Opencv Java图像转换

Question

我正在关注this tutorial为我的Android应用创建图像转换器。我已将代码转换为Java但结果并不完全符合我的预期。我想知道是否有任何方法可以修改代码，以便可以将图像转换为与教程相似。

到目前为止我的代码：

// This method is called when a button is pressed. 
//Unlike the tutorial post, the 4 corner coordinates are manually marked by the user. 

// Bitmap is the image taken by the user
private void thresholdPhoto(Bitmap bitmap) {

    // I am using the OpenCV library so I need to convert it to a matrix
    Mat matrixImage = new Mat();
    Utils.bitmapToMat(bitmap, matrixImage);


    // Convert to gray
    Imgproc.cvtColor(matrixImage, matrixImage, Imgproc.COLOR_BGR2GRAY);

    // Gaussian blur
    Imgproc.GaussianBlur(matrixImage, matrixImage, new Size(5,5), 0);

    // The conversion to gray and blurring is for my app later on but I don't think it should affect the warping process. 

    // Get the coordinates marked by the user
    PointF bottomRight = new PointF(polygonView.pointer4.getX(), polygonView.pointer4.getY());
    PointF bottomLeft = new PointF(polygonView.pointer3.getX(), polygonView.pointer3.getY());
    PointF topRight = new PointF(polygonView.pointer2.getX(), polygonView.pointer2.getY());
    PointF topLeft = new PointF(polygonView.pointer1.getX(), polygonView.pointer1.getY());


    // Code following the tutorial post above
    double widthA = Math.sqrt(Math.pow(bottomRight.x-bottomLeft.x, 2)+Math.pow(bottomRight.y-bottomLeft.y, 2));
    double widthB = Math.sqrt(Math.pow(topRight.x-topLeft.x, 2)+Math.pow(topRight.y-topLeft.y, 2));

    double maxWidth =  Math.max(widthA, widthB);

    double heightA = Math.sqrt(Math.pow(topRight.x-bottomRight.x, 2)+Math.pow(topRight.y-bottomRight.y, 2));
    double heightB = Math.sqrt(Math.pow(topLeft.x-bottomLeft.x, 2)+Math.pow(topLeft.y-bottomLeft.y, 2));

    double maxHeight = Math.max(heightA, heightB);

    // To apply the final perspective transform I had to create new Matrices
    Point tl = new Point(topLeft.x, topLeft.y);
    Point tr = new Point(topRight.x, topLeft.y);
    Point bl = new Point(bottomLeft.x, bottomLeft.y);
    Point br = new Point(bottomRight.x, bottomRight.y);

    MatOfPoint2f src = new MatOfPoint2f(tl, tr, br, bl);

    MatOfPoint2f dst = new MatOfPoint2f(
            new Point(0,0), // top left
            new Point(maxWidth-1, 0), // top right
            new Point(maxWidth-1, maxHeight-1), // bottom right
            new Point(0, maxHeight-1) // bottom left
    );

    Mat perspectiveTransform = Imgproc.getPerspectiveTransform(src, dst);

    Imgproc.warpPerspective(matrixImage, matrixImage, perspectiveTransform, new Size(maxWidth, maxHeight));


    // Convert matrix back to bitmap to display inside imageview. This final part is just for my visualization purposes.
    Bitmap bm = Bitmap.createBitmap(matrixImage.cols(), matrixImage.rows(),Bitmap.Config.ARGB_8888);
    Utils.matToBitmap(matrixImage, bm);

    polygonView.setVisibility(View.GONE);

    scannedImage.setImageBitmap(bm);

}

使用的图像：

翘曲的结果并不是我想要的，所以我想知道是否有其他参数/​​设置我可以修改以使其更好。