每日日报52——身份证识别&车牌识别

百度文字识别SDK进行身份证识别以及车牌识别

首先我们得在百度智能云上开发者平台上申请一个应用，得到其AK及SK，链接为：https://cloud.baidu.com/?from=console

之后参考官方文档链接：https://ai.baidu.com/ai-doc/OCR/zk3h7xw5e

整体实现效果如下：

工程目录如下：

代码如下：

AuthService.java

 1 package text;
 2 
 3 import org.json.JSONObject;
 4 
 5 import java.io.BufferedReader;
 6 import java.io.InputStreamReader;
 7 import java.net.HttpURLConnection;
 8 import java.net.URL;
 9 import java.util.List;
10 import java.util.Map;
11 
12 /**
13  * 获取token类
14  */
15 public class AuthService {
16     
17     /**
18      * 获取权限token
19      * @return 返回示例：
20      * {
21      * "access_token": "24.460da4889caad24cccdb1fea17221975.2592000.1491995545.282335-1234567",
22      * "expires_in": 2592000
23      * }
24      */
25     public static String getAuth() {
26         // 官网获取的 API Key 更新为你注册的
27         String clientId = "AK";
28         // 官网获取的 Secret Key 更新为你注册的
29         String clientSecret = "SK";
30         return getAuth(clientId, clientSecret);
31     }
32 
33     /**
34      * 获取API访问token
35      * 该token有一定的有效期，需要自行管理，当失效时需重新获取.
36      * @param ak - 百度云官网获取的 API Key
37      * @param sk - 百度云官网获取的 Securet Key
38      * @return assess_token 示例：
39      * "24.460da4889caad24cccdb1fea17221975.2592000.1491995545.282335-1234567"
40      */
41     public static String getAuth(String ak, String sk) {
42         // 获取token地址
43         String authHost = "https://aip.baidubce.com/oauth/2.0/token?";
44         String getAccessTokenUrl = authHost
45                 // 1. grant_type为固定参数
46                 + "grant_type=client_credentials"
47                 // 2. 官网获取的 API Key
48                 + "&client_id=" + ak
49                 // 3. 官网获取的 Secret Key
50                 + "&client_secret=" + sk;
51         try {
52             URL realUrl = new URL(getAccessTokenUrl);
53             // 打开和URL之间的连接
54             HttpURLConnection connection = (HttpURLConnection) realUrl.openConnection();
55             connection.setRequestMethod("GET");
56             connection.connect();
57             // 获取所有响应头字段
58             Map<String, List<String>> map = connection.getHeaderFields();
59             // 遍历所有的响应头字段
60             for (String key : map.keySet()) {
61                 System.err.println(key + "--->" + map.get(key));
62             }
63             // 定义 BufferedReader输入流来读取URL的响应
64             BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
65             String result = "";
66             String line;
67             while ((line = in.readLine()) != null) {
68                 result += line;
69             }
70             /**
71              * 返回结果示例
72              */
73             System.err.println("result:" + result);
74             JSONObject jsonObject = new JSONObject(result);
75             String access_token = jsonObject.getString("access_token");
76             return access_token;
77         } catch (Exception e) {
78             System.err.printf("获取token失败！");
79             e.printStackTrace(System.err);
80         }
81         return null;
82     }
83     
84 }

Base64Util.java

 1 package text;
 2 
 3 /**
 4  * Base64 工具类
 5  */
 6 public class Base64Util {
 7     private static final char last2byte = (char) Integer.parseInt("00000011", 2);
 8     private static final char last4byte = (char) Integer.parseInt("00001111", 2);
 9     private static final char last6byte = (char) Integer.parseInt("00111111", 2);
10     private static final char lead6byte = (char) Integer.parseInt("11111100", 2);
11     private static final char lead4byte = (char) Integer.parseInt("11110000", 2);
12     private static final char lead2byte = (char) Integer.parseInt("11000000", 2);
13     private static final char[] encodeTable = new char[]{'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'};
14 
15     public Base64Util() {
16     }
17 
18     public static String encode(byte[] from) {
19         StringBuilder to = new StringBuilder((int) ((double) from.length * 1.34D) + 3);
20         int num = 0;
21         char currentByte = 0;
22 
23         int i;
24         for (i = 0; i < from.length; ++i) {
25             for (num %= 8; num < 8; num += 6) {
26                 switch (num) {
27                     case 0:
28                         currentByte = (char) (from[i] & lead6byte);
29                         currentByte = (char) (currentByte >>> 2);
30                     case 1:
31                     case 3:
32                     case 5:
33                     default:
34                         break;
35                     case 2:
36                         currentByte = (char) (from[i] & last6byte);
37                         break;
38                     case 4:
39                         currentByte = (char) (from[i] & last4byte);
40                         currentByte = (char) (currentByte << 2);
41                         if (i + 1 < from.length) {
42                             currentByte = (char) (currentByte | (from[i + 1] & lead2byte) >>> 6);
43                         }
44                         break;
45                     case 6:
46                         currentByte = (char) (from[i] & last2byte);
47                         currentByte = (char) (currentByte << 4);
48                         if (i + 1 < from.length) {
49                             currentByte = (char) (currentByte | (from[i + 1] & lead4byte) >>> 4);
50                         }
51                 }
52 
53                 to.append(encodeTable[currentByte]);
54             }
55         }
56 
57         if (to.length() % 4 != 0) {
58             for (i = 4 - to.length() % 4; i > 0; --i) {
59                 to.append("=");
60             }
61         }
62 
63         return to.toString();
64     }
65 }

FileUtil.java

 1 package text;
 2 
 3 import java.io.*;
 4 
 5 /**
 6  * 文件读取工具类
 7  */
 8 public class FileUtil {
 9 
10     /**
11      * 读取文件内容，作为字符串返回
12      */
13     public static String readFileAsString(String filePath) throws IOException {
14         File file = new File(filePath);
15         if (!file.exists()) {
16             throw new FileNotFoundException(filePath);
17         } 
18 
19         if (file.length() > 1024 * 1024 * 1024) {
20             throw new IOException("File is too large");
21         } 
22 
23         StringBuilder sb = new StringBuilder((int) (file.length()));
24         // 创建字节输入流  
25         FileInputStream fis = new FileInputStream(filePath);  
26         // 创建一个长度为10240的Buffer
27         byte[] bbuf = new byte[10240];  
28         // 用于保存实际读取的字节数  
29         int hasRead = 0;  
30         while ( (hasRead = fis.read(bbuf)) > 0 ) {  
31             sb.append(new String(bbuf, 0, hasRead));  
32         }  
33         fis.close();  
34         return sb.toString();
35     }
36 
37     /**
38      * 根据文件路径读取byte[] 数组
39      */
40     public static byte[] readFileByBytes(String filePath) throws IOException {
41         File file = new File(filePath);
42         if (!file.exists()) {
43             throw new FileNotFoundException(filePath);
44         } else {
45             ByteArrayOutputStream bos = new ByteArrayOutputStream((int) file.length());
46             BufferedInputStream in = null;
47 
48             try {
49                 in = new BufferedInputStream(new FileInputStream(file));
50                 short bufSize = 1024;
51                 byte[] buffer = new byte[bufSize];
52                 int len1;
53                 while (-1 != (len1 = in.read(buffer, 0, bufSize))) {
54                     bos.write(buffer, 0, len1);
55                 }
56 
57                 byte[] var7 = bos.toByteArray();
58                 return var7;
59             } finally {
60                 try {
61                     if (in != null) {
62                         in.close();
63                     }
64                 } catch (IOException var14) {
65                     var14.printStackTrace();
66                 }
67 
68                 bos.close();
69             }
70         }
71     }
72 }

HttpUtil.java

 1 package text;
 2 
 3 import java.io.BufferedReader;
 4 import java.io.DataOutputStream;
 5 import java.io.InputStreamReader;
 6 import java.net.HttpURLConnection;
 7 import java.net.URL;
 8 import java.util.List;
 9 import java.util.Map;
10 
11 /**
12  * http 工具类
13  */
14 public class HttpUtil {
15 
16     public static String post(String requestUrl, String accessToken, String params)
17             throws Exception {
18         String contentType = "application/x-www-form-urlencoded";
19         return HttpUtil.post(requestUrl, accessToken, contentType, params);
20     }
21 
22     public static String post(String requestUrl, String accessToken, String contentType, String params)
23             throws Exception {
24         String encoding = "UTF-8";
25         if (requestUrl.contains("nlp")) {
26             encoding = "GBK";
27         }
28         return HttpUtil.post(requestUrl, accessToken, contentType, params, encoding);
29     }
30 
31     public static String post(String requestUrl, String accessToken, String contentType, String params, String encoding)
32             throws Exception {
33         String url = requestUrl + "?access_token=" + accessToken;
34         return HttpUtil.postGeneralUrl(url, contentType, params, encoding);
35     }
36 
37     public static String postGeneralUrl(String generalUrl, String contentType, String params, String encoding)
38             throws Exception {
39         URL url = new URL(generalUrl);
40         // 打开和URL之间的连接
41         HttpURLConnection connection = (HttpURLConnection) url.openConnection();
42         connection.setRequestMethod("POST");
43         // 设置通用的请求属性
44         connection.setRequestProperty("Content-Type", contentType);
45         connection.setRequestProperty("Connection", "Keep-Alive");
46         connection.setUseCaches(false);
47         connection.setDoOutput(true);
48         connection.setDoInput(true);
49 
50         // 得到请求的输出流对象
51         DataOutputStream out = new DataOutputStream(connection.getOutputStream());
52         out.write(params.getBytes(encoding));
53         out.flush();
54         out.close();
55 
56         // 建立实际的连接
57         connection.connect();
58         // 获取所有响应头字段
59         Map<String, List<String>> headers = connection.getHeaderFields();
60         // 遍历所有的响应头字段
61         for (String key : headers.keySet()) {
62             System.err.println(key + "--->" + headers.get(key));
63         }
64         // 定义 BufferedReader输入流来读取URL的响应
65         BufferedReader in = null;
66         in = new BufferedReader(
67                 new InputStreamReader(connection.getInputStream(), encoding));
68         String result = "";
69         String getLine;
70         while ((getLine = in.readLine()) != null) {
71             result += getLine;
72         }
73         in.close();
74         System.err.println("result:" + result);
75         return result;
76     }
77 }

Identity.java

 1 package text;
 2 
 3 import java.net.URLEncoder;
 4 
 5 public class Identity {
 6     /**
 7     * 重要提示代码中所需工具类
 8     * FileUtil,Base64Util,HttpUtil,GsonUtils请从
 9     * https://ai.baidu.com/file/658A35ABAB2D404FBF903F64D47C1F72
10     * https://ai.baidu.com/file/C8D81F3301E24D2892968F09AE1AD6E2
11     * https://ai.baidu.com/file/544D677F5D4E4F17B4122FBD60DB82B3
12     * https://ai.baidu.com/file/470B3ACCA3FE43788B5A963BF0B625F3
13     * 下载
14     */
15     public static String idcard() {
16         // 请求url
17         String url = "https://aip.baidubce.com/rest/2.0/ocr/v1/idcard";
18         try {
19             // 本地文件路径
20             String filePath = "image/identity.png";
21             byte[] imgData = FileUtil.readFileByBytes(filePath);
22             String imgStr = Base64Util.encode(imgData);
23             String imgParam = URLEncoder.encode(imgStr, "UTF-8");
24 
25             String param = "id_card_side=" + "front" + "&image=" + imgParam;
26 
27             // 注意这里仅为了简化编码每一次请求都去获取access_token，线上环境access_token有过期时间， 客户端可自行缓存，过期后重新获取。
28             String accessToken = AuthService.getAuth();
29 
30             String result = HttpUtil.post(url, accessToken, param);
31             System.out.println(result);
32             return result;
33         } catch (Exception e) {
34             e.printStackTrace();
35         }
36         return null;
37     }
38 
39     public static void main(String[] args) {
40         Identity.idcard();
41     }
42 }

LicensePlate.java

 1 package text;
 2 
 3 import java.net.URLEncoder;
 4 
 5 /**
 6 * 车牌识别
 7 */
 8 public class LicensePlate {
 9 
10     /**
11     * 重要提示代码中所需工具类
12     * FileUtil,Base64Util,HttpUtil,GsonUtils请从
13     * https://ai.baidu.com/file/658A35ABAB2D404FBF903F64D47C1F72
14     * https://ai.baidu.com/file/C8D81F3301E24D2892968F09AE1AD6E2
15     * https://ai.baidu.com/file/544D677F5D4E4F17B4122FBD60DB82B3
16     * https://ai.baidu.com/file/470B3ACCA3FE43788B5A963BF0B625F3
17     * 下载
18     */
19     public static String licensePlate() {
20         // 请求url
21         String url = "https://aip.baidubce.com/rest/2.0/ocr/v1/license_plate";
22         try {
23             // 本地文件路径
24             String filePath = "image/car.jpg";
25             byte[] imgData = FileUtil.readFileByBytes(filePath);
26             String imgStr = Base64Util.encode(imgData);
27             String imgParam = URLEncoder.encode(imgStr, "UTF-8");
28 
29             String param = "image=" + imgParam;
30 
31             // 注意这里仅为了简化编码每一次请求都去获取access_token，线上环境access_token有过期时间， 客户端可自行缓存，过期后重新获取。
32             String accessToken = AuthService.getAuth();
33 
34             String result = HttpUtil.post(url, accessToken, param);
35             System.out.println(result);
36             return result;
37         } catch (Exception e) {
38             e.printStackTrace();
39         }
40         return null;
41     }
42 
43     public static void main(String[] args) {
44         LicensePlate.licensePlate();
45     }
46 }

以上参考于文字识别OCR