java实现百度云OCR文字识别 高精度OCR识别身份证信息

本文为大家分享了java实现百度云OCR识别的具体代码，高精度OCR识别身份证信息，供大家参考，具体内容如下

1.通用OCR文字识别

这种OCR只能按照识别图片中的文字，且是按照行识别返回结果，精度较低。

首先引入依赖包：

<dependency>
  <groupId>com.baidu.aip</groupId>
  <artifactId>java-sdk</artifactId>
  <version>4.6.0</version>
</dependency>

通过OCR工具类：

package util;

import com.baidu.aip.ocr.AipOcr;
import org.json.JSONObject;
import java.util.HashMap;

public class OcrApi {
  private static final String APP_ID = "你的 App ID";
  private static final String API_KEY = "Xb12m5t4jS2n7";
  private static final String SECRET_KEY = "9XVx9GPcSbSUTZ";

  private static AipOcr getAipClient() {
    return getAipClient(API_KEY, SECRET_KEY);
  }

  public static AipOcr getAipClient(String apiKey, String secretKey) {
    AipOcr client = new AipOcr(APP_ID, apiKey, secretKey);
    // 可选：设置网络连接参数
    client.setConnectionTimeoutInMillis(2000);
    client.setSocketTimeoutInMillis(60000);
    return client;
  }

  public static String result(AipOcr client) {
    // 传入可选参数调用接口
    HashMap<String, String> options = new HashMap<>();
    options.put("language_type", "CHN_ENG");
    options.put("detect_direction", "true");
    options.put("detect_language", "true");
    options.put("probability", "true");

    JSONObject res = client.basicGeneralUrl(
        "https://lichunyu1234.oss-cn-shanghai.aliyuncs.com/1.png", options);
    return res.toString(2);
  }

  public static void main(String[] args) {
    System.out.println(result(getAipClient()));
  }
}

结果如下，识别有两行信息（words即是识别的信息）：

2.高精度OCR识别身份证信息 

这种就比较高精度，且按照分类显示，返回数据更友好，高可用。

2.1 接口说明及请求参数是地址官方截图如下：

2.2 OCR身份证识别工具类

package util;

import com.alibaba.druid.util.Base64;
import com.alibaba.fastjson.JSONObject;
import java.io.*;
import java.net.*;
import java.nio.charset.StandardCharsets;
import java.util.List;
import java.util.Map;

public class OcrUtil {
  // Access_Token获取
  private static final String ACCESS_TOKEN_HOST = "https://aip.baidubce.com/oauth/2.0/token?";
  // 身份证识别请求URL
  private static final String OCR_HOST = "https://aip.baidubce.com/rest/2.0/ocr/v1/idcard?";
  // apiKey,secretKey
  private static final String API_KEY ="Xb12m5t4jS";
  private static final String SECRET_KEY = "9XVx9GPcSbSUT";

  // 获取百度云OCR的授权access_token
  public static String getAccessToken() {
    return getAccessToken(API_KEY, SECRET_KEY);
  }

  /**
   * 获取百度云OCR的授权access_token
   * @param apiKey
   * @param secretKey
   * @return
   */
  public static String getAccessToken(String apiKey, String secretKey) {
    String accessTokenURL = ACCESS_TOKEN_HOST
        // 1. grant_type为固定参数
        + "grant_type=client_credentials"
        // 2. 官网获取的 API Key
        + "&client_id=" + apiKey
        // 3. 官网获取的 Secret Key
        + "&client_secret=" + secretKey;

    try {
      URL url = new URL(accessTokenURL);
      // 打开和URL之间的连接
      HttpURLConnection connection = (HttpURLConnection) url.openConnection();
      connection.setRequestMethod("GET");
      connection.connect();

      // 获取响应头
      Map<String, List<String>> map = connection.getHeaderFields();
      // 遍历所有的响应头字段
      for (String key : map.keySet()) {
        System.out.println(key + "---->" + map.get(key));
      }

      // 定义 BufferedReader输入流来读取URL的响应
      BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
      StringBuilder result = new StringBuilder();
      String inputLine;
      while ((inputLine = bufferedReader.readLine()) != null) {
        result.append(inputLine);
      }
      JSONObject jsonObject = JSONObject.parseObject(result.toString());
      return jsonObject.getString("access_token");

    } catch (Exception e) {
      e.printStackTrace();
      System.err.print("获取access_token失败");
    }
    return null;
  }

  /**
   * 获取身份证识别后的数据
   * @param imageUrl
   * @param idCardSide
   * @return
   */
  public static String getStringIdentityCard(File imageUrl, String idCardSide) {
    // 身份证OCR的http URL+鉴权token
    String OCRUrl = OCR_HOST+"access_token="+getAccessToken();
    System.out.println(OCRUrl);
    System.out.println("***************************************************");
    System.out.println(getAccessToken());
    // 对图片进行base64处理
    String image = encodeImageToBase64(imageUrl);
    // 请求参数
    String requestParam = "detect_direction=true&id_card_side="+idCardSide+"&image="+image;

    try {
      // 请求OCR地址
      URL url = new URL(OCRUrl);
      HttpURLConnection connection = (HttpURLConnection) url.openConnection();
      // 设置请求方法为POST
      connection.setRequestMethod("POST");

      // 设置请求头
      connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
      connection.setRequestProperty("apiKey", API_KEY);
      connection.setDoOutput(true);
      connection.getOutputStream().write(requestParam.getBytes(StandardCharsets.UTF_8));
      connection.connect();

      // 定义 BufferedReader输入流来读取URL的响应
      BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(connection.getInputStream(), StandardCharsets.UTF_8));
      StringBuilder result = new StringBuilder();
      String inputLine;
      while ((inputLine = bufferedReader.readLine()) != null) {
        result.append(inputLine);
      }
      bufferedReader.close();
      return result.toString();
    } catch (Exception e) {
      e.printStackTrace();
      System.err.println("身份证OCR识别异常");
      return null;
    }
  }

  /**
   * 对图片url进行Base64编码处理
   * @param imageUrl
   * @return
   */
  public static String encodeImageToBase64(File imageUrl) {
    // 将图片文件转化为字节数组字符串，并对其进行Base64编码处理
    byte[] data = null;
    try {
      InputStream inputStream = new FileInputStream(imageUrl);
      data = new byte[inputStream.available()];
      inputStream.read(data);
      inputStream.close();

      // 对字节数组Base64编码
      return URLEncoder.encode(Base64.byteArrayToBase64(data), "UTF-8");
    } catch (Exception e) {
      e.printStackTrace();
      return null;
    }

  }

  /**
   * 提取OCR识别身份证有效信息
   * @param
   * @return
   */
  public static Map<String, String> getIdCardInfo(MultipartFile image, int idCardSide) {
    String value = getStringIdentityCard(image, idCardSide);
    String side;
    if (idCardSide == 1) {
      side = "正面";
    }else {
      side = "背面";
    }
    Map<String, String> map = new HashMap<>();
    JSONObject jsonObject = JSONObject.parseObject(value);
    JSONObject words_result = jsonObject.getJSONObject("words_result");
    if (words_result == null || words_result.isEmpty()) {
      throw new MyException("请提供身份证"+side+"图片");
    }
    for (String key : words_result.keySet()) {
      JSONObject result = words_result.getJSONObject(key);
      String info = result.getString("words");
      switch (key) {
        case "姓名":
          map.put("name", info);
          break;
        case "性别":
          map.put("sex", info);
          break;
        case "民族":
          map.put("nation", info);
          break;
        case "出生":
          map.put("birthday", info);
          break;
        case "住址":
          map.put("address", info);
          break;
        case "公民身份号码":
          map.put("idNumber", info);
          break;
        case "签发机关":
          map.put("issuedOrganization", info);
          break;
        case "签发日期":
          map.put("issuedAt", info);
          break;
        case "失效日期":
          map.put("expiredAt", info);
          break;
      }
    }
    return map;

  }

}

官方返回示例：

对于身份证识别有个大坑：

1.有的base64编码后有头部“Base64：”要去掉，阿里巴巴的base64可以正常使用。

2.OCR识别官方只说明图片要Base64编码，但是实际上还是要再UrlEncode再编码一次才可以。

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