Comment ajouter des filtres à une application camera en temps rl

<uses-permission android:name="android.permission.CAMERA" />
<uses-feature android:name="android.hardware.camera" />
<uses-feature android:name="android.hardware.camera.autofocus" />

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/relativeLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:keepScreenOn="true"
    android:orientation="vertical">

    <Spinner
        android:id="@+id/effects"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"/>

    <org.camdemo.CamView
        android:id="@+id/camera"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"/>
</LinearLayout>

package org.camdemo;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;


public class MainActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener {

  private CamView m_cv = null;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    m_cv = (CamView)findViewById(R.id.camera);
    /* init du spinner pour les effets */
    Spinner spinner = (Spinner) findViewById(R.id.effects);

    ArrayAdapter<String> adapter = new ArrayAdapter<>(this,
      android.R.layout.simple_spinner_item, m_cv.supportedEffects());
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    spinner.setAdapter(adapter);
    spinner.setOnItemSelectedListener(this);
  }

  @Override
  public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
    /* application du filtre en fonction de celui choisi */
    m_cv.setEffect(adapterView.getItemAtPosition(i).toString());
  }

  @Override
  public void onNothingSelected(AdapterView<?> adapterView) {

  }
}

package org.camdemo;

import android.content.Context;
import android.content.res.Configuration;
import android.hardware.Camera;
import android.util.AttributeSet;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

import java.util.List;


public class CamView extends SurfaceView implements SurfaceHolder.Callback {
  private SurfaceHolder m_holder = null;
  private Camera m_cam = null;
  private boolean m_running = false;

  public CamView(final Context context, AttributeSet attrs) {
    super(context, attrs);
    init();
  }
  public CamView(final Context context) {
    super(context);
    init();
  }
  public CamView(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
    init();
  }

  public List<String> supportedEffects() {
    Camera.Parameters parameters = m_cam.getParameters();
    return parameters.getSupportedColorEffects();
  }

  @SuppressWarnings("deprecation")
  private void init() {
    /* Installation du callback pour être notif lorsque la surface est créée/détruite. */
    m_holder = getHolder();
    m_holder.addCallback(this);
    m_holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    /* récupération d'une instance sur la camera */
    m_cam = Camera.open();
  }

  public void setEffect(final String s) {
    if(s.isEmpty()) return;
    Log.i(getClass().getSimpleName(), "Apply new effect: " + s);
    /* Reload de la surface avec le nouveau filtre */
    Camera.Parameters parameters = m_cam.getParameters();
    parameters.setColorEffect(s);
    m_cam.setParameters(parameters);
    m_cam.startPreview();
    try {
      m_cam.setPreviewDisplay(m_holder);
    } catch (final Throwable e) {
      Log.e(getClass().getName(), "Exception : " + e.getMessage(), e);
    }
  }

  @Override
  public void surfaceCreated(final SurfaceHolder holder) {
    try {
      m_cam.setPreviewDisplay(holder);
    } catch (final Throwable e) {
      Log.e(getClass().getName(), "Exception : " + e.getMessage(), e);
    }
  }

  @Override
  public void surfaceDestroyed(final SurfaceHolder holder) {
    if (m_running) {
      m_cam.stopPreview();
      m_cam.setPreviewCallback(null);
      m_cam.release();
      m_running = false;
    }
  }

  @Override
  public void surfaceChanged(final SurfaceHolder holder, final int format,
                             final int w, final int h) {

    if (m_running) m_cam.stopPreview();

    // Prise en compte de la rotation de l’écran
    if (this.getResources().getConfiguration().orientation != Configuration.ORIENTATION_LANDSCAPE)
      m_cam.setDisplayOrientation(90);
    else
      m_cam.setDisplayOrientation(0);

    try {
      m_cam.setPreviewDisplay(holder);
      m_cam.startPreview();
    } catch (final Exception e) {
      Log.e(getClass().getName(), "Exception : " + e.getMessage(), e);
    }
    m_running = true;
  }
}