如何利用Java技術識別合約中公章的真假程度
摘要:
公章在合約中扮演重要角色,確保合約的合法性和真實性。然而,偽造公章的技術也不斷更新,為合約識別帶來挑戰。本文將介紹如何利用Java技術來識別合約中公章的真假程度,並給出對應的程式碼範例。
一、辨識公章的真假原則
公章是企事業單位的法定印章,具有唯一性、封閉性、規範性。公章的真偽可透過以下幾個面向來辨識:
二、Java技術辨識公章的真假方法
程式碼範例:
import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.core.MatOfPoint;
import org.opencv.core.Point;
import org.opencv.core.Scalar;
import org.opencv.core.Size;
import org.opencv.imgproc.Imgproc;
import org.opencv.core.CvType;
import org.opencv.core.CvType.CV_8U;
public class SealDetection {
public static void main(String[] args) {
// 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);
}
}
程式碼範例:
import org.opencv.core.Core;
import org.opencv.core.CvType;
import org.opencv.core.Mat;
import org.opencv.core.MatOfFloat;
import org.opencv.core.MatOfKeyPoint;
import org.opencv.core.Point;
import org.opencv.core.Scalar;
import org.opencv.core.Size;
import org.opencv.highgui.HighGui;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.features2d.FeatureDetector;
import org. opencv.features2d.Features2d;
import org.opencv.features2d.FlannBasedMatcher;
import org.opencv.features2d.KAZE;
import org.opencv.features2d.KeyPoint; #open#import org.cv. features2d.DescriptorExtractor;
import org.opencv.features2d.DescriptorMatcher;
import java.util.ArrayList;
import java.util.LinkedList;
import java.ut#il.List; ##import java.util.LinkedList;
import java.ut#il.List;
public class SealValidation {
public static void main(String[] args) {
//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);
}
}
三、結論
利用Java技術識別合約中公章的真假程度是一項複雜而有挑戰性的任務。透過影像處理和特徵匹配技術,我們可以對公章進行各種維度的分析和比對,從而識別公章的真偽程度。當然,由於偽造技術不斷變化,識別公章的方法也需要不斷更新、改進。
公章真偽識別是合約中的重要環節,對企事業單位和個人來說都具有重要意義。希望本文提供的Java技術方法和程式碼範例能對讀者在識別合約中公章的真假程度方面提供一些幫助。
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