Recapture Detection

Function

As a statistical method in the retailing industry, barcodes are used to calculate retailers' sales volumes as the evidence of sales incentives. This API can recognize whether a barcode image is the original one or the one that is recaptured or printed for recapturing by using the deep neural network algorithm. It enables you to detect the invalid barcode images and makes the statistics more precise and valid.

Currently, only barcodes of Huawei products. For other service scenarios, submit a service ticket to reach technical support.

Prerequisites

Before using Recapture Detection, you need to apply for the service and complete authentication. For details, see Applying for a Service and Authentication.
By default, the maximum number of concurrent API calls is 1. To increase concurrency, contact Huawei technical support.

URI

URI format

POST /v1.0/image/recapture-detect

Request Message

Table 1 describes the request parameters.

**Table 1** Parameter description
Parameter	Mandatory	Type	Description
image	Configure either this parameter or url.	String	Indicates the Base64 character string converted from the image. The size cannot exceed 10 MB. The image resolution of the narrow sides must be greater than 15 pixels, and that of the wide sides cannot exceed 4096 pixels. The supported image formats include JPEG, PNG, BMP, and WEBP.
url	Configure either this parameter or image.	String	Indicates the URL of an image. The options are as follows: HTTP/HTTPS URLs on the public network HUAWEI CLOUD OBS URLs. To use OBS data, authorization is required, including service authorization, temporary authorization, and anonymous public authorization. For details, see Configuring Access Permissions of OBS. NOTE: The API response time depends on the image download time. If the image download takes a long time, the API call will fail. Ensure that the storage service where the image to be detected resides is stable and reliable. You are advised to use HUAWEI CLOUD OBS.
threshold	No	Float	Indicates the threshold used to identify whether an image is real or fake. The default value is 0.95. The value ranges from 0 to 1. If you input a value beyond the value range, the default value is used.
scene	No	List	Indicates the detection scenario. Currently, only the recapture scenario is supported. This parameter can be left empty. If it is left empty, the detection results of all scenarios are returned.

Response Message

Table 2 describes the response parameters.

**Table 2** Parameter description
Parameter	Type	Description
result	JSON	Indicates the content of the image tag when the API is successfully called. This parameter is not included when the API fails to be called.
suggestion	String	Indicates the conclusion. Possible values are as follows: true: indicates that the image is valid. false: indicates that image is a fake one. uncertainty: indicates that whether the image is valid or fake is uncertain.
category	String	Indicates the tag (if suggestion is true, the value will be a null string. Otherwise, the value will not be a null string). recapture: indicates that the image is a recaptured one.
score	Float	Indicates the overall confidence score. The value ranges from 0 to 1.
detail	List	Indicates the recognition result details.
label	String	Indicates the tag value. Possible values are as follows: original: indicates that the image is the original one. recapture: indicates that the image is a recaptured one.
confidence	Float	Indicates the confidence score. The value ranges from 0 to 1.
error_code	String	Indicates the error code of a failed API call. For details, see Error Codes. This parameter is not included when the API is successfully called.
error_msg	String	Indicates the error message of a failed API call. This parameter is not included when the API is successfully called.

Examples

Example request (Method 1: Use a Base64-encoded image.)

POST https://image.ap-southeast-1.myhuaweicloud.com/v1.0/image/recapture-detect
   
Request Header:  
Content-Type:application/json
X-Auth-Token: MIINRwYJKoZIhvcNAQcCoIINODCCDTQCAQExDTALBglghkgBZQMEAgEwgguVBgkqhkiG...   

Request Body:
{
 "image":"/9j/4AAQSkZJRgABAgEASABIAAD/4RFZRXhpZgAATU0AKgAAAAgABwESAAMAAAABAAEAAAEaAAUAAAABAAAAYgEbAAUAAAABAAAAagEoAAMAAAABAAIAAAExAAIAAAAcAAAAcgEyAAIAAAAUAAAAjodpAAQAAAABAAAApAAAANAACvyAAAAnEAAK/IAAACcQQWRvYmUgUGhvdG9zaG9wIENTMyBXaW5kb3dzADIwMTc6MTA6MjAgMTA6NDU6MzYAAAAAA6ABAAMAAAAB//8AAKACAAQAAAABAAALIKADAAQAAAABAAAGQAAAAAAAAAAGAQMAAwAAAAEABgAAARoABQAAAAEAAAEeARsABQAAAAEAAAEmASgAAwAAAAEAAgAAAgEABAAAAAEAAAEuAgIABAAAAAEAABAj...",
  "url": "",
  "threshold":0.99,
  "scene":["recapture"]
}

Example request (Method 2: Use the URL redirecting to an image file.)

POST https://image.ap-southeast-1.myhuaweicloud.com/v1.0/image/recapture-detect
   
Request Header:  
Content-Type:application/json
X-Auth-Token: MIINRwYJKoZIhvcNAQcCoIINODCCDTQCAQExDTALBglghkgBZQMEAgEwgguVBgkqhkiG...   

Request Body:
{
  "image":"",
  "url":"https://<bucketName>.obs.<region>.myhuaweicloud.com/<objectName>",
  "threshold":0.99,
  "scene":["recapture"]
}

Example successful response

{
  "result": {
    "suggestion": "false",
    "category": "recapture",
    "score": "0.9998",
    "detail": [
      {
        "label": "recapture",
        "confidence": "0.9998"
      }
    ]
  }
}

Example failed response

{
    "error_code": "AIS.0105",
    "error_msg": "Recognize Failed"
}

Return Value

Normal
200

Abnormal

Return Value	Description
400	The request cannot be understood by the server due to malformed syntax. The client should not repeat the request without modifications. The request parameter is incorrect.
401	The request requires user authentication.
403	No operation permission.
404	The server has not found anything matching the Request-URI.
500	The server encountered an unexpected condition which prevented it from fulfilling the request.