Автоматическая коррекция перспективы с использованием OpenCV и Java

Question

Я смотрю на перспективную коррекцию для изображений, снятых с камеры Android, как это определено в this question, размещенном ранее. Однако я не могу получить правильный рабочий код Java.

Если кто-то заработал на Java, помогите.

Answer 1

Я нашел ответ на свой запрос here. Нанесите небольшой уточненный фрагмент кода ниже:

public static void correctPerspective() { 

    String fileName = "IMG_20141024_132131.jpg"; 
    Mat imgSource = Highgui.imread(fileName, Highgui.CV_LOAD_IMAGE_UNCHANGED); 
    // convert the image to black and white does (8 bit) 
    Imgproc.Canny(imgSource.clone(), imgSource, 50, 50); 

    // apply gaussian blur to smoothen lines of dots 
    Imgproc.GaussianBlur(imgSource, imgSource, new org.opencv.core.Size(5, 5), 5); 

    // find the contours 
    List<MatOfPoint> contours = new ArrayList<MatOfPoint>(); 
    Imgproc.findContours(imgSource, contours, new Mat(), Imgproc.RETR_LIST, Imgproc.CHAIN_APPROX_SIMPLE); 

    double maxArea = -1; 
    MatOfPoint temp_contour = contours.get(0); // the largest is at the 
               // index 0 for starting 
               // point 
    MatOfPoint2f approxCurve = new MatOfPoint2f(); 

    for (int idx = 0; idx < contours.size(); idx++) { 
     temp_contour = contours.get(idx); 
     double contourarea = Imgproc.contourArea(temp_contour); 
     // compare this contour to the previous largest contour found 
     if (contourarea > maxArea) { 
      // check if this contour is a square 
      MatOfPoint2f new_mat = new MatOfPoint2f(temp_contour.toArray()); 
      int contourSize = (int) temp_contour.total(); 
      MatOfPoint2f approxCurve_temp = new MatOfPoint2f(); 
      Imgproc.approxPolyDP(new_mat, approxCurve_temp, contourSize * 0.05, true); 
      if (approxCurve_temp.total() == 4) { 
       maxArea = contourarea; 
       approxCurve = approxCurve_temp; 
      } 
     } 
    } 

    Imgproc.cvtColor(imgSource, imgSource, Imgproc.COLOR_BayerBG2RGB); 
    Mat sourceImage = Highgui.imread(fileName, Highgui.CV_LOAD_IMAGE_UNCHANGED); 
    double[] temp_double; 
    temp_double = approxCurve.get(0, 0); 
    Point p1 = new Point(temp_double[0], temp_double[1]); 
    // Core.circle(imgSource,p1,55,new Scalar(0,0,255)); 
    // Imgproc.warpAffine(sourceImage, dummy, rotImage,sourceImage.size()); 
    temp_double = approxCurve.get(1, 0); 
    Point p2 = new Point(temp_double[0], temp_double[1]); 
    // Core.circle(imgSource,p2,150,new Scalar(255,255,255)); 
    temp_double = approxCurve.get(2, 0); 
    Point p3 = new Point(temp_double[0], temp_double[1]); 
    // Core.circle(imgSource,p3,200,new Scalar(255,0,0)); 
    temp_double = approxCurve.get(3, 0); 
    Point p4 = new Point(temp_double[0], temp_double[1]); 
    // Core.circle(imgSource,p4,100,new Scalar(0,0,255)); 
    List<Point> source = new ArrayList<Point>(); 
    source.add(p1); 
    source.add(p2); 
    source.add(p3); 
    source.add(p4); 
    Mat startM = Converters.vector_Point2f_to_Mat(source); 
    Mat result = warp(sourceImage, startM); 

    Highgui.imwrite("corrected.jpg", result); 
} 

public static Mat warp(Mat inputMat, Mat startM) { 

    int resultWidth = 1200; 
    int resultHeight = 680; 

    Point ocvPOut4 = new Point(0, 0); 
    Point ocvPOut1 = new Point(0, resultHeight); 
    Point ocvPOut2 = new Point(resultWidth, resultHeight); 
    Point ocvPOut3 = new Point(resultWidth, 0); 

    if (inputMat.height() > inputMat.width()) { 
     // int temp = resultWidth; 
     // resultWidth = resultHeight; 
     // resultHeight = temp; 

     ocvPOut3 = new Point(0, 0); 
     ocvPOut4 = new Point(0, resultHeight); 
     ocvPOut1 = new Point(resultWidth, resultHeight); 
     ocvPOut2 = new Point(resultWidth, 0); 
    } 

    Mat outputMat = new Mat(resultWidth, resultHeight, CvType.CV_8UC4); 

    List<Point> dest = new ArrayList<Point>(); 
    dest.add(ocvPOut1); 
    dest.add(ocvPOut2); 
    dest.add(ocvPOut3); 
    dest.add(ocvPOut4); 

    Mat endM = Converters.vector_Point2f_to_Mat(dest); 

    Mat perspectiveTransform = Imgproc.getPerspectiveTransform(startM, endM); 

    Imgproc.warpPerspective(inputMat, outputMat, perspectiveTransform, new Size(resultWidth, resultHeight), Imgproc.INTER_CUBIC); 

    return outputMat; 
}