how can we measure distance between object and android phone camera

Question

I want to calculate the distance between the camera and the recognized object.For this I tried a lot of methods, I tried to find the angle between the object and the camera

Answer 1

The final code is

mSensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
            accSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
            magnetSensor = mSensorManager
                    .getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD);
    @Override
    public void onAccuracyChanged(Sensor sensor, int accuracy) {
        // TODO Auto-generated method stub

    }

    @Override
    public void onSensorChanged(SensorEvent event) {
        // TODO Auto-generated method stub
        if (event.sensor.getType() == Sensor.TYPE_ACCELEROMETER)
            gravity = event.values;
        if (event.sensor.getType() == Sensor.TYPE_MAGNETIC_FIELD)
            geoMagnetic = event.values;
        if (gravity != null && geoMagnetic != null) {
            float R[] = new float[9];
            float I[] = new float[9];
            boolean success = SensorManager.getRotationMatrix(R, I, gravity,
                    geoMagnetic);
            if (success) {
                /* Orientation has azimuth, pitch and roll */
                float orientation[] = new float[3];
                //SensorManager.remapCoordinateSystem(R, 1, 3, orientation);
                SensorManager.getOrientation(R, orientation);
                azimut = 57.29578F * orientation[0];
                pitch = 57.29578F * orientation[1];
                roll = 57.29578F * orientation[2];
            }
        }
    }


        captureButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // get an image from the camera

                float d = Math.abs((float) (1.4f * Math.tan(pitch * Math.PI / 180)));
                Toast.makeText(
                        getApplicationContext(),
                        "Distance = "
                                + String.valueOf(d)
                                        + "m  Angle = "
                                        + String.valueOf(Math.toRadians(Math.abs(pitch))),
                        Toast.LENGTH_LONG).show();


            }
        });



protected void onResume() {
        super.onResume();
        mSensorManager.registerListener(this, accSensor,
                SensorManager.SENSOR_DELAY_NORMAL);
        mSensorManager.registerListener(this, magnetSensor,
                SensorManager.SENSOR_DELAY_NORMAL);
    }