カメラアプリケーションを使用せずにバックグラウンドで画像をキャプチャする方法
私はAndroidボタンで構成されるアプリを持っています。
ボタンをクリックすると、カメラアプリケーションを開かずにカメラから画像をキャプチャする必要があります（画像はバックグラウンドでキャプチャする必要があります）。
この機能を実装するには？
どんな提案も大いに役立ちます。
よろしくお願いします。
これは、SurfaceViewを使用せずにバックグラウンドで画像をキャプチャする方法に関する私の全体的な作業プロジェクトです。
//サービスを開始して、活動から除外したくない場所に画像をキャプチャできます。
Intent front_translucent = new Intent(getApplication()
.getApplicationContext(), CameraService.class);
front_translucent.putExtra("Front_Request", true);
front_translucent.putExtra("Quality_Mode",
camCapture.getQuality());
getApplication().getApplicationContext().startService(
front_translucent);
public class CamerService extends Service implements
SurfaceHolder.Callback {
// Camera variables
// a surface holder
// a variable to control the camera
private Camera mCamera;
// the camera parameters
private Parameters parameters;
private Bitmap bmp;
FileOutputStream fo;
private String FLASH_MODE;
private int QUALITY_MODE = 0;
private boolean isFrontCamRequest = false;
private Camera.Size pictureSize;
SurfaceView sv;
private SurfaceHolder sHolder;
private WindowManager windowManager;
WindowManager.LayoutParams params;
public Intent cameraIntent;
SharedPreferences pref;
Editor editor;
int width = 0, height = 0;
/** Called when the activity is first created. */
@Override
public void onCreate() {
super.onCreate();
}
private Camera openFrontFacingCameraGingerbread() {
if (mCamera != null) {
mCamera.stopPreview();
mCamera.release();
}
int cameraCount = 0;
Camera cam = null;
Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
cameraCount = Camera.getNumberOfCameras();
for (int camIdx = 0; camIdx < cameraCount; camIdx++) {
Camera.getCameraInfo(camIdx, cameraInfo);
if (cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
try {
cam = Camera.open(camIdx);
} catch (RuntimeException e) {
Log.e("Camera",
"Camera failed to open: " + e.getLocalizedMessage());
/*
* Toast.makeText(getApplicationContext(),
* "Front Camera failed to open", Toast.LENGTH_LONG)
* .show();
*/
}
}
}
return cam;
}
private void setBesttPictureResolution() {
// get biggest picture size
width = pref.getInt("Picture_Width", 0);
height = pref.getInt("Picture_height", 0);
if (width == 0 | height == 0) {
pictureSize = getBiggesttPictureSize(parameters);
if (pictureSize != null)
parameters
.setPictureSize(pictureSize.width, pictureSize.height);
// save width and height in sharedprefrences
width = pictureSize.width;
height = pictureSize.height;
editor.putInt("Picture_Width", width);
editor.putInt("Picture_height", height);
editor.commit();
} else {
// if (pictureSize != null)
parameters.setPictureSize(width, height);
}
}
private Camera.Size getBiggesttPictureSize(Camera.Parameters parameters) {
Camera.Size result = null;
for (Camera.Size size : parameters.getSupportedPictureSizes()) {
if (result == null) {
result = size;
} else {
int resultArea = result.width * result.height;
int newArea = size.width * size.height;
if (newArea > resultArea) {
result = size;
}
}
}
return (result);
}
/** Check if this device has a camera */
private boolean checkCameraHardware(Context context) {
if (context.getPackageManager().hasSystemFeature(
PackageManager.FEATURE_CAMERA)) {
// this device has a camera
return true;
} else {
// no camera on this device
return false;
}
}
/** Check if this device has front camera */
private boolean checkFrontCamera(Context context) {
if (context.getPackageManager().hasSystemFeature(
PackageManager.FEATURE_CAMERA_FRONT)) {
// this device has front camera
return true;
} else {
// no front camera on this device
return false;
}
}
Handler handler = new Handler();
private class TakeImage extends AsyncTask<Intent, Void, Void> {
@Override
protected Void doInBackground(Intent... params) {
takeImage(params[0]);
return null;
}
@Override
protected void onPostExecute(Void result) {
}
}
private synchronized void takeImage(Intent intent) {
if (checkCameraHardware(getApplicationContext())) {
Bundle extras = intent.getExtras();
if (extras != null) {
String flash_mode = extras.getString("FLASH");
FLASH_MODE = flash_mode;
boolean front_cam_req = extras.getBoolean("Front_Request");
isFrontCamRequest = front_cam_req;
int quality_mode = extras.getInt("Quality_Mode");
QUALITY_MODE = quality_mode;
}
if (isFrontCamRequest) {
// set flash 0ff
FLASH_MODE = "off";
// only for Gingerbread and newer versions
if (Android.os.Build.VERSION.SDK_INT >= Android.os.Build.VERSION_CODES.Gingerbread) {
mCamera = openFrontFacingCameraGingerbread();
if (mCamera != null) {
try {
mCamera.setPreviewDisplay(sv.getHolder());
} catch (IOException e) {
handler.post(new Runnable() {
@Override
public void run() {
Toast.makeText(getApplicationContext(),
"API dosen't support front camera",
Toast.LENGTH_LONG).show();
}
});
stopSelf();
}
Camera.Parameters parameters = mCamera.getParameters();
pictureSize = getBiggesttPictureSize(parameters);
if (pictureSize != null)
parameters
.setPictureSize(pictureSize.width, pictureSize.height);
// set camera parameters
mCamera.setParameters(parameters);
mCamera.startPreview();
mCamera.takePicture(null, null, mCall);
// return 4;
} else {
mCamera = null;
handler.post(new Runnable() {
@Override
public void run() {
Toast.makeText(
getApplicationContext(),
"Your Device dosen't have Front Camera !",
Toast.LENGTH_LONG).show();
}
});
stopSelf();
}
/*
* sHolder = sv.getHolder(); // tells Android that this
* surface will have its data // constantly // replaced if
* (Build.VERSION.SDK_INT < 11)
*
* sHolder.setType(SurfaceHolder.SURFACE_TYPE_Push_BUFFERS)
*/
} else {
if (checkFrontCamera(getApplicationContext())) {
mCamera = openFrontFacingCameraGingerbread();
if (mCamera != null) {
try {
mCamera.setPreviewDisplay(sv.getHolder());
} catch (IOException e) {
handler.post(new Runnable() {
@Override
public void run() {
Toast.makeText(
getApplicationContext(),
"API dosen't support front camera",
Toast.LENGTH_LONG).show();
}
});
stopSelf();
}
Camera.Parameters parameters = mCamera.getParameters();
pictureSize = getBiggesttPictureSize(parameters);
if (pictureSize != null)
parameters
.setPictureSize(pictureSize.width, pictureSize.height);
// set camera parameters
mCamera.setParameters(parameters);
mCamera.startPreview();
mCamera.takePicture(null, null, mCall);
// return 4;
} else {
mCamera = null;
/*
* Toast.makeText(getApplicationContext(),
* "API dosen't support front camera",
* Toast.LENGTH_LONG).show();
*/
handler.post(new Runnable() {
@Override
public void run() {
Toast.makeText(
getApplicationContext(),
"Your Device dosen't have Front Camera !",
Toast.LENGTH_LONG).show();
}
});
stopSelf();
}
// Get a surface
/*
* sHolder = sv.getHolder(); // tells Android that this
* surface will have its data // constantly // replaced
* if (Build.VERSION.SDK_INT < 11)
*
* sHolder.setType(SurfaceHolder.SURFACE_TYPE_Push_BUFFERS
* );
*/
}
}
} else {
if (mCamera != null) {
mCamera.stopPreview();
mCamera.release();
mCamera = Camera.open();
} else
mCamera = getCameraInstance();
try {
if (mCamera != null) {
mCamera.setPreviewDisplay(sv.getHolder());
parameters = mCamera.getParameters();
if (FLASH_MODE == null || FLASH_MODE.isEmpty()) {
FLASH_MODE = "auto";
}
parameters.setFlashMode(FLASH_MODE);
// set biggest picture
setBesttPictureResolution();
// log quality and image format
Log.d("Qaulity", parameters.getJpegQuality() + "");
Log.d("Format", parameters.getPictureFormat() + "");
// set camera parameters
mCamera.setParameters(parameters);
mCamera.startPreview();
Log.d("ImageTakin", "OnTake()");
mCamera.takePicture(null, null, mCall);
} else {
handler.post(new Runnable() {
@Override
public void run() {
Toast.makeText(getApplicationContext(),
"Camera is unavailable !",
Toast.LENGTH_LONG).show();
}
});
}
// return 4;
} catch (IOException e) {
// TODO Auto-generated catch block
Log.e("TAG", "CmaraHeadService()::takePicture", e);
}
// Get a surface
/*
* sHolder = sv.getHolder(); // tells Android that this surface
* will have its data constantly // replaced if
* (Build.VERSION.SDK_INT < 11)
*
* sHolder.setType(SurfaceHolder.SURFACE_TYPE_Push_BUFFERS);
*/
}
} else {
// display in long period of time
/*
* Toast.makeText(getApplicationContext(),
* "Your Device dosen't have a Camera !", Toast.LENGTH_LONG)
* .show();
*/
handler.post(new Runnable() {
@Override
public void run() {
Toast.makeText(getApplicationContext(),
"Your Device dosen't have a Camera !",
Toast.LENGTH_LONG).show();
}
});
stopSelf();
}
// return super.onStartCommand(intent, flags, startId);
}
@SuppressWarnings("deprecation")
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
// sv = new SurfaceView(getApplicationContext());
cameraIntent = intent;
Log.d("ImageTakin", "StartCommand()");
pref = getApplicationContext().getSharedPreferences("MyPref", 0);
editor = pref.edit();
windowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
params = new WindowManager.LayoutParams(
WindowManager.LayoutParams.WRAP_CONTENT,
WindowManager.LayoutParams.WRAP_CONTENT,
WindowManager.LayoutParams.TYPE_PHONE,
WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE,
PixelFormat.TRANSLUCENT);
params.gravity = Gravity.TOP | Gravity.LEFT;
params.width = 1;
params.height = 1;
params.x = 0;
params.y = 0;
sv = new SurfaceView(getApplicationContext());
windowManager.addView(sv, params);
sHolder = sv.getHolder();
sHolder.addCallback(this);
// tells Android that this surface will have its data constantly
// replaced
if (Build.VERSION.SDK_INT < 11)
sHolder.setType(SurfaceHolder.SURFACE_TYPE_Push_BUFFERS);
return 1;
}
Camera.PictureCallback mCall = new Camera.PictureCallback() {
@Override
public void onPictureTaken(byte[] data, Camera camera) {
// decode the data obtained by the camera into a Bitmap
Log.d("ImageTakin", "Done");
if (bmp != null)
bmp.recycle();
System.gc();
bmp = decodeBitmap(data);
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
if (bmp != null && QUALITY_MODE == 0)
bmp.compress(Bitmap.CompressFormat.JPEG, 70, bytes);
else if (bmp != null && QUALITY_MODE != 0)
bmp.compress(Bitmap.CompressFormat.JPEG, QUALITY_MODE, bytes);
File imagesFolder = new File(
Environment.getExternalStorageDirectory(), "MYGALLERY");
if (!imagesFolder.exists())
imagesFolder.mkdirs(); // <----
File image = new File(imagesFolder, System.currentTimeMillis()
+ ".jpg");
// write the bytes in file
try {
fo = new FileOutputStream(image);
} catch (FileNotFoundException e) {
Log.e("TAG", "FileNotFoundException", e);
// TODO Auto-generated catch block
}
try {
fo.write(bytes.toByteArray());
} catch (IOException e) {
Log.e("TAG", "fo.write::PictureTaken", e);
// TODO Auto-generated catch block
}
// remember close de FileOutput
try {
fo.close();
if (Build.VERSION.SDK_INT < 19)
sendBroadcast(new Intent(
Intent.ACTION_MEDIA_MOUNTED,
Uri.parse("file://"
+ Environment.getExternalStorageDirectory())));
else {
MediaScannerConnection
.scanFile(
getApplicationContext(),
new String[] { image.toString() },
null,
new MediaScannerConnection.OnScanCompletedListener() {
public void onScanCompleted(
String path, Uri uri) {
Log.i("ExternalStorage", "Scanned "
+ path + ":");
Log.i("ExternalStorage", "-> uri="
+ uri);
}
});
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
if (mCamera != null) {
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
/*
* Toast.makeText(getApplicationContext(),
* "Your Picture has been taken !", Toast.LENGTH_LONG).show();
*/
com.integreight.onesheeld.Log.d("Camera", "Image Taken !");
if (bmp != null) {
bmp.recycle();
bmp = null;
System.gc();
}
mCamera = null;
handler.post(new Runnable() {
@Override
public void run() {
Toast.makeText(getApplicationContext(),
"Your Picture has been taken !", Toast.LENGTH_SHORT)
.show();
}
});
stopSelf();
}
};
@Override
public IBinder onBind(Intent intent) {
return null;
}
public static Camera getCameraInstance() {
Camera c = null;
try {
c = Camera.open(); // attempt to get a Camera instance
} catch (Exception e) {
// Camera is not available (in use or does not exist)
}
return c; // returns null if camera is unavailable
}
@Override
public void onDestroy() {
if (mCamera != null) {
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
if (sv != null)
windowManager.removeView(sv);
Intent intent = new Intent("custom-event-name");
// You can also include some extra data.
intent.putExtra("message", "This is my message!");
LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
super.onDestroy();
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
// TODO Auto-generated method stub
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
if (cameraIntent != null)
new TakeImage().execute(cameraIntent);
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
if (mCamera != null) {
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
}
public static Bitmap decodeBitmap(byte[] data) {
Bitmap bitmap = null;
BitmapFactory.Options bfOptions = new BitmapFactory.Options();
bfOptions.inDither = false; // Disable Dithering mode
bfOptions.inPurgeable = true; // Tell to gc that whether it needs free
// memory, the Bitmap can be cleared
bfOptions.inInputShareable = true; // Which kind of reference will be
// used to recover the Bitmap data
// after being clear, when it will
// be used in the future
bfOptions.inTempStorage = new byte[32 * 1024];
if (data != null)
bitmap = BitmapFactory.decodeByteArray(data, 0, data.length,
bfOptions);
return bitmap;
}
}
ユーザーには表示されない偽のサーフェスビューを作成する必要があります。その後、次のコードで達成できます。
public class MainActivity extends Activity {
public static final int DONE = 1;
public static final int NEXT = 2;
public static final int PERIOD = 1;
private Camera camera;
private int cameraId = 0;
private ImageView display;
private Timer timer;
SurfaceHolder previewHolder;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
display = (ImageView) findViewById(R.id.imageView1);
// 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
{
safeCameraOpen(cameraId);
}
}
// THIS IS JUST A FAKE SURFACE TO TRICK THE CAMERA PREVIEW
// http://stackoverflow.com/questions/17859777/how-to-take-pictures-in-Android-
// application-without-the-user-interface
SurfaceView dummy = new SurfaceView(this);
previewHolder = dummy.getHolder();
previewHolder.setType(SurfaceHolder.SURFACE_TYPE_Push_BUFFERS);
try {
camera.setPreviewDisplay(previewHolder);
} catch (IOException e1) {
e1.printStackTrace();
}
/*SurfaceView view = new SurfaceView(this);
try {
// camera.setPreviewDisplay(view.getHolder());
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}*/
Camera.Parameters params = camera.getParameters();
params.setJpegQuality(100);
camera.setParameters(params);
// We need something to trigger periodically the capture of a
// picture to be processed
timer = new Timer(getApplicationContext(), threadHandler);
timer.execute();
}
// thread Handler //
private Handler threadHandler = new Handler() {
public void handleMessage(Android.os.Message msg) {
switch (msg.what) {
case DONE:
camera.startPreview();
previewHolder.setType(SurfaceHolder.SURFACE_TYPE_Push_BUFFERS);
try {
camera.setPreviewDisplay(previewHolder);
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
camera.takePicture(null, null, mCall);
break;
case NEXT:
timer = new Timer(getApplicationContext(), threadHandler);
timer.execute();
break;
}
}
};
Camera.PictureCallback mCall = new Camera.PictureCallback() {
public void onPictureTaken(byte[] data, Camera camera) {
// decode the data obtained by the camera into a Bitmap
// display.setImageBitmap(photo);
Bitmap bitmapPicture = BitmapFactory.decodeByteArray(data, 0,
data.length);
display.setImageBitmap(bitmapPicture);
Message.obtain(threadHandler, MainActivity.NEXT, "").sendToTarget();
// Log.v("MyActivity","Length: "+data.length);
}
};
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.v("MyActivity", "Camera found");
cameraId = i;
break;
}
}
return cameraId;
}
@Override
protected void onPause() {
if (timer != null) {
timer.cancel(true);
}
releaseCamera();
super.onPause();
}
// I think Android Documentation recommends doing this in a separate
// task to avoid blocking main UI
private boolean safeCameraOpen(int id) {
boolean qOpened = false;
try {
releaseCamera();
camera = Camera.open(id);
qOpened = (camera != null);
} catch (Exception e) {
Log.e(getString(R.string.app_name), "failed to open Camera");
e.printStackTrace();
}
return qOpened;
}
private void releaseCamera() {
if (camera != null) {
camera.stopPreview();
camera.release();
camera = null;
}
}
}
CAMERA2 API（API 21で追加）を使用している場合は、ここで私の答えを親切に確認してください camera2 APIを使用してプレビューせずに画像をキャプチャする
それが役に立てば幸い:)