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在Android上使用ZXing识别条形码/二维码

2011-06-12 07:57 671 查看
       越来越多的手机具备自动对焦的拍摄功能,这也意味着这些手机可以具备条码扫描的功能.......手机具备条码扫描的功能,可以优化购物流程,快速存储电子名片(二维码)等。

      本文使用ZXing 1.6实现条码/二维码识别。ZXing是个很经典的条码/二维码识别的开源类库,long long ago,就有开发者在J2ME上使用ZXing了,不过要支持JSR-234规范(自动对焦)的手机才能发挥其威力,而目前已经有不少Android手机具备自动对焦的功能。

本文代码运行的结果如下,使用91手机助手截图时,无法截取SurfaceView的实时图像:

 

 

 

本文使用了ZXing1.6的core,即把/zxing-1.6/core/下的src复制覆盖工程的src;另外还要使用到/zxing-1.6/android/下的PlanarYUVLuminanceSource.java。

PS:/zxing-1.6/android/ 是BarcodeScanner的源码,本文程序相当于BarcodeScanner的精简版,只保留最基本的识别功能。

本文源码工程的下载地址如下:http://www.pudn.com/downloads349/sourcecode/comm/android/detail1521939.html

源码目录结果如下图,ChecksumException.java下面还有很多源文件,截图尚未列出:

 

本文例子必须要开摄像头和自动对焦的权限,不然启动时会报异常,所用的权限如下:

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<uses-permission android:name="android.permission.CAMERA"></uses-permission> 
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission> 
<uses-feature android:name="android.hardware.camera" /> 
<uses-feature android:name="android.hardware.camera.autofocus" /> 
<uses-permission android:name="android.permission.CAMERA"></uses-permission>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>
<uses-feature android:name="android.hardware.camera" />
<uses-feature android:name="android.hardware.camera.autofocus" />

main.xml源码如下,main.xml必须要用到FrameLayout才能重叠控件实现“范围框”的效果:

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<?xml version="1.0" encoding="utf-8"?> 
<FrameLayout android:id="@+id/FrameLayout01" 
    android:layout_width="fill_parent" android:layout_height="fill_parent" 
    xmlns:android="http://schemas.android.com/apk/res/android"> 
    <SurfaceView android:layout_height="fill_parent" 
        android:id="@+id/sfvCamera" android:layout_width="fill_parent"></SurfaceView> 
    <RelativeLayout android:id="@+id/RelativeLayout01" 
        android:layout_height="fill_parent" android:layout_width="fill_parent"> 
        <ImageView android:id="@+id/ImageView01" 
            android:layout_height="100dip" android:layout_width="160dip"></ImageView> 
        <View android:layout_centerVertical="true" 
            android:layout_centerHorizontal="true" android:layout_width="300dip" 
            android:background="#55FF6666" android:id="@+id/centerView" 
            android:layout_height="180dip"></View> 
        <TextView android:layout_centerHorizontal="true" 
            android:layout_width="wrap_content" android:layout_below="@+id/centerView" 
            android:layout_height="wrap_content" android:text="Scanning..." 
            android:id="@+id/txtScanResult" android:textColor="#FF000000"></TextView> 
    </RelativeLayout> 
</FrameLayout> 
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout android:id="@+id/FrameLayout01"
 android:layout_width="fill_parent" android:layout_height="fill_parent"
 xmlns:android="http://schemas.android.com/apk/res/android">
 <SurfaceView android:layout_height="fill_parent"
  android:id="@+id/sfvCamera" android:layout_width="fill_parent"></SurfaceView>
 <RelativeLayout android:id="@+id/RelativeLayout01"
  android:layout_height="fill_parent" android:layout_width="fill_parent">
  <ImageView android:id="@+id/ImageView01"
   android:layout_height="100dip" android:layout_width="160dip"></ImageView>
  <View android:layout_centerVertical="true"
   android:layout_centerHorizontal="true" android:layout_width="300dip"
   android:background="#55FF6666" android:id="@+id/centerView"
   android:layout_height="180dip"></View>
  <TextView android:layout_centerHorizontal="true"
   android:layout_width="wrap_content" android:layout_below="@+id/centerView"
   android:layout_height="wrap_content" android:text="Scanning..."
   android:id="@+id/txtScanResult" android:textColor="#FF000000"></TextView>
 </RelativeLayout>
</FrameLayout>

testCamera.java是主类,负责控制Camera和对图像做解码,源码如下:

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package com.testCamera;  
import java.util.Timer;  
import java.util.TimerTask;  
import com.google.zxing.BinaryBitmap;  
import com.google.zxing.MultiFormatReader;  
import com.google.zxing.Result;  
import com.google.zxing.Android.PlanarYUVLuminanceSource;  
import com.google.zxing.common.HybridBinarizer;  
import android.app.Activity;  
import android.graphics.Bitmap;  
import android.hardware.Camera;  
import android.os.Bundle;  
import android.view.SurfaceView;  
import android.view.View;  
import android.widget.ImageView;  
import android.widget.TextView;  
public class testCamera extends Activity {  
    /** Called when the activity is first created. */ 
    private SurfaceView sfvCamera;  
    private SFHCamera sfhCamera;  
    private ImageView imgView;  
    private View centerView;  
    private TextView txtScanResult;  
    private Timer mTimer;  
    private MyTimerTask mTimerTask;  
    // 按照标准HVGA  
    final static int width = 480;  
    final static int height = 320;  
    int dstLeft, dstTop, dstWidth, dstHeight;  
    @Override 
    public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.main);  
        this.setTitle("Android条码/二维码识别Demo-----hellogv");  
        imgView = (ImageView) this.findViewById(R.id.ImageView01);  
        centerView = (View) this.findViewById(R.id.centerView);  
        sfvCamera = (SurfaceView) this.findViewById(R.id.sfvCamera);  
        sfhCamera = new SFHCamera(sfvCamera.getHolder(), width, height,  
                previewCallback);  
        txtScanResult=(TextView)this.findViewById(R.id.txtScanResult);  
        // 初始化定时器  
        mTimer = new Timer();  
        mTimerTask = new MyTimerTask();  
        mTimer.schedule(mTimerTask, 0, 80);  
    }  
      
    class MyTimerTask extends TimerTask {  
        @Override 
        public void run() {  
            if (dstLeft == 0) {//只赋值一次  
                dstLeft = centerView.getLeft() * width  
                        / getWindowManager().getDefaultDisplay().getWidth();  
                dstTop = centerView.getTop() * height  
                        / getWindowManager().getDefaultDisplay().getHeight();  
                dstWidth = (centerView.getRight() - centerView.getLeft())* width  
                        / getWindowManager().getDefaultDisplay().getWidth();  
                dstHeight = (centerView.getBottom() - centerView.getTop())* height  
                        / getWindowManager().getDefaultDisplay().getHeight();  
            }  
            sfhCamera.AutoFocusAndPreviewCallback();  
        }  
    }  
    /** 
     *  自动对焦后输出图片 
     */ 
    private Camera.PreviewCallback previewCallback = new Camera.PreviewCallback() {  
        @Override 
        public void onPreviewFrame(byte[] data, Camera arg1) {  
            //取得指定范围的帧的数据  
            PlanarYUVLuminanceSource source = new PlanarYUVLuminanceSource(  
                    data, width, height, dstLeft, dstTop, dstWidth, dstHeight);  
            //取得灰度图  
            Bitmap mBitmap = source.renderCroppedGreyscaleBitmap();  
            //显示灰度图  
            imgView.setImageBitmap(mBitmap);  
            BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));  
            MultiFormatReader reader = new MultiFormatReader();  
            try {  
                Result result = reader.decode(bitmap);  
                String strResult = "BarcodeFormat:" 
                        + result.getBarcodeFormat().toString() + "  text:" 
                        + result.getText();  
                txtScanResult.setText(strResult);  
            } catch (Exception e) {  
                txtScanResult.setText("Scanning");  
            }  
        }  
    };  

package com.testCamera;
import java.util.Timer;
import java.util.TimerTask;
import com.google.zxing.BinaryBitmap;
import com.google.zxing.MultiFormatReader;
import com.google.zxing.Result;
import com.google.zxing.Android.PlanarYUVLuminanceSource;
import com.google.zxing.common.HybridBinarizer;
import android.app.Activity;
import android.graphics.Bitmap;
import android.hardware.Camera;
import android.os.Bundle;
import android.view.SurfaceView;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;
public class testCamera extends Activity {
 /** Called when the activity is first created. */
 private SurfaceView sfvCamera;
 private SFHCamera sfhCamera;
 private ImageView imgView;
 private View centerView;
 private TextView txtScanResult;
 private Timer mTimer;
 private MyTimerTask mTimerTask;
 // 按照标准HVGA
 final static int width = 480;
 final static int height = 320;
 int dstLeft, dstTop, dstWidth, dstHeight;
 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
  this.setTitle("Android条码/二维码识别Demo-----hellogv");
  imgView = (ImageView) this.findViewById(R.id.ImageView01);
  centerView = (View) this.findViewById(R.id.centerView);
  sfvCamera = (SurfaceView) this.findViewById(R.id.sfvCamera);
  sfhCamera = new SFHCamera(sfvCamera.getHolder(), width, height,
    previewCallback);
  txtScanResult=(TextView)this.findViewById(R.id.txtScanResult);
  // 初始化定时器
  mTimer = new Timer();
  mTimerTask = new MyTimerTask();
  mTimer.schedule(mTimerTask, 0, 80);
 }
 
 class MyTimerTask extends TimerTask {
  @Override
  public void run() {
   if (dstLeft == 0) {//只赋值一次
    dstLeft = centerView.getLeft() * width
      / getWindowManager().getDefaultDisplay().getWidth();
    dstTop = centerView.getTop() * height
      / getWindowManager().getDefaultDisplay().getHeight();
    dstWidth = (centerView.getRight() - centerView.getLeft())* width
      / getWindowManager().getDefaultDisplay().getWidth();
    dstHeight = (centerView.getBottom() - centerView.getTop())* height
      / getWindowManager().getDefaultDisplay().getHeight();
   }
   sfhCamera.AutoFocusAndPreviewCallback();
  }
 }
 /**
  *  自动对焦后输出图片
  */
 private Camera.PreviewCallback previewCallback = new Camera.PreviewCallback() {
  @Override
  public void onPreviewFrame(byte[] data, Camera arg1) {
   //取得指定范围的帧的数据
   PlanarYUVLuminanceSource source = new PlanarYUVLuminanceSource(
     data, width, height, dstLeft, dstTop, dstWidth, dstHeight);
   //取得灰度图
   Bitmap mBitmap = source.renderCroppedGreyscaleBitmap();
   //显示灰度图
   imgView.setImageBitmap(mBitmap);
   BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
   MultiFormatReader reader = new MultiFormatReader();
   try {
    Result result = reader.decode(bitmap);
    String strResult = "BarcodeFormat:"
      + result.getBarcodeFormat().toString() + "  text:"
      + result.getText();
    txtScanResult.setText(strResult);
   } catch (Exception e) {
    txtScanResult.setText("Scanning");
   }
  }
 };
}

SFHCamera.java是Camera控制类,源码如下:

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package com.testCamera;  
import java.io.IOException;  
import android.graphics.PixelFormat;  
import android.hardware.Camera;  
import android.util.Log;  
import android.view.SurfaceHolder;  
public class SFHCamera implements SurfaceHolder.Callback{  
    private SurfaceHolder holder = null;  
    private Camera mCamera;  
    private int width,height;  
    private Camera.PreviewCallback previewCallback;  
      
    public SFHCamera(SurfaceHolder holder,int w,int h,Camera.PreviewCallback previewCallback) {  
        this.holder = holder;    
        this.holder.addCallback(this);    
        this.holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);  
        width=w;  
        height=h;  
        this.previewCallback=previewCallback;  
    }  
      
    @Override 
    public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {  
        Camera.Parameters parameters = mCamera.getParameters();    
        parameters.setPreviewSize(width, height);//设置尺寸    
        parameters.setPictureFormat(PixelFormat.JPEG);  
        mCamera.setParameters(parameters);    
        mCamera.startPreview();//开始预览  
        Log.e("Camera","surfaceChanged");  
    }  
    @Override 
    public void surfaceCreated(SurfaceHolder arg0) {  
        mCamera = Camera.open();//启动服务    
        try {    
            mCamera.setPreviewDisplay(holder);//设置预览   
            Log.e("Camera","surfaceCreated");  
        } catch (IOException e) {    
            mCamera.release();//释放    
            mCamera = null;    
        }  
          
    }  
    @Override 
    public void surfaceDestroyed(SurfaceHolder arg0) {  
        mCamera.setPreviewCallback(null);  
        mCamera.stopPreview();//停止预览    
        mCamera = null;  
        Log.e("Camera","surfaceDestroyed");  
    }  
    /** 
     * 自动对焦并回调Camera.PreviewCallback 
     */ 
    public void AutoFocusAndPreviewCallback()  
    {  
        if(mCamera!=null)  
            mCamera.autoFocus(mAutoFocusCallBack);  
    }  
      
    /** 
     * 自动对焦 
     */ 
    private Camera.AutoFocusCallback mAutoFocusCallBack = new Camera.AutoFocusCallback() {    
            
        @Override    
        public void onAutoFocus(boolean success, Camera camera) {        
            if (success) {  //对焦成功,回调Camera.PreviewCallback  
                mCamera.setOneShotPreviewCallback(previewCallback);   
            }    
        }    
    };  
      
 

package com.testCamera;
import java.io.IOException;
import android.graphics.PixelFormat;
import android.hardware.Camera;
import android.util.Log;
import android.view.SurfaceHolder;
public class SFHCamera implements SurfaceHolder.Callback{
 private SurfaceHolder holder = null;
 private Camera mCamera;
    private int width,height;
    private Camera.PreviewCallback previewCallback;
   
 public SFHCamera(SurfaceHolder holder,int w,int h,Camera.PreviewCallback previewCallback) {
  this.holder = holder; 
  this.holder.addCallback(this); 
  this.holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
        width=w;
        height=h;
        this.previewCallback=previewCallback;
 }
 
 @Override
 public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {
  Camera.Parameters parameters = mCamera.getParameters(); 
        parameters.setPreviewSize(width, height);//设置尺寸 
        parameters.setPictureFormat(PixelFormat.JPEG);
        mCamera.setParameters(parameters); 
        mCamera.startPreview();//开始预览
        Log.e("Camera","surfaceChanged");
 }
 @Override
 public void surfaceCreated(SurfaceHolder arg0) {
  mCamera = Camera.open();//启动服务 
        try { 
            mCamera.setPreviewDisplay(holder);//设置预览
            Log.e("Camera","surfaceCreated");
        } catch (IOException e) { 
            mCamera.release();//释放 
            mCamera = null; 
        }
  
 }
 @Override
 public void surfaceDestroyed(SurfaceHolder arg0) {
  mCamera.setPreviewCallback(null);
  mCamera.stopPreview();//停止预览 
        mCamera = null;
        Log.e("Camera","surfaceDestroyed");
 }
 /**
  * 自动对焦并回调Camera.PreviewCallback
  */
 public void AutoFocusAndPreviewCallback()
 {
  if(mCamera!=null)
   mCamera.autoFocus(mAutoFocusCallBack);
 }
 
 /**
     * 自动对焦
     */
    private Camera.AutoFocusCallback mAutoFocusCallBack = new Camera.AutoFocusCallback() { 
      
        @Override 
        public void onAutoFocus(boolean success, Camera camera) {     
            if (success) {  //对焦成功,回调Camera.PreviewCallback
             mCamera.setOneShotPreviewCallback(previewCallback);
            } 
        } 
    };
   

}
 

其中testCamera.java的Camera.PreviewCallback previewCallback 是整个程序的逻辑核心,作为回调函数给SFHCamera.java的内部Camera类调用。

 

本文来自CSDN博客,转载出处:http://blog.csdn.net/hellogv/archive/2010/12/27/6101663.aspx
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