android camera2 api capture still image

Android tutorial describing how to capture a still image using the camera2 api.

This android tutorial describes the steps involved for the android camera2 api capture still image.

Get Code

You can get it from here https://github.com/mobapptuts/recyclerview_image_gallery.git Tag camera2-still-capture

or else run this command
git clone —branch camera2-still-capture https://github.com/mobapptuts/recyclerview_image_gallery.git

Code Samples

Clean up the ImageReader resource when the application is closed

private void closeCamera() {

     if(mCameraCaptureSession != null) {
         mCameraCaptureSession.close();
         mCameraCaptureSession = null;
     }
     if(mCameraDevice != null) {
         mCameraDevice.close();
         mCameraDevice = null;
     }
     if(mImageReader != null) {
         mImageReader.close();
         mImageReader = null;
     }
 }

Create a SparseIntArray member to translating the orientations from the display screen to jpeg images.

private static final SparseIntArray ORIENTATIONS = new SparseIntArray();
  static {
      ORIENTATIONS.append(Surface.ROTATION_0, 90);
      ORIENTATIONS.append(Surface.ROTATION_90, 0);
      ORIENTATIONS.append(Surface.ROTATION_180, 270);
      ORIENTATIONS.append(Surface.ROTATION_270, 180);
  }

Add the ImageReader to the CameraCaptureSession

private void createCameraPreviewSession() {
       try {
           SurfaceTexture surfaceTexture = mTextureView.getSurfaceTexture();
           surfaceTexture.setDefaultBufferSize(mPreviewSize.getWidth(), mPreviewSize.getHeight());
           Surface previewSurface = new Surface(surfaceTexture);
           mPreviewCaptureRequestBuilder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
           mPreviewCaptureRequestBuilder.addTarget(previewSurface);
           mCameraDevice.createCaptureSession(Arrays.asList(previewSurface, mImageReader.getSurface()),
                   new CameraCaptureSession.StateCallback() {
                       @Override
                       public void onConfigured(CameraCaptureSession session) {
                           if(mCameraDevice == null) {
                               return;
                           }
                           try {
                               mPreviewCaptureRequest = mPreviewCaptureRequestBuilder.build();
                               mCameraCaptureSession = session;
                               mCameraCaptureSession.setRepeatingRequest(
                                       mPreviewCaptureRequest,
                                       mSessionCaptureCallback,
                                       mBackgroundHandler
                               );
                           } catch (CameraAccessException e) {
                               e.printStackTrace();
                           }
                       }

                       @Override
                       public void onConfigureFailed(CameraCaptureSession session) {
                           Toast.makeText(
                                   getApplicationContext(),
                                   "create camera session failed!",
                                   Toast.LENGTH_SHORT
                           ).show();
                       }
                   }, null);
       } catch (CameraAccessException e) {
           e.printStackTrace();
       }
   }

Create captureStillImage method

private void captureStillImage() {
     try {
         CaptureRequest.Builder captureStillBuilder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);
         captureStillBuilder.addTarget(mImageReader.getSurface());

         int rotation = getWindowManager().getDefaultDisplay().getRotation();
         captureStillBuilder.set(CaptureRequest.JPEG_ORIENTATION,
                 ORIENTATIONS.get(rotation));

         CameraCaptureSession.CaptureCallback captureCallback =
                 new CameraCaptureSession.CaptureCallback() {
                     @Override
                     public void onCaptureCompleted(CameraCaptureSession session, CaptureRequest request, TotalCaptureResult result) {
                         super.onCaptureCompleted(session, request, result);

                         Toast.makeText(getApplicationContext(),
                                 "Image Captured!", Toast.LENGTH_SHORT).show();
                         unLockFocus();
                     }
                 };

         mCameraCaptureSession.capture(
                 captureStillBuilder.build(), captureCallback, null
         );

     } catch (CameraAccessException e) {
         e.printStackTrace();
     }
 }

Call the captureStillImage method from within CameraCaptureSession callback STATE_WAIT_LOCK       state.

private CameraCaptureSession.CaptureCallback mSessionCaptureCallback
          = new CameraCaptureSession.CaptureCallback() {

      private void process(CaptureResult result) {
          switch(mState) {
              case STATE_PREVIEW:
                  // Do nothing
                  break;
              case STATE__WAIT_LOCK:
                  Integer afState = result.get(CaptureResult.CONTROL_AF_STATE);
                  if(afState == CaptureRequest.CONTROL_AF_STATE_FOCUSED_LOCKED) {
                      /*
                      unLockFocus();
                      Toast.makeText(getApplicationContext(), "Focus Lock Successful", Toast.LENGTH_SHORT).show();
                      */
                      captureStillImage();
                  }
                  break;
          }
      }
      @Override
      public void onCaptureStarted(CameraCaptureSession session, CaptureRequest request, long timestamp, long frameNumber) {
          super.onCaptureStarted(session, request, timestamp, frameNumber);
      }

      @Override
      public void onCaptureCompleted(CameraCaptureSession session, CaptureRequest request, TotalCaptureResult result) {
          super.onCaptureCompleted(session, request, result);

          process(result);
      }

      @Override
      public void onCaptureFailed(CameraCaptureSession session, CaptureRequest request, CaptureFailure failure) {
          super.onCaptureFailed(session, request, failure);

          Toast.makeText(getApplicationContext(), "Focus Lock Unsuccessful", Toast.LENGTH_SHORT).show();
      }
  };