Android自動聚焦、網路攝影機拍照、縮放至標準大小的完整實現

     為什麼把自動聚焦放在前面呢？因為前文http://blog.csdn.net/yanzi1225627/article/details/7738736已經實現了拍照功能，且網上拍照的源碼例子很多，自動聚焦很多人寫的很簡單，但結果發現不中。我這裡就總結下，我的自動聚焦的實現。

手機華為U9200，

android4.0.3,

預覽的參數：myParameters.setPreviewSize(1280, 720）

圖片參數：myParameters.setPictureSize(2048, 1152); //1280, 720

圖片最終尺寸:寬600 * 高800

（關於setPreviewSize和setPictureSize的問題可以參照我以前的文章http://blog.csdn.net/yanzi1225627/article/details/7738736）

 

         參照http://www.cnblogs.com/liuan/archive/2012/01/10/2318300.html，上面的思路是弄了一個定時器來進行自動聚焦，但發現根本不中，一按拍照程式就掛掉。而且由於定時器一直在重複迴圈，相機就在那聚焦來聚焦去，也就是一下清晰一下又模糊了。後來我把程式改成，當拍照後把定時器關閉掉發現還是不中。經反覆實驗，終於成功。南無阿彌陀佛，本著我為人人，人人為我。將源碼貼在此處：

第一，布局檔案。裡面有一個surfaceview和三個按鈕，分別是預覽、拍照、儲存。

 

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:orientation="vertical" ><SurfaceView    android:id="@+id/mySurfaceView"      android:layout_width="fill_parent"    android:background="#D1EEEE"    android:layout_height="800px"    android:gravity="center" /><LinearLayout    android:id="@+id/LinearLayout01"    android:layout_width="wrap_content"    android:layout_height="wrap_content"    android:layout_gravity="center_horizontal"    android:paddingTop="20dip"        android:orientation="horizontal" >    <Button        android:id="@+id/btnPreview"        android:layout_width="wrap_content"        android:layout_height="wrap_content"                android:text="預覽" />    <Button        android:id="@+id/btnPhoto"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="拍照" />    <Button        android:id="@+id/btnSave"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="儲存" /></LinearLayout></LinearLayout>

第2，來源程式：

package yan.guoqi.testphoto;import java.io.BufferedOutputStream;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.util.Timer;import java.util.TimerTask;import android.app.Activity;import android.app.AlertDialog;import android.app.AlertDialog.Builder;import android.content.DialogInterface;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.PixelFormat;import android.hardware.Camera;import android.hardware.Camera.PictureCallback;import android.hardware.Camera.ShutterCallback;import android.os.Bundle;import android.util.Log;import android.view.SurfaceHolder;import android.view.SurfaceView;import android.view.View;import android.view.View.OnClickListener;import android.view.Window;import android.view.WindowManager;import android.widget.Button;import android.widget.Toast;public class TestPhotoActivity extends Activity implements SurfaceHolder.Callback{    /** Called when the activity is first created. */private static final  String TAG = "yan:";SurfaceView mySurfaceView = null;SurfaceHolder mySurfaceHolder = null;Button btnPreview = null;Button btnPhoto = null;Button btnSave = null;Camera myCamera = null;Camera.Parameters myParameters;boolean isView = false;Bitmap bm;String savePath = "/mnt/sdcard/testPhoto/";int cntSave = 0;private Camera.AutoFocusCallback mAutoFocusCallback;//private Camera.PreviewCallback mPreviewCallback;private Timer mTimer;private TimerTask mTimerTask;    @Override    public void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    //璁劇疆鍏ㄥ睆鏃犳爣棰?    requestWindowFeature(Window.FEATURE_NO_TITLE);    int flag = WindowManager.LayoutParams.FLAG_FULLSCREEN;    Window myWindow = this.getWindow();    myWindow.setFlags(flag, flag);    setContentView(R.layout.main); //璁劇疆甯冨矓    mySurfaceView = (SurfaceView)findViewById(R.id.mySurfaceView);    mySurfaceView.setZOrderOnTop(true);    mySurfaceHolder = mySurfaceView.getHolder();    mySurfaceHolder.setFormat(PixelFormat.TRANSLUCENT);    btnPreview = (Button)findViewById(R.id.btnPreview);    btnPhoto = (Button)findViewById(R.id.btnPhoto);    btnSave = (Button)findViewById(R.id.btnSave);    if(!isFolderExist(savePath)) //濡傛灉鍒涘緩鏂囦歡澶瑰け璐?    {    AlertDialog.Builder alertDialog = new Builder(TestPhotoActivity.this);    alertDialog.setTitle("閿欒");    alertDialog.setMessage("鍥劇墖淇濆瓨鏂囦歡澶瑰壋寤哄け璐ワ紒");    alertDialog.setPositiveButton("紜畾", new DialogInterface.OnClickListener() {public void onClick(DialogInterface dialog, int which) {// TODO Auto-generated method stubdialog.dismiss();TestPhotoActivity.this.finish();}});    alertDialog.show();    }    else    Toast.makeText(TestPhotoActivity.this,    "鎮ㄧ殑鐓х墖灝嗕繚瀛樺湪錛? + savePath,    Toast.LENGTH_SHORT).show();    mySurfaceHolder.addCallback(this);    mySurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);    mAutoFocusCallback = new Camera.AutoFocusCallback() {public void onAutoFocus(boolean success, Camera camera) {// TODO Auto-generated method stubif(success){myCamera.setOneShotPreviewCallback(null);    Toast.makeText(TestPhotoActivity.this,    "鑷姩鑱氱劍鎴愬姛錛?,    Toast.LENGTH_SHORT).show();}}}; mTimer = new Timer();mTimerTask = new CameraTimerTask();//mTimer.schedule(mTimerTask, 0, 500);    btnPreview.setOnClickListener(new BtnListener());    btnPhoto.setOnClickListener(new BtnListener());    btnSave.setOnClickListener(new BtnListener());        }    ShutterCallback myShutterCallback = new ShutterCallback() {public void onShutter() {// TODO Auto-generated method stub}};PictureCallback myRawCallback = new PictureCallback() {public void onPictureTaken(byte[] data, Camera camera) {// TODO Auto-generated method stub}};PictureCallback myjpegCalback = new PictureCallback() {public void onPictureTaken(byte[] data, Camera camera) {// TODO Auto-generated method stubLog.i(TAG, "onPictureTaken........");bm = BitmapFactory.decodeByteArray(data, 0, data.length);isView = false;myCamera.stopPreview();myCamera.release();myCamera = null;isView = false;}};    class BtnListener implements OnClickListener{public void onClick(View v) {// TODO Auto-generated method stubswitch(v.getId()){case R.id.btnPreview:Toast.makeText(TestPhotoActivity.this,"鎮ㄦ寜浜嗛瑙堟寜閽?,Toast.LENGTH_SHORT).show();initCamera();break;case R.id.btnPhoto:if(isView && myCamera!=null){myCamera.takePicture(myShutterCallback, myRawCallback, myjpegCalback);}elseToast.makeText(TestPhotoActivity.this, "璿峰厛棰勮鐒跺悗鎷嶇収錛?, Toast.LENGTH_SHORT).show();break;case R.id.btnSave:                  if(bm == null)                  {                  Toast.makeText(TestPhotoActivity.this, "璿鋒媿鎽勬垚鍔熷悗鍐嶄繚瀛橈紒錛侊紒", Toast.LENGTH_SHORT).show();                  return;                  }      int b =0, c=1;    File fTest = new File(savePath + b + c + ".JPG");    while(fTest.exists()){    if(c==9){    b++;    c = 0;    }    else    c++;    if(b==9){    b = 0;    Toast.makeText(TestPhotoActivity.this, "姝ゅ織鎰胯€呮牱鏈暟鐩凡瓚呰繃100錛?,     Toast.LENGTH_SHORT).show();    }    fTest = new File(savePath + b + c + ".JPG");    }    try {FileOutputStream fout = new FileOutputStream(fTest);BufferedOutputStream bos = new BufferedOutputStream(fout);Bitmap mBitmap = Bitmap.createScaledBitmap(bm, 600, 800, false);mBitmap.compress(Bitmap.CompressFormat.JPEG, 100, bos);//bm.compress(Bitmap.CompressFormat.JPEG, 100, bos);bos.flush();bos.close();cntSave++;Toast.makeText(TestPhotoActivity.this, "鎮ㄦ媿鐨勭"+cntSave+"寮爌icture淇濆瓨鎴愬姛錛佺紪鍙鳳細"+ b + c,Toast.LENGTH_SHORT).show();}  catch (IOException e) {// TODO Auto-generated catch blocke.printStackTrace();Toast.makeText(TestPhotoActivity.this,"淇濆瓨澶辮觸",Toast.LENGTH_SHORT).show();}                      break;default:}}        }    public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {// TODO Auto-generated method stub}public void surfaceCreated(SurfaceHolder arg0) {// TODO Auto-generated method stub}public void surfaceDestroyed(SurfaceHolder arg0) {// TODO Auto-generated method stub}//鍒濆鍖栨憚鍍忓ごpublic void initCamera(){if(myCamera == null && !isView){myCamera = Camera.open();Log.i(TAG, "camera.open");}if(myCamera != null && !isView) {try {myParameters = myCamera.getParameters();myParameters.setPictureFormat(PixelFormat.JPEG);myParameters.setPreviewSize(1280, 720);//myParameters.setFocusMode("auto");myParameters.setPictureSize(2048, 1152); //1280, 720myParameters.set("rotation", 90);myCamera.setDisplayOrientation(90);myCamera.setParameters(myParameters);myCamera.setPreviewDisplay(mySurfaceHolder);myCamera.startPreview();isView = true;myCamera.autoFocus(mAutoFocusCallback);} catch (Exception e) {// TODO: handle exceptione.printStackTrace();Toast.makeText(TestPhotoActivity.this, "鍒濆鍖栫溮鏈洪敊璿?,Toast.LENGTH_SHORT).show();}}}class CameraTimerTask extends TimerTask{@Overridepublic void run() {// TODO Auto-generated method stubif(myCamera != null){myCamera.autoFocus(mAutoFocusCallback);}}}//鍒ゆ柇鏂囦歡澶規槸鍚﹀瓨鍦紝濡傛灉涓嶅瓨鍦ㄥ墶鍒涘緩涓€涓?public boolean isFolderExist(String folderPath){boolean result = false;File f = new File(folderPath);if(!f.exists()){if(f.mkdir()){result = true;}elseresult = false;}elseresult = true;return result;}}

自動聚焦部分，核心的代碼有，建構函式裡的

private Camera.AutoFocusCallback mAutoFocusCallback;
mAutoFocusCallback = new Camera.AutoFocusCallback() {
   
   public void onAutoFocus(boolean success, Camera camera) {
    // TODO Auto-generated method stub
    if(success){
     myCamera.setOneShotPreviewCallback(null);
        Toast.makeText(TestPhotoActivity.this,
          "自動聚焦成功" , Toast.LENGTH_SHORT).show();
    }
     
   }
  };
和initCamera裡的myCamera.autoFocus(mAutoFocusCallback);調用！

 

第三，AndroidManifest檔案，紅線部分是添加的對網路攝影機操作、sd儲存的許可權許可。

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="yan.guoqi.testphoto"
    android:versionCode="1"
    android:versionName="1.0" >
    <uses-sdk android:minSdkVersion="15" />
    <!-- 鍦╯d鍗′腑鍒涘緩鍜屽垹闄ゆ枃浠剁殑鏉冮檺 -->
    <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />
    <!-- 鍦╯d鍗′腑鍐欏靉鏁版嵁鐨勬潈闄?-->
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <!-- 浣跨敤鎷嶇収鐨勬潈闄?-->
    <uses-permission android:name="android.permission.CAMERA" />

    <uses-feature android:name="android.hardware.camera" />

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <activity
            android:name=".TestPhotoActivity"
            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>

 

   上兩張，來看下網路攝影機相同的previewSize、pictureSize下，自動對焦前後的差別：

效果差別不是一般的大啊！

1，上面的來源程式裡mTimer、mTimerTask等這些是我第一種思路，用定時器來控制聚焦，結果是失敗的。碰到這些，大家略過去就行了。

2，這裡控制聚焦的核心實現時，在initCamera函數裡，執行myCamera.autoFocus(mAutoFocusCallback);自動聚焦這句話！在建構函式裡定義了一個mAutoFocusCallback的回呼函數變數。還可以在按下拍照按鈕後判斷當前是否自動聚焦成功，如果聚焦成功再拍照！mAutoFocusCallback裡的if（success）就是標示自動聚焦成功

3，網上有很多，只是簡單的在建構函式裡寫一句myCamera.setFocus(null),我真懷疑，這不是坑爹嗎？反正我這樣是沒弄成功。

4，程式裡的亂碼部分是文字，由於從linux下拷出來就成亂碼了，大家不用太關心，都是些提示性的話。

5，另外還要交代一下，自動聚焦這句話一定要在網路攝影機正常預覽的時候調用，否則是沒有意義的，程式也會掛掉。

6，我核心的參考文章：

http://www.cnblogs.com/liuan/archive/2012/01/10/2318300.html

http://www.cnblogs.com/skyseraph/archive/2012/03/26/2418665.html

向他們表示感謝！ 

遺留的問題：

我第一次按下預覽按鈕後，會進行自動聚焦，並提示自動聚焦成功。如果此時執行拍照--儲存--再次預覽，則自動聚焦是成功的。 如果我預覽後，調整了和拍攝物的距離這時想再次自動聚焦，即連續兩次按下預覽按鈕，怎麼第二次就不自動聚焦了呢？？？這是不是和android網路攝影機內建的屬性有關係？

源碼下載連結：http://download.csdn.net/detail/yanzi1225627/4538626

                                                                                                                                                                                                          ----------------------作者yanzi1225627
轉載請註明 2012.8.31