Cheque MICR Code reader from image using tesseract.js

Cheque (MICR Code) Reader for Ionic 4
description: Cheque (MICR Code) Reader for Ionic 4 using tesseract.js ocr library

Installation:

Create an ionic project :

ionic start MicrChequeProject blank --type=angular

Install the dependencies:

```
npm install tesseract.js@1.0.14
npm install underscore
```

Create a service provider:

ionic generate service services/ocr_provider

Use this below code in your service provider

	import { Injectable } from '@angular/core';
	import { Platform } from '@ionic/angular';
	import Tesseract from 'tesseract.js'
	import _ from 'underscore';
	export type ProgressFn = (progress: number) => void;
	@Injectable({
	providedIn: 'root'
	})
	export class OcrProviderService {
	public tesseract;
	MICR_CHARACTERS = '0123456789abcd';
	constructor(
	private platform: Platform) { }
	public text(image: any, progressCallback: ProgressFn): Promise<any> {
	const path = this.path();
	console.log('Hello OcrProvider', path + 'assets/lib/tesseract.js-');
	this.tesseract = Tesseract.create({
	langPath: path + 'assets/lib/tesseract.js-',
	corePath: path + 'assets/lib/tesseract.js-core_0.1.0.js',
	workerPath: path + 'assets/lib/tesseract.js-worker_1.0.10.js',
	});
	return new Promise<any>((resolve, reject) => {
	const tesseractConfig = {
	lang: 'micr',
	tessedit_char_whitelist: this.MICR_CHARACTERS
	}
	this.tesseract.recognize(image, tesseractConfig)
	.progress((status) => {
	if (progressCallback != null) {
	const progress = status.status == 'recognizing text'
	? status.progress
	: 0
	progressCallback(progress)
	}
	})
	.catch((err) => {
	console.error('OcrProvider.text: Failed to analyze text.', err)
	reject(err)
	})
	.then((result) => {
	console.log("raw text : "+result.text)
	var response = {
	rawText: result.text,
	error: '',
	confidence: '',
	chequeNo : '',
	routeNo: '',
	accountNo: '',
	cheque_number: ''
	};
	if (result.blocks.length === 0 || result.blocks[0].lines.length === 0) {
	response.error = "NO_TEXT_BLOCKS_FOUND";
	return resolve(response);
	}
	else
	{
	var lines = result.blocks[0].lines;
	var chequeLineWords = lines[lines.length - 1].words;
	var confidentSymbols = this.getConfidentSymbols(chequeLineWords);
	var parsedChequeNumber = confidentSymbols.map(function(symbol) { return symbol.text; }).join("");
	response.cheque_number = parsedChequeNumber;
	var removedAlphabetChequeNumber = this.removeNonNumericSymbols(parsedChequeNumber, '');
	console.log("cheque "+removedAlphabetChequeNumber);
	console.log("cheque "+removedAlphabetChequeNumber.length);
	if(removedAlphabetChequeNumber.length == 25)
	{
	response.chequeNo = removedAlphabetChequeNumber.substr(0,6)
	response.routeNo = removedAlphabetChequeNumber.substr(6,9);
	response.accountNo = removedAlphabetChequeNumber.substr(15,10);
	}
	else{
	parsedChequeNumber = parsedChequeNumber.replace('ca', 'c');
	var forSplit = this.removeNonNumericSymbols(parsedChequeNumber, '-');
	var splitCheque = forSplit.split("-");
	response.chequeNo = splitCheque[0];
	response.routeNo = splitCheque[1];
	response.accountNo = splitCheque[2];
	}
	console.log("response "+JSON.stringify(response));
	resolve(response);
	}
	})
	});
	}
	removeNonNumericSymbols(text, symbol) {
	return text.replace(/\D/g, symbol);
	}
	getConfidentSymbols(words) {
	return _.flatten(words.map(function(word) {
	return word.symbols;
	})).filter(function(symbol) {
	return symbol.confidence > 45;
	});
	}
	private path(): string {
	console.log("platform "+this.platform.is('android'))
	//If using ionic serve
	// return 'http://localhost:8100/';
	// For Android build
	return 'http://localhost:8100/';
	}
	}

view raw Ionic4_Tesseract_Micr_Service hosted with ❤ by GitHub

Add the provider class name in the appmodule.ts

Execute the project in the browser:

ionic serve

You can clone the full code from the below GitHub URL

Github Repository:
https://github.com/AndroidManikandan5689/IonicMICRCodeReader


Demo Screenshot:

https://github.com/AndroidManikandan5689/IonicMICRCodeReader/tree/master/screenshot/micr_tesseract.png



Happy Coding...:)