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百度OCR图片内容识别为文字详细教程

一、百度OCR图片内容转换为文字

1.进入对应链接根据图片指示进行相关操作

https://ai.baidu.com/ai-doc

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2.进入页面点击技术文档

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3.个人示例代码实现(仅供参考)
3.1 重要提示代码中所需工具类
  • FileUtil,Base64Util,HttpUtil,GsonUtils请从

https://ai.baidu.com/file/658A35ABAB2D404FBF903F64D47C1F72

package com.xigao.util;

import java.io.*;

/**
 * 文件读取工具类
 */
public class FileUtil {

    /**
     * 读取文件内容,作为字符串返回
     */
    public static String readFileAsString(String filePath) throws IOException {
        File file = new File(filePath);
        if (!file.exists()) {
            throw new FileNotFoundException(filePath);
        } 

        if (file.length() > 1024 * 1024 * 1024) {
            throw new IOException("File is too large");
        } 

        StringBuilder sb = new StringBuilder((int) (file.length()));
        // 创建字节输入流  
        FileInputStream fis = new FileInputStream(filePath);  
        // 创建一个长度为10240的Buffer
        byte[] bbuf = new byte[10240];  
        // 用于保存实际读取的字节数  
        int hasRead = 0;  
        while ( (hasRead = fis.read(bbuf)) > 0 ) {  
            sb.append(new String(bbuf, 0, hasRead));  
        }  
        fis.close();  
        return sb.toString();
    }

    /**
     * 根据文件路径读取byte[] 数组
     */
    public static byte[] readFileByBytes(String filePath) throws IOException {
        File file = new File(filePath);
        if (!file.exists()) {
            throw new FileNotFoundException(filePath);
        } else {
            ByteArrayOutputStream bos = new ByteArrayOutputStream((int) file.length());
            BufferedInputStream in = null;

            try {
                in = new BufferedInputStream(new FileInputStream(file));
                short bufSize = 1024;
                byte[] buffer = new byte[bufSize];
                int len1;
                while (-1 != (len1 = in.read(buffer, 0, bufSize))) {
                    bos.write(buffer, 0, len1);
                }

                byte[] var7 = bos.toByteArray();
                return var7;
            } finally {
                try {
                    if (in != null) {
                        in.close();
                    }
                } catch (IOException var14) {
                    var14.printStackTrace();
                }

                bos.close();
            }
        }
    }
}
  • Base64Util

    https://ai.baidu.com/file/C8D81F3301E24D2892968F09AE1AD6E2

    package com.xigao.util;
    
    /**
     * Base64 工具类
     */
    public class Base64Util {
        private static final char last2byte = (char) Integer.parseInt("00000011", 2);
        private static final char last4byte = (char) Integer.parseInt("00001111", 2);
        private static final char last6byte = (char) Integer.parseInt("00111111", 2);
        private static final char lead6byte = (char) Integer.parseInt("11111100", 2);
        private static final char lead4byte = (char) Integer.parseInt("11110000", 2);
        private static final char lead2byte = (char) Integer.parseInt("11000000", 2);
        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', '+', '/'};
    
        public Base64Util() {
        }
    
        public static String encode(byte[] from) {
            StringBuilder to = new StringBuilder((int) ((double) from.length * 1.34D) + 3);
            int num = 0;
            char currentByte = 0;
    
            int i;
            for (i = 0; i < from.length; ++i) {
                for (num %= 8; num < 8; num += 6) {
                    switch (num) {
                        case 0:
                            currentByte = (char) (from[i] & lead6byte);
                            currentByte = (char) (currentByte >>> 2);
                        case 1:
                        case 3:
                        case 5:
                        default:
                            break;
                        case 2:
                            currentByte = (char) (from[i] & last6byte);
                            break;
                        case 4:
                            currentByte = (char) (from[i] & last4byte);
                            currentByte = (char) (currentByte << 2);
                            if (i + 1 < from.length) {
                                currentByte = (char) (currentByte | (from[i + 1] & lead2byte) >>> 6);
                            }
                            break;
                        case 6:
                            currentByte = (char) (from[i] & last2byte);
                            currentByte = (char) (currentByte << 4);
                            if (i + 1 < from.length) {
                                currentByte = (char) (currentByte | (from[i + 1] & lead4byte) >>> 4);
                            }
                    }
    
                    to.append(encodeTable[currentByte]);
                }
            }
    
            if (to.length() % 4 != 0) {
                for (i = 4 - to.length() % 4; i > 0; --i) {
                    to.append("=");
                }
            }
    
            return to.toString();
        }
    }
    
  • HttpUtil

    https://ai.baidu.com/file/544D677F5D4E4F17B4122FBD60DB82B3

    package com.xigao.util;
    
    import java.io.BufferedReader;
    import java.io.DataOutputStream;
    import java.io.InputStreamReader;
    import java.net.HttpURLConnection;
    import java.net.URL;
    import java.util.List;
    import java.util.Map;
    
    /**
     * http 工具类
     */
    public class HttpUtil {
    
        public static String post(String requestUrl, String accessToken, String params)
                throws Exception {
            String contentType = "application/x-www-form-urlencoded";
            return HttpUtil.post(requestUrl, accessToken, contentType, params);
        }
    
        public static String post(String requestUrl, String accessToken, String contentType, String params)
                throws Exception {
            String encoding = "UTF-8";
            if (requestUrl.contains("nlp")) {
                encoding = "GBK";
            }
            return HttpUtil.post(requestUrl, accessToken, contentType, params, encoding);
        }
    
        public static String post(String requestUrl, String accessToken, String contentType, String params, String encoding)
                throws Exception {
            String url = requestUrl + "?access_token=" + accessToken;
            return HttpUtil.postGeneralUrl(url, contentType, params, encoding);
        }
    
        public static String postGeneralUrl(String generalUrl, String contentType, String params, String encoding)
                throws Exception {
            URL url = new URL(generalUrl);
            // 打开和URL之间的连接
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("POST");
            // 设置通用的请求属性
            connection.setRequestProperty("Content-Type", contentType);
            connection.setRequestProperty("Connection", "Keep-Alive");
            connection.setUseCaches(false);
            connection.setDoOutput(true);
            connection.setDoInput(true);
    
            // 得到请求的输出流对象
            DataOutputStream out = new DataOutputStream(connection.getOutputStream());
            out.write(params.getBytes(encoding));
            out.flush();
            out.close();
    
            // 建立实际的连接
            connection.connect();
            // 获取所有响应头字段
            Map<String, List<String>> headers = connection.getHeaderFields();
            // 遍历所有的响应头字段
            for (String key : headers.keySet()) {
                System.err.println(key + "--->" + headers.get(key));
            }
            // 定义 BufferedReader输入流来读取URL的响应
            BufferedReader in = null;
            in = new BufferedReader(
                    new InputStreamReader(connection.getInputStream(), encoding));
            String result = "";
            String getLine;
            while ((getLine = in.readLine()) != null) {
                result += getLine;
            }
            in.close();
            System.err.println("result:" + result);
            return result;
        }
    }
    
    
  • GsonUtils
    https://ai.baidu.com/file/470B3ACCA3FE43788B5A963BF0B625F3

    /*
     * Copyright (C) 2017 Baidu, Inc. All Rights Reserved.
     */
    package com.xigao.util;
    
    import com.google.gson.Gson;
    import com.google.gson.GsonBuilder;
    import com.google.gson.JsonParseException;
    
    import java.lang.reflect.Type;
    
    /**
     * Json工具类.
     */
    public class GsonUtils {
        private static Gson gson = new GsonBuilder().create();
    
        public static String toJson(Object value) {
            return gson.toJson(value);
        }
    
        public static <T> T fromJson(String json, Class<T> classOfT) throws JsonParseException {
            return gson.fromJson(json, classOfT);
        }
    
        public static <T> T fromJson(String json, Type typeOfT) throws JsonParseException {
            return (T) gson.fromJson(json, typeOfT);
        }
    }
    
3.2 controller层代码(前端照片以Base64格式传输)
package com.xigao.controller;

import com.xigao.service.OcrService;
import lombok.AllArgsConstructor;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

@RequestMapping("/api")
@RestController
@AllArgsConstructor
@CrossOrigin(origins = "*")
public class OcrController {
    private final OcrService ocrService;

    @PostMapping(value = "/recognize")
    public String recognizeImage(@RequestParam("file") String file){
      // 调用OcrService中的方法进行文字识别
      return ocrService.recognizeText(file);
    }
}
3.3 service实现类层代码
package com.xigao.service.impl;

/**
 * 重要提示代码中所需工具类
 * FileUtil,Base64Util,HttpUtil,GsonUtils请从
 * https://ai.baidu.com/file/658A35ABAB2D404FBF903F64D47C1F72
 * https://ai.baidu.com/file/C8D81F3301E24D2892968F09AE1AD6E2
 * https://ai.baidu.com/file/544D677F5D4E4F17B4122FBD60DB82B3
 * https://ai.baidu.com/file/470B3ACCA3FE43788B5A963BF0B625F3
 * 下载
 */

import com.xigao.service.OcrService;
import com.xigao.util.*;
import org.springframework.stereotype.Service;


import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.URLEncoder;
import java.util.Base64;

/**
 * 通用文字识别(高精度版)
 */
@Service
public class OcrServiceImpl implements OcrService {
    public String recognizeText(String file) {
        String substring = file.substring(file.lastIndexOf(",") + 1);
        String replace = substring.replace(" ", "+");
        // 请求url
        String url = "https://aip.baidubce.com/rest/2.0/ocr/v1/accurate_basic";
        try {

            String imgParam = URLEncoder.encode(replace, "UTF-8");

            String param = "image=" + imgParam;
            String auth = GetTokenUtil.getAuth();
            // 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。
            String accessToken = auth;

            String result = HttpUtil.post(url, accessToken, param);
            System.out.println(result);
            return result;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
}
3.4 获取token的代码
package com.xigao.util;

import org.json.JSONObject;
 
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.List;
import java.util.Map;
 
/**
 * 获取权限token
 * @return 返回示例:
 * {
 * "access_token": "24.460da4889caad24cccdb1fea17221975.2592000.1491995545.282335-1234567",
 * "expires_in": 2592000
 * }
 */
public  class GetTokenUtil {

    public static String getAuth() {
        // 官网获取的 API Key 更新为你注册的
        String clientId = "API Key";
        // 官网获取的 Secret Key 更新为你注册的
        String clientSecret = "Secret Key";
        return getAuth(clientId, clientSecret);
    }
 
    /**
     * 获取API访问token
     * 该token有一定的有效期,需要自行管理,当失效时需重新获取.
     * @param ak - 百度云官网获取的 API Key
     * @param sk - 百度云官网获取的 Securet Key
     * @return assess_token 示例:
     * "24.460da4889caad24cccdb1fea17221975.2592000.1491995545.282335-1234567"
     */
    public static String getAuth(String ak, String sk) {
        // 获取token地址
        String authHost = "https://aip.baidubce.com/oauth/2.0/token?";
        String getAccessTokenUrl = authHost
                // 1. grant_type为固定参数
                + "grant_type=client_credentials"
                // 2. 官网获取的 API Key
                + "&client_id=" + ak
                // 3. 官网获取的 Secret Key
                + "&client_secret=" + sk;
        try {
            URL realUrl = new URL(getAccessTokenUrl);
            // 打开和URL之间的连接
            HttpURLConnection connection = (HttpURLConnection) realUrl.openConnection();
            connection.setRequestMethod("GET");
            connection.connect();
            // 获取所有响应头字段
            Map<String, List<String>> map = connection.getHeaderFields();
            // 遍历所有的响应头字段
            for (String key : map.keySet()) {
                System.err.println(key + "--->" + map.get(key));
            }
            // 定义 BufferedReader输入流来读取URL的响应
            BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
            String result = "";
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
            /**
             * 返回结果示例
             */
            System.err.println("result:" + result);
            JSONObject jsonObject = new JSONObject(result);
            String access_token = jsonObject.getString("access_token");
            return access_token;
        } catch (Exception e) {
            System.err.printf("获取token失败!");
            e.printStackTrace(System.err);
        }
        return null;
    }
}

二、百度开发Api创建并生成API Key(新手可领取免费测试版本)

1.进入对应的创建界面

https://console.bce.baidu.com/ai/#/ai/ocr/overview/index

img

2.根据需求选择相应的文字识别接口

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3.创建成功的资源将会显示在[资源列表]的「已领取资源」中。您可以选择「查看领取记录」去往「资源列表」查看。

资源列表地址:资源列表

img

4.创建应用
4.1 进入 文字识别控制台,点击 「去创建」,即可进入应用创建页面。

文字识别控制台地址:文字识别控制台
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4.2 根据需要,填写完毕相应信息后,点击「立即创建」,即可完成应用的创建。应用创建完毕后,点击左侧导航中的「应用列表」,进行查看和管理。

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4.3 创建完的应用 就可以看到API KEY以及 Secret KEY了。

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