openCV for Android的搭建并把普通图像转换为灰度

1.下载openCV for Android 库 链接 https://github.com/opencv/opencv/releases/tag/3.3.0
2.导入添加依赖，

QQ截图20171113233914.jpg QQ截图20171113234127.jpg
QQ截图20171113234538.jpg

openCV SDK结构

QQ截图20171113234710.jpg

3.导入libs

QQ截图20171113234929.jpg
QQ截图20171113235259.jpg

so mips就不导了
最终是这个样子的

QQ截图20171113235528.jpg

4.openCVLibrary的build.gradle和你项目的build.gradle 的 需要保持一致
自己项目的：

  compileSdkVersion 26
    buildToolsVersion "25.0.2"
    defaultConfig {
        applicationId "com.doudoubird.opencv_one"
        minSdkVersion 15
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"

    }
}

openCV的

    compileSdkVersion 25
    buildToolsVersion "25.0.2"
    defaultConfig {
 //       applicationId "com.doudoubird.myopencv"
        minSdkVersion 15
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }

5.最后需要构建自己的Native_Libs， build.gradle中需要这样写

apply plugin: 'com.android.application'

android {
    compileSdkVersion 26
    buildToolsVersion "25.0.2"

    defaultConfig {
        applicationId "com.doudoubird.opencv_one"
        minSdkVersion 15
        targetSdkVersion 25
        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')
    compile fileTree(dir: "$buildDir/native-libs", include: 'native-libs.jar')
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:26.+'
    compile 'com.android.support.constraint:constraint-layout:1.0.2'
    testCompile 'junit:junit:4.12'
    compile project(':openCVLibrary330')
}
task nativeLibsToJar(type: Zip, description: "create a jar archive of the native libs") {
    destinationDir file("$projectDir/libs")
    baseName "Native_Libs2"
    extension "jar"
    from fileTree(dir: "libs", include: "**/*.so")
    into "lib"
}

tasks.withType(JavaCompile) {
    compileTask -> compileTask.dependsOn(nativeLibsToJar)
}

以上也可以参考这篇博客 http://blog.csdn.net/qq_18870023/article/details/58203990
现在可以编写代码把一张彩色图变成灰度图啦

public class MainActivity extends AppCompatActivity implements View.OnClickListener{
    private static String  TAG = "TAG";
    private Button button;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initLoadOpenCVLibs();
        button = (Button) findViewById(R.id.button);
        button.setOnClickListener(this);
    }

    private void initLoadOpenCVLibs() {
        boolean success = OpenCVLoader.initDebug();
        if (success){
            Log.e(TAG, "加载完了 ");
        }
    }

    @Override
    public void onClick(View view) {
        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inPreferredConfig = Bitmap.Config.ARGB_8888;
        Bitmap bitmap = BitmapFactory.decodeResource(this.getResources(),R.mipmap.ic_launcher,options);
        Mat src = new Mat();
        Mat dst = new Mat();
        Utils.bitmapToMat(bitmap,src);
        Imgproc.cvtColor(src,dst,Imgproc.COLOR_BGRA2GRAY);
        Utils.matToBitmap(dst,bitmap);
        ImageView imagview = (ImageView) this.findViewById(R.id.imageView);
        imagview.setImageBitmap(bitmap);
    }
}

布局文件

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools" 
    android:layout_width="match_parent"
    android:layout_height="match_parent" 
    tools:context="com.doudoubird.opencv_one.MainActivity">


    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="环境测试-灰度"
         />

    <ImageView
        android:layout_below="@+id/button"
        android:id="@+id/imageView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:srcCompat="@mipmap/ic_launcher"
        />

</RelativeLayout>

效果如下

没变前 Screenshot_2017-11-14-00-14-24-139_com.doudoubird.png
变后 Screenshot_2017-11-14-00-14-28-472_com.doudoubird.png