JavaCV — Перспективная коррекция

Я преобразовал код коррекции перспективы, реализованный с использованием OpenCV и C ++, по адресу:
https://opencv-code.com/tutorials/automatic-perspective-correction-for-quadrilateral-objects/

чтобы получить следующий код OpenCV, реализованный на Java:

public class project
{
static Point2f center;
public static void main(String args[])
{
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
center = new Point2f(0,0);
Mat src = new Mat();
src = Highgui.imread("image.jpg");
if(src == null)
{
System.out.println("Image not loaded");
System.exit(1);
}

Mat bw = new Mat();

Imgproc.cvtColor(src, bw, Imgproc.COLOR_BGR2GRAY);
Imgproc.blur(bw, bw, new Size(3,3));
Imgproc.Canny(bw, bw, 100, 100, 3,true);

Mat lines = new Mat();
int threshold = 70;
int minLineSize = 30;
int lineGap = 10;

Imgproc.HoughLinesP(bw, lines, 1, Math.PI / 180, threshold,
minLineSize, lineGap);

for (int x = 0; x < lines.cols(); x++)
{

double[] vec = lines.get(0, x);
double[] val = new double[4];

val[0] = 0;
val[1] = ((float) vec[1] - vec[3]) / (vec[0] - vec[2]) * -vec[0] + vec[1];
val[2] = src.cols();
val[3] = ((float) vec[1] - vec[3]) / (vec[0] - vec[2]) * (src.cols() - vec[2]) + vec[3];

lines.put(0, x, val);

}

List<Point2f> corners = new ArrayList<Point2f>();
for (int i = 0; i < lines.cols(); i++)
{
for (int j = i+1; j < lines.cols(); j++)
{
Mat m1 = null,m2 = null;
double[] d1 = lines.get(0,i);
double[] d2 = lines.get(0, j);
m1.put(0, i, d1);
m2.put(0, j, d2);
Point2f pt = computeIntersect(m1, m2);
if (pt.x >= 0 && pt.y >= 0)
corners.add(pt);
}
}

List<Point2f> approx = new ArrayList<Point2f>();
List<Point2f> curve;
MatOfPoint2f mat2f = new MatOfPoint2f();
for(int k=0;k<corners.size();++k)
{
Point2f rec = corners.get(k);
Point p = new Point(rec.x,rec.y);
mat2f.fromArray(p);
}
MatOfPoint2f mat2frec = new MatOfPoint2f();
Imgproc.approxPolyDP(mat2f, mat2frec, Imgproc.arcLength(mat2f, true) * 0.02,true);

if (approx.size() != 4)
{
System.out.println("The object is not quadrilateral!");

}

// Get mass center
for (int i = 0; i < corners.size(); i++)
{
center.x = center.x + corners.get(i).x;
center.y = center.y + corners.get(i).y;
}
center.x *= (1. / corners.size());
center.y *= (1. / corners.size());

sortCorners(corners, center);

Mat dst = src.clone();

// Draw lines
for (int i = 0; i < lines.cols(); i++)
{
double[] v = lines.get(0, i);
Scalar cc = new Scalar(0,255,0,0);
Core.line(dst, new Point(v[0], v[1]), new Point(v[2], v[3]), cc);

}

Scalar c1 = new Scalar(0,0,255,0);
Scalar c2 = new Scalar(0,255,0,0);
Scalar c3 = new Scalar(255,0,0,0);
Scalar c4 = new Scalar(255,255,255,0);

// Draw corner points

Core.circle(dst, new Point(corners.get(0).x,corners.get(0).y), 3, c1, 2);
Core.circle(dst, new Point(corners.get(1).x,corners.get(1).y), 3, c2, 2);
Core.circle(dst, new Point(corners.get(2).x,corners.get(2).y), 3, c3, 2);
Core.circle(dst, new Point(corners.get(3).x,corners.get(3).y), 3, c4, 2);

Scalar c5 = new Scalar(0,255,255,0);
// Draw mass center
Core.circle(dst, new Point(center.x,center.y), 3, c5, 2);

Mat quad = Mat.zeros(300, 220, CvType.CV_8UC3);

List<Point2f> quad_pts = new ArrayList<Point2f>();
quad_pts.add(new Point2f(0, 0));
quad_pts.add(new Point2f(quad.cols(), 0));
quad_pts.add(new Point2f(quad.cols(), quad.rows()));
quad_pts.add(new Point2f(0, quad.rows()));Mat transmtx = Imgproc.getPerspectiveTransform((Mat) corners, (Mat) quad_pts);
Imgproc.warpPerspective(src, quad, transmtx, quad.size());

MatOfByte matOfByte = new MatOfByte();

Highgui.imencode(".jpg", dst, matOfByte);
byte[] byteArray = matOfByte.toArray();
BufferedImage bufImage = null;
try
{
InputStream in = new ByteArrayInputStream(byteArray);
bufImage = ImageIO.read(in);
File outputfile = new File("Image.jpg");
ImageIO.write(bufImage, "jpg", outputfile);
}
catch (Exception e) {
e.printStackTrace();
}

MatOfByte matOfByte2 = new MatOfByte();

Highgui.imencode(".jpg", dst, matOfByte2);
byte[] byteArray2 = matOfByte2.toArray();
BufferedImage bufImage2 = null;
try
{
InputStream in = new ByteArrayInputStream(byteArray2);
bufImage2 = ImageIO.read(in);
File outputfile2 = new File("Quadrilateral.jpg");
ImageIO.write(bufImage, "jpg", outputfile2);
}
catch (Exception e) {
e.printStackTrace();
}}
static Point2f computeIntersect(Mat es, Mat es2)
{
int size = (int) es.total() * es.channels();
float[] buff = new float[size];
es.get(0, 0, buff);

int size1 = (int) es.total() * es.channels();
float[] buff1 = new float[size1];
es.get(0, 0, buff1);

float x1=buff[0], y1 = buff[1], x2 = buff[2], y2 = buff[3];
float x3 = buff1[0], y3 = buff1[1], x4 = buff1[2], y4 = buff1[3];
float denom;
float d;
d = (Float) null;
d = (float)((x1 - x2) * (y3 - y4)) - ((y1 - y2) * (x3 - x4));
if (d != (Float) null)
{
Point2f pt = new Point2f();
pt.x = ((x1 * y2 - y1 * x2) * (x3 - x4) - (x1 - x2) * (x3 * y4 - y3 * x4)) / d;
pt.y = ((x1 * y2 - y1 * x2) * (y3 - y4) - (y1 - y2) * (x3 * y4 - y3 * x4)) / d;
return pt;
}
else
return new Point2f(-1, -1);
}

static void sortCorners(List<Point2f> corners,Point2f center)
{
List<Point2f> top = null, bot = null;

for (int i = 0; i < corners.size(); i++)
{
if (corners.get(i).y < center.y)
top.add(corners.get(i));
else
bot.add(corners.get(i));
}

Point2f tl = top.get(0).x > top.get(1).x ? top.get(1) : top.get(0);
Point2f tr = top.get(0).x > top.get(1).x ? top.get(0) : top.get(1);
Point2f bl = bot.get(0).x > bot.get(1).x ? bot.get(1) : bot.get(0);
Point2f br = bot.get(0).x > bot.get(1).x ? bot.get(0) : bot.get(1);

corners.clear();
corners.add(tl);
corners.add(tr);
corners.add(br);
corners.add(bl);
}}

У меня проблемы с преобразованием списка< Point2f> в MatOfPoint2f. Поэтому функция arcLength (..) не работает, а код, похоже, не работает. Я надеюсь, что кто-то может помочь.