If the target image has insufficient recognizable areas (such as white walls or solid color blocks) or overly simplistic textures, its recognition success rate will significantly decrease. This chapter details CRS's rating mechanism to help you select high-quality AR recognition materials.
We primarily focus on the following two comprehensive indicators, each with its own dedicated API interface providing an overall rating:
These metrics are rated from an image algorithm dimension, with each metric still scored on a difficulty scale from 0 to 4.
Detailed ratings for each target image in the database are available on the target image detail page. You can view them either through the API when retrieving target image attributes, or through the EasyAR cloud recognition management platform.
As shown below, the details page displays two core comprehensive metrics, and a five-pointed shape presents five detailed metrics.
When building an automated upload backend, it is recommended to call the rating interface before the actual upload.
- First convert the local target image to Base64 (macOS/Linux), save the result to image_base64.txt
base64 -i ./target.jpg | tr -d '\n' > image_base64.txt
- Replace 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 POST "https://<Your-Server-side-URL>/grade/detail" \
-H "Content-Type: application/json" \
-H "Authorization: <YOUR-TOKEN>" \
-d '{
"appId": "<Your-CRS-AppId>",
"image": "'"$(cat image_base64.txt)"'"
}'
Download java samples
Import project via maven
Step 1. Open the relevant code file Grade.java
Step 2. Modify global variables, replacing authentication parameters from your manifest
- CRS AppId
- API Key / API Secret
- Server-end URL
- IMAGE_PATH : Target image file to upload
import okhttp3.*;
import org.json.JSONObject;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Base64;
import java.util.HashMap;
import java.util.Map;
public class Grade {
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--";
private static final String IMAGE_PATH = "test_target_image.jpg";
enum GradeType {
DETAIL,
DETECTION,
TRACKING
}
private static final Map<GradeType, String> GRADE_URL = new HashMap<GradeType, String>(){
{
put(GradeType.DETAIL, "/grade/detail") ;
put(GradeType.DETECTION, "/grade/detection") ;
put(GradeType.TRACKING, "/grade/tracking") ;
}
};
public String grade(Auth auth, String imgPath, GradeType gradeType) throws IOException {
final Path mImagePath = Paths.get(imgPath);
JSONObject params = new JSONObject().put("image", Base64.getEncoder().encodeToString(
Files.readAllBytes(mImagePath)
));
Auth.signParam(params, auth.getAppId(), auth.getApiKey(), auth.getApiSecret());
RequestBody requestBody = FormBody.create(MediaType.parse("application/json; charset=utf-8")
, params.toString());
Request request = new Request.Builder()
.url(auth.getCloudURL() + GRADE_URL.get(gradeType))
.post(requestBody)
.build();
return new OkHttpClient.Builder().build().newCall(request).execute().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("================== grade details ==================");
System.out.println(new Grade().grade(accessInfo, IMAGE_PATH, GradeType.DETAIL));
System.out.println("================== grade for detection ==================");
JSONObject gradeResp = new JSONObject(new Grade().grade(accessInfo, IMAGE_PATH, GradeType.DETECTION));
System.out.println("Detection grade: " + gradeResp.getJSONObject(Common.KEY_RESULT).get(Common.KEY_GRADE));
System.out.println("================== grade for tracking =================== ");
gradeResp = new JSONObject(new Grade().grade(accessInfo, IMAGE_PATH, GradeType.TRACKING));
System.out.println("Tracking grade: " + gradeResp.getJSONObject(Common.KEY_RESULT).get(Common.KEY_GRADE));
}
}
Step 3. Run main
Download NodeJS sample code
Step 1. Configure 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 test image, keys file and Server-end URL
node bin/grade test.jpeg -t <Server-end-URL> -c keys.json
var argv = require('yargs')
.usage('Usage: $0 [image] -t [host] -c [keys]')
.demand(1)
.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 imageFn = argv._[0];
var host = argv.host;
var keys = JSON.parse(fs.readFileSync(argv.keys));
var farmer = require('../farmer')(host, keys);
farmer.getTrackingGrade({
'image': fs.readFileSync(imageFn).toString('base64')
})
.then(function(resp) {
console.log(resp);
})
.fail(function(err) {
console.log(err);
});
Download PHP sample code
Step 1. Open entry code demo.php
Step 2. Modify global variables, replace authentication parameters in your preparation list
- CRS AppId
- API Key / API Secret
- Server-end URL
- imageFilePath : Path to the target image file to be uploaded
<?php
include 'EasyARClientSdkCRS.php';
$apiKey = 'API Key';
$apiSecret = 'API Secret';
$crsAppId = 'CRS AppId'
$crsCloudUrl = 'https://cn1-crs.easyar.com';
$imageFilePath = '1.jpg'
$sdk = new EasyARClientSdkCRS($apiKey, $apiSecret, $crsAppId, $crsCloudUrl);
$image = base64_encode(file_get_contents($imageFilePath));
$rs = $sdk->detection($image);
if ($rs->statusCode == 0) {
print_r($rs->result->grade);
} else {
print_r($rs);
}
Step 3. Run php demo.php
Create relevant code files grade.py, modify global variables, then run
pip install requests
python grade.py
import time
import hashlib
import requests
import base64
# --- Global configuration ---
API_KEY = "YOUR_API_KEY"
API_SECRET = "YOUR_API_SECRET"
APP_ID = "YOUR_APP_ID"
HOST = "https://crs-cn1.easyar.com"
IMAGE_PATH = "test.jpg"
def main():
# 1. Read and encode image
with open(IMAGE_PATH, "rb") as f:
image_base64 = base64.b64encode(f.read()).decode('utf-8')
timestamp = str(int(time.time() * 1000)) # Milliseconds timestamp
# 2. Build parameter dictionary (including image)
params = {
'apiKey': API_KEY,
'appId': APP_ID,
'timestamp': timestamp,
'image': image_base64
}
# 3. Sort by key and concatenate
sorted_keys = sorted(params.keys())
builder = "".join([f"{k}{params[k]}" for k in sorted_keys])
builder += API_SECRET
# 4. Generate SHA256 signature
signature = hashlib.sha256(builder.encode('utf-8')).hexdigest()
# 5. Send POST request
payload = {**params, "signature": signature, "timestamp": int(timestamp)}
response = requests.post(f"{HOST}/grade/detection", json=payload)
print(f"Status: {response.status_code}")
print(f"Response: {response.text}")
if __name__ == "__main__":
main()
Create a new code file main.go, modify the global variables, then run:
go run main.go
Main.go:
package main
import (
"bytes"
"crypto/sha256"
"encoding/base64"
"encoding/json"
"fmt"
"io"
"net/http"
"os"
"sort"
"strconv"
"time"
)
var (
ApiKey = "YOUR_API_KEY"
ApiSecret = "YOUR_API_SECRET"
AppId = "YOUR_APP_ID"
Host = "https://crs-cn1.easyar.com"
ImagePath = "test.jpg"
)
func main() {
fileData, _ := os.ReadFile(ImagePath)
imgBase64 := base64.StdEncoding.EncodeToString(fileData)
tsInt := time.Now().UnixNano() / 1e6
tsStr := strconv.FormatInt(tsInt, 10)
params := map[string]string{
"apiKey": ApiKey,
"appId": AppId,
"timestamp": tsStr,
"image": imgBase64,
}
keys := make([]string, 0, len(params))
for k := range params { keys = append(keys, k) }
sort.Strings(keys)
var builder bytes.Buffer
for _, k := range keys {
builder.WriteString(k)
builder.WriteString(params[k])
}
builder.WriteString(ApiSecret)
signature := fmt.Sprintf("%x", sha256.Sum256(builder.Bytes()))
payload := map[string]interface{}{
"image": imgBase64,
"apiKey": ApiKey,
"appId": AppId,
"timestamp": tsInt,
"signature": signature,
}
jsonBytes, _ := json.Marshal(payload)
resp, _ := http.Post(Host+"/grade/detection", "application/json", bytes.NewBuffer(jsonBytes))
defer resp.Body.Close()
body, _ := io.ReadAll(resp.Body)
fmt.Printf("Response: %s\n", string(body))
}
Add dependencies reqwest, tokio, sha2, hex in Cargo.toml.
Execute cargo run.
use sha2::{Sha256, Digest};
use std::collections::BTreeMap;
use std::time::{SystemTime, UNIX_EPOCH};
use base64::{Engine as _, engine::general_purpose};
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";
const IMAGE_PATH: &str = "test.jpg";
#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
let img_bytes = std::fs::read(IMAGE_PATH)?;
let img_b64 = general_purpose::STANDARD.encode(img_bytes);
let ts_raw = SystemTime::now().duration_since(UNIX_EPOCH)?.as_millis();
let ts_str = ts_raw.to_string();
// 1. Collect params in BTreeMap for automatic sorting
let mut params = BTreeMap::new();
params.insert("apiKey", API_KEY);
params.insert("appId", APP_ID);
params.insert("timestamp", &ts_str);
params.insert("image", &img_b64);
// 2. Build sign string
let mut builder = String::new();
for (k, v) in ¶ms {
builder.push_str(k);
builder.push_str(v);
}
builder.push_str(API_SECRET);
// 3. Hash
let mut hasher = Sha256::new();
hasher.update(builder.as_bytes());
let signature = hex::encode(hasher.finalize());
let mut body = serde_json::Map::new();
body.insert("image".into(), img_b64.into());
body.insert("apiKey".into(), API_KEY.into());
body.insert("appId".into(), APP_ID.into());
body.insert("timestamp".into(), ts_raw.into());
body.insert("signature".into(), signature.into());
let client = reqwest::Client::new();
let res = client.post(format!("{}/grade/detection", HOST))
.json(&body)
.send()
.await?;
println!("Response: {}", res.text().await?);
Ok(())
}
Create .NET console project.
dotnet new console
dotnet run
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Net.Http;
using System.Text.Json;
class Program {
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 string IMAGE_PATH = "test.jpg";
static async System.Threading.Tasks.Task Main() {
string timestamp = DateTimeOffset.Now.ToUnixTimeMilliseconds().ToString();
string imageBase64 = Convert.ToBase64String(File.ReadAllBytes(IMAGE_PATH));
// 1. Prepare data for signing
var data = new SortedDictionary<string, string> {
{ "apiKey", API_KEY },
{ "appId", APP_ID },
{ "timestamp", timestamp },
{ "image", imageBase64 }
};
// 2. Concatenate keys and values
StringBuilder sb = new StringBuilder();
foreach (var pair in data) sb.Append(pair.Key).Append(pair.Value);
sb.Append(API_SECRET);
string signature = Sha256(sb.ToString());
// 3. Construct JSON body
var body = new {
image = imageBase64,
apiKey = API_KEY,
appId = APP_ID,
timestamp = long.Parse(timestamp),
signature = signature
};
using var client = new HttpClient();
var content = new StringContent(JsonSerializer.Serialize(body), Encoding.UTF8, "application/json");
var response = await client.PostAsync($"{HOST}/grade/detection", content);
Console.WriteLine($"Response: {await response.Content.ReadAsStringAsync()}");
}
static string Sha256(string str) {
byte[] bytes = SHA256.HashData(Encoding.UTF8.GetBytes(str));
return BitConverter.ToString(bytes).Replace("-", "").ToLower();
}
}
- Runtime environment
- Unity 2020 LTS or above
- Scripting Backend: Mono or IL2CPP (both acceptable)
- API Compatibility Level: .NET Standard 2.1 (recommended)
Step 1: Prepare image files
- Create directories in Unity project:
Assets/
└── StreamingAssets/
| └── target.jpg
└── Scripts/
└── GrageImage.cs
- According to Assets directory name
- Create GrageImage.cs script, copy example code below
- Prepare a target test image
using System;
using System.IO;
using System.Text;
using UnityEngine;
using UnityEngine.Networking;
using System.Collections;
public class GrageImage : MonoBehaviour
{
[Header("Config")]
public string apiUrl = "https://Your-Server-end-URL" + "/grade/detection";
public string authorizationToken = "YOUR API KEY AUTH TOKEN";
public string imageFilePath = "target.jpg"; // StreamingAssets
public string crsAppId = "<Your-CRS-AppId>";
private void Start()
{
StartCoroutine(Grade());
}
private IEnumerator Grade()
{
// Read image file（Unity StreamingAssets）
string fullPath = Path.Combine(Application.streamingAssetsPath, imageFilePath);
if (!File.Exists(fullPath))
{
Debug.LogError($"Image file not found: {fullPath}");
yield break;
}
byte[] imageBytes = File.ReadAllBytes(fullPath);
string imageBase64 = Convert.ToBase64String(imageBytes);
TargetRequestBody body = new TargetRequestBody
{
appId = crsAppId,
image = imageBase64,
};
string json = JsonUtility.ToJson(body);
// UnityWebRequest
UnityWebRequest request = new UnityWebRequest(apiUrl, "POST");
byte[] jsonBytes = Encoding.UTF8.GetBytes(json);
request.uploadHandler = new UploadHandlerRaw(jsonBytes);
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("Grade detail success:");
Debug.Log(request.downloadHandler.text);
}
else
{
Debug.LogError("Grade detail failed:");
Debug.LogError(request.error);
Debug.LogError(request.downloadHandler.text);
}
}
[Serializable]
private class TargetRequestBody
{
public string appId;
public string image;
}
}
- In Unity Editor:
- Create an empty GameObject
- Name it GradeImage
- Drag GrageImage script onto this object
Step 3: Configure parameters (Inspector)
Modify in Inspector panel. Change according to preparation list data.
- Api Url
- Authorization Token
- Image File Path: default target.jpg
- CRS AppId
Only modify these four items to run, fill in parameters from preparation list
Step 4: Run
- Click Play
- View results in Console:
- Success: returns JSON (result contains object)
- Failure: HTTP/error message
