VIN code identification

Update time ： 2022-11-15

Interface description

It supports the identification of the frame number at the windshield of the vehicle.

Online debugging

You can visit Sample Code Center Debug the interface in , you can perform signature verification, view the request content and return results of online calls, and automatically generate sample code.

Request Description

Request Example

HTTP method: POST

Request URL: https://aip.baidubce.com/rest/2.0/ocr/v1/vin_code

URL parameter:

parameter	value
access_token	Access_token obtained through API Key and Secret Key, refer to“ Access Token acquisition ”

The headers are as follows:

parameter	value
Content-Type	application/x-www-form-urlencoded

Place the request parameters in the body. The details of the parameters are as follows:

Request Parameters

parameter	Required	type	Optional value range	explain
image	Or url	string	-	Image data is encoded with urlencode after base64 encoding. The size after base64 encoding and urlencode is required not to exceed 4M, the shortest side is at least 15px, and the longest side is at most 4096px. It supports jpg/jpeg/png/bmp format
url	And image	string	-	The image is a complete URL. The URL length does not exceed 1024 bytes. The size of the image corresponding to the URL after base64 encoding does not exceed 4M. The shortest side is at least 15px, and the longest side is at most 4096px. It supports the jpg/jpeg/png/bmp format. When the image field exists, the url field is invalid Please close the URL anti-theft chain

Request Code Example

Prompt 1 : Before using the sample code, remember to replace the sample token, image address or Base64 information.

Prompt 2 : Some languages depend on classes or libraries. Please check the download address in the code comment.

 curl -i -k ' https://aip.baidubce.com/rest/2.0/ocr/v1/vin_code?access_token= [Call the token obtained from the authentication interface] ' --data 'image=[Picture Base64 encoding, UrlEncode required]' -H 'Content-Type:application/x-www-form-urlencoded'

 # encoding:utf-8

 import requests import base64 ''' VIN code identification ''' request_url =  " https://aip.baidubce.com/rest/2.0/ocr/v1/vin_code "
 #Open picture file in binary mode f =  open ( '[Local file]' ,  'rb' ) img = base64 . b64encode ( f . read ( ) ) params =  { "image" : img } access_token =  '[Token obtained by calling the authentication interface]' request_url = request_url +  "?access_token="  + access_token headers =  { 'content-type' :  'application/x-www-form-urlencoded' } response = requests . post ( request_url , data = params , headers = headers )
 if response :
     print  ( response . json ( ) )

 package  com . baidu . ai . aip ;

 import  com . baidu . ai . aip . utils . Base64Util ;
 import  com . baidu . ai . aip . utils . FileUtil ;
 import  com . baidu . ai . aip . utils . HttpUtil ;

 import  java . net . URLEncoder ;

 /** *VIN code identification */
 public  class  VinCode  {

     /** *Tool class required in important tip code *FileUtil, Base64Util, HttpUtil, GsonUtils *  https://ai.baidu.com/file/658A35ABAB2D404FBF903F64D47C1F72 *  https://ai.baidu.com/file/C8D81F3301E24D2892968F09AE1AD6E2 *  https://ai.baidu.com/file/544D677F5D4E4F17B4122FBD60DB82B3 *  https://ai.baidu.com/file/470B3ACCA3FE43788B5A963BF0B625F3 *Download */
     public  static  String  vinCode ( )  {
         //Request url
         String url =  " https://aip.baidubce.com/rest/2.0/ocr/v1/vin_code " ;
         try  {
             //Local file path
             String filePath =  [Local file path] ;
             byte [ ] imgData =  FileUtil . readFileByBytes ( filePath ) ;
             String imgStr =  Base64Util . encode ( imgData ) ;
             String imgParam =  URLEncoder . encode ( imgStr ,  "UTF-8" ) ;

             String param =  "image="  + imgParam ;

             //Note that the purpose here is to simplify the encoding and obtain access_token for each request. The online environment access_token has an expiration time, and the client can cache it and retrieve it after expiration.
             String accessToken =  "[Token obtained by calling the authentication interface]" ;

             String result =  HttpUtil . post ( url , accessToken , param ) ;
             System . out . println ( result ) ;
             return result ;
         }  catch  ( Exception e )  { e . printStackTrace ( ) ;
         }
         return  null ;
     }

     public  static  void  main ( String [ ] args )  {
         VinCode . vinCode ( ) ;
     }
 }

 # include  <iostream>
 # include  <curl/curl.h>

 //Download link of libcurl library: https://curl.haxx.se/download.html
 //Download link of jsoncpp library: https://github.com/open-source-parsers/jsoncpp/
 const  static std :: string request_url =  " https://aip.baidubce.com/rest/2.0/ocr/v1/vin_code " ;
 static std :: string vinCode_result ;
 /** *The curl sends the callback function called by the http request. The returned body in json format is parsed in the callback function, and the parsing result is stored in the global static variable *See the libcurl document for @ param parameter definitions *@ return See the libcurl document for the definition of the return value */
 static size_t callback ( void  * ptr , size_t size , size_t nmemb ,  void  * stream )  {
     //The obtained body is stored in ptr and converted to string format first vinCode_result = std :: string ( ( char  * ) ptr , size * nmemb ) ;
     return size * nmemb ;
 }
 /** *VIN code identification *@ return If the call is successful, 0 will be returned. If an error occurs, other error codes will be returned */
 int  vinCode ( std :: string & json_result ,  const std :: string & access_token )  { std :: string url = request_url +  "?access_token="  + access_token ; CURL * curl =  NULL ; CURLcode result_code ;
     int is_success ; curl =  curl_easy_init ( ) ;
     if  ( curl )  {
         curl_easy_setopt ( curl , CURLOPT_URL , url . data ( ) ) ;
         curl_easy_setopt ( curl , CURLOPT_POST ,  one ) ; curl_httppost * post =  NULL ; curl_httppost * last =  NULL ;
         curl_formadd ( & post ,  & last , CURLFORM_COPYNAME ,  "image" , CURLFORM_COPYCONTENTS ,  "【base64_img】" , CURLFORM_END ) ;

         curl_easy_setopt ( curl , CURLOPT_HTTPPOST , post ) ;
         curl_easy_setopt ( curl , CURLOPT_WRITEFUNCTION , callback ) ; result_code =  curl_easy_perform ( curl ) ;
         if  ( result_code != CURLE_OK )  {
             fprintf ( stderr ,  "curl_easy_perform() failed: %s\n" ,
                     curl_easy_strerror ( result_code ) ) ; is_success =  one ;
             return is_success ;
         } json_result = vinCode_result ;
         curl_easy_cleanup ( curl ) ; is_success =  zero ;
     }  else  {
         fprintf ( stderr ,  "curl_easy_init() failed." ) ; is_success =  one ;
     }
     return is_success ;
 }

 <? php
 /** *Initiate http post requests (REST APIs) and obtain the results of REST requests * @param string $url * @param string $param * @return - http response body if succeeds, else false. */
 function  request_post ( $url  =  '' ,  $param  =  '' )
 {
     if  ( empty ( $url )  ||  empty ( $param ) )  {
         return  false ;
     }

     $postUrl  =  $url ;
     $curlPost  =  $param ;
     //Initialize curl
     $curl  =  curl_init ( ) ;
     curl_setopt ( $curl ,  CURLOPT_URL ,  $postUrl ) ;
     curl_setopt ( $curl ,  CURLOPT_HEADER ,  zero ) ;
     //The result is required to be a string and output to the screen
     curl_setopt ( $curl ,  CURLOPT_RETURNTRANSFER ,  one ) ;
     curl_setopt ( $curl ,  CURLOPT_SSL_VERIFYPEER ,  false ) ;
     //Post submission method
     curl_setopt ( $curl ,  CURLOPT_POST ,  one ) ;
     curl_setopt ( $curl ,  CURLOPT_POSTFIELDS ,  $curlPost ) ;
     //Run curl
     $data  =  curl_exec ( $curl ) ;
     curl_close ( $curl ) ;

     return  $data ;
 }

 $token  =  '[Token obtained by calling the authentication interface]' ;
 $url  =  ' https://aip.baidubce.com/rest/2.0/ocr/v1/vin_code?access_token= '  .  $token ;
 $img  =  file_get_contents ( '[Local file path]' ) ;
 $img  =  base64_encode ( $img ) ;
 $bodys  =  array (
     'image'  = >  $img
 ) ;
 $res  =  request_post ( $url ,  $bodys ) ;

 var_dump ( $res ) ;

 using System ;
 using System . IO ;
 using System . Net ;
 using System . Text ;
 using System . Web ;

 namespace com . baidu . ai {
     public  class  VinCode
     {
         //VIN code identification
         public  static  string  vinCode ( )
         {
             string token =  "[Token obtained by calling the authentication interface]" ;
             string host =  " https://aip.baidubce.com/rest/2.0/ocr/v1/vin_code?access_token= "  + token ;
             Encoding encoding = Encoding . Default ;
             HttpWebRequest request =  ( HttpWebRequest ) WebRequest . Create ( host ) ; request . Method =  "post" ; request . KeepAlive =  true ;
             //Base64 encoding of pictures
             string base64 =  getFileBase64 ( [Local picture file] ) ;
             String str =  "image="  + HttpUtility . UrlEncode ( base64 ) ;
             byte [ ] buffer = encoding . GetBytes ( str ) ; request . ContentLength = buffer . Length ; request . GetRequestStream ( ) . Write ( buffer ,  zero , buffer . Length ) ;
             HttpWebResponse response =  ( HttpWebResponse ) request . GetResponse ( ) ;
             StreamReader reader =  new  StreamReader ( response . GetResponseStream ( ) , Encoding . Default ) ;
             string result = reader . ReadToEnd ( ) ; Console . WriteLine ( "VIN code identification:" ) ; Console . WriteLine ( result ) ;
             return result ;
         }

         public  static  String  getFileBase64 ( String fileName )  {
             FileStream filestream =  new  FileStream ( fileName , FileMode . Open ) ;
             byte [ ] arr =  new  byte [ filestream . Length ] ; filestream . Read ( arr ,  zero ,  ( int ) filestream . Length ) ;
             string baser64 = Convert . ToBase64String ( arr ) ; filestream . Close ( ) ;
             return baser64 ;
         }
     }
 }

Return description

Return parameters

field	Required	type	explain
log_id	yes	uint64	Unique log ID for problem location
words_result_num	yes	int	The number of recognition results, representing the number of words_result elements
words_result	yes	array[]	Positioning and recognition result array
+ location	yes	object	Position array (coordinate 0 point is the upper left corner)
++ left	yes	uint32	The horizontal coordinate of the top left vertex of the rectangle representing the positioning position
++ top	yes	uint32	The vertical coordinate of the top left vertex of the rectangle representing the positioning position
++ width	yes	uint32	The width of the rectangle representing the positioning position
++ height	yes	uint32	The height of the rectangle representing the positioning position
+ words	yes	string	VIN code identification result

Return to Example

 {
	 "log_id" :  two hundred and forty-six million five hundred and eighty-nine thousand eight hundred and seventy-seven ,
	 "words_result" :  [
		 {
			 "location" :  {
				 "left" :  one hundred and twenty-four ,
				 "top" :  eleven ,
				 "width" :  fifty-eight ,
				 "height" :  three hundred and fifty-nine
			 } ,
			 "words" :  "LFV2A11K8D4010942"
		 }
	 ] ,
	 "words_result_num" :  one
 }

License plate recognition

Identification of motor vehicle sales invoice