Android:在Android相机预览上叠加层

39
我正在使用相机API并调用相机。
我想在相机预览的顶部显示一个标头(用于品牌推广)。标头是一张JPEG图片。
这可能吗?任何帮助都将不胜感激。
提前致谢。
我的代码如下。
public class CameraActivity extends Activity {
    @Override
    protected void onPause() {

        super.onPause();
    }

    private static final int CAMERA_PIC_REQUEST = 2500;
    private Bitmap image2;
    private Bitmap bm;
    public static String imagepath;
    public static int x=1;
    private RdmsDbAdapter dbHelper;
    @Override



    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.header);
        setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
        //caling new incident
        if(IncidentFormActivity.incident_id == null || IncidentFormActivity.isDisable==true){
            //DBAdapter instance created and connection opened. 
            dbHelper = new RdmsDbAdapter(CameraActivity.this);
            dbHelper.open();

            //setting up flags
            NewIncidentHelper nih = new NewIncidentHelper();
            nih.setUpNewIncident();

            //setting up incident_id
            String Date= IncidentIdGenerator.getDate();
            String Time = IncidentIdGenerator.getTime();

            IncidentFormActivity.incident_id = IncidentIdGenerator.now("ddMMyyyyHHmmss");
            dbHelper.executeSQL("insert into incident values ('" + IncidentFormActivity.incident_id
                    + "', ' ', ' ', ' ', ' ', '"+Date+"', '0','0','0','0','0','0','0','0','0','"+Time+"')");
            dbHelper.close();
        }

        //calling camera
        Intent cameraIntent = new Intent(
                android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
        startActivityForResult(cameraIntent, CAMERA_PIC_REQUEST);


    }
    public String getPath(Uri uri) {
        String[] projection = { MediaStore.Images.Media.DATA };
        Cursor cursor = managedQuery(uri, projection, null, null, null);
        int column_index = cursor
                .getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
        cursor.moveToFirst();
        return cursor.getString(column_index);
    }

    //back key on phone pressed
    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        switch (keyCode) {
        case KeyEvent.KEYCODE_BACK:
            Intent i= new Intent(CameraActivity.this, IncidentFormActivity.class);
            startActivity(i);
            this.finish();

            break;

        default:
            break;
        }
        return super.onKeyDown(keyCode, event);
    }

    //handle response came from camera when the picture is taken.
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == CAMERA_PIC_REQUEST && resultCode == RESULT_OK) {
                final ImageView img = new ImageView(this);
                img.setLayoutParams(new LayoutParams(100, 100));
                image2 = (Bitmap) data.getExtras().get("data");
                img.setImageBitmap(image2);
                String incident_ID = IncidentFormActivity.incident_id;
                //l2.addView(img);
                    imagepath="/sdcard/RDMS/"+incident_ID+ x + ".png";
                File file = new File(imagepath);
                try {
                     bm = Bitmap.createScaledBitmap( image2,400, 300, true);
                    file.createNewFile();
                    FileOutputStream ostream = new FileOutputStream(file);
                    bm.compress(CompressFormat.PNG, 90, ostream);
                    ostream.close(); 
                    //Initialising db class and inserting values
                    dbHelper = new RdmsDbAdapter(CameraActivity.this);
                    dbHelper.open();
                    dbHelper.executeSQL("insert into files values ('"+imagepath+"', '"+IncidentFormActivity.incident_id+"')");
                    dbHelper.close();

                } catch (Exception e) {
                    e.printStackTrace();
                    Toast.makeText(getApplicationContext(),"yourfirst  error message is "
                                            + e.toString(), 1000).show();
                }
                x++;
                final AlertDialog.Builder alert = new AlertDialog.Builder(
                        CameraActivity.this);

                alert.setTitle(getString(R.string.anotherimage));
                alert.setCancelable(false);
                //alert.setMessage("Play or Delete the Video selected");
                //alert.setIcon(R.drawable.vid_red);
                alert.setPositiveButton(getString(R.string.yes), new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        Intent sendingpage = new Intent(CameraActivity.this, CameraActivity.class);
                          startActivity(sendingpage);

                    }
                });
                alert.setNegativeButton(getString(R.string.no),
                        new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int id) {
                                Intent callback = new Intent (CameraActivity.this, IncidentFormActivity.class);
                                startActivity(callback);
                            }
                        });

                alert.show();


            }
            if(resultCode==RESULT_CANCELED)
            {

                AlertDialog.Builder builder = new AlertDialog.Builder(CameraActivity.this);

                builder.setMessage(getString(R.string.areuexit)).setCancelable(
                        false).setPositiveButton(getString(R.string.yes),
                        new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int id) {
                                Intent i= new Intent(CameraActivity.this, IncidentFormActivity.class);
                                startActivity(i);
                                CameraActivity.this.finish();
                            }
                        }).setNegativeButton(getString(R.string.no),
                        new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int id) {
                                dialog.cancel();
                                Intent i= new Intent(CameraActivity.this, CameraActivity.class);                            startActivity(i);
                                CameraActivity.this.finish();
                            }
                        });

                builder.show();



            }
        }
    }

通过标题,您是指相机应用程序顶部的图形还是类似于水印的图形? - jfisk
是的,我想在顶部作为标题显示一个图形。谢谢。 - Jay Mayu
是的,我想在相机预览的顶部显示一个图形作为标题。没什么大不了的,我甚至不想改变拍摄的图像。谢谢。 - Jay Mayu
很好的关注点分离。 - Roel
6个回答

23
你可以使用SurfaceView并创建一个自定义视图来打开相机,你可以在xml中调整其大小。下面是伪代码。
创建一个继承自SurfaceView的类,并在其中打开相机。
CapturePreview.java
public class CapturePreview extends SurfaceView implements SurfaceHolder.Callback{

    public static Bitmap mBitmap;
    SurfaceHolder holder;
    static Camera mCamera;

    public CapturePreview(Context context, AttributeSet attrs) {
        super(context, attrs);

        holder = getHolder();
        holder.addCallback(this);
        holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width,int height) {

        Camera.Parameters parameters = mCamera.getParameters();
        parameters.getSupportedPreviewSizes();
        mCamera.setParameters(parameters);
        mCamera.startPreview();
    }
    @Override
    public void surfaceCreated(SurfaceHolder holder) {

        try {
            mCamera = Camera.open();
            mCamera.setPreviewDisplay(holder);

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        mCamera.stopPreview();
        mCamera.release();
    }
    /***
     * 
     *  Take a picture and and convert it from bytes[] to Bitmap.
     *  
     */
    public static void takeAPicture(){  

        Camera.PictureCallback mPictureCallback = new PictureCallback() {
            @Override
            public void onPictureTaken(byte[] data, Camera camera) {

                BitmapFactory.Options options = new BitmapFactory.Options();
                mBitmap = BitmapFactory.decodeByteArray(data, 0, data.length, options);
            }
        };
        mCamera.takePicture(null, null, mPictureCallback);
    }
}

现在你需要像这样在xml中包含使用SurfaceView创建的视图:

main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent">

  <FrameLayout 
  android:id="@+id/mySurfaceView"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content">

  <com.cam.CapturePreview 
  android:layout_width="fill_parent"
  android:layout_height="wrap_content">
  </com.cam.CapturePreview>

  </FrameLayout>

  <LinearLayout 
  android:layout_below="@id/mySurfaceView" 
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:layout_centerInParent="true"
  android:gravity="center">

  <ImageView android:id="@+id/myImageView" 
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:src="@drawable/icon"/>
  </LinearLayout>  

</RelativeLayout>

现在你可以在打开带有ImageView的相机的任何Activity中使用此main.xml

谢谢....

1
为了让代码正常工作,必须删除 android:layout_below="@id/mySurfaceView" - Pierre-Antoine
1
相机预览非常失真。 - Rohit Tigga
那现在的解决方案是什么? - Shadow
请查看我从Google的Camera2Video分叉出来的示例代码,其中包含了解决陈旧问题的方案。https://github.com/chriscborg/android-Camera2Video - ChrisBorg

20

8
链接怎么了?似乎被重定向了。你能重新提供正确的链接吗? - BigBoy1337
损坏的链接已更新 - https://developer.android.com/samples/RuntimePermissionsBasic/src/com.example.android.basicpermissions/camera/CameraPreview.html - Pavan K
@PavanK,你的链接已经失效了。 - valerybodak
抱歉,但谷歌更新了他们的API,您可以在https://developer.android.com/samples/下搜索它。 - Pavan K

4
你可以通过使用 FrameLayout 来实现这个功能,代码如下:
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
  xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent" >

  <android.view.SurfaceView
  android:id="@+id/surface"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent" />

<ImageView
    android:id = "@+id/header"
    android:layout_width = "wrap_content"
    android:layout_height = "wrap_content" />

</FrameLayout>

这个相机项目能为你提供帮助。

1
看起来你的XML将会是这样的:
 <?xml version="1.0" encoding="utf-8"?>
<FrameLayout
 xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent" >

<android.view.SurfaceView
 android:id="@+id/surface"
 android:layout_width="fill_parent"
 android:layout_height="fill_parent" />

<ImageView
android:id = "@+id/header"
android:layout_width = "wrap_content"
android:layout_height = "wrap_content" />

</FrameLayout>

对于Java代码,您应该在活动中扩展SurfaceHolder.Callback,然后像这样将相机连接到SurfaceView。这是我的完整代码,请小心处理位图和画布,这是棘手的部分:

 public class MainActivity extends Activity implements SurfaceHolder.Callback 
{
  private Camera camera = null;
  private SurfaceView cameraSurfaceView = null;
  private SurfaceHolder cameraSurfaceHolder = null;
  private boolean previewing = false;
  RelativeLayout relativeLayout;





  private Button btnCapture = null;
  private Button btnsave = null;
  private Button btnshare = null;
  private boolean isSaved=false;
  private boolean isCaptured=false;

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

    getWindow().setFormat(PixelFormat.TRANSLUCENT);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    getWindow().setFlags(
                         WindowManager.LayoutParams.FLAG_FULLSCREEN,
                         WindowManager.LayoutParams.FLAG_FULLSCREEN);

    setContentView(R.layout.activity_main);

    relativeLayout=(RelativeLayout) findViewById(R.id.containerImg);
    relativeLayout.setDrawingCacheEnabled(true);
    cameraSurfaceView = (SurfaceView)
                                       findViewById(R.id.surfaceView1);
  //  cameraSurfaceView.setLayoutParams(new FrameLayout.LayoutParams(640, 480));
    cameraSurfaceHolder = cameraSurfaceView.getHolder();
    cameraSurfaceHolder.addCallback(this);
//    cameraSurfaceHolder.setType(SurfaceHolder.
  //                                               SURFACE_TYPE_PUSH_BUFFERS);




    btnCapture = (Button)findViewById(R.id.capturebtn);
    btnCapture.setOnClickListener(new OnClickListener() 
    {   
      @Override
      public void onClick(View v) 
      {
         camera.takePicture(cameraShutterCallback, 
                                       cameraPictureCallbackRaw,
                                       cameraPictureCallbackJpeg);
         isCaptured=true;
      }
    });
    btnsave = (Button)findViewById(R.id.savebtn);
    btnsave.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
             FrameLayout frm = (FrameLayout)findViewById(R.id.frameLayout1);
                frm.setDrawingCacheEnabled(true);
                frm.buildDrawingCache();
                Bitmap bitmap = frm.getDrawingCache();
                try {
                    File rootFile=new File(Environment.getExternalStorageDirectory().toString()+"/MYCAMERAOVERLAY");
                    rootFile.mkdirs();
                    Random generator = new Random();
                    int n = 10000;
                    n = generator.nextInt(n);
                    String fname = "Image-"+ n +".png";

                    File resultingfile = new File(rootFile, fname);

                    if (resultingfile.exists ()) resultingfile.delete (); 
                    try {
                           FileOutputStream Fout = new FileOutputStream(resultingfile);
                           bitmap.compress(CompressFormat.PNG, 100, Fout);
                           Fout.flush();
                           Fout.close();

                    } catch (FileNotFoundException e) {
                        Log.d("In Saving File", e + "");
                }
                } catch(IOException e){
                    Log.d("In Saving File", e + "");
                }
                isSaved=true;
            }
        });
    btnshare = (Button)findViewById(R.id.sharebtn);
    btnshare.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            if((isSaved)&&(isCaptured)){
                // TODO sharing what ever we saved 
                // take the path


            }

        }
    });
   } 


  ShutterCallback cameraShutterCallback = new ShutterCallback() 
  {  
    @Override
    public void onShutter() 
    {
      // TODO Auto-generated method stub   
    }
  };

  PictureCallback cameraPictureCallbackRaw = new PictureCallback() 
  {  
    @Override
    public void onPictureTaken(byte[] data, Camera camera) 
    {
      // TODO Auto-generated method stub   
    }
  };

  PictureCallback cameraPictureCallbackJpeg = new PictureCallback() 
  {  
    @Override
    public void onPictureTaken(byte[] data, Camera camera) 
    {
      // TODO Auto-generated method stub   
      Bitmap cameraBitmap = BitmapFactory.decodeByteArray
                                                                  (data, 0, data.length);

   int   wid = cameraBitmap.getWidth();
     int  hgt = cameraBitmap.getHeight();

    //  Toast.makeText(getApplicationContext(), wid+""+hgt, Toast.LENGTH_SHORT).show();
      Bitmap newImage = Bitmap.createBitmap
                                        (wid, hgt, Bitmap.Config.ARGB_8888);

      Canvas canvas = new Canvas(newImage);

      canvas.drawBitmap(cameraBitmap, 0f, 0f, null);

      camera.startPreview();

      newImage.recycle();
      newImage = null;

      Intent intent = new Intent();
      intent.setAction(Intent.ACTION_VIEW);

      startActivity(intent);

    }
  };

  @Override
  public void surfaceChanged(SurfaceHolder holder, 
                                       int format, int width, int height) 
  {
    // TODO Auto-generated method stub

    if(previewing)
    {
      camera.stopPreview();
      previewing = false;
    }
    try 
    {
      Camera.Parameters parameters = camera.getParameters();
      parameters.setPreviewSize(640, 480);
      parameters.setPictureSize(640, 480);
      if (this.getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE) {
          camera.setDisplayOrientation(-90);

      }

     // parameters.setRotation(90);
      camera.setParameters(parameters);

      camera.setPreviewDisplay(cameraSurfaceHolder);
      camera.startPreview();
      previewing = true;
    } 
    catch (IOException e) 
    {
      // TODO Auto-generated catch block
      e.printStackTrace();  
    }
  }

  @Override
  public void surfaceCreated(SurfaceHolder holder) 
  {
    // TODO Auto-generated method stub
    try
    {
      camera = Camera.open();
    }
    catch(RuntimeException e)
    {
      Toast.makeText(getApplicationContext(), "Device camera  is not working properly, please try after sometime.", Toast.LENGTH_LONG).show();
    }
  }

  @Override
  public void surfaceDestroyed(SurfaceHolder holder) 
  {
    // TODO Auto-generated method stub
      try{


    camera.stopPreview();
    camera.release();
    camera = null;
    previewing = false;
      }catch(Exception e){
          e.printStackTrace();
      }
  }

}

我想现在应该给你完整的XML部分。这是它:

  <?xml version="1.0" encoding="utf-8"?>
 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:android1="http://schemas.android.com/apk/res/android"
android:id="@+id/containerImg"
android:layout_width="fill_parent"
android:layout_height="match_parent"
android1:layout_gravity="bottom"
android:orientation="vertical"
android1:gravity="bottom" >

    <FrameLayout
    android:id="@+id/frameLayout1"
    android1:layout_width="wrap_content"
    android1:layout_height="wrap_content"
    android:gravity="center|top"
     >

 <SurfaceView
     android1:id="@+id/surfaceView1"
     android1:layout_width="100dip"
     android1:layout_height="150dip"
     android1:layout_gravity="center_horizontal" />

<ImageView
android1:id="@+id/imageView1"
android1:layout_width="fill_parent"
android1:layout_height="fill_parent"
android:contentDescription="@string/app_dress_desc"
android:gravity="center|bottom"
android1:scaleType="center"
android1:src="@drawable/dress" />

</FrameLayout>


<GridLayout
    android1:id="@+id/gridLayout1"
    android1:layout_width="match_parent"
    android1:layout_height="wrap_content"
    android1:layout_alignParentBottom="true"
    android1:layout_alignParentLeft="true"
    android1:columnCount="1"
    android1:gravity="center|bottom"
    android1:orientation="vertical" >

    <ImageButton
        android1:id="@+id/capturebtn"
        android1:layout_width="60dp"
        android1:layout_height="wrap_content"
        android1:layout_gravity="left"
        android1:src="@drawable/camera"
        android:contentDescription="@string/app_icon_camera_desc" />

    <ImageButton
        android1:id="@+id/savebtn"
        android1:layout_width="60dp"
        android1:layout_height="wrap_content"
        android1:layout_column="0"
        android1:layout_gravity="center_horizontal|top"
        android1:layout_row="0"
        android1:src="@drawable/save"
        android:contentDescription="@string/app_icon_save_desc" />

    <ImageButton
        android1:id="@+id/sharebtn"
        android1:layout_width="60dp"
        android1:layout_height="wrap_content"
        android1:layout_column="0"
        android1:layout_gravity="right|top"
        android1:layout_row="0"
        android1:src="@drawable/share"
        android:contentDescription="@string/app_icon_share_desc" />
</GridLayout>

分享按钮目前无法使用,但是在点击捕获时它会保存整个框架布局。希望这对您有所帮助。

1

很抱歉,您必须自己实现相机预览屏幕。理论上,可以通过修改其布局或创建覆盖窗口来向其他应用程序添加叠加层。第一种方法无法实现,第二种方法我认为可以实现,但这是一种有缺陷的方法。

实现自己的相机活动并不是一项非常困难的任务,但它确实具有挑战性。我建议您查看默认的相机应用程序。这是它的源代码:https://github.com/android/platform_packages_apps_camera


1
这不是非常困难的任务,但它确实具有挑战性。那么,它到底是哪一个? - Joshua Pinter

1
一种解决方法是使用另一个包含标题图片的XML文件覆盖Activity XML文件。操作步骤如下:
  1. Create a new Layout file inside the layout folder. For eg: overlay.xml
  2. Insert an ImageView inside it, something like:

    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    
    <ImageView
        android:id="@+id/imageView1"
        android:layout_centerInParent="true"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/android" />
    
    
    </RelativeLayout>
    
  3. Then inside the Activity java file, ie MotionDetector.java file , create a new method addView() :

       private void addView()
       {
           controlInflater = LayoutInflater.from(getBaseContext());
           View viewControl = controlInflater.inflate(R.layout.overlay, null);
           LayoutParams layoutParamsControl = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
           this.addContentView(viewControl, layoutParamsControl);
    
       }
    
  4. Finally invoke the addView() method from onCreate() to add the image:

    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.header);
    addView();
    
最终结果将是在SurfaceView上方的图像叠加。根据标题图像的质量,标题的呈现质量应当看起来很原始。希望这有所帮助。

网页内容由stack overflow 提供, 点击上面的
可以查看英文原文,
原文链接