We Keep Coding

How to extract the line item dynamically using zonal OCR method?

Currently I am creating an OCR application. It's okay to extract the fixed area based on the predefined template but having the difficulty in extracting the line item from the scanned invoices as every invoice has the different line item.

It sounds like you are looking into dynamically extracting information from unstructured forms.
The term 'Unstructured forms processing' refers to capturing data from documents that do not have a fixed structure. Examples of unstructured forms are documents such as purchase orders, invoices, bills, and tabs. These types of documents have a general template but certain parts of the form can vary depending on how many line items or purchases are included in the form.
To extract the data from the form, you will need to use some sort of OCR to convert the image to text. You can use tesseract if you are looking for an open source solution and extract all of the data from the invoice. I did a search on Stack Overflow for using Tesseract on unstructured forms and came across these solutions which you can take a look at :
Tesseract receipt scanning advice needed
How to extract relevant information from receipt
Another option is to look into a commercial solution who has libraries that solve this issue for you. The company I work for LEADTOOLS has an Invoice Recognition and Processing library that allows you to define your Master and then easily process your filled invoices against the invoices. Here is a video overview of the Invoice Recognition and Processing SDK:
Invoice Recognition and Processing
Screenshot of the invoice demo included with the SDK:

C# compatible Finger print reader and receipt generator

I am planning to create School Management System in C# and I'm gonna provide these features:
Biometric attendance system
Fee Slip Printing
I did some search and found these 2 products (fits my needs, I think):
Finger Print Reader - ZK4500
Thermal Receipt Printer - XP200 (not official link)
I was about to order these products but I read on a website, Make Sure the Device is compatible with Programming language (in my case C#). I try to find the answer on Google but no luck! :(
I am totally hopeless and helpless but still happy :) because Stack Over Flow community is always here to help and give the right direction.
So, Here are my questions:
Does these devices are configurable with C#? (if possible, please share any helpful resource)
Is it better choice to use receipt printer instead of regular printer?
Is there any better alternative available for fingerprint reader and receipt generator?
PS: I wanted to keep the printer and fingerprint reader cost as low as possible so customer can afford it easily.

I don't know about the ZK4500, but I can guarantee you that the Digital Persona U.are.U series can be used with C#. The SDK can be purchased as part of a package or standalone. I don't know how many devices you need, but I can tell you that I've had fairly good experience with the U.are.U 4500. The scanners are $99 each, SDK not included.
It also comes with examples for implementation with C#. You can choose to let the SDK handle everything for you, which means capturing a print, finding minutiae points, and creating a biometric template for you, or you can capture the raw image and do your own processing. The examples also show how to store it in your database.
Another option if you are set on a particular scanner is the neurotechnology fingerprint SDK. It includes drivers for many scanners and I can verify that it works well with C#.
Yet another option is the Griaule Biometrics SDK. This SDK also supports C# and is easy to use. It does not include drivers and only officially supports 6 scanners. Additionally, it may be a bit more difficult to get these days because Griaule recently changed their website and ended support for the older SDK. They seem to offer new SDKs, but I haven't used their newer products.
Regarding receipt printers...can't help you there.

OCR for extracting text from cedula/passport C#

I'm looking for a Tesseract or Google's Vision API type of OCR which can help in extracting textual information in passport / ID card image, (which may be captured from mobile or may be scanned. Hence frame size may vary a little). I have been through several posts, and and found Tesseract as preferred solution.
I also tested my test data using Vision API, and got 99% accurate and satisfactory results. But I have following problems/requirements:
Problems:
Tesseract is the suggested solution that i found on most of the posts i had been through, but it gives very bad results, as frame may vary. I can't train data, and I'm okay with any paid library available to help me in my scenario.
Vision API gives accurate result, but my requirement is to not to use cloud based solution.
There are few providers, (eg, LeadTool, IdScan etc.) which provide this feature, but they use their scanners first to scan the passport. Hence their SDK works for their scanners device.
Summary: Is there any available (paid or opensource) c# library available, which takes passport/cedula image as input, and returns accurate text?. Any suggestion/help will be appreciated.

Company called MicroBlink created BlinkID SDK to scan passports, ID cards. It is not free for commercial usage, but free for development. Link to SDK's site HERE. Tesseract OCR tool may give you false results because you probably have not done any processing for an image before OCR scan, which is mandatory if you want a proper result, especially for images of passports and ID's and so on. For image processing you can use OpenCV (free), but it may take you time to learn computer vision and image processing (which are very rewarding actually).

I'm one of the developers in MicroBlink, which is a company specializing in development of barcode and OCR solutions.
Tesseract is indeed one of the options you have. The problem with Tesseract is that it's hard to set the right parameters to get really accurate OCR results. And you still need to implement the data extraction logic on top of the OCR results. And integration on iOS/Android requires two separate codebases.
Google Cloud Vision gives very accurate OCR result, but as you said, it performs image processing on server side, which raises privacy and security concerns regarding sending private ID information over the network to third parties.
There are other companies developing similar products with similar properties (server side, no data extraction, etc..)
MicroBlink's BlinkID is different in the sense that it performs all processing locally (without server side connection). It uses our proprietary machine-learning based OCR engine to ensure data is captured correctly. It supports MRZ, PDF417 barcodes, and scanning the front side of some ID documents (such as UK Driver's licenses, Malaysian IDs, EU IDs...). All ID data is parsed and verified according to country's standards with checksum validation.
BlinkID is provided as a native iOS, Android and Windows Phone 8 SDKs, Phonegap / Cordova plugins for iOS and Android, and Xamarin component (C#) for iOS and Android.
There are also server side library (available on request) which can run on Linux / Windows / MacOS and which has C API and that can be used from .NET application using C++/CLI. Our development team is here to help with the integration in a .NET app.
Please contact support#microblink.com for more information on the subject.

Asprise C# .NET OCR and Barcode Recognition SDK can recognize both normal text, MRZ data and barcodes on passports and other identity documents. The accuracy rate for MRZ data is extremely high.
You can simply pass input images in formats like BMP, JPG, PNG, PDF or TIFF.
Many government agencies use Asprise OCR to read passport MRZ information.
You may contact Asprise support to obtain a special evaluation version for your scenario.

Just a correction about LEADTOOLS needing to...
"use their scanners first to scan the passport. Hence their SDK
works for their scanners device"
This part is not correct. We do not make or sell any type of scanning device. LEADTOOLS SDKs can use different standard devices (Twain and WIA on Windows, Sane on Linux, and cameras on Android and iOS devices using the operating system's own APIs). The OCR and ID recognition is then done through software.

Get encoded barcode as string

I am creating a web application (ASP.NET C#) where I need the encoded barcode text.
Example: EAN13 numbers: 460650003296. The output encoded barcode is then: Y(6A65AA*KNMTQT(
And that is the value I will need to have.
I have tried to use BarCodeLib and that it´s working great to generate barcodes images but I can´t find any way to get the encoded text, I have also tried KA Barcode but with the same result.
Does anyone have any experience in this libaries and if it´s possible to get the encoded text from them, or some other suggestion how I can get the encoded value?

I don't have any experience with this library that you are using. However, my company created a web application that use different commercial library for reading and writing 1-D barcodes (including the EAN13).
We started our web application using the following 2 tutorials:
Reading Barcodes
Writing Barcodes
You can get more details from their support team using this email:
support#leadtools.com

Barcode to Product Name Converter

We are designing a mobile shopping system.
The camera on the phone will read the barcode and then we have to convert the barcode to a standard product name in order to save it to our database.
We are saving it to our database because we are connecting to a web service of local e-commerce sites to get their price about the related product. We are sending the product name to get the price from them, so that the user can see the prices, compare and buy.
We cannot send barcode number to get the data from the e-commerce sites because some sites do not have the info of the barcode number.
I have to somehow get the product name by only knowing the barcode. Google returns the result when barcode number is searched. But how am I going to parse the data? or how am I going to know which answer of google search best suits my input?
Is there a site that sells barcode and product name data match?
We are designing the system with C#
Thanks alot.

I think what you are looking for is a "UPC lookup" website. Try googling for "UPC lookup". There are lots of possibilities like upcdatabase.com.

I've had pretty good luck using https://developers.google.com/shopping-search/. I believe you can look at how the barcode scanning app Zxing uses it # Android Bar Code results from lookup into app ZXing

Instead of searching Google's general web index, search Google Shopping or amazon.