Compare two objects

FindFace Multi allows you to compare two objects of the same type (such as two faces, two bodies, or two vehicles) and determine their similarity.

To perform a comparison, use the following method:

GET /verify

The REQUEST contains the following QUERY-STRING PARAMETERS:

Name	Type	Description
card_id	string	ID of the record that contains objects to be compared with the main object defined in the object1 parameter. Constraint: Min 1 char.
object1*	string	Reference expression that identifies the main object used for comparison. One of the following expressions must be specified: detection:<detection_id> faceevent:<event_id> carevent:<event_id> bodyevent:<event_id> faceobject:<object_id> carobject:<object_id> bodyobject:<object_id> Constraint: Min 1 char.
object2	string	Reference expression that identifies a specific object to be compared with the main object defined in the object1 parameter. Only a single expression is allowed. The format of the expression is the same as for the object1 parameter. If card_id is not specified, the object defined in the object1 parameter is compared with the object defined in the object2 parameter. If card_id is specified, object2 is ignored, and the object defined in the object1 parameter is compared with each object of the same type in the record. Constraint: Min 1 char.

CURL example

curl -X GET "http://<findface-ip:port>/verify?object1=faceobject%3A4693621634822370700&object2=detection%3Ad1rqpj4kd5qs72mq5290" \
 -H "Authorization: Token <token>"

For example, to compare two faces, follow these steps:

1. Use the POST /detect method to detect a face in a photo and copy the id of the detected face.

2. In the object1 parameter of the GET /verify method, specify the copied id in the following format: detection:<detection_id>.

3. In the object2 parameter of the GET /verify method, specify the event ID of the face to be compared with the face defined in the object1 parameter. Use the following format: faceevent:<event_id>.

   If the response is successful (200 OK), it returns a JSON object with the confidence field that holds the estimated similarity score between the two objects (in this case, faces).

Name	Type	Description
confidence*	number|object	Similarity score between two feature vectors in the database. If the object1 and object2 parameters are specified in the request, the confidence field contains the similarity score represented as a single number. Example. If the object1 and card_id parameters are specified in the request, the confidence field contains an object that includes the following indicators: similarity scores between the object defined in the object1 parameter and each object of the same type in the record; average similarity score (average_conf). Example. Constraints: Min 0┃Max 1.

Response example (object1 and object2 specified)

{
 "confidence": 0.86446184
}

Response example (object1 and card_id specified)

{
 "confidence": {
   "face_objects": {
     "4689934075046362827": 0.7640308,
     "4693436597895149109": 0.9912036,
     "4693621634822370700": 0.8532853
   },
   "average_conf": 0.86950657
 }
}