion 24
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
        }
    }
}

        15. 检查一下项目根目录的build.gradle文件是否为如下内容： 

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.3.3'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        jcenter()
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

运行效果

        右上角的菜单选择Optical Flow，移动手机时，在画面上局部像素的运动会以下图中的白线表示出来。

        选择KLT Tracker，则程序会在第一帧图像中选取若干追踪点，并在移动镜头时进行追踪。如果追踪点超出画面的范围，就会造成追踪失败，需要再一次点击KLT Tracker开始新的追踪。

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jwj
jwj
2 年 之前

光流的点有点少，怎么取消采样

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shadow_wxh
shadow_wxh
2 年 之前

200行后面建议加上两句：

Core.normalize(srcResult,srcResult,0,255,Core.NORM_MINMAX);
Core.add(srcResult,new Mat(srcResult.rows(),srcResult.cols(),CvType.CV_8UC4, new Scalar(0,0,0,255)),srcResult);

一个是增加对比度，一个是把Alpha值加回去

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shadow_wxh
shadow_wxh
2 年 之前

在我的机器上scrRes格式为RGBA

224行：imwrite 执行后，文件浏览呈反色

227行: Imgproc.cvtColor(srcRes, src1, Imgproc.COLOR_BGR2BGRA) 执行后，scr1 为BGRA，imwrite 执行后，文件浏览正常彩色。（此处不应该啊BGR to BGRA不应该出现调换啊）

230行：Imgproc.cvtColor(srcRes, src1, Imgproc.COLOR_BGR2RGBA)执行后，scr1为RGBA和scrRes格式一样。（此处也不正常该调换的又没调换）

难道OPENCV源码可以自己纠正到底是RGBA还是BGRA？我是这么写的：

 Imgcodecs.imwrite(Environment.getExternalStorageDirectory() + "/Download/MOAAP/Chapter5/" + ACTION_MODE + "-imwrite.png", srcRes);

 Mat src1 = new Mat();

Imgproc.cvtColor(srcRes, src1, Imgproc.COLOR_RGBA2BGRA);

Imgcodecs.imwrite(Environment.getExternalStorageDirectory() + "/Download/MOAAP/Chapter5/" + ACTION_MODE + "-imwriteBGRA.png", src1);

230 ，231行去掉

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