Kairos enroll API returns confidence in the response. What does it mean? - image-uploading

Question

I am exploring Kairos Facial Recognition APIs. The API /enroll is used for uploading an image to Kairos for a subject_id. I noticed that the response of enroll API contains a confidence score. The image is treated as a new image. What does this confidence mean? When you verify an image, in that case the confidence score is important. But while uploading an image, why does the API return a confidence?
I assume, the API compares the image to the images uploaded before for that subject_id and returns the confidence. Is this the case or is it something else?
API Documentation: API_docs.
Here is a sample response for reference:
{
"face_id": "f2f0f8de43e545f8aff",
"images": [
{
"attributes": {
"age": 40,
"asian": 0.13225,
"black": 0.00103,
"gender": {
"femaleConfidence": 0.00028,
"maleConfidence": 0.99972,
"type": "M"
},
"glasses": "None",
"hispanic": 0.09578,
"lips": "Together",
"other": 0.27899,
"white": 0.49195
},
"transaction": {
"confidence": 0.99932,
"eyeDistance": 30,
"face_id": "f2f0f8de43e545f8aff",
"gallery_name": "ps-recognize",
"height": 70,
"image_id": 1,
"pitch": -14,
"quality": 0.10107,
"roll": -4,
"status": "success",
"subject_id": "vinod-khanna.&**#~`%$#_=+/",
"timestamp": "1526029231708",
"topLeftX": 124,
"topLeftY": 42,
"width": 70,
"yaw": 1
}
}
]
}

Answer 1

Yes, this isn't clear from the documentation.
For /recognize and /verify the confidence % represents how similar the face sent in with the request is to the the face being compared against.
For /detect and /enroll the confidence represents how confident the engine is that it found a face. Usually you will see 98-99 percent range for those values.
Disclosure: Kairos.com CTO