使用闪光灯拍摄的Android保存图像（Nexus 4）

Question

以下是我正在处理的自定义相机应用的代码。 Everthing工作正常，除非使用闪光灯拍摄图像。启用闪光灯后，预览显示用户接受图像看起来正确，但保存到SD卡的图像非常暗（只有白色物体略微可见），而且通常只是黑色。我一直试图解决这个问题好几天了。可能会发生什么想法？

public class CustomCamera extends Activity implements SurfaceHolder.Callback{
Camera camera;
Surfaceview surfaceView;
SurfaceHolder surfaceHolder;
boolean previewing = false;
LayoutInflater controlInflater = null;


@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    requestWindowFeature(Window.FEATURE_NO_TITLE);

    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
    setContentView(R.layout.main);

    setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);

    getWindow().setFormat(PixelFormat.UNKNOWN);
    surfaceView = (SurfaceView)findViewById(R.id.camerapreview);
    surfaceHolder = surfaceView.getHolder();
    surfaceHolder.addCallback(this);
    surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

    ...

  }


  public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
    if(previewing){
        camera.stopPreview();
        previewing = false;
    }

    if (camera != null){
        try {
            Camera.Parameters parameters = camera.getParameters();              
            camera.setDisplayOrientation(90);
            determineDisplayOrientation();
            camera.setPreviewDisplay(surfaceHolder);
            previewing = true;


            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB){
                List<String> supportedFocusModes = parameters.getSupportedFocusModes();

                if (supportedFocusModes.contains(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE)){
                    parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);
                } else{
                    parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
                }

            }


            if (parameters.getSupportedWhiteBalance().contains(
                    Parameters.WHITE_BALANCE_AUTO)) {
                parameters.setWhiteBalance(Parameters.WHITE_BALANCE_AUTO);
            }

            if (parameters.getSupportedSceneModes().contains(
                    Parameters.SCENE_MODE_AUTO)) {
                parameters.setSceneMode(Parameters.SCENE_MODE_AUTO);
            }


            camera.setParameters(parameters);
            camera.startPreview();

        } catch (IOException e) {
            e.printStackTrace();
        }
    }


@Override
public void surfaceCreated(SurfaceHolder holder) {
    flashButton.setBackgroundResource(R.drawable.auto_flash);
    camera = Camera.open(CURRENT_CAMERA_ID);
    Camera.Parameters camParameters = camera.getParameters();
    flashSupported = getApplicationContext().getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH);


    if ( flashSupported){
        camParameters.setFlashMode(Parameters.FLASH_MODE_AUTO);
        lastFlashMode = AUTO_FLASH;
        camera.setParameters(camParameters);
    }       
}

@Override
public void surfaceDestroyed(SurfaceHolder holder) {
    camera.stopPreview();
    camera.release();
    camera = null;
    previewing = false;
}

//click listener for button to take picture
public void takePicture(View view){     
    if (camera != null){
        orientationListener.rememberOrientation();
        camera.takePicture(myShutterCallback, myPictureCallback_RAW, myPictureCallback_JPG);
        showPicPreviewScreen();
    }

}


Camera.ShutterCallback myShutterCallback = new Camera.ShutterCallback() {

    @Override
    public void onShutter() {

    }
};

Camera.PictureCallback myPictureCallback_RAW = new Camera.PictureCallback(){

    @Override
    public void onPictureTaken(byte[] arg0, Camera arg1) {
    }
};

Camera.PictureCallback myPictureCallback_JPG = new Camera.PictureCallback(){

    @Override
    public void onPictureTaken(byte[] arg0, Camera arg1) {
        bitmapPicture = BitmapFactory.decodeByteArray(arg0, 0, arg0.length);


        int rotation = (displayOrientation + orientationListener.getRememberedOrientation() + layoutOrientation) % 360;
        if (rotation != 0){
            Log.e("rotaion", "not 0, rotating");
            Bitmap oldBitmap = bitmapPicture;
            Matrix matrix = new Matrix();
            matrix.postRotate(rotation);

            bitmapPicture = Bitmap.createBitmap(bitmapPicture, 0, 0, bitmapPicture.getWidth(), bitmapPicture.getHeight(), matrix, false);
            oldBitmap.recycle();
        }


        camera.stopPreview();
        previewing = false;


        ImageSaver imageSaver = new ImageSaver();
        imageSaver.saveImage(getApplicationContext(), bitmapPicture);
    }
};        

}

这是保存图像的课程

public class ImageSaver{
private Context context;
private String NameOfFolder = "/ProjectFolder";

String fileName;

String file_path;
public void saveImage(Context context,Bitmap ImageToSave){
    context = context;
    file_path  = Environment.getExternalStorageDirectory().getAbsolutePath()+ NameOfFolder;
    String CurrentDateAndTime= getCurrentDateAndTime();
    File dir = new File(file_path);

    if(!dir.exists()){
        dir.mkdirs();
    }

    fileName = CurrentDateAndTime+ ".jpg";
    File file = new File(dir, fileName);

    try {
        FileOutputStream fOut = new FileOutputStream(file);
        ImageToSave.compress(Bitmap.CompressFormat.JPEG, 100, fOut);  //85
        fOut.flush();
        fOut.close();
    }
    catch (FileNotFoundException e) {UnableToSave();}
    catch (IOException e){UnableToSave();}
}


private String getCurrentDateAndTime() {
    Calendar c = Calendar.getInstance();
    SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd-HH-mm-ss");
    String formattedDate = df.format(c.getTime());
    return formattedDate;
}

}

非常感谢！