安装JDK

网上一堆教程：略。

安装Android Studio

网上一堆教程：略。

安装OpenCV4Android

到opencv官网下载地址下载opencv4android包。这边下载3.4.4版本的Android pack。

下载后解压可以看到以下几个文件。

apk：opencv已经编译好的Android可执行程序，拷贝到手机上即可运行。

samples：生成这些apk的Android代码工程。

sdk：里面是opencv的Java的接口和JNI接口等。

在Android Studio上配置OpenCV环境

1.打开Android studio新建一个新的Android空工程。

2.在Android Studio的菜单选择File-->New-->Import Module。

3.选择opencv android pack解压出来的sdk目录下的java文件夹，点击下一步，出现三个复选框，都选上，点击Finish。

4.菜单栏选择File-->Project Structure。

5.按照如下图步骤操作，选择app-->Dependencies-->+-->3 Module dependency，点击ok退出，然后再点击ok退出。

6.修改build.gradle(Module:openCVLibrary344)文件，将compileSdkVersion，minSdkVersion，targetSdkVersion改成你对应安卓版本，这边目标为Android8.0，最低为Android7.0.

7.在工程目录下的app/src/main目录下新建文件夹jniLibs，将我们下载解压的OpenCV-android-sdk下的sdk/native/libs下的所有文件拷贝到jniLibs下。

8.到此，opencv环境配置完成。

在Android上使用opencv写图像处理算法

activity_main.xml

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

MainActivity.java

package com.example.administrator.cv4andoird;import android.content.Intent;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.net.Uri;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.util.Log;import android.view.View;import android.widget.Button;import android.widget.ImageView;import org.opencv.android.OpenCVLoader;import org.opencv.android.Utils;import org.opencv.core.CvType;import org.opencv.core.Mat;import org.opencv.imgproc.Imgproc;import java.io.InputStream;public class MainActivity extends AppCompatActivity {    private double max_size = 1024;    private int PICK_IMAGE_REQUEST = 1;    private ImageView myImageView;    private Bitmap selectbp;    private Bitmap selectbptmp;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        staticLoadCVLibraries();        myImageView = (ImageView)findViewById(R.id.imageView);        myImageView.setScaleType(ImageView.ScaleType.FIT_CENTER);        Button selectImageBtn = (Button)findViewById(R.id.select_btn);        selectImageBtn.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                // makeText(MainActivity.this.getApplicationContext(), "start to browser image", Toast.LENGTH_SHORT).show();                selectImage();            }        });        Button processBtn = (Button)findViewById(R.id.process_btn);        processBtn.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                // makeText(MainActivity.this.getApplicationContext(), "hello, image process", Toast.LENGTH_SHORT).show();                convertGray();            }        });        Button cannyBtn = (Button)findViewById(R.id.canny_btn);        cannyBtn.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                // makeText(MainActivity.this.getApplicationContext(), "hello, image process", Toast.LENGTH_SHORT).show();                kayCanny();            }        });        Button srcBtn = (Button)findViewById(R.id.src_btn);        srcBtn.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                // makeText(MainActivity.this.getApplicationContext(), "hello, image process", Toast.LENGTH_SHORT).show();                kaySrc();            }        });        Button hsvBtn = (Button)findViewById(R.id.hsv_btn);        hsvBtn.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                // makeText(MainActivity.this.getApplicationContext(), "hello, image process", Toast.LENGTH_SHORT).show();                kayHsv();            }        });    }    private void staticLoadCVLibraries(){        boolean load = OpenCVLoader.initDebug();        if(load) {            Log.i("CV", "Open CV Libraries loaded...");        }    }    private void convertGray() {        Mat src = new Mat();        Mat temp = new Mat();        Mat dst = new Mat();        Utils.bitmapToMat(selectbp, src);        Imgproc.cvtColor(src, temp, Imgproc.COLOR_BGRA2BGR);        Log.i("CV", "image type:" + (temp.type() == CvType.CV_8UC3));        Imgproc.cvtColor(temp, dst, Imgproc.COLOR_BGR2GRAY);        Utils.matToBitmap(dst, selectbptmp);        myImageView.setImageBitmap(selectbptmp);    }    private void kayCanny() {        Mat src = new Mat();        Mat temp = new Mat();        Mat gray = new Mat();        Mat dst = new Mat();        Utils.bitmapToMat(selectbp, src);        Imgproc.cvtColor(src, temp, Imgproc.COLOR_BGRA2BGR);        Imgproc.cvtColor(temp, gray, Imgproc.COLOR_BGR2GRAY);        Imgproc.Canny(gray, dst, 80, 90);        Utils.matToBitmap(dst, selectbptmp);        myImageView.setImageBitmap(selectbptmp);    }    private void kaySrc() {        myImageView.setImageBitmap(selectbp);    }    private void kayHsv() {        Mat src = new Mat();        Mat temp = new Mat();        Mat dst = new Mat();        Utils.bitmapToMat(selectbp, src);        Imgproc.cvtColor(src, temp, Imgproc.COLOR_BGRA2BGR);        Log.i("CV", "image type:" + (temp.type() == CvType.CV_8UC3));        Imgproc.cvtColor(temp, dst, Imgproc.COLOR_BGR2HSV);        Utils.matToBitmap(dst, selectbptmp);        myImageView.setImageBitmap(selectbptmp);    }    @Override    protected void onActivityResult(int requestCode, int resultCode, Intent data) {        super.onActivityResult(requestCode, resultCode, data);        if(requestCode == PICK_IMAGE_REQUEST && resultCode == RESULT_OK && data != null && data.getData() != null) {            Uri uri = data.getData();            try {                Log.d("image-tag", "start to decode selected image now...");                InputStream input = getContentResolver().openInputStream(uri);                BitmapFactory.Options options = new BitmapFactory.Options();                options.inJustDecodeBounds = true;                BitmapFactory.decodeStream(input, null, options);                int raw_width = options.outWidth;                int raw_height = options.outHeight;                int max = Math.max(raw_width, raw_height);                int newWidth = raw_width;                int newHeight = raw_height;                int inSampleSize = 1;                if(max > max_size) {                    newWidth = raw_width / 2;                    newHeight = raw_height / 2;                    while((newWidth/inSampleSize) > max_size || (newHeight/inSampleSize) > max_size) {                        inSampleSize *=2;                    }                }                options.inSampleSize = inSampleSize;                options.inJustDecodeBounds = false;                options.inPreferredConfig = Bitmap.Config.ARGB_8888;                selectbp = BitmapFactory.decodeStream(getContentResolver().openInputStream(uri), null, options);                selectbptmp = BitmapFactory.decodeStream(getContentResolver().openInputStream(uri), null, options);                myImageView.setImageBitmap(selectbptmp);            } catch (Exception e) {                e.printStackTrace();            }        }    }    private void selectImage() {        Intent intent = new Intent();        intent.setType("image/*");        intent.setAction(Intent.ACTION_GET_CONTENT);        startActivityForResult(Intent.createChooser(intent,"选择图像..."), PICK_IMAGE_REQUEST);    }}

在魅族note5上的运行效果

参考

https://www.cnblogs.com/ckb58/p/6242040.html

http://xinzhi.wenda.so.com/a/1522931091614032

https://blog.csdn.net/qq_36992688/article/details/79214273

Android上跑OpenCV