在Android平台上利用opencv进行图像处理之边缘检测、灰度变换、缩小

转载请注明本文出自这么远_那么近的博客（http://blog.csdn.net/u010585964），谢谢支持！

在网上找资料学习利用opencv开发Android还算挺顺利的，以下是今天在Android平台上利用opencv对图片进行边缘检测、灰度变换、缩小的实现。

运行结果如下：

   

代码如下：

MainActivity:

package com.cdq.opencvtest;import java.io.File;import org.opencv.android.BaseLoaderCallback;import org.opencv.android.LoaderCallbackInterface;import org.opencv.android.OpenCVLoader;import org.opencv.android.Utils;import org.opencv.core.CvType;import org.opencv.core.Mat;import org.opencv.core.Size;import org.opencv.highgui.Highgui;import org.opencv.imgproc.Imgproc;import android.os.Bundle;import android.os.Environment;import android.app.Activity;import android.graphics.Bitmap;import android.graphics.Bitmap.Config;import android.graphics.BitmapFactory;import android.util.Log;import android.view.Menu;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.ImageView;import android.widget.Toast;public class MainActivity extends Activity{String sdcard = Environment.getExternalStorageDirectory().getPath();private ImageView iv = null;private Button btn1 = null;private Button btn2 = null;private Button btn3 = null;private Button btn4 = null;private Bitmap btmp=null;String tag = "MainActivity";// OpenCV类库加载并初始化成功后的回调函数private BaseLoaderCallback mLoader = new BaseLoaderCallback(this){@Overridepublic void onManagerConnected(int status){switch (status){case LoaderCallbackInterface.SUCCESS:{}break;default:{super.onManagerConnected(status);}break;}}};@Overrideprotected void onResume(){super.onResume();// 通过OpenCV引擎服务加载并初始化OpenCV类库，所谓OpenCV引擎服务即是 OpenCV ManagerOpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_9, this, mLoader);}@Overrideprotected void onCreate(Bundle savedInstanceState){super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);iv = (ImageView) findViewById(R.id.iv);btn1 = (Button) findViewById(R.id.btn1);btn2 = (Button) findViewById(R.id.btn2);btn3 = (Button) findViewById(R.id.btn3);btn4 = (Button) findViewById(R.id.btn4);btmp = BitmapFactory.decodeFile("/sdcard/face8.jpg");iv.setImageBitmap(btmp);btn1.setOnClickListener(new OnClickListener(){@Overridepublic void onClick(View arg0){bianyuanjiance();}});btn2.setOnClickListener(new OnClickListener(){@Overridepublic void onClick(View arg0){huidubianhuan();}});btn3.setOnClickListener(new OnClickListener(){@Overridepublic void onClick(View arg0){suoxiao();}});btn4.setOnClickListener(new OnClickListener(){@Overridepublic void onClick(View arg0){iv.setImageBitmap(btmp);}});}protected void suoxiao(){double scale=0.5;Mat img1 = Highgui.imread("/sdcard/face8.jpg");Size size=new Size(img1.width()*scale,img1.height()*scale);Mat img2=new Mat(size,CvType.CV_16S);Imgproc.resize(img1,img2,size);Boolean flag=Highgui.imwrite("/sdcard/suoxiao.jpg", img2);if (flag){Bitmap bitmap=BitmapFactory.decodeFile("/sdcard/suoxiao.jpg");iv.setImageBitmap(bitmap);}else {Toast.makeText(getApplicationContext(), "图片写入失败", Toast.LENGTH_SHORT).show();}}protected void huidubianhuan(){Bitmap btmp2=Bitmap.createBitmap(btmp.getWidth(), btmp.getHeight(), Config.RGB_565);Mat rgbImg = Highgui.imread("/sdcard/face8.jpg");Size size=new Size((double)rgbImg.width(),(double)rgbImg.height());Mat grayImg=new Mat(size,CvType.CV_8UC1);Imgproc.cvtColor(rgbImg, grayImg, Imgproc.COLOR_RGB2GRAY);Utils.matToBitmap(grayImg, btmp2);iv.setImageBitmap(btmp2);}private void bianyuanjiance(){Mat img = Highgui.imread("/sdcard/face8.jpg");Size dSize = new Size((double) img.width(), (double) img.height());Mat img2 = new Mat(dSize, CvType.CV_8SC1);Mat img3 = new Mat();img.convertTo(img2, CvType.CV_8SC1);Imgproc.Canny(img, img3, 123, 250);boolean flag = Highgui.imwrite( "/sdcard/huidubianhuan.jpg", img3);Log.i(tag, "onClick");if (flag){Log.i(tag, "flag");File file = new File("/sdcard/huidubianhuan.jpg");if (file.exists()){Bitmap bitmap2 = BitmapFactory.decodeFile(sdcard + "/huidubianhuan.jpg");iv.setImageBitmap(bitmap2);}}else{Toast.makeText(getApplicationContext(), "图片写入失败", Toast.LENGTH_SHORT).show();}}@Overridepublic boolean onCreateOptionsMenu(Menu menu){// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.main, menu);return true;}}

activity_main.xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    android:orientation="vertical"    tools:context=".MainActivity" >    <TableLayout        android:layout_width="match_parent"        android:layout_height="wrap_content"         android:layout_weight="1"        >        <TableRow            android:id="@+id/tableRow3"            android:layout_width="match_parent"            android:layout_height="0dp"            android:layout_weight="9"            android:gravity="center" >            <ImageView                android:id="@+id/iv"                android:layout_width="wrap_content"                android:layout_height="wrap_content"                />        </TableRow>        <TableRow            android:id="@+id/tableRow1"            android:layout_width="wrap_content"            android:layout_height="wrap_content" >            <Button                android:id="@+id/btn1"                android:layout_width="0dp"                android:layout_height="wrap_content"                android:text="边缘检测"                android:layout_weight="1"/><Button                android:id="@+id/btn2"                android:layout_width="0dp"                android:layout_height="wrap_content"                android:text="灰度变换"                android:layout_weight="1"/><Button                android:id="@+id/btn3"                android:layout_width="0dp"                android:layout_height="wrap_content"                android:text="缩小一半"                android:layout_weight="1"/>        </TableRow>        <TableRow            android:id="@+id/tableRow2"            android:layout_width="wrap_content"            android:layout_height="wrap_content" >        </TableRow>        <Button            android:id="@+id/btn4"            android:layout_width="match_parent"            android:layout_height="wrap_content"            android:text="恢复" />    </TableLayout></LinearLayout>

Manifest.xml:

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.cdq.opencvtest"    android:versionCode="1"    android:versionName="1.0" >    <uses-sdk        android:minSdkVersion="14"        android:targetSdkVersion="14" /><uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/><uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>    <application        android:allowBackup="true"        android:icon="@drawable/ic_launcher"        android:label="@string/app_name"        android:theme="@style/AppTheme" >        <activity            android:name="com.cdq.opencvtest.MainActivity"            android:label="@string/app_name" >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>    </application></manifest>