如何利用Java技术识别合同中公章的真假程度

  // 加载本地库
  System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
  
  // 读取图片文件
  Mat sourceImage = Imgcodecs.imread("contract_seal.jpg");
  
  // 灰度处理
  Mat grayImage = new Mat();
  Imgproc.cvtColor(sourceImage, grayImage, Imgproc.COLOR_BGR2GRAY);
  
  // 图像边缘检测
  Mat edgeImage = new Mat();
  Imgproc.Canny(grayImage, edgeImage, 100, 200);
  
  // 圆查找
  Mat circles = new Mat();
  Imgproc.HoughCircles(edgeImage, circles, Imgproc.CV_HOUGH_GRADIENT, 1, edgeImage.rows()/8, 200, 100, 0, 0);
  
  // 绘制检测到的圆
  for (int i = 0; i < circles.cols(); i++) {
     double[] circleData = circles.get(0, i);
     Point center = new Point(Math.round(circleData[0]), Math.round(circleData[1]));
     int radius = (int) Math.round(circleData[2]);
     Imgproc.circle(sourceImage, center, radius, new Scalar(0, 255, 0), 2);
  }
  
  // 显示处理结果
  HighGui.imshow("Detected Seals", sourceImage);
  HighGui.waitKey(0);

  //加载本地库
  System.loadLibrary(Core.NATIVE_LIBRARY_NAME); 

  //读取真实公章图像
  Mat refImage = Imgcodecs.imread("real_seal.jpg"); 
  
  //读取合同公章图像
  Mat testImage = Imgcodecs.imread("contract_seal.jpg"); 
  
  //创建KAZE关键点检测器
  FeatureDetector detector = FeatureDetector.create(FeatureDetector.KAZE); 
  
  //检测关键点
  MatOfKeyPoint refKp = new MatOfKeyPoint(); 
  MatOfKeyPoint testKp = new MatOfKeyPoint(); 
  detector.detect(refImage, refKp); 
  detector.detect(testImage, testKp); 
  
  //提取特征描述子
  DescriptorExtractor extractor = DescriptorExtractor.create(DescriptorExtractor.KAZE); 
  
  Mat descriptorRef = new Mat(); 
  Mat descriptorTest = new Mat(); 
  extractor.compute(refImage, refKp, descriptorRef); 
  extractor.compute(testImage, testKp, descriptorTest); 
  
  //创建FLANN特征匹配器
  DescriptorMatcher matcher = DescriptorMatcher.create(DescriptorMatcher.BRUTEFORCE_HAMMING); 
  
  //匹配特征描述子
  MatOfDMatch matches = new MatOfDMatch(); 
  matcher.match(descriptorRef, descriptorTest, matches); 
  
  //绘制匹配结果
  Mat outputImage = new Mat(); 
  Scalar matchColor = new Scalar(0, 255, 0); 
  Features2d.drawMatches(refImage, refKp, testImage, testKp, matches, outputImage, matchColor, 
     Scalar.all(-1), new MatOfByte(), 
     Features2d.NOT_DRAW_SINGLE_POINTS); 
  
  //计算匹配度
  double totalMatches = matches.rows(); 
  System.out.println("总匹配点数: " + totalMatches); 
  
  double maxDist = 0; 
  double minDist = 100; 
  List<DMatch> matchList = matches.toList(); 
  
  //获取匹配点的最大和最小距离
  for (int i = 0; i < totalMatches; i++) { 
     double dist = matchList.get(i).distance; 
     if (dist < minDist) minDist = dist; 
     if (dist > maxDist) maxDist = dist; 
  } 
  
  //选择适合的匹配点
  LinkedList<DMatch> goodMatches = new LinkedList<DMatch>(); 
  for (int i = 0; i < totalMatches; i++) { 
     if (matchList.get(i).distance <= 3 * minDist) { 
        goodMatches.addLast(matchList.get(i)); 
     } 
  } 
  
  //计算匹配率
  double matchPercentage = (goodMatches.size() / totalMatches) * 100; 
  System.out.println("公章匹配率: " + matchPercentage + "%"); 
  
  //显示处理结果
  HighGui.imshow("Matched Seals", outputImage); 
  HighGui.waitKey(0);