java 二维码几何变形恢复
时间: 2023-10-14 12:03:00 浏览: 66
二维码的几何变形恢复是通过图像处理技术实现的。常用的方法包括透视变换和仿射变换。下面简单介绍一下这两种方法。
透视变换是指将一个平面上的图像投影到另一个平面上,同时保持原来图像的线段在新图像中仍然是直线。在二维码的几何变形恢复中,可以通过寻找二维码的四个角点,确定变换前后的对应关系,从而进行透视变换,恢复原来的二维码图像。
仿射变换是指在平面上对图像进行任意角度的旋转、平移、缩放等变换。在二维码的几何变形恢复中,可以通过检测二维码的基准位置和方向,确定变换前后的对应关系,从而进行仿射变换,恢复原来的二维码图像。
需要注意的是,二维码的几何变形恢复不仅需要考虑图像处理技术,还需要考虑摄像头的畸变、光照条件等因素对图像的影响,因此需要综合运用多种技术手段,才能实现准确的二维码几何变形恢复。
相关问题
java 代码 二维码几何变形恢复
以下是 Java 代码示例,演示了如何使用 OpenCV 库实现二维码几何变形恢复:
```java
import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.core.MatOfPoint2f;
import org.opencv.core.Point;
import org.opencv.core.Scalar;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;
import java.util.ArrayList;
import java.util.List;
public class QRCodeGeometryCorrection {
public static void main(String[] args) {
// 加载 OpenCV 库
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
// 读取二维码图片
Mat img = Imgcodecs.imread("qrcode.jpg");
// 转换为灰度图
Mat gray = new Mat();
Imgproc.cvtColor(img, gray, Imgproc.COLOR_BGR2GRAY);
// 二值化处理
Mat threshold = new Mat();
Imgproc.threshold(gray, threshold, 0, 255, Imgproc.THRESH_BINARY_INV | Imgproc.THRESH_OTSU);
// 查找轮廓
List<MatOfPoint> contours = new ArrayList<>();
Mat hierarchy = new Mat();
Imgproc.findContours(threshold, contours, hierarchy, Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE);
// 查找最大轮廓
int maxContourIndex = 0;
double maxContourArea = -1;
for (int i = 0; i < contours.size(); i++) {
double area = Imgproc.contourArea(contours.get(i));
if (area > maxContourArea) {
maxContourArea = area;
maxContourIndex = i;
}
}
// 查找轮廓的四个角点
MatOfPoint2f maxContour2f = new MatOfPoint2f(contours.get(maxContourIndex).toArray());
MatOfPoint2f approx = new MatOfPoint2f();
double epsilon = 0.01 * Imgproc.arcLength(maxContour2f, true);
Imgproc.approxPolyDP(maxContour2f, approx, epsilon, true);
Point[] points = approx.toArray();
// 透视变换
Point topLeft = points[0];
Point topRight = points[1];
Point bottomRight = points[2];
Point bottomLeft = points[3];
MatOfPoint2f src = new MatOfPoint2f(topLeft, topRight, bottomRight, bottomLeft);
MatOfPoint2f dst = new MatOfPoint2f(new Point(0, 0), new Point(200, 0), new Point(200, 200), new Point(0, 200));
Mat perspectiveTransform = Imgproc.getPerspectiveTransform(src, dst);
Mat corrected = new Mat();
Imgproc.warpPerspective(img, corrected, perspectiveTransform, new org.opencv.core.Size(200, 200));
// 显示结果
Imgproc.putText(img, "Original", new Point(10, 30), Core.FONT_HERSHEY_SIMPLEX, 1, new Scalar(0, 0, 255), 2);
Imgproc.putText(corrected, "Corrected", new Point(10, 30), Core.FONT_HERSHEY_SIMPLEX, 1, new Scalar(0, 0, 255), 2);
Imgcodecs.imwrite("original.jpg", img);
Imgcodecs.imwrite("corrected.jpg", corrected);
}
}
```
这段代码使用了 OpenCV 库中的图像处理函数,实现了对二维码图像的几何变形恢复。其中,`Imgcodecs.imread` 函数用于读取图像,`Imgproc.cvtColor` 函数用于将彩色图像转换为灰度图,`Imgproc.threshold` 函数用于二值化处理,`Imgproc.findContours` 函数用于查找轮廓,`Imgproc.approxPolyDP` 函数用于对轮廓进行多边形逼近,`Imgproc.getPerspectiveTransform` 函数用于计算透视变换矩阵,`Imgproc.warpPerspective` 函数用于进行透视变换。最后,使用 `Imgcodecs.imwrite` 函数将结果保存到文件中。
变形二维码图片恢复 java 代码
变形二维码图片恢复是一个比较复杂的过程,需要使用到图像处理和计算机视觉的知识。下面给你提供一个简单的Java代码示例用于变形二维码图片的恢复,仅供参考:
```java
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.core.MatOfPoint2f;
import org.opencv.core.Point;
import org.opencv.core.Size;
import org.opencv.imgproc.Imgproc;
public class QRCodeRestorer {
static {
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
}
public static BufferedImage restore(BufferedImage image) {
// 将Java的BufferedImage转成OpenCV的Mat
Mat mat = ImageUtils.bufferedImage2Mat(image);
// 二值化处理
Mat grayMat = new Mat();
Imgproc.cvtColor(mat, grayMat, Imgproc.COLOR_BGR2GRAY);
Mat binaryMat = new Mat();
Imgproc.threshold(grayMat, binaryMat, 0, 255, Imgproc.THRESH_BINARY | Imgproc.THRESH_OTSU);
// 查找二维码区域
MatOfPoint2f qrRegion = findQRRegion(binaryMat);
// 透视变换
Mat warpedMat = new Mat();
MatOfPoint2f destPoints = new MatOfPoint2f(new Point(0, 0), new Point(0, 399), new Point(399, 399), new Point(399, 0));
Mat perspectiveTransform = Imgproc.getPerspectiveTransform(qrRegion, destPoints);
Imgproc.warpPerspective(mat, warpedMat, perspectiveTransform, new Size(400, 400));
// 将OpenCV的Mat转成Java的BufferedImage
BufferedImage result = ImageUtils.mat2BufferedImage(warpedMat);
return result;
}
/**
* 查找二维码区域
*/
private static MatOfPoint2f findQRRegion(Mat binaryMat) {
// 查找轮廓
Mat contoursMat = new Mat();
Imgproc.findContours(binaryMat, contoursMat, new Mat(), Imgproc.RETR_EXTERNAL, Imgproc.CHAIN_APPROX_SIMPLE);
// 查找最大的轮廓
double maxArea = 0;
int maxAreaContourIndex = -1;
for (int i = 0; i < contoursMat.rows(); i++) {
double area = Imgproc.contourArea(contoursMat.row(i));
if (area > maxArea) {
maxArea = area;
maxAreaContourIndex = i;
}
}
MatOfPoint2f maxContour = new MatOfPoint2f(contoursMat.row(maxAreaContourIndex));
// 逼近多边形
MatOfPoint2f approx = new MatOfPoint2f();
Imgproc.approxPolyDP(maxContour, approx, Imgproc.arcLength(maxContour, true) * 0.02, true);
// 查找四边形
if (approx.rows() != 4) {
throw new RuntimeException("Failed to find QR code region");
}
// 对四个点进行排序
Point[] points = approx.toArray();
Point[] sortedPoints = sortPoints(points);
// 构造四边形的MatOfPoint2f
MatOfPoint2f qrRegion = new MatOfPoint2f(sortedPoints[0], sortedPoints[1], sortedPoints[2], sortedPoints[3]);
return qrRegion;
}
/**
* 对四个点进行排序
*/
private static Point[] sortPoints(Point[] points) {
Point[] sortedPoints = new Point[4];
// 找到左上、右上、左下、右下四个点
Point2D center = new Point2D.Float(0, 0);
for (Point point : points) {
center.setLocation(center.getX() + point.x, center.getY() + point.y);
}
center.setLocation(center.getX() / 4, center.getY() / 4);
Point2D[] topPoints = new Point2D[2];
Point2D[] bottomPoints = new Point2D[2];
int topIndex = 0;
int bottomIndex = 0;
for (Point point : points) {
if (point.y < center.getY()) {
topPoints[topIndex++] = new Point2D.Float(point.x, point.y);
} else {
bottomPoints[bottomIndex++] = new Point2D.Float(point.x, point.y);
}
}
Point2D topLeft = topPoints[0].getX() < topPoints[1].getX() ? topPoints[0] : topPoints[1];
Point2D topRight = topPoints[0].getX() < topPoints[1].getX() ? topPoints[1] : topPoints[0];
Point2D bottomLeft = bottomPoints[0].getX() < bottomPoints[1].getX() ? bottomPoints[0] : bottomPoints[1];
Point2D bottomRight = bottomPoints[0].getX() < bottomPoints[1].getX() ? bottomPoints[1] : bottomPoints[0];
sortedPoints[0] = new Point((int) topLeft.getX(), (int) topLeft.getY());
sortedPoints[1] = new Point((int) topRight.getX(), (int) topRight.getY());
sortedPoints[2] = new Point((int) bottomRight.getX(), (int) bottomRight.getY());
sortedPoints[3] = new Point((int) bottomLeft.getX(), (int) bottomLeft.getY());
return sortedPoints;
}
}
```
上面的代码使用了OpenCV库进行图像处理和计算机视觉的操作,其中 `ImageUtils` 类是用于Mat和BufferedImage之间的转换的工具类。请注意,这里的代码只是一个简单的示例,对于不同的变形程度和变形类型的二维码,可能需要调整代码中的参数和算法,才能达到更好的效果。