本文叙述使用Android Studio新建OpenCV工程。

1.构建OpenCV环境

下载Opencv for Android
新建一个工程

1.1导入OpenCV Module

File --> New --> Import Module

修改openCVLibrary410/build.gradle

apply plugin: 'com.android.library'

android {
    compileSdkVersion 28
    buildToolsVersion "28.0.3"

    defaultConfig {
//        applicationId "org.opencv"
    }

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

1.2导入OPenCV的依赖

File --> Project Structure

将OpenCV-android-sdk\sdk\native\libs下所有文件夹复制到工程目录中的app\libs中，并在app模块对应的build.gradle中增加如下内容：

sourceSets{
    main{
        jniLibs.srcDirs=['libs']
    }
}

在MainActivity中增加代码

    if (OpenCVLoader.initDebug()) {
        Log.i(TAG, "Loaded successfully...");
    } else {
        Log.i(TAG, "Can not to loaded...");
    }

编译并运行app，在logcat中会出现如下内容

2.测试

1.res/drawable中添加一个图片

2.修改activity_main.xml

<?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="vertical"
    tools:context=".MainActivity">

    <ImageView
        android:id="@+id/imageView1"
        android:layout_weight="1"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:src="@drawable/pikaqiu" />
 <ImageView
        android:id="@+id/imageView2"
        android:layout_weight="1"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:src="@drawable/pikaqiu" />

</LinearLayout>

修改MAinActivity.java

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.ImageView;

import org.opencv.android.OpenCVLoader;
import org.opencv.android.Utils;
import org.opencv.core.Mat;
import org.opencv.imgproc.Imgproc;

public class MainActivity extends AppCompatActivity {

    private static final String TAG = "MainActivity";
    ImageView[] imageView = new ImageView[2];

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if (OpenCVLoader.initDebug()) {
            Log.i(TAG, "Loaded successfully...");
        } else {
                Log.i(TAG, "Can not to loaded...");
        }

        imageView[0] = findViewById(R.id.imageView1);
        imageView[1] = findViewById(R.id.imageView2);

        Bitmap srcBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.youname);
          Bitmap grayBitmap = rgb2gray(srcBitmap);
        imageView[0].setImageBitmap(srcBitmap);
        imageView[1].setImageBitmap(grayBitmap);
    }

    public Bitmap rgb2gray(Bitmap rgbBm){
        Mat rgbMat = new Mat();
        Mat grayMat = new Mat();
        Bitmap grayBm = Bitmap.createBitmap(rgbBm.getWidth(),
                rgbBm.getHeight(),
                Bitmap.Config.RGB_565);
        Utils.bitmapToMat(rgbBm, rgbMat);
           Imgproc.cvtColor(rgbMat, grayMat, Imgproc.COLOR_RGB2GRAY);
        Utils.matToBitmap(grayMat, grayBm);
        rgbMat.release();
        grayMat.release();
        Log.i(TAG, "procSrc2Gray sucess...");
        return grayBm;
    }
}

编译并运行app，出现如下结果说明环境搭建成功了：