在android中使用自定义相机拍照

Posted 2023-04-17

【中文标题】在android中使用自定义相机拍照

【英文标题】：Take a photo using custom camera in android

【发布时间】：2017-08-05 05:33:47

【问题描述】：

我不是要配置自定义相机，我只需要用它拍照。 我的 xml 中有一个 SurfaceView 和一个拍照按钮。我找到这个方法来拍照： mCamera.takePicture(null, null, mPicture);

mPicture 定义如下：

Camera.PictureCallback mPicture = new Camera.PictureCallback() 
    @Override
    public void onPictureTaken(byte[] data, Camera camera) 
        pictureFile = getOutputMediaFile();
        if (pictureFile == null) 
            return;
        
        try 
            FileOutputStream fos = new FileOutputStream(pictureFile);
            fos.write(data);
            fos.close();


         catch (FileNotFoundException e) 

         catch (IOException e) 
        
    
;

我需要一张拍摄图像的位图，以便在另一个 Activity 中使用它。 提前致谢！

【问题讨论】：

为什么要显示所有代码！无关紧要。您的设备中有一个 jpg 文件，并且您想要它的位图就是您想要的。就这样。究竟是什么问题？告诉其他活动该文件的路径。

【参考方案1】：

我需要一张拍摄图像的位图，以便在另一个 Activity 中使用它。提前致谢！

您只需要解码从相机接收到的字节数组，然后将其旋转到正确的方向。

获取相机显示方向：

private static int getCameraDisplayOrientation(int cameraId, Activity activity) 
    int rotation = ((WindowManager)activity.getSystemService(Context.WINDOW_SERVICE))
            .getDefaultDisplay().getRotation();
    android.hardware.Camera.CameraInfo info =
            new android.hardware.Camera.CameraInfo();
    android.hardware.Camera.getCameraInfo(cameraId, info);
    int result;
    if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) 
        result = (info.orientation + rotation) % 360;
        result = (360 - result) % 360;  // compensate the mirror
     else   // back-facing
        result = (info.orientation - rotation + 360) % 360;
    
    return result;

将字节数组解码为位图：

public static Bitmap decodeByteArray(byte[] data, float rotationDegree) 
    try 
        Bitmap bm = BitmapFactory.decodeByteArray(data, 0, data.length);
        if (rotationDegree != 0) 
            bm = createRotatedBitmap(bm, rotationDegree);
        
        return  bm;
     catch (OutOfMemoryError e) 
        e.printStackTrace();
        return null;
    

旋转位图：

public static Bitmap createRotatedBitmap(Bitmap bm, float rotation) 
    Matrix matrix = new Matrix();
    matrix.postRotate(rotation, bm.getWidth()/2, bm.getHeight()/2);
    try 
        Bitmap result =  Bitmap.createBitmap(bm, 0, 0, bm.getWidth(), bm.getHeight(), matrix, true);
        return result;
     catch (OutOfMemoryError e) 
        return null;
    

【参考方案2】：

> I asked my instructor about this question and he told me that the
> code below should work fine for you.

public class Custom_Camera

private Camera a;
private ab1 ab2;

/** Called when the activity is first created. */
@Override
public void onCreate(Total State) 
    super.onCreate(Saved State);
    setContentView(R.layout.main);
    a = getCameraInstance();
    ab1 = new ab2(this, a);
    FrameLayout= (FrameLayout) findViewById(R.id.a_b2);
    preview.addView(ab2);

    Button captureButton = (Button) findViewById(R.id.button_capture);
    captureButton.setOnClickListener(new View.OnClickListener() 
        @Override
        public void onClick(View v) 
            mCamera.takePicture(null, null, mPicture);
        
    );

private Camera a getCameraInstance() 
    Camera a = null;
    try 
        camera = Camera.open();
     catch (Exception e) 
    
    return camera a;


Picture = new Picture() 
    public void taken(byte[] data, Camera camera) 
        File = getOutputMediaFile();
        if (pictureFile == null) 
            return;
        
        try 
            FileOutputStream fos = new FileOutputStream(pictureFile);
            fos.write(data);
            fos.close();
         catch (FileNotFoundException e) 

         catch (IOException e) 
        
    
;

private static File getOutputMediaFile() 
    File mediaStorageDir = new File(
            Environment
                    .getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),
            "MyCameraApp");
    if (!mediaStorageDir.exists()) 
        if (!mediaStorageDir.mkdirs()) 
            Log.d("MyCameraApp", "failed to create directory");
            return null;
        
    
    // Create a media file name
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss")
            .format(new Date());
    File mediaFile;
    mediaFile = new File(mediaStorageDir.getPath() + File.separator
            + "IMG_" + timeStamp + ".jpg");

    return mediaFile;
   

【讨论】：

另一个人在这里问过这个问题：link