How to get degree of rotation of image

问题

I'm getting an image from gallery and display it in an imageView. Sometimes, image displays 90 degrees CCW.

So, my question is: 1- is it possible to get angle of rotation of image? 2- is it possible to get angle by a face detection library? if yes, which library you suggest?

any recommendation would be appreciated. Thanks.

回答1:

Okay, I found a solution that I share it with you.

public class ImageCorrection extends Activity {

    private final static String TAG = MainActivity.class.getSimpleName();
    private final static int RESULT_LOAD_IMAGE = 100;

    private ImageButton imageButton;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_face_detection);

        imageButton = (ImageButton) findViewById(R.id.imageButton);
        imageButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
                startActivityForResult(intent, RESULT_LOAD_IMAGE);
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        switch (requestCode) {
            case RESULT_LOAD_IMAGE:
                if (data != null) {
                    Uri imageUri = data.getData();
                    Log.d(TAG, "Image Uri: " + imageUri.toString());

                    try {
                        Bitmap myImg = MediaStore.Images.Media.getBitmap(this.getContentResolver(), imageUri);
                        if(myImg == null) {
                            Log.e(TAG, "Image bitmap is null...");
                            return;
                        }

                        Cursor cur;
                        String[] orientationColumn = {MediaStore.Images.Media.ORIENTATION};
                        if(Build.VERSION.SDK_INT < 11)
                            cur = managedQuery(imageUri, orientationColumn, null, null, null);
                        else
                            cur = getContentResolver().query(imageUri, orientationColumn, null, null, null);

                        int orientation = -1;
                        if (cur != null && cur.moveToFirst()) {
                            orientation = cur.getInt(cur.getColumnIndex(orientationColumn[0]));
                            Log.d(TAG, "Image Orientation: " + orientation);
                        }

                        Matrix matrix = new Matrix();
                        matrix.reset();
                        matrix.postRotate(orientation);

                        Bitmap rotated = Bitmap.createBitmap(myImg, 0, 0, myImg.getWidth(), myImg.getHeight(), matrix, true);
                        imageButton.setImageBitmap(rotated);

                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
                break;
            default:
                break;
        }
    }
}

来源：https://stackoverflow.com/questions/24968677/how-to-get-degree-of-rotation-of-image