com.soviby.unity.ui.ugui-toolkit/Assets/Editor/Helper/ImageUtils.cs

using OpenCVForUnity.CoreModule;
using OpenCVForUnity.Features2dModule;
using OpenCVForUnity.ImgprocModule;
using OpenCVForUnity.Calib3dModule;
using System;
using System.IO;
using System.Collections.Generic;
using UnityEngine;
using OpenCVForUnity.ImgcodecsModule;
using System.Threading.Tasks;
using UguiToolkit.Editor;

public static class ImageUtils
{
    public static string FormatImgFilePath(string imgFilePath)
    {
        string projectPath = Directory.GetParent(Application.dataPath).FullName;
        return Path.GetRelativePath(projectPath, imgFilePath).Replace("\\", "/");
    }

    public static void LoadPngImagesFromFolder(string folderPath, List<Mat> images, List<string> imagePaths)
    {
        foreach (string file in Directory.GetFiles(folderPath, "*.png"))
        {
            Mat img = Imgcodecs.imread(file);
            if (!img.empty())
            {
                images.Add(img);
                imagePaths.Add(FormatImgFilePath(file));
            }
        }
    }

    public static async Task ProcessFolderAsync(List<Mat> images, string targetFilePath, RotationScaleDetector detector, 
        double distanceDifference, Action<int, (double, (double, double))> callback,
        Action endCallback)
    {
        Debug.Log("GetRotationScaleAsync: " + targetFilePath);
        Mat targetImage = Imgcodecs.imread(targetFilePath);
        for (int index = 0; index < images.Count; index++)
        {
            var img = images[index];
            var result = await detector.GetRotationScaleAsync(targetImage, img, distanceDifference);
            int _index = index;
            UnityMainThreadDispatcher.Instance().Enqueue(() =>
            {
                if (result.Item1.HasValue && result.Item2.HasValue)
                {
                    double rotationAngleDegrees = result.Item1.Value;
                    var scale = result.Item2.Value;
                    double scaleX = scale.Item1;
                    double scaleY = scale.Item2;

                    callback(_index, (rotationAngleDegrees, (scaleX, scaleY)));
                    Debug.Log($"Target Image -> Image {_index}");
                    Debug.Log($"Rotation Angle: {rotationAngleDegrees} degrees");
                    Debug.Log($"Scale X: {scaleX}");
                    Debug.Log($"Scale Y: {scaleY}");
                }
            });
        }

        UnityMainThreadDispatcher.Instance().Enqueue(() =>
        {
            endCallback();
        });
    }
}

public class RotationScaleDetector
{
    private SIFT sift;
    private BFMatcher bf;
    private Mat gray;
    private Mat descriptors1;
    private Mat descriptors2;
    private MatOfKeyPoint keypoints;
    private Mat inliers;
    private List<MatOfDMatch> knnMatches;
    private List<DMatch> goodMatches;
    private List<Point> srcPts;
    private List<Point> dstPts;

    public RotationScaleDetector()
    {
        sift = SIFT.create();
        bf = BFMatcher.create();
        gray = new Mat();
        descriptors1 = new Mat();
        descriptors2 = new Mat();
        keypoints = new MatOfKeyPoint();
        inliers = new Mat();
        knnMatches = new List<MatOfDMatch>();
        goodMatches = new List<DMatch>();
        srcPts = new List<Point>();
        dstPts = new List<Point>();
    }

    private KeyPoint[] Sift(Mat image, Mat descriptors)
    {
        Imgproc.cvtColor(image, gray, Imgproc.COLOR_BGR2GRAY);
        sift.detectAndCompute(gray, new Mat(), keypoints, descriptors);
        return keypoints.toArray();
    }

    public async Task<(double?, (double, double)?)> GetRotationScaleAsync(Mat img0, Mat img1, double distanceDifference)
    {
        KeyPoint[] kp1 = Sift(img0, descriptors1);
        KeyPoint[] kp2 = Sift(img1, descriptors2);

        if (kp1.Length == 0 || kp2.Length == 0)
        {
            return (null, null);
        }

        knnMatches.Clear();
        goodMatches.Clear();
        bf.knnMatch(descriptors1, descriptors2, knnMatches, 2);

        foreach (MatOfDMatch matofDMatch in knnMatches)
        {
            DMatch[] matches = matofDMatch.toArray();
            if (matches[0].distance < distanceDifference * matches[1].distance)
            {
                goodMatches.Add(matches[0]);
            }
        }

        if (goodMatches.Count < 3)
        {
            return (null, null);
        }

        srcPts.Clear();
        dstPts.Clear();
        foreach (DMatch match in goodMatches)
        {
            srcPts.Add(kp1[match.queryIdx].pt);
            dstPts.Add(kp2[match.trainIdx].pt);
        }

        MatOfPoint2f srcMatOfPoint2f = new MatOfPoint2f(srcPts.ToArray());
        MatOfPoint2f dstMatOfPoint2f = new MatOfPoint2f(dstPts.ToArray());

        Mat M = Calib3d.estimateAffinePartial2D(srcMatOfPoint2f, dstMatOfPoint2f, inliers, Calib3d.RANSAC, 5);
        if (M.empty())
        {
            return (null, null);
        }

        Mat R = M.colRange(0, 2);
        double theta = Math.Atan2(R.get(1, 0)[0], R.get(0, 0)[0]);
        double rotationAngleDegrees = theta * 180.0 / Math.PI;

        double scaleX = Core.norm(R.row(0));
        double scaleY = Core.norm(R.row(1));

        return (rotationAngleDegrees, (scaleX, scaleY));
    }
}