using IronOcr;
使用系统；

// Initialize a new instance of the IronTesseract class
// This is the main OCR engine that will process our invoice
var ocr = new IronTesseract();

// Configure OCR settings for better invoice processing
ocr.Configuration.BlackListCharacters = "~`$#^*_}{]___PROTECTED_LINK_48___ method from ___PROTECTED_LINK_49___ class. Key enhancements include:

- **Image preprocessing**: ___PROTECTED_LINK_50___ corrects tilted scans; ___PROTECTED_LINK_51___ removes artifacts
- **Resolution enhancement**: Setting ___PROTECTED_LINK_52___ improves recognition
- **Character blacklisting**: Prevents common OCR misinterpretations
- **Confidence scoring**: Assesses extraction reliability

!___PROTECTED_LINK_53___
**Invoice Parser**

### How Do I Handle Different Invoice Formats?

Invoice formats vary between vendors, but IronOCR provides flexible solutions:

1. **Template-based**: Define ___PROTECTED_LINK_54___
2. **Computer vision**: Use ___PROTECTED_LINK_55___ to locate text
3. **Table extraction**: Leverage ___PROTECTED_LINK_56___ for line items
4. **Multi-format**: Process ___PROTECTED_LINK_57___, ___PROTECTED_LINK_58___, and ___PROTECTED_LINK_59___

For complex layouts, implement the ___PROTECTED_LINK_60___ which uses machine learning to identify structures automatically.

### What Are Common Extraction Patterns for Invoice Data?

Invoice data follows recognizable patterns extractable using regular expressions with OCR results:

```C#
using IronOCR;
使用系统；
using System.Text.`RegularExpressions`;
using System.Collections.Generic;

public class `InvoiceDataExtractor`
{
    private readonly `IronTesseract` ocr;
  
    public `InvoiceDataExtractor`()
    {
        ocr = new `IronTesseract`();
        // Configure for optimal invoice reading
        `ocr.Configuration`.`ReadBarcodes` = true; // Many invoices include barcodes
        `ocr.Configuration`.`TesseractVersion` = `TesseractVersion`.Tesseract5;
    }
  
    public `InvoiceData` `ExtractInvoiceData`(string imagePath)
    {
        var invoiceData = new `InvoiceData`();
  
        using (var input = new `OcrInput`(imagePath/))
        {
            // Apply filters for better accuracy
            input.`EnhanceResolution`(300/);
            `input.Sharpen`();
  
            var result = `ocr.Read`(input/);
            var text = `result.Text`;
  
            // Extract invoice number
            invoiceData.`InvoiceNumber` = `ExtractPattern`(text,
                @"INV[/-]?\d{4}[/-]?\d{5}|Invoice\s*#?\s*:?\s*(\d+)");
  
            // Extract dates
            invoiceData.`InvoiceDate` = `ExtractDate`(text,
                @"Invoice\s*Date\s*:?\s*(\d{1,2}[/-]\d{1,2}[/-]\d{2,4})");
            invoiceData.`DueDate` = `ExtractDate`(text,
                @"Due\s*Date\s*:?\s*(\d{1,2}[/-]\d{1,2}[/-]\d{2,4})");
  
            // Extract amounts
            `invoiceData.Total` = `ExtractAmount`(text,
                @"Total\s*:?\s*\$?\s*([\d,]+\.?\d*)");
            `invoiceData.Tax` = `ExtractAmount`(text,
                @"Tax\s*:?\s*\$?\s*([\d,]+\.?\d*)");
  
            // Extract vendor information
            invoiceData.`VendorName` = `ExtractVendorName`(text/);
  
            // Extract line items using table detection
            invoiceData.`LineItems` = `ExtractLineItems`(result/);
  
            // Extract any barcodes found
            if (`result.Barcodes`.Length > 0)
            {
                invoiceData.`BarcodeValues` = new List<string>();
                foreach (var barcode in `result.Barcodes`)
                {
                    invoiceData.`BarcodeValues`.Add(`barcode.Value`);
                }
            }
        }
  
        return invoiceData;
    }
  
    private string `ExtractPattern`(string text, string pattern)
    {
        var match = Regex.Match(text, pattern, `RegexOptions`.`IgnoreCase`);
        return `match.Success` ? `match.Value` : `string.Empty`;
    }
  
    private `DateTime`? `ExtractDate`(string text, string pattern)
    {
        var match = Regex.Match(text, pattern, `RegexOptions`.`IgnoreCase`);
        if (`match.Success` && `match.Groups`.Count > 1)
        {
            if (`DateTime`.`TryParse`(`match.Groups`[1].Value, out `DateTime` date))
                return date;
        }
        return null;
    }
  
    private decimal `ExtractAmount`(string text, string pattern)
    {
        var match = Regex.Match(text, pattern, `RegexOptions`.`IgnoreCase`);
        if (`match.Success` && `match.Groups`.Count > 1)
        {
            var amountStr = `match.Groups`[1].Value.Replace(",", "");
            if (decimal.`TryParse`(amountStr, out decimal amount))
                return amount;
        }
        return 0;
    }
  
    private string `ExtractVendorName`(string text)
    {
        // Usually the vendor name appears in the first few lines
        var lines = `text.Split`('\n'/);
        if (`lines.Length` > 0)
        {
            // Simple heuristic: first non-empty line that's not a common header
            foreach (var line in lines)
            {
                var trimmed = `line.Trim`();
                if (!string.`IsNullOrEmpty`(trimmed/) &&
                    !trimmed.`ToLower`().Contains("invoice") &&
                    `trimmed.Length` > 3)
                {
                    return trimmed;
                }
            }
        }
        return `string.Empty`;
    }
  
    private List<`LineItem`> `ExtractLineItems`(`OcrResult` result)
    {
        var lineItems = new List<`LineItem`>();
  
        // Use IronOCR's table detection capabilities
        if (`result.Tables` != null && `result.Tables`.Count > 0)
        {
            foreach (var table in `result.Tables`)
            {
                // Process each row as a potential line item
                for (int i = 1; i < table.`RowCount`; i++) // Skip header row
                {
                    var item = new `LineItem`
                    {
                        Description = table[i, 0]?.Text ?? "",
                        Quantity = `ParseQuantity`(table[i, 1]?.Text),
                        `UnitPrice` = `ParseAmount`(table[i, 2]?.Text),
                        Total = `ParseAmount`(table[i, 3]?.Text)
                    };
  
                    if (!string.`IsNullOrEmpty`(`item.Description`/))
                        `lineItems.Add`(item/);
                }
            }
        }
  
        return lineItems;
    }
  
    private int `ParseQuantity`(string text)
    {
        if (string.`IsNullOrEmpty`(text/)) return 0;
        var cleaned = Regex.Replace(text, @"[^\d]", "");
        return int.`TryParse`(cleaned, out int qty) ? qty : 0;
    }
  
    private decimal `ParseAmount`(string text)
    {
        if (string.`IsNullOrEmpty`(text/)) return 0;
        var cleaned = Regex.Replace(text, @"[^\d.]", "");
        return decimal.`TryParse`(cleaned, out decimal amt) ? amt : 0;
    }
}

// Data classes for structured invoice information
public class `InvoiceData`
{
    public string `InvoiceNumber` { get; set; }
    public `DateTime`? `InvoiceDate` { get; set; }
    public `DateTime`? `DueDate` { get; set; }
    public string `VendorName` { get; set; }
    public decimal Total { get; set; }
    public decimal Tax { get; set; }
    public List<`LineItem`> `LineItems` { get; set; }
    public List<string> `BarcodeValues` { get; set; }
}

public class `LineItem`
{
    public string Description { get; set; }
    public int Quantity { get; set; }
    public decimal `UnitPrice` { get; set; }
    public decimal Total { get; set; }
}

using IronOcr;
使用系统；

// Initialize a new instance of the IronTesseract class
// This is the main OCR engine that will process our invoice
var ocr = new IronTesseract();

// Configure OCR settings for better invoice processing
ocr.Configuration.BlackListCharacters = "~`$#^*_}{]___PROTECTED_LINK_48___ method from ___PROTECTED_LINK_49___ class. Key enhancements include:

- **Image preprocessing**: ___PROTECTED_LINK_50___ corrects tilted scans; ___PROTECTED_LINK_51___ removes artifacts
- **Resolution enhancement**: Setting ___PROTECTED_LINK_52___ improves recognition
- **Character blacklisting**: Prevents common OCR misinterpretations
- **Confidence scoring**: Assesses extraction reliability

!___PROTECTED_LINK_53___
**Invoice Parser**

### How Do I Handle Different Invoice Formats?

Invoice formats vary between vendors, but IronOCR provides flexible solutions:

1. **Template-based**: Define ___PROTECTED_LINK_54___
2. **Computer vision**: Use ___PROTECTED_LINK_55___ to locate text
3. **Table extraction**: Leverage ___PROTECTED_LINK_56___ for line items
4. **Multi-format**: Process ___PROTECTED_LINK_57___, ___PROTECTED_LINK_58___, and ___PROTECTED_LINK_59___

For complex layouts, implement the ___PROTECTED_LINK_60___ which uses machine learning to identify structures automatically.

### What Are Common Extraction Patterns for Invoice Data?

Invoice data follows recognizable patterns extractable using regular expressions with OCR results:

```C#
using IronOCR;
使用系统；
using System.Text.`RegularExpressions`;
using System.Collections.Generic;

public class `InvoiceDataExtractor`
{
    private readonly `IronTesseract` ocr;
  
    public `InvoiceDataExtractor`()
    {
        ocr = new `IronTesseract`();
        // Configure for optimal invoice reading
        `ocr.Configuration`.`ReadBarcodes` = true; // Many invoices include barcodes
        `ocr.Configuration`.`TesseractVersion` = `TesseractVersion`.Tesseract5;
    }
  
    public `InvoiceData` `ExtractInvoiceData`(string imagePath)
    {
        var invoiceData = new `InvoiceData`();
  
        using (var input = new `OcrInput`(imagePath/))
        {
            // Apply filters for better accuracy
            input.`EnhanceResolution`(300/);
            `input.Sharpen`();
  
            var result = `ocr.Read`(input/);
            var text = `result.Text`;
  
            // Extract invoice number
            invoiceData.`InvoiceNumber` = `ExtractPattern`(text,
                @"INV[/-]?\d{4}[/-]?\d{5}|Invoice\s*#?\s*:?\s*(\d+)");
  
            // Extract dates
            invoiceData.`InvoiceDate` = `ExtractDate`(text,
                @"Invoice\s*Date\s*:?\s*(\d{1,2}[/-]\d{1,2}[/-]\d{2,4})");
            invoiceData.`DueDate` = `ExtractDate`(text,
                @"Due\s*Date\s*:?\s*(\d{1,2}[/-]\d{1,2}[/-]\d{2,4})");
  
            // Extract amounts
            `invoiceData.Total` = `ExtractAmount`(text,
                @"Total\s*:?\s*\$?\s*([\d,]+\.?\d*)");
            `invoiceData.Tax` = `ExtractAmount`(text,
                @"Tax\s*:?\s*\$?\s*([\d,]+\.?\d*)");
  
            // Extract vendor information
            invoiceData.`VendorName` = `ExtractVendorName`(text/);
  
            // Extract line items using table detection
            invoiceData.`LineItems` = `ExtractLineItems`(result/);
  
            // Extract any barcodes found
            if (`result.Barcodes`.Length > 0)
            {
                invoiceData.`BarcodeValues` = new List<string>();
                foreach (var barcode in `result.Barcodes`)
                {
                    invoiceData.`BarcodeValues`.Add(`barcode.Value`);
                }
            }
        }
  
        return invoiceData;
    }
  
    private string `ExtractPattern`(string text, string pattern)
    {
        var match = Regex.Match(text, pattern, `RegexOptions`.`IgnoreCase`);
        return `match.Success` ? `match.Value` : `string.Empty`;
    }
  
    private `DateTime`? `ExtractDate`(string text, string pattern)
    {
        var match = Regex.Match(text, pattern, `RegexOptions`.`IgnoreCase`);
        if (`match.Success` && `match.Groups`.Count > 1)
        {
            if (`DateTime`.`TryParse`(`match.Groups`[1].Value, out `DateTime` date))
                return date;
        }
        return null;
    }
  
    private decimal `ExtractAmount`(string text, string pattern)
    {
        var match = Regex.Match(text, pattern, `RegexOptions`.`IgnoreCase`);
        if (`match.Success` && `match.Groups`.Count > 1)
        {
            var amountStr = `match.Groups`[1].Value.Replace(",", "");
            if (decimal.`TryParse`(amountStr, out decimal amount))
                return amount;
        }
        return 0;
    }
  
    private string `ExtractVendorName`(string text)
    {
        // Usually the vendor name appears in the first few lines
        var lines = `text.Split`('\n'/);
        if (`lines.Length` > 0)
        {
            // Simple heuristic: first non-empty line that's not a common header
            foreach (var line in lines)
            {
                var trimmed = `line.Trim`();
                if (!string.`IsNullOrEmpty`(trimmed/) &&
                    !trimmed.`ToLower`().Contains("invoice") &&
                    `trimmed.Length` > 3)
                {
                    return trimmed;
                }
            }
        }
        return `string.Empty`;
    }
  
    private List<`LineItem`> `ExtractLineItems`(`OcrResult` result)
    {
        var lineItems = new List<`LineItem`>();
  
        // Use IronOCR's table detection capabilities
        if (`result.Tables` != null && `result.Tables`.Count > 0)
        {
            foreach (var table in `result.Tables`)
            {
                // Process each row as a potential line item
                for (int i = 1; i < table.`RowCount`; i++) // Skip header row
                {
                    var item = new `LineItem`
                    {
                        Description = table[i, 0]?.Text ?? "",
                        Quantity = `ParseQuantity`(table[i, 1]?.Text),
                        `UnitPrice` = `ParseAmount`(table[i, 2]?.Text),
                        Total = `ParseAmount`(table[i, 3]?.Text)
                    };
  
                    if (!string.`IsNullOrEmpty`(`item.Description`/))
                        `lineItems.Add`(item/);
                }
            }
        }
  
        return lineItems;
    }
  
    private int `ParseQuantity`(string text)
    {
        if (string.`IsNullOrEmpty`(text/)) return 0;
        var cleaned = Regex.Replace(text, @"[^\d]", "");
        return int.`TryParse`(cleaned, out int qty) ? qty : 0;
    }
  
    private decimal `ParseAmount`(string text)
    {
        if (string.`IsNullOrEmpty`(text/)) return 0;
        var cleaned = Regex.Replace(text, @"[^\d.]", "");
        return decimal.`TryParse`(cleaned, out decimal amt) ? amt : 0;
    }
}

// Data classes for structured invoice information
public class `InvoiceData`
{
    public string `InvoiceNumber` { get; set; }
    public `DateTime`? `InvoiceDate` { get; set; }
    public `DateTime`? `DueDate` { get; set; }
    public string `VendorName` { get; set; }
    public decimal Total { get; set; }
    public decimal Tax { get; set; }
    public List<`LineItem`> `LineItems` { get; set; }
    public List<string> `BarcodeValues` { get; set; }
}

public class `LineItem`
{
    public string Description { get; set; }
    public int Quantity { get; set; }
    public decimal `UnitPrice` { get; set; }
    public decimal Total { get; set; }
}

using IronOCR;
使用系统；
using System.Text.`RegularExpressions`;

// 初始化`IronTesseract`类的新实例
var ocr = new `IronTesseract`();

// 使用`OcrInput`对象加载图像文件
using (var input = new `OcrInput`(@"`r2.png`"/))
{
    // 对图像执行OCR
    var result = `ocr.Read`(input/);
  
    // 为发票编号定义正则表达式模式
    var linePattern = @"INV\/\d{4}\/\d{5}";

    // 在提取的文本中匹配该模式
    var lineMatch = Regex.Match(`result.Text`, linePattern);

    // 检查模式是否与文本的任何部分匹配
    if (`lineMatch.Success`)
    {
        // 如果找到匹配项，则打印发票编号
        var lineValue = `lineMatch.Value`;
        Console.`WriteLine`("客户发票号码: " + lineValue);
    }
}

using IronOCR;
使用系统；
using System.Text.`RegularExpressions`;

// 初始化`IronTesseract`类的新实例
var ocr = new `IronTesseract`();

// 使用`OcrInput`对象加载图像文件
using (var input = new `OcrInput`(@"`r2.png`"/))
{
    // 对图像执行OCR
    var result = `ocr.Read`(input/);
  
    // 为发票编号定义正则表达式模式
    var linePattern = @"INV\/\d{4}\/\d{5}";

    // 在提取的文本中匹配该模式
    var lineMatch = Regex.Match(`result.Text`, linePattern);

    // 检查模式是否与文本的任何部分匹配
    if (`lineMatch.Success`)
    {
        // 如果找到匹配项，则打印发票编号
        var lineValue = `lineMatch.Value`;
        Console.`WriteLine`("客户发票号码: " + lineValue);
    }
}