Rotate camera preview to Portrait Android OpenCV Camera

Question

I am trying to use OpenCV 2.4.3.2 to create a camera app and do some opencv processing. I would like it to be able to have multiple UI orientations, not just Landscape.

Answer 1

Another solution. i think this better

protected void deliverAndDrawFrame(CvCameraViewFrame frame) {
    Mat modified;

    if (mListener != null) {
        modified = mListener.onCameraFrame(frame);
    } else {
        modified = frame.rgba();
    }

    boolean bmpValid = true;
    if (modified != null) {
        try {
            Utils.matToBitmap(modified, mCacheBitmap);
        } catch(Exception e) {
            Log.e(TAG, "Mat type: " + modified);
            Log.e(TAG, "Bitmap type: " + mCacheBitmap.getWidth() + "*" + mCacheBitmap.getHeight());
            Log.e(TAG, "Utils.matToBitmap() throws an exception: " + e.getMessage());
            bmpValid = false;
        }
    }

    if (bmpValid && mCacheBitmap != null) {
        Canvas canvas = getHolder().lockCanvas();
        if (canvas != null) {
            canvas.drawColor(0, android.graphics.PorterDuff.Mode.CLEAR);
            if (BuildConfig.DEBUG)
                Log.d(TAG, "mStretch value: " + mScale);

            int currentOrientation = getResources().getConfiguration().orientation;
            if (currentOrientation == Configuration.ORIENTATION_LANDSCAPE) {
                if (mScale != 0) {
                    canvas.drawBitmap(mCacheBitmap, new Rect(0,0,mCacheBitmap.getWidth(), mCacheBitmap.getHeight()),
                            new Rect((int)((canvas.getWidth() - mScale*mCacheBitmap.getWidth()) / 2),
                                    (int)((canvas.getHeight() - mScale*mCacheBitmap.getHeight()) / 2),
                                    (int)((canvas.getWidth() - mScale*mCacheBitmap.getWidth()) / 2 + mScale*mCacheBitmap.getWidth()),
                                    (int)((canvas.getHeight() - mScale*mCacheBitmap.getHeight()) / 2 + mScale*mCacheBitmap.getHeight())), null);
                } else {
                    canvas.drawBitmap(mCacheBitmap, new Rect(0,0,mCacheBitmap.getWidth(), mCacheBitmap.getHeight()),
                            new Rect((canvas.getWidth() - mCacheBitmap.getWidth()) / 2,
                                    (canvas.getHeight() - mCacheBitmap.getHeight()) / 2,
                                    (canvas.getWidth() - mCacheBitmap.getWidth()) / 2 + mCacheBitmap.getWidth(),
                                    (canvas.getHeight() - mCacheBitmap.getHeight()) / 2 + mCacheBitmap.getHeight()), null);
                }
            } else {

                if (mScale != 0) {
                    Bitmap bitmap = Bitmap.createScaledBitmap(mCacheBitmap, canvas.getHeight(), canvas.getWidth(), true);
                    canvas.drawBitmap(bitmap, new Rect(0,0,bitmap.getWidth(), bitmap.getHeight()), new Rect(
                            (int)((canvas.getWidth() - mScale*bitmap.getWidth()) / 2),
                            (int)(0),
                            (int)((canvas.getWidth() - mScale*bitmap.getWidth()) / 2 + mScale*bitmap.getWidth()),
                            (int)((canvas.getHeight()))), null);
                } else {
                    Bitmap bitmap = Bitmap.createScaledBitmap(mCacheBitmap, canvas.getHeight(), canvas.getWidth(), true);
                    canvas.drawBitmap(bitmap, new Rect(0,0,bitmap.getWidth(), bitmap.getHeight()), new Rect(
                            (int)((canvas.getWidth() - bitmap.getWidth()) / 2),
                            (int)(0),
                            (int)((canvas.getWidth() - bitmap.getWidth()) / 2 + bitmap.getWidth()),
                            (int)(canvas.getHeight())), null);
                }
            }

            if (mFpsMeter != null) {
                mFpsMeter.measure();
                mFpsMeter.draw(canvas, 20, 30);
            }
            getHolder().unlockCanvasAndPost(canvas);
        }
    }
}

and...

@Override
public Mat onCameraFrame(CameraBridgeViewBase.CvCameraViewFrame inputFrame) {
    MatOfRect faces = new MatOfRect();
    int currentOrientation = getResources().getConfiguration().orientation;
    if (currentOrientation == Configuration.ORIENTATION_LANDSCAPE) { 
        mRgba = inputFrame.rgba();
        mGray = inputFrame.gray();

        int height = mGray.rows();
        if (Math.round(height * 0.2) > 0) {
            mFaceSize = (int) Math.round(height * 0.2);
        }

        cascadeClassifier.detectMultiScale(mGray, faces, 1.1, 3, 2,
                new Size(mFaceSize, mFaceSize));
        Rect[] facesArray = faces.toArray();
        for (int i = 0; i < facesArray.length; i++) {
            Point center = new Point(facesArray[i].x + facesArray[i].width / 2,
                    facesArray[i].y + facesArray[i].height / 2);
            rectangle(mRgba, facesArray[i].tl(), facesArray[i].br(), FACE_RECT_COLOR, 3);
        }

    } else {
        mRgba = inputFrame.rgba();
        mGray = inputFrame.gray();

        Mat rotImage = Imgproc.getRotationMatrix2D(new Point(mRgba.cols() / 2,
                mRgba.rows() / 2), 90, 1.0);

        Imgproc.warpAffine(mRgba, mRgba, rotImage, mRgba.size());
        Imgproc.warpAffine(mGray, mGray, rotImage, mRgba.size());

        Core.flip(mRgba, mRgba, 1);
        Core.flip(mGray, mGray, 1);

        int height = mGray.rows();
        if (Math.round(height * 0.2) > 0) {
            mFaceSize = (int) Math.round(height * 0.2);
        }

        cascadeClassifier.detectMultiScale(mGray, faces, 1.1, 3, 2,
                new Size(mFaceSize, mFaceSize));
        Rect[] facesArray = faces.toArray();
        for (int i = 0; i < facesArray.length; i++) {
            Point center = new Point(facesArray[i].x + facesArray[i].width / 2,
                    facesArray[i].y + facesArray[i].height / 2);
            rectangle(mRgba, facesArray[i].tl(), facesArray[i].br(), FACE_RECT_COLOR, 3);
        }
    }

    return mRgba;