基于Android studio3.6的java api方式调用opencv

基本环境：

Android studio3.6

NDK:r15c（尽量使用该版本）

OpenCV3.4.1 android sdk

操作：

(1)新建工程，选择Empty Activity，工程名为op

(2)File->New->Import Module，然后选择自己的java-opencv的相对应路径，比如，D:\Android\OpenCV-android-sdk\sdk\java

(3)修改openCVlibrary341下面的build.gradle中的，compileSdkVersion，buildToolsVersion，minSdkVersion，targetSdkVersion，使得和自己的工程下面的app/build.gradle的版本一致。

(4)修改openCVlibrary341下面的src/main中的AndroidManifest.xml中的minSdkVersion，targetSdkVersion，使得和自己的工程下面的app/build.gradle的版本一致。

(5)app/src/main/res/drawable下面增加一张图片

(6)app/src/main/res/layout中修改布局文件activity_main.xml

    "

(7)修改app/src/main/java/com.example.op下面的MainActivity

package com.example.op;
import androidx.appcompat.app.AppCompatActivity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import org.opencv.android.BaseLoaderCallback;
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 {
    Button btnProcess;
    Bitmap srcBitmap;
    Bitmap grayBitmap;
    ImageView img;
    private static boolean flag = true;
    private static boolean isFirst = true;
    private static final String TAG = "MainActivity";
    private BaseLoaderCallback mLoaderCallback = new BaseLoaderCallback(this) {
        @Override
        public void onManagerConnected(int status) {
            // TODO Auto-generated method stub
            switch (status){
                case BaseLoaderCallback.SUCCESS:
                    Log.i(TAG, "baseloader success");
                    break;
                default:
                    super.onManagerConnected(status);
                    Log.i(TAG, String.valueOf(status));
                    break;
            }
        }
    };
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        btnProcess = (Button)findViewById(R.id.btn_gray_process);
        img = (ImageView)findViewById(R.id.img);
        Log.i(TAG, "initUI sucess...");
        btnProcess.setOnClickListener(new ProcessClickListener());
    }
    public void procSrc2Gray(){
        Mat rgbMat = new Mat();
        Mat grayMat = new Mat();
        srcBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.dilireba);
        grayBitmap = Bitmap.createBitmap(srcBitmap.getWidth(), srcBitmap.getHeight(), Bitmap.Config.ARGB_8888);
        Utils.bitmapToMat(srcBitmap, rgbMat);//convert original bitmap to Mat, R G B.
        Imgproc.cvtColor(rgbMat, grayMat, Imgproc.COLOR_RGB2GRAY);//rgbMat to gray grayMat
        Utils.matToBitmap(grayMat, grayBitmap); //convert mat to bitmap
        Log.i(TAG, "procSrc2Gray sucess...");
    }
    private class ProcessClickListener implements View.OnClickListener {
        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            if(isFirst)
            {
                procSrc2Gray();
                isFirst = false;
            }
            if(flag){
                img.setImageBitmap(grayBitmap);
                btnProcess.setText("gray image");
                flag = false;
            }
            else{
                img.setImageBitmap(srcBitmap);
                btnProcess.setText("rgb image");
                flag = true;
            }
        }
    }
    @Override
    protected void onResume() {
        // TODO Auto-generated method stub
        super.onResume();
        //load OpenCV engine and init OpenCV library
        OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION, getApplicationContext(), mLoaderCallback);
        Log.i(TAG, "onResume sucess load OpenCV...");
    }
}

(8)app/build.gradledependencies中增加，

implementation project(path: ':openCVLibrary341')

(9)环境变量，path中增加adb所在路径，C:\Users\xxx\AppData\Local\Android\Sdk\platfORM-tools

(10)命令行进入apk所在的路径D:\Android\OpenCV-android-sdk\apk，执行，

adb install OpenCV_3.4.1_Manager_3.41_x86.apk

在模拟器中安装opencv-manager，然后重启模拟器

工程目录结构：

运行：

The Code:

https://download.csdn.net/download/qq_14845119/12272674