Develop Reference

using camera.hardware reduces image quality

I have been following two links to create custom camera for my application. I have been successful in opening the camera. The problem is that it reduces that image quality. The links I have been following are these:
http://www.coderzheaven.com/2011/12/28/how-to-create-a-custom-layout-for-your-camera-in-android/
http://blog.rhesoft.com/2015/04/02/tutorial-how-to-use-camera-with-android-and-android-studio/
and my code is:
Camera Activity:
public class CameraSetter extends Activity {
public Context context;
public int CAMERA;
// ImageView photo_setter;
private Camera mCamera = null;
private CameraView mCameraView = null;
public CameraSetter() {
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
TypefaceProvider.registerDefaultIconSets();
setContentView(R.layout.camera_preview);
Initialize();
}
private void Initialize() {
//photo_setter = (ImageView)findViewById(R.id.imview_camera_setter);
try {
mCamera = Camera.open();//you can use open(int) to use different cameras
} catch (Exception e) {
Log.d("ERROR", "Failed to get camera: " + e.getMessage());
}
if (mCamera != null) {
mCameraView = new CameraView(this, mCamera);//create a SurfaceView to show camera data
FrameLayout camera_view = (FrameLayout) findViewById(R.id.camera_view);
camera_view.addView(mCameraView);//add the SurfaceView to the layout
}
//btn to close the application
ImageButton imgClose = (ImageButton) findViewById(R.id.imgClose);
imgClose.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
System.exit(0);
}
});
}
}
and my cameraview class is:
public class CameraView extends SurfaceView implements SurfaceHolder.Callback {
private SurfaceHolder mHolder;
private Camera mCamera;
public CameraView(Context context, Camera camera) {
super(context);
mCamera = camera;
mCamera.setDisplayOrientation(90);
//get the holder and set this class as the callback, so we can get camera data here
mHolder = getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_NORMAL);
}
#Override
public void surfaceCreated(SurfaceHolder surfaceHolder) {
try {
//when the surface is created, we can set the camera to draw images in this surfaceholder
mCamera.setPreviewDisplay(surfaceHolder);
mCamera.startPreview();
} catch (IOException e) {
Log.d("ERROR", "Camera error on surfaceCreated " + e.getMessage());
}
}
#Override
public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i2, int i3) {
if (mHolder.getSurface() == null)//check if the surface is ready to receive camera data
return;
try {
mCamera.stopPreview();
} catch (Exception e) {
//this will happen when you are trying the camera if it's not running
}
//now, recreate the camera preview
try {
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
} catch (IOException e) {
Log.d("ERROR", "Camera error on surfaceChanged " + e.getMessage());
}
}
#Override
public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
//our app has only one screen, so we'll destroy the camera in the surface
//if you are unsing with more screens, please move this code your activity
mCamera.stopPreview();
mCamera.release();
}
}
Can I increase the image quality using the same code or I have to do something else?

problem is solved by adding in surfacechanged:
Camera.Parameters parameters = mCamera.getParameters();
parameters.setFlashMode(Camera.Parameters.FLASH_MODE_AUTO);
parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);
parameters.setJpegQuality(100);
parameters.setRotation(90);
List<Camera.Size> sizes = parameters.getSupportedPictureSizes();
Camera.Size size = sizes.get(0);
for(int j=0;j<sizes.size();j++)
{
if(sizes.get(j).width > size.width)
size = sizes.get(j);
}
parameters.setPictureSize(size.width, size.height);
Display display = ((WindowManager) getContext().getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
if (display.getRotation() == Surface.ROTATION_0) {
mCamera.setDisplayOrientation(90);
} else if (display.getRotation() == Surface.ROTATION_270) {
mCamera.setDisplayOrientation(180);
}
mCamera.setParameters(parameters);

Why does scheduleWithFixedDelay only run once?

My program is suppose to store a byte[] image from the camera in an ArrayList every 250 ms.
I am testing the same code on 2 separate devices:
the first is a Nexus 7 running Android 4.4.2 and the second is a Nexus 10 running Android 4.4.3.
The Nexus 7 runs the scheduleWithFixedDelay function perfectly, but the Nexus 10 does not. The Nexus 10 runs it once and then stops.
class RunnableCamera implements Runnable {
ScheduledExecutorService serviceCam = Executors.newSingleThreadScheduledExecutor();
#Override
public void run() {
startCamera CAM = new startCamera();
serviceCam.scheduleWithFixedDelay(new Runnable()
{
#Override
public void run()
{
camera.takePicture(null, null, mPicture);
}
}, 0, 250, TimeUnit.MILLISECONDS);
}
private PictureCallback mPicture = new PictureCallback() {
#Override
public void onPictureTaken(byte[] data, Camera camera) {
camera.startPreview();
imagesArrayList.add(data);
Log.d("image", "byte[] added to ArrayList");
}
};
public class startCamera implements Callback {
//private Camera camera;
private SurfaceHolder holder = null;
public startCamera() {
videoView = (VideoView) findViewById(R.id.vwCamera);
holder = videoView.getHolder();
holder.addCallback(this);
Log.d("bro", "startCamera() constructor");
}
#Override
public void surfaceCreated(SurfaceHolder holder) {
try {
Log.i("bro", "surfaceCreated");
camera = Camera.open(0);
camera.setDisplayOrientation(90);
if (camera != null) {
camera.setPreviewDisplay(holder);
} else {
Log.i("bro", "camera = null");
}
} catch (Exception e) {
Log.v(TAG, "Could not start the preview-Display123");
e.printStackTrace();
}
}
#Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
Log.i("bro", "surfaceChanged");
//Sets correct preview resolution
if (holder.getSurface() == null){
Log.i("bro", "holder.getSurface() == null");
return;
}
Camera.Parameters parameters = camera.getParameters();
Log.i("bro", "camera.getParameters();");
sizes = parameters.getSupportedPreviewSizes();
Log.i("bro", "parameters.getSupportedPreviewSizes();");
Camera.Size optimalSize = getBestPreviewSize(width, height);
try {
parameters.setPreviewSize(optimalSize.width, optimalSize.height);
camera.setParameters(parameters);
} catch (NullPointerException a) {
}
Log.i("bro", "startPreview()");
camera.startPreview();
}
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
Log.i("bro", "surfaceDestroyed");
if (camera != null) {
camera.stopPreview();
camera.release();
Log.i("bro", "CAMERA STOPPED");
}
}
private Camera.Size getBestPreviewSize(int width, int height) {
Camera.Size result = null;
Camera.Parameters p = camera.getParameters();
for (Camera.Size size : p.getSupportedPreviewSizes()) {
if (size.width <= width && size.height <= height) {
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;
}
}
}
In my onCreate method I start the Runnable class like:
Thread thread1 = new Thread(new RunnableCamera());
thread1.start();
If I change the time delay to 600 ms, the Nexus 10 runs it perfectly. I'm wondering if this is a device issue with the first generation Nexus 10, an Android 4.4.3 issue or something wrong with my code. Is there a better way to do this?

app hanging on camera.release()

I'm working on a flashlight app using the camera flash. It seems to work fine but on occasion calling camera.release() causes a hang for about a minute or so. I've included the code below. I've looked at a bunch of examples and I don't see anything that could cause such a thing. Any ideas?
//latest
public void setOn(boolean on, Context context) {
if (lock) {
Log.i(TAG, "lock: true");
return;
}
if (on) {
if (mCamera == null) {
mCamera = Camera.open();
}
Parameters params = mCamera.getParameters();
params.setFlashMode(MODE_TORCH);
mCamera.setParameters(params);
mCamera.startPreview();
} else {
if (mCamera != null) {
try {
Parameters params = mCamera.getParameters();
params.setFlashMode(MODE_OFF);
mCamera.setParameters(params);
} finally {
new Thread(new Runnable() {
public void run() {
Log.i(TAG, "new Thread - start");
lock = true;
mCamera.setPreviewCallback(null);
mCamera.stopPreview();
mCamera.release();
mCamera = null;
lock = false;
Log.i(TAG, "new Thread - end");
}
}).start();
}
}
}
}
//original
public void setOn(boolean on, Context context) {
Camera camera = mCamera;
if (on) {
if (camera == null) {
mCamera = camera = Camera.open();
}
Parameters params = camera.getParameters();
params.setFlashMode(MODE_TORCH);
camera.setParameters(params);
camera.startPreview();
} else {
if (camera != null) {
try {
Parameters params = camera.getParameters();
params.setFlashMode(MODE_OFF);
camera.setParameters(params);
} finally {
camera.stopPreview();
camera.release();
mCamera = camera = null;
}
}
}
}

Try putting it in a thread to run in the background so it wont hang up the UI.
new Thread(new Runnable(){
public void run(){
camera.setPreviewCallback(null); // PreviewCallback de_init.
camera.stopPreview(); // stop Preview
camera.release();
}
}).start();

For me, the solution that works is:
Try{
camera.stopPreview();
camera.setPreviewCallback(null);
camera.release();
camera = null;
} catch (Exception e){
//...
}

I`ve solved this isuue adding camera.unlock() before release()
camera.stopPreview();
camera.setPreviewCallback(null);
camera.unlock();
camera.release();
camera = null;
test on more devices needed...

just call your methods like
mCamera.stopPreview();
mCamera.setPreviewCallback(null);
mCamera.release();
you have to call setPreviewCallback(null) betweeen stopPreview and camera.releass

onPictureTaken function the light is automatically go down

I've run into such a problem. The problem is that when I use onPictureTaken function the light is automatically go down. What should I do with it? I want the light not to turn off.
Photo :
if (v == shot)
{
camera.takePicture (null, null, null, this);
}
flashlight:
if (prefs.getBoolean (getString (R.string.torch), false))
{
Parameters params = camera.getParameters ();
params.setFlashMode (Parameters.FLASH_MODE_TORCH);
camera.setParameters (params);
}
#Override
public void surfaceCreated(SurfaceHolder holder)
{
try
{
camera.setPreviewCallback(this);
camera.setPreviewDisplay(holder);
Camera.Parameters p = camera.getParameters();
p.setPictureSize(1024, 768);
p.setPictureFormat (PixelFormat.RGB_565);
camera.setParameters(p);
}
catch (IOException e)
{
e.printStackTrace();
}
LayoutParams lp = preview.getLayoutParams();
if (this.getResources().getConfiguration().orientation != Configuration.UI_MODE_TYPE_CAR)
{
camera.setDisplayOrientation(90);
}
else
{
camera.setDisplayOrientation(0);
}
preview.setLayoutParams(lp);
camera.startPreview();
return;
}
#Override
protected void onPause()
{
if (camera != null)
{
camera.setPreviewCallback(null);
camera.stopPreview();
camera.release();
camera = null;
}
super.onPause();
return ;
}
protected void onResume()
{
super.onResume();
camera = Camera.open();
}

switch back/front camera on fly

If I use only CAMERA_FACING_BACK or CAMERA_FACING_FRONT all works fine.
I have trouble with switch from CAMERA_FACING_BACK to CAMERA_FACING_FRONT.
My code snippet:
public class PhotoCameraActivity extends Activity implements OnClickListener {
private SurfaceView cameraView;
private Button turnButton;
private Camera camera = null;
private Callback listener;
private static int camId = Camera.CameraInfo.CAMERA_FACING_BACK;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.photo_camera_main);
prepareActivity();
}
private void prepareActivity() {
cameraView = (SurfaceView) findViewById(R.id.photo_camera_surface_view);
turnButton = (ImageButton) findViewById(R.id.turn_button);
turnButton.setOnClickListener(this);
}
#Override
public void onClick(View v) {
if (v.equals(turnButton)) {
if (Camera.getNumberOfCameras() > 1 && camId < Camera.getNumberOfCameras() - 1) {
startCamera(camId + 1);
} else {
startCamera(Camera.CameraInfo.CAMERA_FACING_BACK);
}
}
}
#Override
protected void onResume() {
startCamera(camId);
super.onResume();
}
#Override
protected void onPause() {
stopCamera();
super.onPause();
}
private void startCamera(int cameraId) {
if (camera != null) {
stopCamera();
}
holder = cameraView.getHolder();
listener = new Callback() {
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
}
#Override
public void surfaceCreated(SurfaceHolder holder) {
try {
camera.setPreviewDisplay(holder);
camera.startPreview();
} catch (IOException e) {
e.printStackTrace();
}
}
#Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {}
};
holder.addCallback(listener);
camId = cameraId;
camera = Camera.open(cameraId);
Camera.Parameters params = camera.getParameters();
if (cameraId == Camera.CameraInfo.CAMERA_FACING_BACK) {
params.setPreviewSize(1280, 800);
} else {
params.setPreviewSize(640, 480);
}
camera.setParameters(params);
}
private void stopCamera(){
System.out.println("stopCamera method");
if (camera != null){
camera.stopPreview();
camera.setPreviewCallback(null);
camera.release();
camera = null;
holder.removeCallback(listener);
holder = null;
}
}
}

In onCreate() of my activity I add the following onClick listener to a button overlayed on my Preview SurfaceView (there are numerous example on the web for previewing):
ImageButton useOtherCamera = (ImageButton) findViewById(R.id.useOtherCamera);
//if phone has only one camera, hide "switch camera" button
if(Camera.getNumberOfCameras() == 1){
useOtherCamera.setVisibility(View.INVISIBLE);
}
else {
useOtherCamera.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (inPreview) {
camera.stopPreview();
}
//NB: if you don't release the current camera before switching, you app will crash
camera.release();
//swap the id of the camera to be used
if(currentCameraId == Camera.CameraInfo.CAMERA_FACING_BACK){
currentCameraId = Camera.CameraInfo.CAMERA_FACING_FRONT;
}
else {
currentCameraId = Camera.CameraInfo.CAMERA_FACING_BACK;
}
camera = Camera.open(currentCameraId);
//Code snippet for this method from somewhere on android developers, i forget where
setCameraDisplayOrientation(CameraActivity.this, currentCameraId, camera);
try {
//this step is critical or preview on new camera will no know where to render to
camera.setPreviewDisplay(previewHolder);
} catch (IOException e) {
e.printStackTrace();
}
camera.startPreview();
}
On my test device the back camera has an ID of 0 and the front has an id of 1. I suggest using Camera.CameraInfo static variables for your camera id's rather than hard-coding values. I am sure that will only cause issues on other devices.

I restart Activity with cameraId = 2 and this is working.

I removed and re-added SurfaceView in my layout and so it worked.
public void switchCamera(int cameraType)
{
if(context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA_FRONT))
{
if(Camera.getNumberOfCameras() > cameraType)
{
// Set selected camera
this.cameraType = cameraType;
}
else
{
// Set default camera (Rear)
this.cameraType = Camera.CameraInfo.CAMERA_FACING_BACK;
}
if(mCamera != null)
{
// Destroy previuos Holder
surfaceDestroyed(holder);
holder.removeCallback(this);
// Remove and re-Add SurfaceView
ViewGroup rootLayout = (ViewGroup) surface.getParent();
rootLayout.removeView(surface);
surface = new SurfaceView(context);
holder = surface.getHolder();
holder.addCallback(this);
rootLayout.addView(surface, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
}
}
}

I have to remove the surface preview before adding a new one:
if (mPreview != null) {
mPreview.surfaceDestroyed(mPreview.getHolder());
mPreview.getHolder().removeCallback(mPreview);
mPreview.destroyDrawingCache();
FrameLayout preview = (FrameLayout) view.findViewById(R.id.camera_frame);
preview.removeView(mPreview);
mPreview.mCamera = null;
mPreview = null;
}
//then add your preview

Use this code:
if (mCamera != null) {
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
//swap the id of the camera to be used
if (currentCameraId == Camera.CameraInfo.CAMERA_FACING_BACK)
currentCameraId = Camera.CameraInfo.CAMERA_FACING_FRONT;
else
currentCameraId = Camera.CameraInfo.CAMERA_FACING_BACK;
try {
mCamera = Camera.open(currentCameraId);
mCamera.setDisplayOrientation(90);
mCamera.setPreviewDisplay(surfaceHolder);
mCamera.startPreview();
}
catch (Exception e) { e.printStackTrace(); }

try using this:
camera.stopPreview();
if(camera != null)
camera.release();
try {
camera = Camera.open(/*new id*/);
camera.setPreviewDisplay(holder);
camera.startPreview();
} catch (Exception ex) { ex.printStackTrace(); }