转载 https://blog.csdn.net/yu540135101/article/details/82593860

1.下载地址（官网）

https://www.opencv.org/opencv-3-4-1.html

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2.导入Module

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3.删除以下代码

在OpenCV模块的清单文件中删除以下代码

 <uses-sdk android:minSdkVersion="8" android:targetSdkVersion="21" />

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4.配置OpenCVLibrary341的SDK版本

在build.gradle(Module：OpenCVLibrary341)中，修改以下属性
改为和build.gradle（Module：app）中的值一样

compileSdkVersion

minSdkVersion

targetSdkVersion

5.复制armeabi-v7a文件夹到项目的libs目录下（注意要有文件夹）

复制成功后，也可以删除掉其他的.a文件，只保留libopencv_java3.so

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6.添加依赖

dependencies {

    ...

    //让app包，与新添加的这个OpenCV库关联

    implementation project(':openCVLibrary341')

    //将打好jar包，添加到依赖中

    implementation fileTree(dir: "$buildDir/native-libs", include: 'native-libs.jar')

 }

//以下很重要

//将添加的.so文件，打包成jar

task nativeLibsToJar(type: Jar, description: 'create a jar archive of the native libs') {

    destinationDir file("$buildDir/native-libs")

    baseName 'native-libs'

    from fileTree(dir: 'libs', include: '**/*.so')

    into 'lib/'

}

tasks.withType(JavaCompile) {

    compileTask -> compileTask.dependsOn(nativeLibsToJar)

}

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7.初始化，图像转成灰色测试

import android.graphics.Bitmap;

import android.graphics.BitmapFactory;

import android.os.Bundle;

import android.support.v7.app.AppCompatActivity;

import android.view.View;

import android.widget.Button;

import android.widget.ImageView;

import android.widget.Toast;

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 ImageView imageView;

    private Button button;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        initView();

        //初始化

        if (OpenCVLoader.initDebug()) {

            Toast.makeText(this, "OpenCVLoader初始化成功", Toast.LENGTH_SHORT).show();

        }

        //测试灰度

        button.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                convert2Grey();

            }

        });

    }

    private void convert2Grey() {

        Mat src = new Mat();//Mat是OpenCV的一种图像格式

        Mat temp = new Mat();

        Mat dst = new Mat();

        Bitmap bitmap = BitmapFactory.decodeResource(this.getResources(), R.mipmap.bd_logo1);

        Utils.bitmapToMat(bitmap, src);

        Imgproc.cvtColor(src, temp, Imgproc.COLOR_RGB2BGR);

        Imgproc.cvtColor(temp, dst, Imgproc.COLOR_BGR2GRAY);

        Utils.matToBitmap(dst, bitmap);

        imageView.setImageBitmap(bitmap);

        //

        src.release();

        temp.release();

        dst.release();

    }

    private void initView() {

        imageView = (ImageView) findViewById(R.id.imageView);

        button = (Button) findViewById(R.id.button);

    }

}

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Demo下载

https://download.csdn.net/download/yu540135101/10659712