在图像中找到qr码并使用zxing解码

izj3ouym 于 2021-07-26 发布在 Java

关注(0)|答案(3)|浏览(383)

首先，我通读了所有这些关于如何在java中使用zxing的主题，但总是在缺少com.google.zxing.client.j2se.*时出错（我在eclipse中加载了zxing core-3.2.1.jar，其他所有的zxing包都可以工作，除非是j2se），或者只是找到了创建qr图像的解决方案。。。
我的目标是编写一个获取图像文件的方法，在该图像中找到qr码，解码qr码并返回字符串，基本上应该如下所示：

import com.google.zxing.*;

public class QRCode {

    /*
     * ...
     */

    public String getDecodedString(SomeStandardImageType photo){
        // detect the qr code in a photo
        // create qr image from detected area in photo
        // decode the new created qr image and return the string
        return "This is the decoded dataString from the qr code in the photo";
    }

}

综上所述，该方法应该得到如下图像文件

并应返回url，如果失败，则返回“”。
代码应与zxing 3.2.1兼容。
编辑：问题解决了。对于其他对此感兴趣的人，我想说添加两个外部jar是很重要的 core-3.2.1.jar 和 javase-3.2.1.jar 到外部jar。我的答案在没有后者的情况下有效，但取决于android镜像库。

Java qr-code zxing

来源：https://stackoverflow.com/questions/65763992/spring-check-if-an-image-has-a-qr-code-then-scan-it

3条答案

按热度按时间

1bqhqjot1#

以下是创建二维码并从二维码中读取消息的代码
你需要建立zxing图书馆
主要描述二维码的创建和提取

package com.attendance.mark;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import javax.imageio.ImageIO;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.BinaryBitmap;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatReader;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.NotFoundException;
import com.google.zxing.Result;
import com.google.zxing.WriterException;
import com.google.zxing.client.j2se.BufferedImageLuminanceSource;
import com.google.zxing.client.j2se.MatrixToImageWriter;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;

public class QRCode {

    /**
     * 
     * @param args 
     * @throws WriterException
     * @throws IOException
     * @throws NotFoundException
     */
  public static void main(String[] args) throws WriterException, IOException,
      NotFoundException {
    String qrCodeData = "student3232_2015_12_15_10_29_46_123";
    String filePath = "F:\\Opulent_ProjectsDirectory_2015-2016\\.metadata\\.plugins\\org.eclipse.wst.server.core\\tmp0\\wtpwebapps\\AttendanceUsingQRCode\\QRCodes\\student3232_2015_12_15_10_29_46_123";
    String charset = "UTF-8"; // or "ISO-8859-1"
    Map<EncodeHintType, ErrorCorrectionLevel> hintMap = new HashMap<EncodeHintType, ErrorCorrectionLevel>();
    hintMap.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L);

    createQRCode(qrCodeData, filePath, charset, hintMap, 200, 200);
    System.out.println("QR Code image created successfully!");

    System.out.println("Data read from QR Code: "
        + readQRCode(filePath, charset, hintMap));

  }

  /***
   * 
   * @param qrCodeData
   * @param filePath
   * @param charset
   * @param hintMap
   * @param qrCodeheight
   * @param qrCodewidth
   * @throws WriterException
   * @throws IOException
   */
  public static void createQRCode(String qrCodeData, String filePath,
      String charset, Map hintMap, int qrCodeheight, int qrCodewidth)
      throws WriterException, IOException {
    BitMatrix matrix = new MultiFormatWriter().encode(
        new String(qrCodeData.getBytes(charset), charset),
        BarcodeFormat.QR_CODE, qrCodewidth, qrCodeheight);
    MatrixToImageWriter.writeToFile(matrix, filePath.substring(filePath
        .lastIndexOf('.') + 1), new File(filePath));
  }

  /**
   * 
   * @param filePath
   * @param charset
   * @param hintMap
   * 
   * @return Qr Code value 
   * 
   * @throws FileNotFoundException
   * @throws IOException
   * @throws NotFoundException
   */
  public static String readQRCode(String filePath, String charset, Map hintMap)
      throws FileNotFoundException, IOException, NotFoundException {
    BinaryBitmap binaryBitmap = new BinaryBitmap(new HybridBinarizer(
        new BufferedImageLuminanceSource(
            ImageIO.read(new FileInputStream(filePath)))));
    Result qrCodeResult = new MultiFormatReader().decode(binaryBitmap, hintMap);
    return qrCodeResult.getText();
  }
}

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u4dcyp6a2#

我现在更深入地阅读了zxing，下面的代码将与zxingv3.2.1一起使用（此代码在没有 javase 库）

// Imports
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;

import com.google.zxing.BinaryBitmap;
import com.google.zxing.ChecksumException;
import com.google.zxing.FormatException;
import com.google.zxing.LuminanceSource;
import com.google.zxing.NotFoundException;
import com.google.zxing.RGBLuminanceSource;
import com.google.zxing.Reader;
import com.google.zxing.Result;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.qrcode.QRCodeReader;

// Interesting method
public static String decodeQRImage(String path) {
    Bitmap bMap = BitmapFactory.decodeFile(path);
    String decoded = null;

    int[] intArray = new int[bMap.getWidth() * bMap.getHeight()];
    bMap.getPixels(intArray, 0, bMap.getWidth(), 0, 0, bMap.getWidth(),
            bMap.getHeight());
    LuminanceSource source = new RGBLuminanceSource(bMap.getWidth(),
            bMap.getHeight(), intArray);
    BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));

    Reader reader = new QRCodeReader();
    try {
        Result result = reader.decode(bitmap);
        decoded = result.getText();
    } catch (NotFoundException e) {
        e.printStackTrace();
    } catch (ChecksumException e) {
        e.printStackTrace();
    } catch (FormatException e) {
        e.printStackTrace();
    }
    return decoded;
}

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mlnl4t2r3#

这个代码对我来说很好用。希望它有助于进口必要的软件包，它应该工作

public class QR_Reader extends JFrame implements Runnable, ThreadFactory {

private static final long serialVersionUID = 6441489157408381878L;

private Executor executor = Executors.newSingleThreadExecutor(this);

private Webcam webcam = null;
private WebcamPanel panel = null;
String s;

public QR_Reader() {
    super();
    setLayout(new FlowLayout());
    setTitle("Reading QR Code");
    Dimension size = WebcamResolution.QVGA.getSize();
    webcam = Webcam.getWebcams().get(0);
    webcam.setViewSize(size);
    panel = new WebcamPanel(webcam);
    panel.setPreferredSize(size);
    add(panel);
    pack();
    setVisible(true);
    setResizable(false);
    executor.execute(this);
}
@Override
public void run() {

    do {
        try {
            Thread.sleep(100);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

        Result result = null;
        BufferedImage image = null;

        if (webcam.isOpen()) {

            if ((image = webcam.getImage()) == null) {
                continue;
            }

            LuminanceSource source = new BufferedImageLuminanceSource(image);
            BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));

            try {
                result = new MultiFormatReader().decode(bitmap);
            } catch (NotFoundException e) {
                // fall thru, it means there is no QR code in image
            }
        }

        if (result != null) {
            String time_then=result.getText();  //this is the text extracted from QR CODE
            webcam.close();
            this.setVisible(false);
            this.dispose();
            try {
                new Compare().C_Main(time_then);
            } catch (ParseException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }

    } while (true);
}

@Override
public Thread newThread(Runnable r) {
    Thread t = new Thread(r, "example-runner");
    t.setDaemon(true);
    return t;
}

void QRC_Main() {
    new QR_Reader();
}
}

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在图像中找到qr码并使用zxing解码

3条答案

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