Taking a photo in the background on click of a button. The app keeps crashing

Question

I am trying to take an image in the background without showing the user the camera. I am saving the byte array to sdcard.This is done on the click of a button.The app keeps crashing after I click on the button.

public class CameraService extends Service {
//Camera variables
//a surface holder
private SurfaceHolder sHolder;
//a variable to control the camera
private Camera mCamera;
//the camera parameters
private Parameters parameters;
/** Called when the activity is first created. */
@Override
public void onCreate()
{
    super.onCreate();

}
@Override
public void onStart(Intent intent, int startId) {
    // TODO Auto-generated method stub
    super.onStart(intent, startId);

    mCamera = Camera.open();
    SurfaceView sv = new SurfaceView(getApplicationContext());


    try {
        mCamera.setPreviewDisplay(sv.getHolder());
        parameters = mCamera.getParameters();

        //set camera parameters
        mCamera.setParameters(parameters);
        mCamera.startPreview();
        mCamera.takePicture(null, null, mCall);

    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }


    //Get a surface
    sHolder = sv.getHolder();
    //tells Android that this surface will have its data constantly replaced
    sHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}



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

    public void onPictureTaken(byte[] data, Camera camera)
    {
        //decode the data obtained by the camera into a Bitmap

        FileOutputStream outStream = null;
        try{
            String path = Environment.getExternalStorageDirectory().getPath();
            outStream = new FileOutputStream(path+"/Image.jpg");

            outStream.write(data);
            outStream.close();
        } catch (FileNotFoundException e){
            Log.d("CAMERA", e.getMessage());
        } catch (IOException e){
            Log.d("CAMERA", e.getMessage());
        }

    }
};


@Override
public IBinder onBind(Intent intent) {
    // TODO Auto-generated method stub
    return null;
}

}

This is my main activity(below)

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                    .setAction("Action", null).show();
        }
    });
}
public void runThis(View view)
{
    Intent intent = new Intent(this,CameraService.class);
    startService(intent);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

}

Here's the logcat

E/AndroidRuntime: FATAL EXCEPTION: main
  Process: com.example.srk97c.elixir, PID: 9320
  java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.srk97c.elixir/com.example.srk97c.elixir.CameraService}: java.lang.ClassCastException: com.example.srk97c.elixir.CameraService cannot be cast to android.app.Activity
      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2227)
      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
      at android.app.ActivityThread.access$800(ActivityThread.java:147)
      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1281)
      at android.os.Handler.dispatchMessage(Handler.java:102)
      at android.os.Looper.loop(Looper.java:135)
      at android.app.ActivityThread.main(ActivityThread.java:5264)
      at java.lang.reflect.Method.invoke(Native Method)
      at java.lang.reflect.Method.invoke(Method.java:372)
      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:900)
      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:695)
   Caused by: java.lang.ClassCastException: com.example.srk97c.elixir.CameraService cannot be cast to android.app.Activity
      at android.app.Instrumentation.newActivity(Instrumentation.java:1065)
      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2217)
      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387) 
      at android.app.ActivityThread.access$800(ActivityThread.java:147) 
      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1281) 
      at android.os.Handler.dispatchMessage(Handler.java:102) 
      at android.os.Looper.loop(Looper.java:135) 
      at android.app.ActivityThread.main(ActivityThread.java:5264) 
      at java.lang.reflect.Method.invoke(Native Method) 
      at java.lang.reflect.Method.invoke(Method.java:372) 
      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:900) 
      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:695)