Target image list query

Cloud Recognition (CRS) databases usually store massive numbers of target images. To help developers quickly locate and manage this data, this chapter describes target image viewing, paginated query, and details.

Manage target image collections through EasyAR Web

In the visual interface, the system displays target images as a paginated list by default and sorts them in reverse order by last modified time (the latest changes are listed first).

Target image collection

Operation path: log in to EasyAR Web [Developer Center] -> [Cloud Recognition Management] -> select gallery -> click [Manage].

In this interface, you can perform the following operations:

List browsing: view the target image collection displayed by page.
Details entry: click [Manage] for button 1 in the image to enter the details page of this target image.
Precise search: input box 2 supports the following two search methods:
- Search by name: if your system names images by rules, such as in-app IDs, you can quickly locate them by name.
- Search by TargetId: for example, after you obtain a specific targetId through the similar image query API, you can query its detailed configuration here.

Target image details

After clicking into the details page, you can view the complete properties of the target image, including:

Grayscale image
Image name: custom target image identifier.
TargetId: unique ID generated by the system.
Status: shows whether the current target image is active or disabled.
Quality score: a quantitative score for recognition and tracking performance. For details, refer to target image recognition difficulty rating.
Custom Meta: metadata associated with this target image, such as model URL.

detail

Query target image collections using API

For developers who need integration with their own backend, REST API management is recommended.

Reference document: Target image collection list API

Preparation checklist

Before sending a request, make sure the following information is ready. For details, refer to API call preparation checklist:

CRS AppId
API Key / API Secret or Token
Server-end URL: target image management URL address, https uses port 443

Replace the placeholders with actual parameters and run the curl script.

Your-Server-side-URL -> actual API host
Your-Token -> actual API Key Authorization Token
Your-CRS-AppId -> your appId

curl -X GET "https://<Your Server-side-URL>/targets/infos?appId=<Your-CRS-AppId>" \
  -H "Content-Type: application/json" \
  -H "Authorization: <Your-Token>"

Download the Java sample code

Java Samples Download

Import the project with Maven

Step 1. Open the related code file ListTargets.java.

Step 2. Modify the global variables and replace them with the authentication parameters in your prepared list.

CRS AppId
API Key / API Secret
TARGET_MGMT_URL → Server-end URL

public class ListTargets {

    private static final String TARGET_MGMT_URL = "http://cn1.crs.easyar.com:8888";
    private static final String CRS_APPID       = "--here is your CRS AppId--";
    private static final String API_KEY         = "--here is your API Key--";
    private static final String API_SECRET      = "--here is your API Secret--";

    public String list(Auth auth) throws IOException {
        OkHttpClient client = new OkHttpClient.Builder().build();
        JSONObject params = new JSONObject();
        Auth.signParam(params, auth.getAppId(), auth.getApiKey(), auth.getApiSecret());
        okhttp3.Request request = new okhttp3.Request.Builder()
                .url(auth.getCloudURL() + "/targets/infos?"+ Common.toParam(params))
                .get()
                .build();
        Response response = client.newCall(request).execute();
        return response.body().string();
    }
    public static void main(String[] args) throws IOException{
        Auth accessInfo  =  new Auth(CRS_APPID, API_KEY, API_SECRET, TARGET_MGMT_URL);
        System.out.println(new ListTargets().list(accessInfo));
    }

}

Step 3. Run Main

Download the NodeJS sample code.

NodeJS Samples Download

Step 1. Configure the key file keys.json.

CRS AppId
API Key / API Secret

{
  "appId": "--here is your appId for CRS App Instance for SDK 4--",
  "apiKey": "--here is your api key which is create from website and which has crs permission--",
  "apiSecret": "--here is your api secret which is create from website--"
}

Step 2. Run it, specifying the key file and Server-end URL.

node bin/getTargets  -t <Server-end-URL> -c keys.json

To change the pagination strategy, pass getTargets pagination parameters.

'pageSize': page size
'pageNum': page number

var argv = require('yargs')
    .usage('Usage: $0 [targetId] -t [host] -c [keys]')
    .demand(0)
    .default('t', 'http://localhost:8888').alias('t', 'host')
    .default('c', 'keys.json').alias('c', 'keys')
    .help('h').alias('h', 'help')
    .epilog('copyright 2015, sightp.com')
    .argv;

var fs = require('fs');
var host = argv.host;
var keys = JSON.parse(fs.readFileSync(argv.keys));
var farmer = require('../farmer')(host, keys.appKey, keys.appSecret);

farmer.getTargets({
  'pageSize': 5,
  'pageNum': 1,
})
.then(function(resp) {
    console.log(resp.result.targets);
})
.fail(function(err) {
    console.log(err);
});

getTargets calls the cloud service API. The sample code is in farmer.js.

function getTargetsByPage(pageNum,pageSize) {
    return Q.promise(function(resolve, reject) {
        request.get(host + '/targets/infos?pageNum=' + pageNum + '&pageSize=' + pageSize)
        .query(auth.signParams(keypair, {
            "pageNum":pageNum,
            "pageSize":pageSize
        }))
        .end(done(resolve, reject));
    });
}

Download the PHP sample code.

PHP Samples Download

Step 1. Open the entry code demo.php.

Step 2. Modify the global variables and replace them with the authentication parameters in your prepared list.

CRS AppId
API Key / API Secret
Server-end URL

<?php
include 'EasyARClientSdkCRS.php';
$apiKey = 'API Key';
$apiSecret = 'API Secret';
$crsAppId = 'CRS AppId'
$crsCloudUrl = 'https://cn1-crs.easyar.com';
$pageNum = 1;
$pageSize = 5;

$sdk = new EasyARClientSdkCRS($apiKey, $apiSecret, $crsAppId, $crsCloudUrl);

$rs = $sdk->targetsV3($pageNum, $pageSize);
if ($rs->statusCode == 0) {
    print_r($rs->result);
} else {
    print_r($rs);
}

Step 3. Run php demo.php.

Create the related code file list_targets.py, modify the global variables, and then run

pip install requests
python list_targets.py

import time
import hashlib
import requests

# --- Global Configuration ---
API_KEY = "YOUR_API_KEY"
API_SECRET = "YOUR_API_SECRET"
APP_ID = "YOUR_APP_ID"
HOST = "https://crs-cn1.easyar.com"

def main():
    timestamp = str(int(time.time() * 1000))
    
    params = {
        'apiKey': API_KEY,
        'appId': APP_ID,
        'timestamp': timestamp
    }

    # Signature: Sort keys -> Concat -> Append Secret -> SHA256
    sorted_keys = sorted(params.keys())
    sign_str = "".join([f"{k}{params[k]}" for k in sorted_keys]) + API_SECRET
    signature = hashlib.sha256(sign_str.encode('utf-8')).hexdigest()

    url = f"{HOST}/targets/infos"
    params['signature'] = signature

    print(f"Requesting GET {url}...")
    response = requests.get(url, params=params)
    print(f"Response: {response.text}")

if __name__ == "__main__":
    main()

Create the related code file main.go, modify the global variables, and then run

go run main.go

main.go:

package main

import (
  "crypto/sha256"
  "fmt"
  "io"
  "net/http"
  "sort"
  "strconv"
  "time"
)

// --- Global Configuration ---
var (
  ApiKey    = "YOUR_API_KEY"
  ApiSecret = "YOUR_API_SECRET"
  AppId     = "YOUR_APP_ID"
  Host      = "https://crs-cn1.easyar.com"
)

func main() {
  ts := strconv.FormatInt(time.Now().UnixNano()/1e6, 10)
  params := map[string]string{
    "apiKey":    ApiKey,
    "appId":     AppId,
    "timestamp": ts,
  }

  keys := make([]string, 0, len(params))
  for k := range params { keys = append(keys, k) }
  sort.Strings(keys)

  builder := ""
  for _, k := range keys { builder += k + params[k] }
  builder += ApiSecret

  signature := fmt.Sprintf("%x", sha256.Sum256([]byte(builder)))

  url := fmt.Sprintf("%s/targets/infos?apiKey=%s&appId=%s&timestamp=%s&signature=%s", 
    Host, ApiKey, AppId, ts, signature)
  
  resp, _ := http.Get(url)
  defer resp.Body.Close()
  body, _ := io.ReadAll(resp.Body)
  fmt.Printf("Response: %s\n", string(body))
}

Add reqwest, tokio, sha2, and hex dependencies in Cargo.toml.

Run cargo run.

use sha2::{Sha256, Digest};
use std::collections::BTreeMap;
use std::time::{SystemTime, UNIX_EPOCH};

// --- Global Configuration ---
const API_KEY: &str = "YOUR_API_KEY";
const API_SECRET: &str = "YOUR_API_SECRET";
const APP_ID: &str = "YOUR_APP_ID";
const HOST: &str = "https://crs-cn1.easyar.com";

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let ts = SystemTime::now().duration_since(UNIX_EPOCH)?.as_millis().to_string();

    let mut params = BTreeMap::new();
    params.insert("apiKey", API_KEY);
    params.insert("appId", APP_ID);
    params.insert("timestamp", &ts);

    let mut sign_str = String::new();
    for (k, v) in &params {
        sign_str.push_str(k);
        sign_str.push_str(v);
    }
    sign_str.push_str(API_SECRET);
    
    let mut hasher = Sha256::new();
    hasher.update(sign_str.as_bytes());
    let signature = hex::encode(hasher.finalize());

    let url = format!("{}/targets/infos?apiKey={}&appId={}&timestamp={}&signature={}", 
                      HOST, API_KEY, APP_ID, ts, signature);
    
    let res = reqwest::get(url).await?;
    println!("Response: {}", res.text().await?);
    Ok(())
}

Create a .NET console project.

dotnet new console
dotnet run

using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Net.Http;

class Program {
    // --- Global Configuration ---
    static string API_KEY = "YOUR_API_KEY";
    static string API_SECRET = "YOUR_API_SECRET";
    static string APP_ID = "YOUR_APP_ID";
    static string HOST = "https://crs-cn1.easyar.com";

    static async System.Threading.Tasks.Task Main() {
        string timestamp = DateTimeOffset.Now.ToUnixTimeMilliseconds().ToString();

        var dict = new SortedDictionary<string, string> {
            { "apiKey", API_KEY },
            { "appId", APP_ID },
            { "timestamp", timestamp }
        };

        StringBuilder sb = new StringBuilder();
        foreach (var kv in dict) sb.Append(kv.Key).Append(kv.Value);
        sb.Append(API_SECRET);
        
        string signature = Sha256(sb.ToString());

        using var client = new HttpClient();
        string query = string.Join("&", dict.Select(x => $"{x.Key}={x.Value}")) + $"&signature={signature}";
        string url = $"{HOST}/targets/infos?{query}";
        
        var response = await client.GetAsync(url);
        Console.WriteLine($"Result: {await response.Content.ReadAsStringAsync()}");
    }

    static string Sha256(string str) {
        byte[] bytes = SHA256.HashData(Encoding.UTF8.GetBytes(str));
        return BitConverter.ToString(bytes).Replace("-", "").ToLower();
    }
}

Runtime environment
- Unity 2020 LTS or later
- Scripting Backend: Mono or IL2CPP are both supported
- API Compatibility Level: .NET Standard 2.1 (recommended)

Step 1: Prepare the image file

Create a directory in the Unity project:

Assets/
└── Scripts/
     └── ListImageTarget.cs

using System.Collections;
using UnityEngine;
using UnityEngine.Networking;

public class ListImageTarget : MonoBehaviour
{
    [Header("Config")]
    public string apiBaseUrl = "https://Your-Server-end-URL";
    public string authorizationToken = "YOUR API KEY AUTH TOKEN"; 
    public string crsAppId = "CRS-AppId"; 
    public int pageSize = 5; 
    public int pageNum  = 1; 
    
    private void Start()
    {
        StartCoroutine(ListTarget());
    }

    private IEnumerator ListTarget()
    {
     
        string url =
            $"{apiBaseUrl}/targets/infos?appId={crsAppId}&pageSize={pageSize}&pageNum={pageNum}";

        UnityWebRequest request = UnityWebRequest.Get(url);
        request.downloadHandler = new DownloadHandlerBuffer();

        request.SetRequestHeader("Content-Type", "application/json");
        request.SetRequestHeader("Authorization", authorizationToken);

        yield return request.SendWebRequest();

        if (request.result == UnityWebRequest.Result.Success)
        {
            Debug.Log("List target success:");
            Debug.Log(request.downloadHandler.text);
        }
        else
        {
            Debug.LogError("List target failed:");
            Debug.LogError(request.error);
            Debug.LogError(request.downloadHandler.text);
        }
    }
}

According to the Assets directory name
- Copy the following sample code ListImageTarget.cs
In Unity Editor:
- Create an empty GameObject
- Name it ListTarget
- Drag the script onto this object

Step 3: Configure parameters (Inspector)

Modify the following in the Inspector panel:
- Api Url
- Authorization Token
- Crs App Id
- page size
- page num
Only modify these items to run, and fill in the parameters prepared in the preparation checklist

Step 4: Run

Click Play
View the result in Console:
- Success: returns JSON (including targetId)
- Failure: HTTP / error information

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