Javaを使用して角度補正を斜めにする方法

Question

私は斜め角度の修正を与えるチュートリアルを読むsite。しかし、私はこれらのコードをJavaに変換する方法を理解していません。

std::vector<cv::Point> points; 
cv::Mat_<uchar>::iterator it = img.begin<uchar>(); 
cv::Mat_<uchar>::iterator end = img.end<uchar>(); 
for (; it != end; ++it)    
    if (*it)       //what is the meaning of this code (1) 
    points.push_back(it.pos());  //what is the meaning of this code (2) 

このコードを理解するのを手伝ってください。ここでOpenCVの3.2.0のために

Answer 1

が（少し変更を加えた）https://felix.abecassis.me/2011/10/opencv-bounding-box-skew-angle/でC++からJavaでデスキューの完全な翻訳である：

public Mat deskew(Mat src, double angle) { 
    Point center = new Point(src.width()/2, src.height()/2); 
    Mat rotImage = Imgproc.getRotationMatrix2D(center, angle, 1.0); 
    //1.0 means 100 % scale 
    Size size = new Size(src.width(), src.height()); 
    Imgproc.warpAffine(src, src, rotImage, size, Imgproc.INTER_LINEAR + Imgproc.CV_WARP_FILL_OUTLIERS); 
    return src; 
} 

public void computeSkew(String inFile) { 
    //Load this image in grayscale 
    Mat img = Imgcodecs.imread(inFile, Imgcodecs.IMREAD_GRAYSCALE); 

    //Binarize it 
    //Use adaptive threshold if necessary 
    //Imgproc.adaptiveThreshold(img, img, 255, ADAPTIVE_THRESH_MEAN_C, THRESH_BINARY, 15, 40); 
    Imgproc.threshold(img, img, 200, 255, THRESH_BINARY); 

    //Invert the colors (because objects are represented as white pixels, and the background is represented by black pixels) 
    Core.bitwise_not(img, img); 
    Mat element = Imgproc.getStructuringElement(Imgproc.MORPH_RECT, new Size(3, 3)); 

    //We can now perform our erosion, we must declare our rectangle-shaped structuring element and call the erode function 
    Imgproc.erode(img, img, element); 

    //Find all white pixels 
    Mat wLocMat = Mat.zeros(img.size(),img.type()); 
    Core.findNonZero(img, wLocMat); 

    //Create an empty Mat and pass it to the function 
    MatOfPoint matOfPoint = new MatOfPoint(wLocMat); 

    //Translate MatOfPoint to MatOfPoint2f in order to user at a next step 
    MatOfPoint2f mat2f = new MatOfPoint2f(); 
    matOfPoint.convertTo(mat2f, CvType.CV_32FC2); 

    //Get rotated rect of white pixels 
    RotatedRect rotatedRect = Imgproc.minAreaRect(mat2f); 

    Point[] vertices = new Point[4]; 
    rotatedRect.points(vertices); 
    List<MatOfPoint> boxContours = new ArrayList<>(); 
    boxContours.add(new MatOfPoint(vertices)); 
    Imgproc.drawContours(img, boxContours, 0, new Scalar(128, 128, 128), -1); 

    double resultAngle = rotatedRect.angle; 
    if (rotatedRect.size.width > rotatedRect.size.height) 
    { 
     rotatedRect.angle += 90.f; 
    } 

    //Or 
    //rotatedRect.angle = rotatedRect.angle < -45 ? rotatedRect.angle + 90.f : rotatedRect.angle; 

    Mat result = deskew(Imgcodecs.imread(inFile), rotatedRect.angle); 
    Imgcodecs.imwrite(outputFile, result); 

}