Android Studio, Capture FrameLayout View, While Camera is StopPreview() - android-studio

Question

This is my CameraView.java (I got it from http://blog.rhesoft.com/)
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);
mHolder = getHolder();
mHolder.addCallback(this);
mHolder.setType(SurfaceHolder.SURFACE_TYPE_NORMAL);
}
#Override
public void surfaceCreated(SurfaceHolder surfaceHolder) {
try{
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)
return;
try{
mCamera.stopPreview();
} catch (Exception e){
}
try{
mCamera.setPreviewDisplay(mHolder);
mCamera.startPreview();
} catch (IOException e) {
Log.d("ERROR", "Camera error on surfaceChanged " + e.getMessage());
}
}
#Override
public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
mCamera.stopPreview();
mCamera.release();
}}
and this is my MainActivity.java.
public class MainActivity extends AppCompatActivity {
private Camera mCamera = null;
private CameraView mCameraView = null;
private FrameLayout camera_view;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
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
camera_view = (FrameLayout)findViewById(R.id.camera_view);
camera_view.addView(mCameraView);//add the SurfaceView to the layout
}
//btn to close the application
final ImageButton imgClose = (ImageButton)findViewById(R.id.imgClose);
final ImageButton capImg = (ImageButton) findViewById(R.id.imgCapture);
imgClose.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
imgClose.setVisibility(View.INVISIBLE);
capImg.setVisibility(View.VISIBLE);
mCamera.startPreview();
}
});
capImg.setOnClickListener(new View.OnClickListener(){
public void onClick(View v){
mCamera.stopPreview();
imgClose.setVisibility(View.VISIBLE);
capImg.setVisibility(View.INVISIBLE);
}
});
}
#Override
public void onBackPressed(){
System.exit(0);
}}
and this my activity_main.xml.
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<FrameLayout
android:id="#+id/camera_view"
android:layout_width="match_parent"
android:layout_height="match_parent">
</FrameLayout>
<ImageButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/imgClose"
android:layout_gravity="right|top"
android:background="#android:drawable/ic_menu_close_clear_cancel"
android:padding="20dp"
android:visibility="invisible" />
<ImageButton
android:layout_width="98dp"
android:layout_height="98dp"
android:id="#+id/imgCapture"
android:layout_gravity="center_horizontal|bottom"
android:background="#android:drawable/ic_menu_camera"
android:padding="20dp"/>
Can I capture this FrameLayout preview as image or do some programing with that preview like delete red color? Can you give me some clue?

Answer 1

So if I understand correctly, you wish to get the image data that is shown when you stop the preview? If you so you can mCamera.takePicture() method. It takes 3 parameters, all of which are useful callbacks. Here is something I recently did to show you.
btn_Capture.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (mCamera == null)
return;
mCamera.takePicture(null, null, mPicture);
}
});
This is my button click listener which is a floating image button (any button will work just fine). The third parameter is a callback that returns an array of pixels that you can convert into a bitmap.
private Camera.PictureCallback mPicture = new Camera.PictureCallback() {
#Override
public void onPictureTaken(byte[] data, Camera camera) {
mCamera.stopPreview();
Bitmap bMap = BitmapFactory.decodeByteArray(data, 0, data.length);
preview.removeView(mPreview);
img_Captured.setImageBitmap(bMap);
}
};
This is the callback which I passed in the takePicture() method. byte[] data is the image that you are trying to get. As you can see I converted it into a bitmap and displayed it to an ImageView after removing the surfaceview (which holds the camera preview). Just a note, the takePicture() method stops the preview automatically so don't stop the preview before taking the photo. You can do it how I did it in the callback. Also, if you want to take another photo, you can start the preview again.
I hope this helps!! Let me know if I left anything out! By the way, it is all documented on the Android Developer site.
http://developer.android.com/training/camera/cameradirect.html#TaskTakePicture