软件版本：

Android Studio Electric Eel 2022.1.1 Patch 2

https://sourceforge.net/projects/opencvlibrary/files/4.5.0/opencv-4.5.0-android-sdk.zip/download

创建工程

with API23:

导入opencv sdk:
File->New->Import Module

添加工程依赖：File->Project Structure， sdk为opencv sdk.

build.gradle(Myopency45)

plugins {
id ‘com.android.application’ version ‘7.4.2’ apply false
id ‘com.android.library’ version ‘7.4.2’ apply false
}

build.gradle(app)

plugins {
id ‘com.android.application’
}

android {
namespace ‘com.michael.myopency45’
compileSdk 33

defaultConfig {
    applicationId "com.michael.myopency45"
    minSdk 23
    targetSdk 33
    versionCode 1
    versionName "1.0"

    testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
}

buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
    }
}
compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_8
    targetCompatibility JavaVersion.VERSION_1_8
}

}

dependencies {

implementation 'androidx.appcompat:appcompat:1.4.1'
implementation 'com.google.android.material:material:1.5.0'
implementation 'androidx.constraintlayout:constraintlayout:2.1.3'
implementation project(path: ':sdk')
testImplementation 'junit:junit:4.13.2'
androidTestImplementation 'androidx.test.ext:junit:1.1.3'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'

}

build.gradle(SDK)

apply plugin: ‘com.android.library’

def openCVersionName = “4.5.0”
def openCVersionCode = ((4 * 100 + 5) * 100 + 0) * 10 + 0

println "OpenCV: " +openCVersionName + " " + project.buildscript.sourceFile

android {
compileSdkVersion 26

defaultConfig {
    minSdkVersion 21
    targetSdkVersion 26

    versionCode openCVersionCode
    versionName openCVersionName

    externalNativeBuild {
        cmake {
            arguments "-DANDROID_STL=c++_shared"
            targets "opencv_jni_shared"
        }
    }
}

buildTypes {
    debug {
        packagingOptions {
            doNotStrip '**/*.so'  // controlled by OpenCV CMake scripts
        }
    }
    release {
        packagingOptions {
            doNotStrip '**/*.so'  // controlled by OpenCV CMake scripts
        }
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
    }
}
compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_6
    targetCompatibility JavaVersion.VERSION_1_6
}

sourceSets {
    main {
        jniLibs.srcDirs = ['native/libs']
        java.srcDirs = ['java/src']
        aidl.srcDirs = ['java/src']
        res.srcDirs = ['java/res']
        manifest.srcFile 'java/AndroidManifest.xml'
    }
}

externalNativeBuild {
    cmake {
        path (project.projectDir.toString() + '/libcxx_helper/CMakeLists.txt')
    }
}

}

dependencies {
}

activity_main.xml

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

<Button
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:id="@+id/bt1"
 android:text="转换灰度"/>

<Button
    android:id="@+id/bt2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginLeft="10dp"
    android:layout_toRightOf="@id/bt1"
    android:text="图片相加" />

<Button
    android:id="@+id/bt3"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginLeft="10dp"
    android:layout_toRightOf="@id/bt2"
    android:text="灰度阈值" />

<ImageView
    android:layout_centerInParent="true"
    android:layout_width="250dp"
    android:layout_height="180dp"
    android:id="@+id/pic1"
    android:src="@drawable/pic1"
    android:layout_below="@id/bt1"/>
<ImageView
    android:layout_centerInParent="true"
    android:layout_width="250dp"
    android:layout_height="180dp"
    android:id="@+id/pic2"
    android:src="@drawable/pic2"
    android:layout_below="@id/pic1"/>
<ImageView
    android:layout_centerInParent="true"
    android:layout_width="250dp"
    android:layout_height="180dp"
    android:id="@+id/pic3"
    android:layout_below="@id/pic2"/>

MainActivity.java

package com.michael.myopency45;

import androidx.appcompat.app.AppCompatActivity;

import android.graphics.Bitmap;
import android.os.Bundle;
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.Core;
import org.opencv.core.Mat;
import org.opencv.imgproc.Imgproc;

import java.io.IOException;

public class MainActivity extends AppCompatActivity {

ImageView iv1,iv2,iv3;
Mat srcmat1, srcmat2, dstmat3;
Button bt1,bt2,bt3;
Bitmap bitmap;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    OpenCVLoader.initDebug();
    iv1 = findViewById(R.id.pic1);
    iv2 = findViewById(R.id.pic2);
    iv3 = findViewById(R.id.pic3);
    bt1 = findViewById(R.id.bt1);
    bt2 = findViewById(R.id.bt2);
    bt3 = findViewById(R.id.bt3);
    srcmat1 = new Mat();
    srcmat2 = new Mat();
    dstmat3 = new Mat();

    try {
        srcmat1 = Utils.loadResource(this,R.drawable.pic1);
        srcmat2 = Utils.loadResource(this,R.drawable.pic2);
    } catch (IOException e) {
        throw new RuntimeException(e);
    }

    bt1.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Imgproc.cvtColor(srcmat1,dstmat3,Imgproc.COLOR_BGRA2GRAY);
            bitmap = Bitmap.createBitmap(dstmat3.width(),dstmat3.height(),Bitmap.Config.ARGB_8888);
            Utils.matToBitmap(dstmat3,bitmap);
            iv3.setImageBitmap(bitmap);
        }
    });

    bt2.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Core.bitwise_and(srcmat1,srcmat2,dstmat3);
            bitmap = Bitmap.createBitmap(dstmat3.width(),dstmat3.height(),Bitmap.Config.ARGB_8888);
            Utils.matToBitmap(dstmat3,bitmap);
            iv3.setImageBitmap(bitmap);
        }
    });

    bt3.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Imgproc.cvtColor(srcmat1,dstmat3,Imgproc.COLOR_BGRA2GRAY);
            Imgproc.adaptiveThreshold(dstmat3,dstmat3,255,Imgproc.ADAPTIVE_THRESH_MEAN_C,Imgproc.THRESH_BINARY,13,5);
            bitmap = Bitmap.createBitmap(dstmat3.width(),dstmat3.height(),Bitmap.Config.ARGB_8888);
            Utils.matToBitmap(dstmat3,bitmap);
            iv3.setImageBitmap(bitmap);
        }
    });
}

@Override
protected void onDestroy() {
    super.onDestroy();
    srcmat1.release();
    srcmat2.release();
    dstmat3.release();
}

}

结果：