如何在不保存/显示图像的情况下拍照

Posted 2023-04-17

【中文标题】如何在不保存/显示图像的情况下拍照

【英文标题】：How to take pictures without saving / displaying image

【发布时间】：2014-04-17 13:31:59

【问题描述】：

我正在与 Eclipse 合作开发适用于 android 的自定义相机应用程序。我已经弄清楚如何显示相机的预览，但我不知道如何在不保存图像的情况下拍照。拍摄照片时，我不想保存图像或将其显示到屏幕上，我只想将其保存为我可以在应用程序中使用的数据类型，并在拍摄另一张照片时覆盖。

编辑：

public class MainActivity extends Activity 

private Camera mCamera;
private CameraPreview mCameraPreview;
private Bitmap picture;
private static Uri mImageCaptureUri;
private static Bitmap photo = null;
private byte[] image;
private int PICK_FROM_CAMERA = 1;

Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);

@Override
protected void onCreate(Bundle savedInstanceState) 

    releaseCameraAndPreview();

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    mCamera = getCameraInstance();
    mCameraPreview = new CameraPreview(this, mCamera);

    FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);

    preview.addView(mCameraPreview);


@Override
public void onActivityResult(int requestCode, int resultCode, Intent data)  

    if (resultCode != Activity.RESULT_OK) return;

    else

        Bundle extras = data.getExtras();

        if (extras != null)                         
            photo = extras.getParcelable("data");
            ByteArrayOutputStream bos = new ByteArrayOutputStream();
            photo.compress(Bitmap.CompressFormat.PNG, 100, bos); 
            image = bos.toByteArray();
        

        File f = new File(mImageCaptureUri.getPath());            

        if (f.exists())
            f.delete();
        
    


@Override
public 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;


//creates camera class for functions
private Camera getCameraInstance() 

    Camera camera = null;

    try 
        camera = Camera.open();
     catch (Exception e) 
        Log.v("Schweigen", "camera will not open");
    
    return camera;


//releases camera on completion
private void releaseCameraAndPreview() 
    if (mCamera != null) 
        mCamera.release();
        mCamera = null;
    


ShutterCallback shutterCallback = new ShutterCallback() 
    public void onShutter() 
        Log.v("Schweigen", "onShutter");
    
;

/** Handles data for raw picture */
 PictureCallback rawCallback = new PictureCallback() 
    public void onPictureTaken(byte[] data, Camera camera) 
        Log.v("Schweigen", "onPictureTaken");
    
;

/** Handles data for jpeg picture */
PictureCallback jpegCallback = new PictureCallback() 
public void onPictureTaken(byte[] data, Camera camera) 
    //picture = BitmapFactory.decodeByteArray(data , 0, data.length);

    intent.putExtra(android.provider.MediaStore.EXTRA_OUTPUT,   mImageCaptureUri);    

        try 
            intent.putExtra("return-data", true);
            startActivityForResult(intent, PICK_FROM_CAMERA);
         catch (ActivityNotFoundException e) 
            e.printStackTrace();
        
    
;

【参考方案1】：

从图片中创建一个Uri。

Intent cameraIntent = new    Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
        Uri uriSavedImage=Uri.fromFile(new File(Environment.getExternalStorageDirectory().toString()+"/ImagesFolder/image.jpg"));
        cameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, uriSavedImage);

编辑：之后您可以将其存储在byte[] 中。

正如我告诉你的，你必须从相机中获取 Intent 并将其设置为 Uri：

private static Uri mImageCaptureUri;

private static Bitmap photo = null;

private byte[] image;

Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);

mImageCaptureUri = Uri.fromFile(new File(Environment.getExternalStorageDirectory(),
                                                               "tmp_avatar_" + String.valueOf(System.currentTimeMillis()) + ".jpg"));

intent.putExtra(android.provider.MediaStore.EXTRA_OUTPUT, mImageCaptureUri);

try 
    intent.putExtra("return-data", true);
    startActivityForResult(intent, PICK_FROM_CAMERA);
 catch (ActivityNotFoundException e) 
    e.printStackTrace();


@Override
public void onActivityResult(int requestCode, int resultCode, Intent data)  

    if (resultCode != Activity.RESULT_OK) return;

    else

                Bundle extras = data.getExtras();

                if (extras != null)                         
                    photo = extras.getParcelable("data");
                    ByteArrayOutputStream bos = new ByteArrayOutputStream();
            photo.compress(Bitmap.CompressFormat.PNG, 100, bos); 
                    image = bos.toByteArray();
                

                File f = new File(mImageCaptureUri.getPath());            

                if (f.exists()) f.delete();

            


  

【讨论】：

使用 byte[] 是我现在想要做的，我只是无法将它转换成位图格式或任何其他有用的格式（我正在尝试：***.com/questions/7620401/…）

我编辑了我的答案以包含您的建议，在这种情况下，图像将存储在文件名 image 下（我认为）。我仍然不明白这将如何解决你

你试过运行它吗？你能发布你的logcat吗

我不明白为什么这是相关的。 URI 和文件路径不一样吗？它仍在保存图像。

【参考方案2】：

直接拍照的API是here。