Target image list query

The cloud recognition (CRS) database typically stores massive amounts of target images. To help developers quickly locate and manage this data, this chapter details how to view, paginate, and understand target image information.

Manage target image collections via EasyAR Web

In the visual interface, the system defaults to displaying target images in a paginated list, sorted in reverse chronological order by last modified time (most recently modified appears first).

Target image collection

Operation path: Log in to EasyAR Web [Development Center] -> [Cloud Recognition Management] -> Select image library -> Click [Manage].

In this interface, you can perform the following operations:

List browsing: View the paginated target image collection.
Detail entry: Click [Manage] at button 1 in the figure to enter the detail page of that target image.
Precise filtering: In input box 2, the following two filtering methods are supported:
- Filter by name: If your system names images according to rules (such as internal application IDs), you can quickly locate them by name.
- Filter by TargetId: For example, after obtaining a specific targetId through a similar image query API, you can query its detailed configuration here.

Target image detail description

After clicking into the detail page, you can view the complete attributes of the target image, including:

Grayscale image
Image name: Custom identifier for the target image.
TargetId: System-generated unique ID.
Status: Shows whether the current target image is active or disabled.
Quality score: Quantitative score regarding recognition and tracking performance. For details, refer to Target Image Recognition Difficulty Rating.
Custom Meta: Metadata associated with this target image (e.g., model URL, etc.)

detail

Query target image collection using API

For developers needing integration into their own backend systems, using the REST API for management is recommended.

Reference documentation: Target Image Collection List API Interface

Preparation checklist

Before making a request, ensure you have the following information ready (details refer to API Call Preparation Checklist):

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

Replace placeholders with actual parameters and execute 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 Java sample code

Java Samples Download

Import the project via Maven

Step 1. Open the relevant code file ListTargets.java

Step 2. Modify the global variables and replace the authentication parameters in your preparation 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 NodeJS sample code

NodeJS Samples Download

Step 1. Configure 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, specify key file and server-end URL

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

To change paging strategy, pass getTargets paging 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 cloud service interface, sample code 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 Php sample code

PHP Samples Download

Step 1. Open the entry code demo.php

Step 2. Modify global variables, replace the authentication parameters from your manifest 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 a new 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 relevant 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.

Execute 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 .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();
    }
}

Running environment
- Unity 2020 LTS or higher
- Scripting Backend: Mono or IL2CPP
- API Compatibility Level: .NET Standard 2.1 (recommended)

Step 1: Prepare image files

Create directories in the Unity project:

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

According to Assets directory name
- Copy the sample code ListImageTarget.cs below

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);
        }
    }
}

In Unity Editor:
- Create an empty GameObject
- Name it ListTarget
- Attach the ListImageTarget script to this object

Step 3: Configure parameters (Inspector)

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

Step 4: Run

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

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