C# 正方形[i]。点（pts）； 对于（int j=0；j

正方形[i]。点（pts）； 对于（int j=0；j<4；++j） { 线（out，pts[j]，pts[（j+1）%4]，标量（0255,0），5）； } } } //调整大小以获得更好的可视化效果 调整大小（向外，向外，大小（），0.25，0.25）； 调整大小（dbg，dbg，Size（），0.25，0.25）； //显示图像 imshow（“步骤”，dbg）； imshow（“结果”，out）； waitKey（）； 返回0； }

private void DetectRectangles(Image<Gray, byte> img)
    {
                        var size = new Size(3, 3);
            CvInvoke.GaussianBlur(img, img, size, 0);
            CvInvoke.AdaptiveThreshold(img, img, 255, AdaptiveThresholdType.MeanC, ThresholdType.Binary, 75, 100);
            UMat cannyEdges = new UMat();
            CvInvoke.Canny(img, cannyEdges, 180, 120);
            var boxList = new List<RotatedRect>();

            using (VectorOfVectorOfPoint contours = new VectorOfVectorOfPoint())
            {
                CvInvoke.FindContours(cannyEdges, contours, null, RetrType.Tree, ChainApproxMethod.ChainApproxSimple);
                int count = contours.Size;
                for (int i = 0; i < count; i++)
                {
                    using (VectorOfPoint contour = contours[i])
                    using (VectorOfPoint approxContour = new VectorOfPoint())
                    {
                        CvInvoke.ApproxPolyDP(contour, approxContour, CvInvoke.ArcLength(contour, true) * 0.05, true);
                        var area = CvInvoke.ContourArea(approxContour);
                        if (area > 800 && area < 1000)
                        {
                            if (approxContour.Size == 4)
                            {
                                bool isRectangle = true;
                                Point[] pts = approxContour.ToArray();
                                LineSegment2D[] edges = PointCollection.PolyLine(pts, true);

                                for (int j = 0; j < edges.Length; j++)
                                {
                                    double angle = Math.Abs(edges[(j + 1) % edges.Length].GetExteriorAngleDegree(edges[j]));
                                    if (angle < 75 || angle > 94)
                                    {
                                        isRectangle = false;
                                        break;
                                    }
                                }

                                if (isRectangle)
                                    boxList.Add(CvInvoke.MinAreaRect(approxContour));
                            }
                        }
                    }
                }
            }
            var resultimg = new Image<Bgr,byte>(img.Width, img.Height);
            CvInvoke.CvtColor(img, resultimg, ColorConversion.Gray2Bgr);
            foreach (RotatedRect box in boxList)
            {
                CvInvoke.Polylines(resultimg, Array.ConvertAll(box.GetVertices(), Point.Round), true, new Bgr(Color.Red).MCvScalar, 2);
            }
            imageBox1.Image = resultimg;
            resultimg.Save("result_img.jpg");       }

#include <opencv2/opencv.hpp>
#include <iostream>
using namespace cv;
using namespace std;

int main()
{
    // Load image
    Mat1b img = imread("path_to_image", IMREAD_GRAYSCALE);

    // Create the output image
    Mat3b out;
    cvtColor(img, out, COLOR_GRAY2BGR);

    // Create debug image
    Mat3b dbg = out.clone();

    // Binarize (to remove jpeg arifacts)
    img = img > 200;

    // Invert image
    img = ~img;

    // Find connected components
    vector<vector<Point>> contours;
    findContours(img.clone(), contours, RETR_EXTERNAL, CHAIN_APPROX_SIMPLE);

    vector<RotatedRect> squares;

    // For each contour
    for (int i = 0; i < contours.size(); ++i)
    {
        // Find rotated bounding box
        RotatedRect box = minAreaRect(contours[i]);

        // Compute the area of the contour
        double carea = contourArea(contours[i]);
        // Compute the area of the box
        double barea = box.size.area();

        // Constraint #1
        if ((carea / barea) > 0.9)
        {
            drawContours(dbg, contours, i, Scalar(0, 0, 255), 7);

            // Constraint #2
            if (min(box.size.height, box.size.width) / max(box.size.height, box.size.width) > 0.95)
            {
                drawContours(dbg, contours, i, Scalar(255, 0, 0), 5);

                // Constraint #3
                if (box.size.width > 25 && box.size.width < 35)
                {
                    drawContours(dbg, contours, i, Scalar(0, 255, 0), 3);

                    // Found the square!
                    squares.push_back(box);
                }
            }
        }

        // Draw output
        for (int i = 0; i < squares.size(); ++i)
        {
            Point2f pts[4];
            squares[i].points(pts);

            for (int j = 0; j < 4; ++j)
            {
                line(out, pts[j], pts[(j + 1) % 4], Scalar(0,255,0), 5);
            }
        }
    }

    // Resize for better visualization
    resize(out, out, Size(), 0.25, 0.25);
    resize(dbg, dbg, Size(), 0.25, 0.25);

    // Show images
    imshow("Steps", dbg);
    imshow("Result", out);
    waitKey();

    return 0;
}