Face comparison

How it works

1. Initialize a client with your AccessKey credentials and the target region.

2. Build a task payload with the URLs of the two face images and set the scene to sface-1.

3. Submit the task using the synchronous or asynchronous scan API.

4. Parse the response to get the similarity score.

Limitations

• Input format: Image URLs only. Local files and binary data are not supported.

• URL protocol: Public HTTP or HTTPS URLs only.

• URL length: Maximum 2,048 characters per URL.

Prerequisites

Before you begin, ensure that you have:

• Go dependencies installed. See Installation for the required Go version. Using a different version causes operation calls to fail.

Submit a face comparison task

The following example uses synchronous detection. For asynchronous detection — where you poll for results or configure a callback notification — see Synchronous moderation and Asynchronous moderation for the full parameter reference.

Reuse the client instance across requests to improve performance and avoid repeated connection overhead.

package main

import (
    "encoding/json"
    "fmt"
    "github.com/aliyun/alibaba-cloud-sdk-go/services/green"
    "strconv"
)

func main() {
    // Initialize the client. Reuse this instance across requests.
    // Obtain credentials from environment variables to avoid hardcoding sensitive values:
    //   AccessKey ID:     os.Getenv("ALIBABA_CLOUD_ACCESS_KEY_ID")
    //   AccessKey secret: os.Getenv("ALIBABA_CLOUD_ACCESS_KEY_SECRET")
    client, _err := green.NewClientWithAccessKey(
        "cn-shanghai",
        "Obtain your AccessKey ID from an environment variable.",
        "Obtain your AccessKey secret from an environment variable.")
    if _err != nil {
        fmt.Println(_err.Error())
        return
    }

    // extras carries the URL of face image 2.
    extras := map[string]interface{}{"faceUrl": "<url-of-face-image-2>"}
    // task1 carries the URL of face image 1.
    task1 := map[string]interface{}{
        "dataId": "dataIdxxx",
        "url":    "<url-of-face-image-1>",
        "extras": extras,
    }

    // scenes: set to "sface-1" for face comparison.
    // bizType: your business scenario identifier.
    content, _ := json.Marshal(
        map[string]interface{}{
            "tasks":   task1,
            "scenes":  [...]string{"sface-1"},
            "bizType": "<your-business-scenario>",
        },
    )

    request := green.CreateImageSyncScanRequest()
    request.SetContent(content)

    response, _err := client.ImageSyncScan(request)
    if _err != nil {
        fmt.Println(_err.Error())
        return
    }
    if response.GetHttpStatus() != 200 {
        fmt.Println("response not success. status:" + strconv.Itoa(response.GetHttpStatus()))
        return
    }
    fmt.Println(response.GetHttpContentString())
}

Replace the following placeholders with actual values:

What's next

• Review the full parameter reference for Synchronous moderation to understand all available request and response fields, including the similarity score returned in the response.

• To receive results without polling, configure a callback notification using Asynchronous moderation.