深入OpenCV Android应用开发中文版 – 第五章代码更新

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：

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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：

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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>

</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" >

<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>

</intent-filter>

</activity>

<activity

android:name=".PyramidActivity"

android:label="@string/title_activity_pyramid"

android:theme="@style/AppTheme"

android:parentActivityName=".HomeActivity" >

<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：

<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：

<item name="colorPrimary">@color/colorPrimary</item>

<item name="colorPrimaryDark">@color/colorPrimaryDark</item>

<item name="colorAccent">@color/colorAccent</item>

</style>

<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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深入OpenCV Android应用开发中文版 – 第五章代码更新

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