🚰🔌 Power Meter and Water Meter OCR

🚰🔌 ระบบสำหรับอ่านตัวเลขบนมิเตอร์ไฟฟ้าและมิเตอร์น้ำ

Water Meter OCR is an iApp's AI service that automatically reads and digitizes water meter and power meter readings. The service can detect and extract numbers from both round and rectangular meter faces.

Try Demo!

Example Images (Click to try)

API Key

Log in to use your API keys or Create an account

Endpoint URL

cURL Command

Upload Image

Getting Started

1. Prerequisites

   • An API key from iApp Technology
   • Clear images of water/power meters
   • Internet connection

2. Quick Start

   • Fast meter reading recognition
   • Support for multiple meter types
   • Simple REST API interface

3. Key Features

   • Automated meter reading detection
   • High accuracy digit recognition
   • Fast response time
   • Easy integration

4. Security & Compliance

   • GDPR and PDPA compliant
   • No data retention after processing

How to get API Key?

Please visit API Key Management page to view your existing API key or request a new one.

API Endpoints

Endpoint	Method	Description	Cost
/v3/store/smart-city/power-meter-and-water-meter Legacy: /meter-number-ocr	POST	Extract readings from power/water meters	1 IC per request
/v3/store/smart-city/power-meter-and-water-meter/file Legacy: /meter-number-ocr/file	POST	Extract readings from meter image file	1 IC per request
/v3/store/smart-city/power-meter-and-water-meter/base64 Legacy: /meter-number-ocr/base64	POST	Extract readings from base64 meter image	1 IC per request

Example

Power and Water Meter in Real Life Application

1. Water Meter With Round Face

Example 1

Example 2

2. Water Meter With Rectangle Face

Request

curl --location --request POST 'https://api.iapp.co.th/meter-number-ocr/file' \
--header 'apikey: ----Your API Key----' \
--form 'file=@"/Users/id_1016_value_367_003.jpg"'

Response

{
    "infer_time": 0.16,
    "label": "024963",
    "message": "success",
    "status": 200
}

Features & Capabilities

Core Features

• Automatic detection of meter faces (round and rectangular)
• High-accuracy digit recognition
• Fast processing time
• Support for multiple image formats

Supported Fields

• Meter reading numbers
• Meter face type detection

API Reference

Endpoint

POST https://api.iapp.co.th/meter-number-ocr/file

Headers

Name	Type	Description
apikey	string	Your API key

Request Body

Name	Type	Description
file	image	Clear meter image

Code Example

Python

import requests

url = "https://api.iapp.co.th/meter-number-ocr/file"

payload = {}
files=[
  ('file',('{YOUR UPLOADED FILE NAME}',open('{YOUR UPLOADED FILE PATH}','rb'),'image/png'))
]
headers = {
  'apikey': '{YOUR_API_KEY}'
}

response = requests.request("POST", url, headers=headers, data=payload, files=files)

print(response.text)

JavaScript

const axios = require('axios');
const FormData = require('form-data');
const fs = require('fs');
let data = new FormData();
data.append('file', fs.createReadStream('{YOUR UPLOADED FILE PATH}'));

let config = {
  method: 'post',
  maxBodyLength: Infinity,
  url: 'https://api.iapp.co.th/meter-number-ocr/file',
  headers: {
    'apikey': '{YOUR_API_KEY}',
    ...data.getHeaders()
  },
  data : data
};

axios.request(config)
.then((response) => {
  console.log(JSON.stringify(response.data));
})
.catch((error) => {
  console.log(error);
});

PHP

<?php

$curl = curl_init();

curl_setopt_array($curl, array(
  CURLOPT_URL => 'https://api.iapp.co.th/meter-number-ocr/file',
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => '',
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 0,
  CURLOPT_FOLLOWLOCATION => true,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => 'POST',
  CURLOPT_POSTFIELDS => array('file'=> new CURLFILE('{YOUR UPLOADED FILE PATH}')),
  CURLOPT_HTTPHEADER => array(
    'apikey: {YOUR_API_KEY}'
  ),
));

$response = curl_exec($curl);

curl_close($curl);
echo $response;

Swift

let parameters = [
  [
    "key": "file",
    "src": "{YOUR UPLOADED FILE PATH}",
    "type": "file"
  ]] as [[String: Any]]

let boundary = "Boundary-\(UUID().uuidString)"
var body = Data()
var error: Error? = nil
for param in parameters {
  if param["disabled"] != nil { continue }
  let paramName = param["key"]!
  body += Data("--\(boundary)\r\n".utf8)
  body += Data("Content-Disposition:form-data; name=\"\(paramName)\"".utf8)
  if param["contentType"] != nil {
    body += Data("\r\nContent-Type: \(param["contentType"] as! String)".utf8)
  }
  let paramType = param["type"] as! String
  if paramType == "text" {
    let paramValue = param["value"] as! String
    body += Data("\r\n\r\n\(paramValue)\r\n".utf8)
  } else {
    let paramSrc = param["src"] as! String
    let fileURL = URL(fileURLWithPath: paramSrc)
    if let fileContent = try? Data(contentsOf: fileURL) {
      body += Data("; filename=\"\(paramSrc)\"\r\n".utf8)
      body += Data("Content-Type: \"content-type header\"\r\n".utf8)
      body += Data("\r\n".utf8)
      body += fileContent
      body += Data("\r\n".utf8)
    }
  }
}
body += Data("--\(boundary)--\r\n".utf8);
let postData = body


var request = URLRequest(url: URL(string: "https://api.iapp.co.th/meter-number-ocr/file")!,timeoutInterval: Double.infinity)
request.addValue("{YOUR_API_KEY}", forHTTPHeaderField: "apikey")
request.addValue("multipart/form-data; boundary=\(boundary)", forHTTPHeaderField: "Content-Type")

request.httpMethod = "POST"
request.httpBody = postData

let task = URLSession.shared.dataTask(with: request) { data, response, error in
  guard let data = data else {
    print(String(describing: error))
    return
  }
  print(String(data: data, encoding: .utf8)!)
}

task.resume()

Kotlin

val client = OkHttpClient()
val mediaType = "text/plain".toMediaType()
val body = MultipartBody.Builder().setType(MultipartBody.FORM)
  .addFormDataPart("file","{YOUR UPLOADED FILE NAME}",
    File("{YOUR UPLOADED FILE PATH}").asRequestBody("application/octet-stream".toMediaType()))
  .build()
val request = Request.Builder()
  .url("https://api.iapp.co.th/meter-number-ocr/file")
  .post(body)
  .addHeader("apikey", "{YOUR_API_KEY}")
  .build()
val response = client.newCall(request).execute()

Java

OkHttpClient client = new OkHttpClient().newBuilder()
  .build();
MediaType mediaType = MediaType.parse("text/plain");
RequestBody body = new MultipartBody.Builder().setType(MultipartBody.FORM)
  .addFormDataPart("file","{YOUR UPLOADED FILE NAME}",
    RequestBody.create(MediaType.parse("application/octet-stream"),
    new File("{YOUR UPLOADED FILE PATH}")))
  .build();
Request request = new Request.Builder()
  .url("https://api.iapp.co.th/meter-number-ocr/file")
  .method("POST", body)
  .addHeader("apikey", "{YOUR_API_KEY}")
  .build();
Response response = client.newCall(request).execute();

Dart

var headers = {
  'apikey': '{YOUR_API_KEY}'
};
var request = http.MultipartRequest('POST', Uri.parse('https://api.iapp.co.th/meter-number-ocr/file'));
request.files.add(await http.MultipartFile.fromPath('file', '{YOUR UPLOADED FILE PATH}'));
request.headers.addAll(headers);

http.StreamedResponse response = await request.send();

if (response.statusCode == 200) {
  print(await response.stream.bytesToString());
}
else {
  print(response.reasonPhrase);
}

Accuracy and Performance

Evaluation done based on Water-Meter image data of both rectangle and round faces (107 images)

Model Evaluation

Model	Description	Accuracy (%)
Water Meter Detection Model	Detects the water meter from the input image	96.22
OCR Model	Recognizes the Digits	76.47
Overall Accuracy	Overall accuracy of the system	73.58

Character Evaluation

Numbers	Total Count	Correct Count	Accuracy (%)
0	197	188	95.43
1	85	80	94.12
2	58	53	91.38
3	69	63	91.3
4	65	62	95.38
5	57	50	87.72
6	51	43	84.31
7	52	48	92.31
8	48	40	83.33
9	59	50	84.75

Overall Accuracy based on True detection of numbers = 90 %

History/Change Logs

Version 1.0 - 2021-10-05

Added

• Introducing iApp's water meter OCR
• Supports all kind of water meter faces

Version 1.1 - 2021-12-02

Fixed

• Detection of 2 digits on same x coordinate
• Increased Accuracy from 62.26 to 73.58

Code Examples

Curl

curl -X POST https://api.iapp.co.th/v3/store/smart-city/meter-reading \
    -H "apikey: YOUR_API_KEY" \
    -F "file=@/path/to/meter.jpg"

Python

import requests

url = "https://api.iapp.co.th/v3/store/smart-city/meter-reading"
files = {"file": ("("/path/to/meter.jpg", "rb"))}
headers = {"apikey": "YOUR_API_KEY"}

response = requests.post(url, headers=headers, files=files)
print(response.json())

JavaScript

const axios = require("axios");
const FormData = require("form-data");
const fs = require("fs");

let data = new FormData();
data.append("file", fs.createReadStream("/path/to/meter.jpg"));

let config = {
    method: "post",
    url: "https://api.iapp.co.th/v3/store/smart-city/meter-reading",
    headers: {
        apikey: "YOUR_API_KEY",
        ...data.getHeaders(),
    },
    data: data,
};

axios(config)
    .then((response) => console.log(response.data))
    .catch((error) => console.log(error));

PHP

<?php
$curl = curl_init();

curl_setopt_array($curl, array(
    CURLOPT_URL => 'https://api.iapp.co.th/v3/store/smart-city/meter-reading',
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_POST => true,
    CURLOPT_POSTFIELDS => array(
        'file'=> new CURLFILE('/path/to/meter.jpg')
    ),
    CURLOPT_HTTPHEADER => array(
        'apikey: YOUR_API_KEY'
    ),
));

$response = curl_exec($curl);
curl_close($curl);
echo $response;
?>

Swift

import Foundation

let url = URL(string: "https://api.iapp.co.th/v3/store/smart-city/meter-reading")!
var request = URLRequest(url: url)
request.httpMethod = "POST"
request.addValue("YOUR_API_KEY", forHTTPHeaderField: "apikey")

let boundary = "Boundary-\(UUID().uuidString)"
request.setValue("multipart/form-data; boundary=\(boundary)", forHTTPHeaderField: "Content-Type")

var body = Data()
body.append("--\(boundary)\r\n".data(using: .utf8)!)
body.append("Content-Disposition: form-data; name=\"file\"; filename=\"file.jpg\"\r\n".data(using: .utf8)!)
body.append("Content-Type: image/jpeg\r\n\r\n".data(using: .utf8)!)

if let fileData = try? Data(contentsOf: URL(fileURLWithPath: "/path/to/meter.jpg")) {
    body.append(fileData)
}
body.append("\r\n--\(boundary)--\r\n".data(using: .utf8)!)

request.httpBody = body

let task = URLSession.shared.dataTask(with: request) { data, response, error in
    if let data = data {
        print(String(data: data, encoding: .utf8)!)
    }
}
task.resume()

Kotlin

import okhttp3.*
import okhttp3.MediaType.Companion.toMediaTypeOrNull
import okhttp3.RequestBody.Companion.asRequestBody
import java.io.File

val client = OkHttpClient()

val file = File("/path/to/meter.jpg")
val requestBody = MultipartBody.Builder()
    .setType(MultipartBody.FORM)
    .addFormDataPart("file", file.name, file.asRequestBody("image/jpeg".toMediaTypeOrNull()))
    .build()

val request = Request.Builder()
    .url("https://api.iapp.co.th/v3/store/smart-city/meter-reading")
    .addHeader("apikey", "YOUR_API_KEY")
    .post(requestBody)
    .build()

client.newCall(request).execute().use { response ->
    println(response.body?.string())
}

Java

import okhttp3.*;
import java.io.File;

OkHttpClient client = new OkHttpClient();

File file = new File("/path/to/meter.jpg");

RequestBody requestBody = new MultipartBody.Builder()
    .setType(MultipartBody.FORM)
    .addFormDataPart("file", file.getName(),
        RequestBody.create(MediaType.parse("image/jpeg"), file))
    .build();

Request request = new Request.Builder()
    .url("https://api.iapp.co.th/v3/store/smart-city/meter-reading")
    .addHeader("apikey", "YOUR_API_KEY")
    .post(requestBody)
    .build();

try (Response response = client.newCall(request).execute()) {
    System.out.println(response.body().string());
}

Dart

import 'package:http/http.dart' as http;

var request = http.MultipartRequest(
    'POST',
    Uri.parse('https://api.iapp.co.th/v3/store/smart-city/meter-reading')
);

request.files.add(await http.MultipartFile.fromPath(
    'file',
    '/path/to/meter.jpg'
));

request.headers.addAll({
    'apikey': 'YOUR_API_KEY'
});

var response = await request.send();
var responseBody = await response.stream.bytesToString();
print(responseBody);

Pricing

AI API Service Name	IC Per Request	On-Premise
Power and Meter OCR	1 IC/Request	Contact