Receipt scanning APIs automate data extraction from receipts using OCR technology, significantly reducing manual entry errors and speeding up processing. This guide shows how to use IronOCR in C# to accurately extract vendor names, dates, items, prices, and totals from receipt images, with built-in image preprocessing and support for multiple formats.
IronOCR is a flexible OCR library offering reliable text extraction from scanned documents, images, and PDFs. With advanced algorithms, computer vision, and machine learning models, IronOCR ensures high accuracy even in challenging scenarios. The library supports multiple languages and font styles, making it suitable for global applications. By incorporating IronOCR into your applications, you can automate data entry and text analysis, boosting productivity.
IronOCR retrieves text from documents, photographs, screenshots, and live camera feeds as JSON responses. Using sophisticated algorithms and machine learning, IronOCR analyzes image data, recognizes characters, and converts them into machine-readable text. The library uses Tesseract 5 technology enhanced with proprietary improvements for superior accuracy.
IronOCR excels at handling low-quality scans, varying receipt formats, and different orientations. Built-in image preprocessing filters automatically improve image quality before processing, ensuring optimal results even from crumpled or faded receipts.
Before working with IronOCR, ensure these prerequisites are in place:
Open Visual Studio and go to Files, then hover on New, and click on Project.
New Project Image
Select Console Application and click Next. This template is ideal for learning IronOCR before implementing in web applications.
Console Application
Write your project name and location, then click Next. Choose a descriptive name like "ReceiptScannerAPI".
Project Configuration
Select .NET 5.0 or later for optimal compatibility, then click Create.
Target Framework
Two simple installation methods are available:
Go to Tools > NuGet Package Manager > Manage NuGet Packages for Solution
NuGet Package Manager
Search for IronOCR and install the package. For non-English receipts, install language-specific packages.
IronOCR
Go to Tools > NuGet Package Manager > Package Manager Console
Enter this command:
Package Manager Console
Extract receipt data with just a few lines of code:
using IronOcr;
using System;
var ocr = new IronTesseract();
// Configure for receipt scanning
ocr.Configuration.ReadBarCodes = true;
ocr.Configuration.WhiteListCharacters = "0123456789.$,ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz% ";
using (var input = new OcrInput(@"receipt.jpg"))
{
// Apply automatic image enhancement
input.DeNoise();
input.Deskew();
input.EnhanceResolution(225);
// Extract text from receipt
var result = ocr.Read(input);
// Display extracted text and confidence
Console.WriteLine($"Extracted Text:\n{result.Text}");
Console.WriteLine($"\nConfidence: {result.Confidence}%");
}
IronOCR extracts line items, pricing, taxes, and totals from various document types. The library supports PDFs, multi-page TIFFs, and various image formats.
using IronOcr;
using System;
using System.Collections.Generic;
using System.Text.RegularExpressions;
class ReceiptScanner
{
static void Main()
{
var ocr = new IronTesseract();
// Configure OCR for optimal receipt reading
ocr.Configuration.WhiteListCharacters = "0123456789.$,ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz% ";
ocr.Configuration.BlackListCharacters = "~`@#*_}{][|\\";
ocr.Configuration.TesseractVersion = TesseractVersion.Tesseract5;
// Load the image of the receipt
using (var input = new OcrInput(@"r2.png"))
{
// Apply image enhancement filters
input.Deskew(); // Fix image rotation
input.EnhanceResolution(225); // Optimal DPI for receipts
input.DeNoise(); // Remove background noise
input.Sharpen(); // Improve text clarity
// Perform OCR on the input image
var result = ocr.Read(input);
// Regular expression patterns to extract relevant details from the OCR result
var descriptionPattern = @"\w+\s+(.*?)\s+(\d+\.\d+)\s+Units\s+(\d+\.\d+)\s+Tax15%\s+\$(\d+\.\d+)";
var pricePattern = @"\$\d+(\.\d{2})?";
var datePattern = @"\d{1,2}[/-]\d{1,2}[/-]\d{2,4}";
// Variables to store extracted data
var descriptions = new List<string>();
var unitPrices = new List<decimal>();
var taxes = new List<decimal>();
var amounts = new List<decimal>();
var lines = result.Text.Split('\n');
foreach (var line in lines)
{
// Match each line against the description pattern
var descriptionMatch = Regex.Match(line, descriptionPattern);
if (descriptionMatch.Success)
{
descriptions.Add(descriptionMatch.Groups[1].Value.Trim());
unitPrices.Add(decimal.Parse(descriptionMatch.Groups[2].Value));
// Calculate tax and total amount for each item
var tax = unitPrices[unitPrices.Count - 1] * 0.15m;
taxes.Add(tax);
amounts.Add(unitPrices[unitPrices.Count - 1] + tax);
}
// Extract date if found
var dateMatch = Regex.Match(line, datePattern);
if (dateMatch.Success)
{
Console.WriteLine($"Receipt Date: {dateMatch.Value}");
}
}
// Output the extracted data
for (int i = 0; i < descriptions.Count; i++)
{
Console.WriteLine($"Description: {descriptions[i]}");
Console.WriteLine($"Quantity: 1.00 Units");
Console.WriteLine($"Unit Price: ${unitPrices[i]:0.00}");
Console.WriteLine($"Taxes: ${taxes[i]:0.00}");
Console.WriteLine($"Amount: ${amounts[i]:0.00}");
Console.WriteLine("-----------------------");
}
// Calculate and display totals
var subtotal = unitPrices.Sum();
var totalTax = taxes.Sum();
var grandTotal = amounts.Sum();
Console.WriteLine($"\nSubtotal: ${subtotal:0.00}");
Console.WriteLine($"Total Tax: ${totalTax:0.00}");
Console.WriteLine($"Grand Total: ${grandTotal:0.00}");
}
}
}Imports IronOcr
Imports System
Imports System.Collections.Generic
Imports System.Text.RegularExpressions
Class ReceiptScanner
Shared Sub Main()
Dim ocr = New IronTesseract()
' Configure OCR for optimal receipt reading
ocr.Configuration.WhiteListCharacters = "0123456789.$,ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz% "
ocr.Configuration.BlackListCharacters = "~`@#*_}{][|\"
ocr.Configuration.TesseractVersion = TesseractVersion.Tesseract5
' Load the image of the receipt
Using input = New OcrInput("r2.png")
' Apply image enhancement filters
input.Deskew() ' Fix image rotation
input.EnhanceResolution(225) ' Optimal DPI for receipts
input.DeNoise() ' Remove background noise
input.Sharpen() ' Improve text clarity
' Perform OCR on the input image
Dim result = ocr.Read(input)
' Regular expression patterns to extract relevant details from the OCR result
Dim descriptionPattern = "\w+\s+(.*?)\s+(\d+\.\d+)\s+Units\s+(\d+\.\d+)\s+Tax15%\s+\$(\d+\.\d+)"
Dim pricePattern = "\$\d+(\.\d{2})?"
Dim datePattern = "\d{1,2}[/-]\d{1,2}[/-]\d{2,4}"
' Variables to store extracted data
Dim descriptions = New List(Of String)()
Dim unitPrices = New List(Of Decimal)()
Dim taxes = New List(Of Decimal)()
Dim amounts = New List(Of Decimal)()
Dim lines = result.Text.Split(ControlChars.Lf)
For Each line In lines
' Match each line against the description pattern
Dim descriptionMatch = Regex.Match(line, descriptionPattern)
If descriptionMatch.Success Then
descriptions.Add(descriptionMatch.Groups(1).Value.Trim())
unitPrices.Add(Decimal.Parse(descriptionMatch.Groups(2).Value))
' Calculate tax and total amount for each item
Dim tax = unitPrices(unitPrices.Count - 1) * 0.15D
taxes.Add(tax)
amounts.Add(unitPrices(unitPrices.Count - 1) + tax)
End If
' Extract date if found
Dim dateMatch = Regex.Match(line, datePattern)
If dateMatch.Success Then
Console.WriteLine($"Receipt Date: {dateMatch.Value}")
End If
Next
' Output the extracted data
For i As Integer = 0 To descriptions.Count - 1
Console.WriteLine($"Description: {descriptions(i)}")
Console.WriteLine("Quantity: 1.00 Units")
Console.WriteLine($"Unit Price: ${unitPrices(i):0.00}")
Console.WriteLine($"Taxes: ${taxes(i):0.00}")
Console.WriteLine($"Amount: ${amounts(i):0.00}")
Console.WriteLine("-----------------------")
Next
' Calculate and display totals
Dim subtotal = unitPrices.Sum()
Dim totalTax = taxes.Sum()
Dim grandTotal = amounts.Sum()
Console.WriteLine(vbCrLf & $"Subtotal: ${subtotal:0.00}")
Console.WriteLine($"Total Tax: ${totalTax:0.00}")
Console.WriteLine($"Grand Total: ${grandTotal:0.00}")
End Using
End Sub
End ClassKey techniques for accurate receipt scanning:
Output
Extract complete receipt content with preserved formatting:
using IronOcr;
using System;
using System.Linq;
class WholeReceiptExtractor
{
static void Main()
{
var ocr = new IronTesseract();
// Configure for receipt scanning
ocr.Configuration.ReadBarCodes = true; // Enable barcode detection
ocr.Configuration.TesseractVersion = TesseractVersion.Tesseract5; // Use latest engine
ocr.Configuration.EngineMode = TesseractEngineMode.TesseractAndLstm; // Best accuracy
using (var input = new OcrInput(@"r3.png"))
{
// Apply automatic image correction
input.WithTitle("Receipt Scan");
// Use computer vision to find text regions
var textRegions = input.FindTextRegions();
Console.WriteLine($"Found {textRegions.Count()} text regions");
// Apply optimal filters for receipt processing
input.ApplyOcrInputFilters();
// Perform OCR on the entire receipt
var result = ocr.Read(input);
// Display extracted text
Console.WriteLine("=== EXTRACTED RECEIPT TEXT ===");
Console.WriteLine(result.Text);
// Get detailed results
Console.WriteLine($"\n=== OCR STATISTICS ===");
Console.WriteLine($"OCR Confidence: {result.Confidence:F2}%");
Console.WriteLine($"Pages Processed: {result.Pages.Length}");
Console.WriteLine($"Paragraphs Found: {result.Paragraphs.Length}");
Console.WriteLine($"Lines Detected: {result.Lines.Length}");
Console.WriteLine($"Words Recognized: {result.Words.Length}");
// Extract any barcodes found
if (result.Barcodes.Any())
{
Console.WriteLine("\n=== BARCODES DETECTED ===");
foreach(var barcode in result.Barcodes)
{
Console.WriteLine($"Type: {barcode.Type}");
Console.WriteLine($"Value: {barcode.Value}");
Console.WriteLine($"Location: X={barcode.X}, Y={barcode.Y}");
}
}
// Save as searchable PDF
result.SaveAsSearchablePdf("receipt_searchable.pdf");
Console.WriteLine("\nSearchable PDF saved as: receipt_searchable.pdf");
// Export as hOCR for preservation
result.SaveAsHocrFile("receipt_hocr.html");
Console.WriteLine("hOCR file saved as: receipt_hocr.html");
}
}
}Imports IronOcr
Imports System
Imports System.Linq
Class WholeReceiptExtractor
Shared Sub Main()
Dim ocr = New IronTesseract()
' Configure for receipt scanning
ocr.Configuration.ReadBarCodes = True ' Enable barcode detection
ocr.Configuration.TesseractVersion = TesseractVersion.Tesseract5 ' Use latest engine
ocr.Configuration.EngineMode = TesseractEngineMode.TesseractAndLstm ' Best accuracy
Using input = New OcrInput("r3.png")
' Apply automatic image correction
input.WithTitle("Receipt Scan")
' Use computer vision to find text regions
Dim textRegions = input.FindTextRegions()
Console.WriteLine($"Found {textRegions.Count()} text regions")
' Apply optimal filters for receipt processing
input.ApplyOcrInputFilters()
' Perform OCR on the entire receipt
Dim result = ocr.Read(input)
' Display extracted text
Console.WriteLine("=== EXTRACTED RECEIPT TEXT ===")
Console.WriteLine(result.Text)
' Get detailed results
Console.WriteLine(vbCrLf & "=== OCR STATISTICS ===")
Console.WriteLine($"OCR Confidence: {result.Confidence:F2}%")
Console.WriteLine($"Pages Processed: {result.Pages.Length}")
Console.WriteLine($"Paragraphs Found: {result.Paragraphs.Length}")
Console.WriteLine($"Lines Detected: {result.Lines.Length}")
Console.WriteLine($"Words Recognized: {result.Words.Length}")
' Extract any barcodes found
If result.Barcodes.Any() Then
Console.WriteLine(vbCrLf & "=== BARCODES DETECTED ===")
For Each barcode In result.Barcodes
Console.WriteLine($"Type: {barcode.Type}")
Console.WriteLine($"Value: {barcode.Value}")
Console.WriteLine($"Location: X={barcode.X}, Y={barcode.Y}")
Next
End If
' Save as searchable PDF
result.SaveAsSearchablePdf("receipt_searchable.pdf")
Console.WriteLine(vbCrLf & "Searchable PDF saved as: receipt_searchable.pdf")
' Export as hOCR for preservation
result.SaveAsHocrFile("receipt_hocr.html")
Console.WriteLine("hOCR file saved as: receipt_hocr.html")
End Using
End Sub
End Class
Scan receipt API output
IronOCR offers several advanced features that significantly improve receipt scanning accuracy:
// Example: Async receipt processing for high-volume scenarios
using IronOcr;
using System;
using System.Threading.Tasks;
using System.Collections.Generic;
using System.IO;
class BulkReceiptProcessor
{
static async Task Main()
{
var ocr = new IronTesseract();
// Configure for optimal performance
ocr.Configuration.TesseractVersion = TesseractVersion.Tesseract5;
ocr.Configuration.UseMultiThreading = true;
ocr.Configuration.ProcessorCount = Environment.ProcessorCount;
// Process multiple receipts asynchronously
var receiptFiles = Directory.GetFiles(@"C:\Receipts\", "*.jpg");
var tasks = new List<Task<OcrResult>>();
foreach (var file in receiptFiles)
{
tasks.Add(ProcessReceiptAsync(ocr, file));
}
// Wait for all receipts to be processed
var results = await Task.WhenAll(tasks);
// Aggregate results
decimal totalAmount = 0;
foreach (var result in results)
{
// Extract total from each receipt
var match = System.Text.RegularExpressions.Regex.Match(
result.Text, @"Total:?\s*\$?(\d+\.\d{2})");
if (match.Success && decimal.TryParse(match.Groups[1].Value, out var amount))
{
totalAmount += amount;
}
}
Console.WriteLine($"Processed {results.Length} receipts");
Console.WriteLine($"Combined total: ${totalAmount:F2}");
}
static async Task<OcrResult> ProcessReceiptAsync(IronTesseract ocr, string filePath)
{
using (var input = new OcrInput(filePath))
{
// Apply preprocessing
input.DeNoise();
input.Deskew();
input.EnhanceResolution(200);
// Process asynchronously
return await ocr.ReadAsync(input);
}
}
}' Example: Async receipt processing for high-volume scenarios
Imports IronOcr
Imports System
Imports System.Threading.Tasks
Imports System.Collections.Generic
Imports System.IO
Class BulkReceiptProcessor
Shared Async Function Main() As Task
Dim ocr = New IronTesseract()
' Configure for optimal performance
ocr.Configuration.TesseractVersion = TesseractVersion.Tesseract5
ocr.Configuration.UseMultiThreading = True
ocr.Configuration.ProcessorCount = Environment.ProcessorCount
' Process multiple receipts asynchronously
Dim receiptFiles = Directory.GetFiles("C:\Receipts\", "*.jpg")
Dim tasks = New List(Of Task(Of OcrResult))()
For Each file In receiptFiles
tasks.Add(ProcessReceiptAsync(ocr, file))
Next
' Wait for all receipts to be processed
Dim results = Await Task.WhenAll(tasks)
' Aggregate results
Dim totalAmount As Decimal = 0
For Each result In results
' Extract total from each receipt
Dim match = System.Text.RegularExpressions.Regex.Match(result.Text, "Total:?\s*\$?(\d+\.\d{2})")
If match.Success AndAlso Decimal.TryParse(match.Groups(1).Value, amount) Then
totalAmount += amount
End If
Next
Console.WriteLine($"Processed {results.Length} receipts")
Console.WriteLine($"Combined total: ${totalAmount:F2}")
End Function
Shared Async Function ProcessReceiptAsync(ocr As IronTesseract, filePath As String) As Task(Of OcrResult)
Using input = New OcrInput(filePath)
' Apply preprocessing
input.DeNoise()
input.Deskew()
input.EnhanceResolution(200)
' Process asynchronously
Return Await ocr.ReadAsync(input)
End Using
End Function
End ClassReceipt scanning presents unique challenges that IronOCR helps address:
Receipt formats vary widely between retailers. IronOCR provides flexible approaches:
using IronOcr;
using System;
using System.Collections.Generic;
using System.Linq;
class ReceiptLayoutHandler
{
static void Main()
{
var ocr = new IronTesseract();
// Configure for different receipt layouts
ocr.Configuration.PageSegmentationMode = TesseractPageSegmentationMode.AutoOsd;
ocr.Configuration.EngineMode = TesseractEngineMode.TesseractAndLstm;
using (var input = new OcrInput(@"complex_receipt.jpg"))
{
// Apply region-specific processing
var cropRegion = new CropRectangle(x: 0, y: 100, width: 400, height: 800);
input.AddImage(@"complex_receipt.jpg", cropRegion);
// Process with confidence tracking
var result = ocr.Read(input);
// Parse using confidence scores
var highConfidenceLines = result.Lines
.Where(line => line.Confidence > 85)
.Select(line => line.Text)
.ToList();
// Extract data with fallback strategies
var total = ExtractTotal(highConfidenceLines)
?? ExtractTotalAlternative(result.Text);
Console.WriteLine($"Receipt Total: {total}");
}
}
static decimal? ExtractTotal(List<string> lines)
{
// Primary extraction method
foreach (var line in lines)
{
if (line.Contains("TOTAL") &&
System.Text.RegularExpressions.Regex.IsMatch(line, @"\d+\.\d{2}"))
{
var match = System.Text.RegularExpressions.Regex.Match(line, @"(\d+\.\d{2})");
if (decimal.TryParse(match.Value, out var total))
return total;
}
}
return null;
}
static decimal? ExtractTotalAlternative(string fullText)
{
// Fallback extraction method
var pattern = @"(?:Total|TOTAL|Grand Total|Amount Due).*?(\d+\.\d{2})";
var match = System.Text.RegularExpressions.Regex.Match(fullText, pattern);
if (match.Success && decimal.TryParse(match.Groups[1].Value, out var total))
return total;
return null;
}
}Imports IronOcr
Imports System
Imports System.Collections.Generic
Imports System.Linq
Class ReceiptLayoutHandler
Shared Sub Main()
Dim ocr = New IronTesseract()
' Configure for different receipt layouts
ocr.Configuration.PageSegmentationMode = TesseractPageSegmentationMode.AutoOsd
ocr.Configuration.EngineMode = TesseractEngineMode.TesseractAndLstm
Using input = New OcrInput("complex_receipt.jpg")
' Apply region-specific processing
Dim cropRegion = New CropRectangle(x:=0, y:=100, width:=400, height:=800)
input.AddImage("complex_receipt.jpg", cropRegion)
' Process with confidence tracking
Dim result = ocr.Read(input)
' Parse using confidence scores
Dim highConfidenceLines = result.Lines _
.Where(Function(line) line.Confidence > 85) _
.Select(Function(line) line.Text) _
.ToList()
' Extract data with fallback strategies
Dim total = ExtractTotal(highConfidenceLines) _
OrElse ExtractTotalAlternative(result.Text)
Console.WriteLine($"Receipt Total: {total}")
End Using
End Sub
Shared Function ExtractTotal(lines As List(Of String)) As Decimal?
' Primary extraction method
For Each line In lines
If line.Contains("TOTAL") AndAlso _
System.Text.RegularExpressions.Regex.IsMatch(line, "\d+\.\d{2}") Then
Dim match = System.Text.RegularExpressions.Regex.Match(line, "(\d+\.\d{2})")
Dim total As Decimal
If Decimal.TryParse(match.Value, total) Then
Return total
End If
End If
Next
Return Nothing
End Function
Shared Function ExtractTotalAlternative(fullText As String) As Decimal?
' Fallback extraction method
Dim pattern = "(?:Total|TOTAL|Grand Total|Amount Due).*?(\d+\.\d{2})"
Dim match = System.Text.RegularExpressions.Regex.Match(fullText, pattern)
Dim total As Decimal
If match.Success AndAlso Decimal.TryParse(match.Groups(1).Value, total) Then
Return total
End If
Return Nothing
End Function
End ClassReceipt scanning APIs like IronOCR offer reliable solutions for automating data extraction from receipts. By using advanced OCR technology, businesses can extract vendor names, purchase dates, itemized lists, prices, taxes, and totals automatically. With support for multiple languages, currencies, and barcode support, businesses can simplify receipt management, save time, and make data-driven decisions.
IronOCR provides the tools developers need for accurate and efficient text extraction, enabling task automation and improved efficiency. The library's complete feature set includes support for various document types and recent improvements like 98% memory reduction.
By meeting the prerequisites and integrating IronOCR, you can reveal automated receipt processing benefits. The library's documentation, examples, and troubleshooting guides ensure smooth implementation.
For more information, visit the licensing page or explore the C# Tesseract OCR tutorial.
IronOCR is a part of IRONSUITE
10 .NET API products for your office documents
Tesseract OCR in the languages you need, We support 125+.
