How to rotate and flip bitmap in onPictureTaken

Question

I'm finding in onPictureTaken that the bitmap saved is mirrored about the y-axis and rotated 90 degrees clockwise even though the camera preview was not. This is on my Nexus S that's running 2.3.6. The same program running on my Nexus 4 with 4.2 has the resulting bitmap mirrored about the y-axis and rotated 180 degrees clockwise.

This is the code I'm running in onPictureTaken:

@Override
public void onPictureTaken(final byte[] data, Camera camera) {
    Bitmap picture = BitmapFactory.decodeByteArray(data, 0, data.length);
    String path = MediaStore.Images.Media.insertImage(getContentResolver(), picture, "name" , "description");
    Log.e("tag", "path: " + path); // prints something like "path: content://media/external/images/media/819"

    try {
        ExifInterface exif = new ExifInterface(path); // prints this error: "04-25 21:28:21.063: E/JHEAD(12201): can't open 'content://media/external/images/media/819'"
        int orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);
        Log.e("tag", "exif orientation: " + orientation); // this is outputting orientation unknown
    } catch (IOException e) {
        e.printStackTrace();
    }
}

Can anyone show me how I rectify this given that I seem to be getting different results from different devices? How do I detect the orientation of the resulting bitmap so that I know to rotate it either 90 or 180 degrees counterclockwise?

[EDIT]

I added some more information using the ExifInterface stuff I've been reading about, but that information doesn't seem to pan out...

Answer 1

Instead of rotating the picture explicitly in the picture taken callback, you can configure the camera to have picture rotated for you when the picture is taken.

camera.SetDisplayOrientation(degrees) //sets the orientation in the preview

while

cameraParameters.SetRotation(degress) //rotates the actual captured image

Answer 2

I have put a lot of work into this and thought, I'd share my solution. It is tested on a Motorola Devy, Samsung Xcover 1 and Samsung XCover 2.

As I work with a custom camera preview, the solution basically has two parts. 1. Take care of the camera preview and set rotation of the preview according to device rotation. 2. Once a picture is taken, that is the 'onPictureTaken' callback is invoked rotate the picture by the correct angle, such that it shows what the preview just showed.

1

---

private void initPreview(int width, int height) {
    if (camera != null && holder.getSurface() != null) {
        try {
            camera.setPreviewDisplay(holder);
        } catch (Throwable t) {
            Log.e("PreviewDemo-surfaceCallback",
              "Exception in setPreviewDisplay()", t);
            Toast.makeText(getContext(), t.getMessage(),
                       Toast.LENGTH_LONG).show();
        }

        try {
            Camera.Parameters parameters=camera.getParameters();

            Camera.Size size=getBestPreviewSize(width, height, parameters);
            Camera.Size pictureSize=getSmallestPictureSize(parameters);

            Display display = windowManager.getDefaultDisplay();
            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.FROYO) { // for 2.1 and before
                if (isPortrait(display)) {
                    parameters.set(CAMERA_PARAM_ORIENTATION, CAMERA_PARAM_PORTRAIT);
                } else {
                    parameters.set(CAMERA_PARAM_ORIENTATION, CAMERA_PARAM_LANDSCAPE);
                }
            } else { // for 2.2 and later
                switch (display.getRotation()) {
                    case Surface.ROTATION_0: // This is display orientation
                        if (size.height > size.width) parameters.setPreviewSize(size.height, size.width);
                        else parameters.setPreviewSize(size.width, size.height);
                        camera.setDisplayOrientation(90);
                        break;
                    case Surface.ROTATION_90:
                        if (size.height > size.width) parameters.setPreviewSize(size.height, size.width);
                        else parameters.setPreviewSize(size.width, size.height);
                        camera.setDisplayOrientation(0);
                        break;
                    case Surface.ROTATION_180:
                        if (size.height > size.width) parameters.setPreviewSize(size.height, size.width);
                        else parameters.setPreviewSize(size.width, size.height);
                        camera.setDisplayOrientation(270);
                        break;
                    case Surface.ROTATION_270:
                        if (size.height > size.width) parameters.setPreviewSize(size.height, size.width);
                        else parameters.setPreviewSize(size.width, size.height);
                        camera.setDisplayOrientation(180);
                        break;
                }
            }

            parameters.setPictureSize(pictureSize.width, pictureSize.height);
            //parameters.setPictureFormat(ImageFormat.JPEG);
            camera.setParameters(parameters);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

---

Your 'surfaceChanged' method, in your camera preview (SurfaceView), you should look like this:

---

public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
        stopPreview();
        initPreview(w, h);
        startPreview();
    }

---

where

stopPreview:

private void stopPreview() {
    if (camera != null) {
        camera.stopPreview();
    }
}

startPreview:

private void startPreview() {
    if (camera != null) {
        camera.startPreview();
    }
}

2

---

In your 'onPictureTaken' callback rotate the picture, using the following code:

Display display = getWindowManager().getDefaultDisplay();
    int rotation = 0;
    switch (display.getRotation()) {
        case Surface.ROTATION_0: // This is display orientation
        rotation = 90;
        break;
    case Surface.ROTATION_90:
        rotation = 0;
        break;
    case Surface.ROTATION_180:
        rotation = 270;
        break;
    case Surface.ROTATION_270:
        rotation = 180;
            break;
     }

     Bitmap bitmap = BitmapTools.toBitmap(data);
     bitmap = BitmapTools.rotate(bitmap, rotation);

---

BitmapTools.java

public class BitmapTools {

        public static Bitmap toBitmap(byte[] data) {
            return BitmapFactory.decodeByteArray(data , 0, data.length);
        }

        public static Bitmap rotate(Bitmap in, int angle) {
            Matrix mat = new Matrix();
            mat.postRotate(angle);
            return Bitmap.createBitmap(in, 0, 0, in.getWidth(), in.getHeight(), mat, true);
        }
    }

Answer 3

you must read about ExifInterface to resolve this issue.

i have this function in my application to check weather weather image taken from camera needs to be rotateed or not.

      if(ExifNeedsRotate(GetPathFromUri(context, selectedImage))){
    // Rotate your bitmap using the Matrix
     }


public static boolean ExifNeedsRotate(String paramString){

      if (android.os.Build.VERSION.SDK_INT >= 5){

          try
          {

                Class localClass = Class.forName("android.media.ExifInterface");
                Class[] arrayOfClass1 = new Class[1];
                arrayOfClass1[0] = String.class;
                Constructor localConstructor = localClass.getConstructor(arrayOfClass1);
                Class[] arrayOfClass2 = new Class[1];
                arrayOfClass2[0] = String.class;
                Method localMethod = localClass.getMethod("getAttribute", arrayOfClass2);
                Object[] arrayOfObject1 = new Object[1];
                arrayOfObject1[0] = paramString;
                Object localObject1 = localConstructor.newInstance(arrayOfObject1);
                Object[] arrayOfObject2 = new Object[1];
                arrayOfObject2[0] = "Orientation";
                Object localObject2 = localMethod.invoke(localObject1, arrayOfObject2);
                if (localObject2 != null){
                      boolean bool = localObject2.equals("6");
                      if (bool)
                         return true;
                }

          }
          catch (Exception localException){
              return false;
          }

    }

    return false;

}

Pass the path of the ImageUri as a input.

 public static String GetPathFromUri(Context paramContext, Uri paramUri)
  {
       String str;
       try
       {
            if (paramUri.toString().startsWith("file:")){
                    str = paramUri.getPath();
            }
            else
            {
                    str = null;
                    String[] arrayOfString = new String[1];
                    arrayOfString[0] = "_data";
                    Cursor localCursor = paramContext.getContentResolver().query(paramUri, arrayOfString, null, null, null);
                    if (localCursor != null)
                    {
                            localCursor.moveToFirst();
                            int i = localCursor.getColumnIndex(arrayOfString[0]);
                            if ((localCursor.getCount() >= 1) && (localCursor.getColumnCount() >= i + 1))
                                str = localCursor.getString(i);
                            localCursor.close();
                    }
            }

      }
      catch (Exception localException){
          str = null;
      }

      return str;
  }

Answer 4

here you go check this out, save the picture and maybe this will work and remember if(bitmap.getWidth > bitmap.getHeight()) as another check

public static int getExifRotation(String imgPath) 
    {
        try 
        {
            ExifInterface exif = new ExifInterface(imgPath);
            String rotationAmount = exif.getAttribute(ExifInterface.TAG_ORIENTATION);
            if (!TextUtils.isEmpty(rotationAmount)) 
            {
                int rotationParam = Integer.parseInt(rotationAmount);
                switch (rotationParam) 
                {
                    case ExifInterface.ORIENTATION_NORMAL:
                        return 0;
                    case ExifInterface.ORIENTATION_ROTATE_90:
                        return 90;
                    case ExifInterface.ORIENTATION_ROTATE_180:
                        return 180;
                    case ExifInterface.ORIENTATION_ROTATE_270:
                        return 270;
                    default:
                        return 0;
                }
            } 
            else 
            {
                return 0;
            }
        }
        catch (Exception ex) 
        {
            return 0;
        }
    }