Develop Reference

making text scanner but shows black screen instead of camera

I am trying to make a text scanner application with camera that recognizes text and shows in screen.But instead of showing camera it shows a black screen. How can I solve this.
My code is here
package com.myapp.game.easynepalirecharge;
import android.Manifest;
import android.app.ActionBar;
import android.content.pm.PackageManager;
import android.graphics.Camera;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.util.SparseArray;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.ViewGroup;
import android.widget.TextView;
import com.google.android.gms.vision.CameraSource;
import com.google.android.gms.vision.Detector;
import com.google.android.gms.vision.text.TextBlock;
import com.google.android.gms.vision.text.TextRecognizer;
import java.io.IOException;
public class MainActivity extends AppCompatActivity {
SurfaceView cameraView;
TextView textView;
CameraSource cameraSource;
final int REQUESTCAMERAPERMISSION = 105;
#Override
public void onRequestPermissionsResult(int requestCode, #NonNull String[] permissions, #NonNull final int[] grantResults) {
switch (requestCode) {
case REQUESTCAMERAPERMISSION:
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
if (ActivityCompat.checkSelfPermission(getApplication(), Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
return;
}
try {
cameraSource.start(cameraView.getHolder());
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
cameraView = (SurfaceView) findViewById(R.id.surfaceView);
textView = (TextView) findViewById(R.id.textView);
TextRecognizer textRecognizer = new TextRecognizer.Builder(getApplicationContext()).build();
if (!textRecognizer.isOperational()) {
Log.v("haha", "error not operational");
} else {
cameraSource = new CameraSource.Builder(getApplicationContext(), textRecognizer).
setFacing(CameraSource.CAMERA_FACING_BACK)
.setRequestedPreviewSize(3840, 2160)
.setRequestedFps(2.0f)
.setAutoFocusEnabled(true)
.build();
cameraView.getHolder().addCallback(new SurfaceHolder.Callback() {
#Override
public void surfaceCreated(SurfaceHolder holder) {
try {
if (ActivityCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.CAMERA}, REQUESTCAMERAPERMISSION);
cameraSource.start(cameraView.getHolder());
return;
}
} catch (Exception e) {
e.printStackTrace();
}
}
#Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
}
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
cameraSource.stop();
}
});
textRecognizer.setProcessor(new Detector.Processor<TextBlock>() {
#Override
public void release() {
}
#Override
public void receiveDetections(Detector.Detections<TextBlock> detections) {
final SparseArray<TextBlock> items = detections.getDetectedItems();
if (items.size() != 0) {
textView.post(new Runnable() {
#Override
public void run() {
StringBuilder stringBuilder = new StringBuilder();
for (int i = 0; i <= items.size(); i++) {
TextBlock item = items.valueAt(i);
stringBuilder.append(item.getValue());
stringBuilder.append("\n");
}
textView.setText(stringBuilder.toString());
}
});
}
}
}
);
}
}
}
and another thing I wanna ask. Which one is better. This or the tess two library?

have you stopped camera properly. Try to do camera functions in thread so that your single task does not be expensive. The reason i thought problem is that get your permission at run time.
try this
https://developer.android.com/training/permissions/requesting.html

ImageWriter alternative for android 19-22?

In version 23 of the android API there was the introduction of the class ImageWriter.
I need to use this class in an app that should run on api 19.
How can I re-implement the class? Is there some equivalent code (I have an Image instance I need to draw to a surface)?

Here you have a code which allows you to take a picture and preview it on a Surface. I'm sure you can adapt the code for your purpose.
Here's the XML code:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<SurfaceView
android:id="#+id/preview"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="100dip"
android:layout_alignParentBottom="true"
android:gravity="center_vertical"
android:background="#A000">
<Button
android:layout_width="100dip"
android:layout_height="wrap_content"
android:text="Cancel"
android:onClick="onCancelClick"
/>
<Button
android:layout_width="100dip"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:text="Snap Photo"
android:onClick="onSnapClick"
/>
</RelativeLayout>
</RelativeLayout>
And here the Java code:
package app.test;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.List;
import android.app.Activity;
import android.hardware.Camera;
import android.os.Bundle;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.Toast;
public class PreviewActivity extends Activity implements SurfaceHolder.Callback, Camera.ShutterCallback, Camera.PictureCallback {
Camera mCamera;
SurfaceView mPreview;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mPreview = (SurfaceView)findViewById(R.id.preview);
mPreview.getHolder().addCallback(this);
mPreview.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
mCamera = Camera.open();
}
#Override
public void onPause() {
super.onPause();
mCamera.stopPreview();
}
#Override
public void onDestroy() {
super.onDestroy();
mCamera.release();
Log.d("CAMERA","Destroy");
}
public void onCancelClick(View v) {
finish();
}
public void onSnapClick(View v) {
mCamera.takePicture(this, null, null, this);
}
#Override
public void onShutter() {
Toast.makeText(this, "Click!", Toast.LENGTH_SHORT).show();
}
#Override
public void onPictureTaken(byte[] data, Camera camera) {
//Here, we chose internal storage
try {
FileOutputStream out = openFileOutput("picture.jpg", Activity.MODE_PRIVATE);
out.write(data);
out.flush();
out.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
camera.startPreview();
}
#Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
Camera.Parameters params = mCamera.getParameters();
List<Camera.Size> sizes = params.getSupportedPreviewSizes();
Camera.Size selected = sizes.get(0);
params.setPreviewSize(selected.width,selected.height);
mCamera.setParameters(params);
mCamera.setDisplayOrientation(90);
mCamera.startPreview();
}
#Override
public void surfaceCreated(SurfaceHolder holder) {
try {
mCamera.setPreviewDisplay(mPreview.getHolder());
} catch (Exception e) {
e.printStackTrace();
}
}
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
Log.i("PREVIEW","surfaceDestroyed");
}
}

Open camera in android using Camera Api

I have tried all the existing methods out there.. but everytime the application force closes. Here is the code. Please help me debugging it.
MainActivity.java
package com.example.camera1;
import android.os.Bundle;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.hardware.Camera;
import android.hardware.Camera.PictureCallback;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.FrameLayout;
import android.widget.ImageView;
import android.widget.Toast;
public class MainActivity extends Activity {
private Camera cameraObject;
private ShowCamera showCamera;
private ImageView pic;
public static Camera isCameraAvailiable(){
Camera object = null;
try { object = Camera.open();
} catch (Exception e){
} return object;
}
private PictureCallback capturedIt = new PictureCallback() {
#Override
public void onPictureTaken(byte[] data, Camera camera) {
Bitmap bitmap = BitmapFactory.decodeByteArray(data , 0, data .length);
if(bitmap==null){
Toast.makeText(getApplicationContext(), "not taken", Toast.LENGTH_SHORT).show();
}
else{
Toast.makeText(getApplicationContext(), "taken", Toast.LENGTH_SHORT).show();
}
cameraObject.release();
}
};
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
pic = (ImageView)findViewById(R.id.imageView1);
cameraObject = isCameraAvailiable();
showCamera = new ShowCamera(this, cameraObject);
FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
preview.addView(showCamera);
}
public void snapIt(View view){
cameraObject.takePicture(null, null, capturedIt);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
ShowCamera.java
package com.example.camera1;
import java.io.IOException;
import android.content.Context;
import android.hardware.Camera;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
public class ShowCamera extends SurfaceView implements SurfaceHolder.Callback {
private SurfaceHolder holdMe;
private Camera theCamera;
public ShowCamera(Context context,Camera camera) {
super(context);
theCamera = camera;
holdMe = getHolder();
holdMe.addCallback(this);
// TODO Auto-generated constructor stub
}
#Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
// TODO Auto-generated method stub
}
#Override
public void surfaceCreated(SurfaceHolder holder) {
// TODO Auto-generated method stub
try {
theCamera.setPreviewDisplay(holder);
theCamera.startPreview();
} catch (IOException e)
{
}
}
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
// TODO Auto-generated method stub
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<FrameLayout
android:id="#+id/camera_preview"
android:layout_width="fill_parent"
android:layout_height="199dp" >
</FrameLayout>
<Button
android:id="#+id/button_capture"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:onClick = "snapIt"
android:text="#string/Capture"/>
<ImageView
android:id="#+id/imageView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:scaleType="fitXY"
android:src="#drawable/ic_launcher"/>
</LinearLayout>
I am making this for android gingerbread and above versions. where my target sdk is Android Kitkat.
While testing the app on gingerbread it opens the application but simply shows a white screen that is it doesnt load the layout and force closes.. please help..!!

To open the camera,use the following code appropriately:
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD) {
Camera.CameraInfo info=new Camera.CameraInfo();
for (int i=0; i < Camera.getNumberOfCameras(); i++) {
Camera.getCameraInfo(i, info);
if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
camera=Camera.open(i);
}
}
}
if (camera == null) {
camera=Camera.open();
}
Add the SurfaceView to a FrameLayout in order to display it.
Instead of returning the Camera,you could instead use the global Camera instance variable.The camera is released in onPause like this:
mCamera.release();
mCamera=null;
//remove SurfaceView from the FrameLayout you added it to
You can retain the Camera.Parameters object and use it to set the parameters to the value by placing a check in your surfaceChanged.
You could also consider starting your Camera in a seperate Thread in onCreate as it has been done here:
//This code is from AOSP ICS:
Thread mCameraOpenThread = new Thread(new Runnable() {
public void run() {
try {
mCameraDevice = Util.openCamera(Camera.this, mCameraId);
} catch (CameraHardwareException e) {
mOpenCameraFail = true;
} catch (CameraDisabledException e) {
mCameraDisabled = true;
}
}
});
This is the onCreate method:
super.onCreate(icicle);
mCameraOpenThread.start();
SurfaceView preview = (SurfaceView) findViewById(R.id.camera_preview);
SurfaceHolder holder = preview.getHolder();
holder.addCallback(this);
holder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
// Make sure camera device is opened.
try {
mCameraOpenThread.join();
mCameraOpenThread = null;
}
catch(InterruptedException e)
{
//ignore
}
The link to the code is here http://android.googlesource.com/platform/packages/apps/Camera/+/ics-factoryrom-2-release/src/com/android/camera/Camera.java

Camera preview stops on activity restart

I made a camera preview app for android and everything works fine even when I press the power button to make device asleep, and waking it up again. But when my activity goes to background (like pressing home button) and then it comes to foreground again the program stops.
This is my activity code:
package com.example.campreview;
import com.example.campreview.CameraPreview;
import com.example.campreview.R;
import android.graphics.ImageFormat;
import android.hardware.Camera;
import android.hardware.Camera.AutoFocusCallback;
import android.hardware.Camera.PreviewCallback;
import android.os.Bundle;
import android.os.Handler;
import android.app.Activity;
import android.content.pm.ActivityInfo;
import android.view.Menu;
import android.view.View;
public class ScanActivity extends Activity {
private CameraPreview CamPrev = null;
private FrameLayout PreviewFrm;
private Camera cam = null;
private Handler atfcs;
private ImageScanner scnr;
private boolean hascam = false;
private boolean prvng = true;
private boolean paused = false;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_scan);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
PreviewFrm = (FrameLayout)findViewById(R.id.PreviewFrm);
StartCamera();
if (cam != null) {
hascam = true;
atfcs = new Handler();
CamPrev = new CameraPreview(this, cam, PreviewCB, AutoFocusCB);
PreviewFrm.addView(CamPrev);
}
}
#Override
public void onPause() {
ReleaseCamera();
paused = true;
super.onPause();
}
#Override
public void onResume() {
super.onResume();
if (paused) StartPreview();
}
private boolean StartCamera() {
boolean r = true;
if (cam == null) {
try {
cam = Camera.open();
} catch (Exception e) {
cam = null;
r = false;
}
if (cam != null) {
try {
Camera.Parameters p = cam.getParameters();
if (p.getSupportedFocusModes().contains(Camera.Parameters.FOCUS_MODE_AUTO))
p.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
if (p.getSupportedFlashModes().contains(Camera.Parameters.FLASH_MODE_OFF))
p.setFlashMode(Camera.Parameters.FLASH_MODE_OFF);
if (p.getSupportedPreviewFormats().contains(ImageFormat.NV21))
p.setPreviewFormat(ImageFormat.NV21);
Camera.Size s = null;
int a = 0, b;
for (Camera.Size z : p.getSupportedPreviewSizes()) {
b = z.width * z.height;
if (Math.abs(b - 307200) < Math.abs(a - 307200)) { //640x480 is the best
s = z;
a = b;
}
}
if (a != 0) p.setPreviewSize(s.width, s.height);
cam.setParameters(p);
cam.setDisplayOrientation(90);
if (CamPrev != null) cam.setPreviewDisplay(CamPrev.getHolder());
} catch (Exception e) {
r = false;
cam.release();
cam = null;
}
}
}
return r;
}
private void ReleaseCamera() {
if (cam != null) {
StopPreview();
cam.release();
cam = null;
}
}
public void StartPreview() {
if ((!prvng) & hascam) {
if (StartCamera()) {
cam.setPreviewCallback(PreviewCB);
cam.startPreview();
cam.autoFocus(AutoFocusCB);
prvng = true;
}
}
}
public void StopPreview() {
if (prvng) {
cam.stopPreview();
cam.setPreviewCallback(null);
prvng = false;
}
}
private Runnable DoAutoFocus = new Runnable() {
public void run() {
if (prvng) cam.autoFocus(AutoFocusCB);
}
};
AutoFocusCallback AutoFocusCB = new AutoFocusCallback() {
public void onAutoFocus(boolean success, Camera camera) {
atfcs.postDelayed(DoAutoFocus, 1000);
}
};
PreviewCallback PreviewCB = new PreviewCallback() {
public void onPreviewFrame(byte[] data, Camera camera) {
//
}
};
}
And this is the preview code:
package com.example.campreview;
import java.io.IOException;
import android.view.SurfaceView;
import android.view.SurfaceHolder;
import android.content.Context;
import android.hardware.Camera;
import android.hardware.Camera.PreviewCallback;
import android.hardware.Camera.AutoFocusCallback;
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
private SurfaceHolder hldr;
private Camera cam;
private PreviewCallback pcb;
private AutoFocusCallback afcb;
public CameraPreview(Context context, Camera camera, PreviewCallback previewCb, AutoFocusCallback autoFocusCb) {
super(context);
cam = camera;
pcb = previewCb;
afcb = autoFocusCb;
hldr = getHolder();
hldr.addCallback(this);
//hldr.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void surfaceCreated(SurfaceHolder holder) {
try {
cam.setPreviewDisplay(holder);
} catch (IOException e) {
// No Code
}
}
public void surfaceDestroyed(SurfaceHolder holder) {}
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
if (hldr.getSurface() == null) return;
try {
cam.stopPreview();
} catch (Exception e){
// No Code
}
try {
cam.setPreviewDisplay(hldr);
cam.setPreviewCallback(pcb);
cam.startPreview();
cam.autoFocus(afcb);
} catch (Exception e) {
// No Code
}
}
}
Is there any idea how can I solve this problem?

I found the problem. It seems the SurfaceView that is made in program destroys on activity stop. So I replaced it with a SurfaceView in my layout.
package com.example.campreview;
import com.example.campreview.R;
import java.io.IOException;
import android.graphics.ImageFormat;
import android.hardware.Camera;
import android.hardware.Camera.AutoFocusCallback;
import android.hardware.Camera.PreviewCallback;
import android.os.Bundle;
import android.os.Handler;
import android.app.Activity;
import android.content.pm.ActivityInfo;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
public class ScanActivity extends Activity implements OnClickListener {
private SurfaceView PreviewSfc;
private Camera cam = null;
private Handler atfcs;
private boolean hascam = false;
private boolean validdisplay = false;
private boolean prvng = false;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_scan);
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
PreviewSfc = (SurfaceView)findViewById(R.id.PreviewSfc);
PreviewSfc.getHolder().addCallback(SurfaceCB);
//PreviewSfc.getHolder().setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
StartCamera();
if (cam != null) {
hascam = true;
atfcs = new Handler();
}
}
#Override
public void onPause() {
ReleaseCamera();
super.onPause();
}
#Override
public void onResume() {
super.onResume();
StartPreview();
}
private boolean StartCamera() {
boolean r = true;
if (cam == null) {
try {
cam = Camera.open();
} catch (Exception e) {
cam = null;
r = false;
}
if (cam != null) {
try {
Camera.Parameters p = cam.getParameters();
if (p.getSupportedFocusModes().contains(Camera.Parameters.FOCUS_MODE_AUTO))
p.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
if (p.getSupportedFlashModes().contains(Camera.Parameters.FLASH_MODE_OFF))
p.setFlashMode(Camera.Parameters.FLASH_MODE_OFF);
if (p.getSupportedPreviewFormats().contains(ImageFormat.NV21))
p.setPreviewFormat(ImageFormat.NV21);
Camera.Size s = null;
int a = 0, b;
for (Camera.Size z : p.getSupportedPreviewSizes()) {
b = z.width * z.height;
if (Math.abs(b - 307200) < Math.abs(a - 307200)) { //640x480 is the best
s = z;
a = b;
}
}
if (a != 0) p.setPreviewSize(s.width, s.height);
cam.setParameters(p);
cam.setDisplayOrientation(90);
if (validdisplay) cam.setPreviewDisplay(PreviewSfc.getHolder());
} catch (Exception e) {
r = false;
cam.release();
cam = null;
}
}
}
//if (!r) Error message that failed to start camera
return r;
}
private void ReleaseCamera() {
if (cam != null) {
StopPreview();
cam.release();
cam = null;
}
}
public void StartPreview() {
if ((!prvng) & (hascam) & (validdisplay)) {
if (StartCamera()) {
cam.setPreviewCallback(PreviewCB);
cam.startPreview();
cam.autoFocus(AutoFocusCB);
prvng = true;
}
}
}
public void StopPreview() {
if (prvng) {
cam.stopPreview();
cam.setPreviewCallback(null);
prvng = false;
}
}
private Runnable DoAutoFocus = new Runnable() {
public void run() {
if (prvng) cam.autoFocus(AutoFocusCB);
}
};
AutoFocusCallback AutoFocusCB = new AutoFocusCallback() {
public void onAutoFocus(boolean success, Camera camera) {
atfcs.postDelayed(DoAutoFocus, 1000);
}
};
PreviewCallback PreviewCB = new PreviewCallback() {
public void onPreviewFrame(byte[] data, Camera camera) {
//
}
};
SurfaceHolder.Callback SurfaceCB = new SurfaceHolder.Callback() {
public void surfaceCreated(SurfaceHolder holder) {
if (cam != null) {
try {
cam.setPreviewDisplay(holder);
} catch (IOException e) {
// No Code
}
}
}
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
validdisplay = true;
StartPreview();
}
public void surfaceDestroyed(SurfaceHolder holder) {
validdisplay = false;
}
};
}

How to switch from front and back cameras on a button click?

i want to switch between the front and back cameras on a button click .
when any one of the camera's is open , i need to release it and open the other one .
could anyone tell me the block of code to switch ?
Thank you in advance . . . .
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<Button
android:id="#+id/Button01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:background="#drawable/camera_btn"/>
<Button
android:id="#+id/Button02"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:background="#drawable/front_back_btn"/>
<ImageView
android:id="#+id/ImageView01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_above="#+id/Button01"
android:contentDescription="#string/app_name">
</ImageView>
<com.example.surfacecamera.CameraView
android:id="#+id/CameraView01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true" />
</RelativeLayout>
THIS IS MY ACTIVITY
and main java class is
package com.example.surfacecamera;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import android.app.Activity;
import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Bitmap.CompressFormat;
import android.hardware.Camera;
public class MainActivity extends Activity implements OnClickListener, Camera.PictureCallback {
CameraView cameraView;
ImageView imv;
Button b2 ;
int cameraCount = 0;
int camIdx = 0;
Camera cam;
Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
//setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
setContentView(R.layout.activity_main);
Button pictureButton = (Button) this.findViewById(R.id.Button01);
Button b2 = (Button) this.findViewById(R.id.Button02);
imv = (ImageView) this.findViewById(R.id.ImageView01);
cameraView = (CameraView) this.findViewById(R.id.CameraView01);
cameraCount = Camera.getNumberOfCameras();
b2.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
}
});
pictureButton.setOnClickListener(this);
}
// From the OnClickListener
public void onClick(View v)
{
cameraView.takePicture(null, null, this);
}
// From the Camera.PictureCallback
public void onPictureTaken(byte[] data, Camera camera)
{
Bitmap bmp = BitmapFactory.decodeByteArray(data, 0, data.length);
imv.setImageBitmap(bmp);
String filename = "apicture.jpg";
File pictureFile = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/" + filename);
try
{
FileOutputStream pfos = new FileOutputStream(pictureFile);
bmp.compress(CompressFormat.JPEG, 75, pfos);
pfos.flush();
pfos.close();
}
catch (FileNotFoundException e)
{
e.printStackTrace();
}
catch (IOException e)
{
e.printStackTrace();
}
}
}
and another class
package com.example.surfacecamera;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import android.content.Context;
import android.content.res.Configuration;
import android.hardware.Camera;
import android.hardware.Camera.Parameters;
import android.util.AttributeSet;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
public class CameraView extends SurfaceView implements SurfaceHolder.Callback
{
SurfaceHolder mHolder;
int width;
int height;
Camera mCamera;
public CameraView(Context context, AttributeSet attrs)
{
super(context,attrs);
holderCreation();
}
public CameraView(Context context)
{
super(context);
holderCreation();
}
public void takePicture(Camera.ShutterCallback shutter, Camera.PictureCallback raw, Camera.PictureCallback jpeg)
{
mCamera.takePicture(shutter, raw, jpeg);
}
#SuppressWarnings("deprecation")
public void holderCreation()
{
// Install a SurfaceHolder.Callback so we get notified when the
// underlying surface is created and destroyed.
mHolder = getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
public void surfaceCreated(SurfaceHolder holder)
{
// The Surface has been created, acquire the camera and tell it where to draw.
mCamera = Camera.open();
Parameters params = mCamera.getParameters();
// If we aren't landscape (the default), tell the camera we want portrait mode
if (this.getResources().getConfiguration().orientation !=
Configuration.ORIENTATION_LANDSCAPE)
{
params.set("orientation", "portrait"); // "landscape"
// And Rotate the final picture if possible
// This works on 2.0 and higher only
//params.setRotation(90);
// Use reflection to see if it exists and to call it so you can support older versions
try {
Method rotateSet = Camera.Parameters.class.getMethod(
"setRotation", new Class[] { Integer.TYPE } );
Object arguments[] = new Object[] { new Integer(90) };
rotateSet.invoke(params, arguments);
} catch (NoSuchMethodException nsme) {
// Older Device
Log.v("CameraView","No Set Rotation");
} catch (IllegalArgumentException e) {
Log.v("CameraView","Exception IllegalArgument");
} catch (IllegalAccessException e) {
Log.v("CameraView","Illegal Access Exception");
} catch (InvocationTargetException e) {
Log.v("CameraView","Invocation Target Exception");
}
}
mCamera.setParameters(params);
try
{
mCamera.setPreviewDisplay(holder);
}
catch (IOException exception)
{
mCamera.release();
mCamera = null;
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
// Surface will be destroyed when we return, so stop the preview.
// Because the CameraDevice object is not a shared resource, it's very
// important to release it when the activity is paused.
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h)
{
width = w;
height = h;
// Now that the size is known, set up the camera parameters and begin the preview.
Camera.Parameters parameters = mCamera.getParameters();
//parameters.setPreviewSize(w, h);
mCamera.setParameters(parameters);
mCamera.startPreview();
}
}