Signature Detection

Endpoint Overview

POST /api/v1/ocr/signature-detection

Description

The Signature Detection API extracts and isolates signatures from uploaded documents or images. This endpoint uses advanced computer vision and machine learning algorithms to identify, crop, and return signature images from various document types. The API supports multiple input formats including direct file upload, base64-encoded images, and image URLs, making it versatile for different integration scenarios.

Key Benefits

Automatically extracts signatures from complex documents with high accuracy

Supports multiple input formats (file upload, base64, URL) for flexible integration

Returns isolated signature images in base64 format for easy processing and storage

Handles multiple signatures in a single document, returning all detected signatures

Use Cases

Banking & Finance

Legal & Compliance

Government & Public Sector

Automated signature verification for loan applications

Streamlining check processing by extracting signature fields

Enhancing KYC processes with signature validation

Detecting signature forgery by comparing extracted signatures with reference samples

Technical Implementation

Authentication

All API requests require authentication using a JWT Bearer token. Authentication follows these steps:

Obtain API Credentials: Register with Surepass to receive your API key.

Generate JWT Token: Use your API key to generate a JWT token.

Include in Requests: Add the token to the Authorization header as Bearer TOKEN.

Different authentication tokens are used for sandbox and production environments:

Sandbox: https://sandbox.surepass.io

Production: https://kyc-api.surepass.io

Request Parameters

Request Headers

Header	Required	Description
Authorization	Yes	Bearer token for authentication (JWT format)
Content-Type	Yes	`application/json` for base64/URL requests or `multipart/form-data` for file uploads

Request Body

The API supports three different input methods. Choose one based on your use case:

Option 1: File Upload

Parameter	Type	Required	Description
file	File	Yes	The signature image file to be uploaded
use_pdf	Boolean	Conditional	Set to `true` if the uploaded file is a PDF document

Option 2: Base64 Encoded Image

Parameter	Type	Required	Description
base_64	String	Yes	Signature image encoded in Base64 format

Option 3: Image URL/Link

Parameter	Type	Required	Description
link	String	Yes	URL pointing to the signature image

Example Request (Base64)

{
  "base_64": "iVBORw0KGgoAAAANSUhEUgAAAMAAAAB1CAIAAACXuXmWAACcDklEQVR4nHy9d9..."
}

Example Request (URL)

{
  "link": "https://example.com/signature-image.jpg"
}

Process Response

Response Parameters

Parameter	Type	Description
data	Object	Contains the detection results
data.client_id	String	Unique identifier for the client request
data.detections	Array	List of detected signatures, each containing a base64-encoded image
data.detections[].image_base64	String	Base64-encoded string of the detected signature image
status_code	Integer	HTTP status code of the response
success	Boolean	Indicates if the request was successful
message	String	Human-readable status message
message_code	String	Machine-readable status code

Example Successful Response

{
  "data": {
    "client_id": "signature_detection_zUcretzhjlOoAEyGlqJv",
    "detections": [
      {
        "image_base64": "iVBORw0KGgoAAAANSUhEUgAAAMAAAAB1CAIAAACXuXmWAACcDklEQVR4nHy9d9xkWVkn/jzPOeemym/R07djSbTf7ET7vdPnTo0IMPPiiK4le+/GW3PyzbJUWQBIRv/dQtWZKub6zGYeQNnGF/MOz2Qz9QBMnQCwVNjzw/S5I0jlVZhoxtrK8zQoqWxQ//jjvuePLJJw3D6Ha77XZbluUoihqNBqXUd73QDzZb7f8HfRAzj5yvluIAAAAASUVORK5CYII="
      },
      {
        "image_base64": "iVBORw0KGgoAAAANSUhEUgAAAk8AAADnCAIAAACIdSWTAABBiElEQVR4nO3deZRtV1Uo/DnX2t1pqk71VbfPvUluQjoI0ajkIwaQByI8Hb58CuKnRAYKn0F8wuPFSKQTCWBo5BFBkzy+/P2z6RWR8PPIBAAAAAElFTkSuQmCC"
      }
    ]
  },
  "status_code": 200,
  "success": true,
  "message": "success",
  "message_code": "success"
}

Possible Error Responses

Authentication Error

Invalid Image

Invalid File Format

Server Error

{
    "error": null,
    "message": "Your token is invalid. Please ensure that correct token is being used.",
    "status_code": 401,
    "success": false,
    "message_code": "invalid_token"
}

Occurs when the JWT token is missing, invalid, or expired.

Integration Best Practices

Security Recommendations

Store JWT tokens securely and never expose them in client-side code

Implement token rotation and expiration policies to minimize risk

Use HTTPS for all API communications to ensure data encryption in transit

Validate and sanitize all input data before sending to the API

Implement proper error handling to avoid exposing sensitive information

User Experience Guidelines

Provide clear feedback to users when signature detection is in progress

Implement retry logic with exponential backoff for temporary failures

Display extracted signatures to users for verification when appropriate

Optimize image quality before submission for better detection results

Consider implementing client-side image preprocessing to improve detection accuracy

Code Samples

cURL

Python

Node.js

Related APIs

OCR Document Extraction API: Extracts structured data from various

{ "data": { "client_id": "signature_detection_zUcretzhjlOoAEyGlqJv", "detections": [ { "image_base64": "iVBORw0KGgoAAAANSUhEUgAAAMAAAAB1CAIAAACXuXmWAACcDklEQVR4nHy9d9xkWVkn/jzPOeemym/R07djSbTf7ET7vdPnTo0IMPPiiK4le+/GW3PyzbJUWQBIRv/dQtWZKub6zGYeQNnGF/MOz2Qz9QBMnQCwVNjzw/S5I0jlVZhoxtrK8zQoqWxQ//jjvuePLJJw3D6Ha77XZbluUoihqNBqXUd73QDzZb7f8HfRAzj5yvluIAAAAASUVORK5CYII=" }, { "image_base64": "iVBORw0KGgoAAAANSUhEUgAAAk8AAADnCAIAAACIdSWTAABBiElEQVR4nO3deZRtV1Uo/DnX2t1pqk71VbfPvUluQjoI0ajkIwaQByI8Hb58CuKnRAYKn0F8wuPFSKQTCWBo5BFBkzy+/P2z6RWR8PPIBAAAAAElFTkSuQmCC" } ] }, "status_code": 200, "success": true, "message": "success", "message_code": "success" }

Provide your bearer token in the

Authorization

header when making requests to protected resources.

Example:

Authorization: Bearer ********************

Signature Detection

Signature Detection#

Description#

Use Cases#

Technical Implementation#

Request Headers#

Request Body#

Option 1: File Upload#

Option 2: Base64 Encoded Image#

Option 3: Image URL/Link#

Example Request (Base64)#

Example Request (URL)#

Response Parameters#

Example Successful Response#

Possible Error Responses#

Integration Best Practices#

Code Samples#

Request

Responses

Signature Detection

Description

Use Cases

Technical Implementation

Request Headers

Request Body

Option 1: File Upload

Option 2: Base64 Encoded Image

Option 3: Image URL/Link

Example Request (Base64)

Example Request (URL)

Response Parameters

Example Successful Response

Possible Error Responses

Integration Best Practices

Code Samples