Android studio 4.0+opencv-4.0.1 图片灰度化处理案例
activity_main.xml 文件
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity"
android:orientation="vertical">
<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentLeft="true"
android:layout_alignParentBottom="true"
android:layout_marginStart="80dp"
android:layout_marginLeft="54dp"
android:layout_marginBottom="80dp"
android:text="灰度" />
<ImageButton
android:id="@+id/imageButton"
android:layout_width="500dp"
android:layout_height="400dp"
android:layout_alignParentEnd="true"
android:layout_alignParentRight="true"
android:layout_alignParentBottom="true"
android:layout_marginEnd="6dp"
android:layout_marginRight="6dp"
android:layout_marginBottom="209dp"
android:scaleType="centerCrop"
app:srcCompat="@drawable/f001" />
<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentEnd="true"
android:layout_alignParentRight="true"
android:layout_alignParentBottom="true"
android:layout_marginEnd="80dp"
android:layout_marginRight="80dp"
android:layout_marginBottom="80dp"
android:text="返回" />
</RelativeLayout>
MainActivity.java 文件
package com.example.opencv;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import org.opencv.android.OpenCVLoader;
import org.opencv.android.Utils;
import org.opencv.core.Mat;
import org.opencv.core.Point;
import org.opencv.core.Scalar;
import org.opencv.imgproc.Imgproc;
import java.io.IOException;
public class MainActivity extends AppCompatActivity {
private Button btn1,btn2;
private ImageView img1;
private Mat srcmat1,srcmat2;
private Bitmap bitmap;
@Override
protected void onDestroy() {
super.onDestroy();
srcmat1.release();
srcmat2.release();
}
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//OpenCV 初始化
inLoadOpenCV();
//按钮 初始化
btn1 = findViewById(R.id.button);
btn2 =findViewById(R.id.button2);
img1 = findViewById(R.id.imageButton);
srcmat1 = new Mat();
srcmat2 = new Mat();
try {
srcmat1 = Utils.loadResource(this, R.drawable.f001);//图片名称
} catch (IOException e) {
e.printStackTrace();
}
// 转成灰度图
btn1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// Toast toast = Toast.makeText(MainActivity.this, "Button被点击了", Toast.LENGTH_SHORT);
// toast.show();
//彩色转灰色
Imgproc.cvtColor(srcmat1,srcmat2,Imgproc.COLOR_BGRA2GRAY);
//Imgproc.putText(srcmat1,"I'm a cat" ,new Point( srcmat1.width()/2.,srcmat1.height()/3),2,2,new Scalar(0,255,0),3);
bitmap = Bitmap.createBitmap(srcmat2.width(), srcmat2.height(), Bitmap.Config.ARGB_8888);
Utils.matToBitmap(srcmat2, bitmap);
img1.setImageBitmap(bitmap);
}
});
// 返回原图
btn2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
bitmap= BitmapFactory.decodeResource(getResources(),R.drawable.f001);//图片名称
img1.setImageBitmap(bitmap);
}
});
}
//OpenCV库的加载
private void inLoadOpenCV(){
boolean success= OpenCVLoader.initDebug();
if (success){
Toast.makeText(this.getApplicationContext(),"成功",Toast.LENGTH_LONG).show();
}else{
Toast.makeText(this.getApplicationContext(),"失败",Toast.LENGTH_LONG).show();
}
}
}
效果展示: