Using the Android Camera via Intent and via the API. This tutorial describes how to use the camera API in Android. The tutorial is based on Eclipse 4.2, Java 1.6 and Android 4.2.
1. Android Camera
Most Android devices have at least one camera. Some devices have a front and a back facing camera.
Using the camera on the Android device can be done via the integration of existing camera application. In this case you would start the existing Camera application via an intent and use the return data of the application to access the result.
Alternatively you can also directly integrate the camera into your
application via
the
Camera
API.
The following description contains examples for both use cases.
2. Android Basics
The following description assumes that you have already basic knowledge in Android development.
Please check https://www.vogella.com/tutorials/Android/article.html - Android development tutorial, to learn the basics. Also see https://www.vogella.com/android.html - Android development tutorials, for more information about Android development.
3. Tutorial: Using an Intent to make a photo
Create a new Android project de.vogella.android.imagepick with an activity called ImagePickActivity.
Adjust the layout of the activity to contain an ImageView with the result ID.
Also add a button with the onClick property pointing to a onClick method.
Change the ImagePickActivity class to the following.
package de.vogella.android.imagepick;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;
public class ImagePickActivity extends Activity {
private static final int REQUEST_CODE = 1;
private Bitmap bitmap;
private ImageView imageView;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
imageView = (ImageView) findViewById(R.id.result);
}
public void onClick(View View) {
Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
intent.addCategory(Intent.CATEGORY_OPENABLE);
startActivityForResult(intent, REQUEST_CODE);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
InputStream stream = null;
if (requestCode == REQUEST_CODE && resultCode == Activity.RESULT_OK)
try {
// recyle unused bitmaps
if (bitmap != null) {
bitmap.recycle();
}
stream = getContentResolver().openInputStream(data.getData());
bitmap = BitmapFactory.decodeStream(stream);
imageView.setImageBitmap(bitmap);
} catch (FileNotFoundException e) {
e.printStackTrace();
} finally ch (IOException e) {
e{
if (stream != null)
try {
stream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}4. Tutorial: Using the camera API
In this tutorial you create application which allows you to make a photo via the front camera and to save it on the SD card.
| If you use the Android emulator ensure that you configured the camera and that you added an SD card during the creation of the your Android virtual device. |
Create a new Android project called
de.vogella.camera.api
with an
activity
called
MakePhotoActivity.
Add the
android.permission.CAMERA
permission to access your camera and the
android.permission.WRITE_EXTERNAL_STORAGE
to be able to write to the SD card to your
AndroidManifest.xml
file.
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="de.vogella.cameara.api"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="15" />
<uses-permission android:name="android.permission.CAMERA"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name" >
<activity
android:name="de.vogella.camera.api.MakePhotoActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>Change the main.xml file in the <filename class="directory">res/layout_ folder to the following
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<Button
android:id="@+id/captureFront"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:onClick="onClick"
android:text="Make Photo" />
</RelativeLayout>Create the following
PhotoHandler
class which will be responsible for saving the photo the SD card.
package de.vogella.camera.api;
import java.io.File;
import java.io.FileOutputStream;
import java.text.SimpleDateFormat;
import java.util.Date;
import android.content.Context;
import android.hardware.Camera;
import android.hardware.Camera.PictureCallback;
import android.os.Environment;
import android.util.Log;
import android.widget.Toast;
public class PhotoHandler implements PictureCallback {
private final Context context;
public PhotoHandler(Context context) {
this.context = context;
}
@Override
public void onPictureTaken(byte[] data, Camera camera) {
File pictureFileDir = getDir();
if (!pictureFileDir.exists() && !pictureFileDir.mkdirs()) {
Log.d(MakePhotoActivity.DEBUG_TAG, "Can't create directory to save image.");
Toast.makeText(context, "Can't create directory to save image.",
Toast.LENGTH_LONG).show();
return;
}
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyymmddhhmmss");
String date = dateFormat.format(new Date());
String photoFile = "Picture_" + date + ".jpg";
String filename = pictureFileDir.getPath() + File.separator + photoFile;
File pictureFile = new File(filename);
try {
FileOutputStream fos = new FileOutputStream(pictureFile);
fos.write(data);
fos.close();
Toast.makeText(context, "New Image saved:" + photoFile,
Toast.LENGTH_LONG).show();
} catch (Exception error) {
Log.d(MakePhotoActivity.DEBUG_TAG, "File" + filename + "not saved: "
+ error.getMessage());
Toast.makeText(context, "Image could not be saved.",
Toast.LENGTH_LONG).show();
}
}
private File getDir() {
File sdDir = Environment
.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
return new File(sdDir, "CameraAPIDemo");
}
}Change the
MakePhotoActivity
`
class to the following. This class assumes that you have a button
in
your layout with the
`onClick
property pointing to a
onClick()
method.
package de.vogella.camera.api;
import android.app.Activity;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.hardware.Camera.CameraInfo;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Toast;
import de.vogella.cameara.api.R;
public class MakePhotoActivity extends Activity {
private final static String DEBUG_TAG = "MakePhotoActivity";
private Camera camera;
private int cameraId = 0;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// do we have a camera?
if (!getPackageManager()
.hasSystemFeature(PackageManager.FEATURE_CAMERA)) {
Toast.makeText(this, "No camera on this device", Toast.LENGTH_LONG)
.show();
} else {
cameraId = findFrontFacingCamera();
if (cameraId < 0) {
Toast.makeText(this, "No front facing camera found.",
Toast.LENGTH_LONG).show();
} else {
camera = Camera.open(cameraId);
}
}
}
public void onClick(View view) {
camera.startPreview();
camera.takePicture(null, null,
new PhotoHandler(getApplicationContext()));
}
private int findFrontFacingCamera() {
int cameraId = -1;
// Search for the front facing camera
int numberOfCameras = Camera.getNumberOfCameras();
for (int i = 0; i < numberOfCameras; i++) {
CameraInfo info = new CameraInfo();
Camera.getCameraInfo(i, info);
if (info.facing == CameraInfo.CAMERA_FACING_FRONT) {
Log.d(DEBUG_TAG, "Camera found");
cameraId = i;
break;
}
}
return cameraId;
}
@Override
protected void onPause() {
if (camera != null) {
camera.release();
camera = null;
}
super.onPause();
}
}