IronOCR 與基於 LLM 的 OCR：.NET 開發人員應該選擇哪一個？

// RapidOcrNet: 4 paths required — any missing file throws at runtime
var engine = new RapidOcrEngine(new RapidOcrOptions
{
    DetModelPath = "./models/det.onnx",      // ~3 MB download
    ClsModelPath = "./models/cls.onnx",      // ~1 MB download
    RecModelPath = "./models/rec_en.onnx",   // ~2–10 MB depending on language
    KeysPath     = "./models/en_keys.txt"    // ~100 KB character dictionary
});

// Text blocks returned — must be sorted and joined manually
var result = engine.Run(imagePath);
var text = string.Join("\n", result.TextBlocks
    .OrderBy(b => b.BoundingBox.Top)
    .ThenBy(b => b.BoundingBox.Left)
    .Select(b => b.Text));

Imports System.Linq

' RapidOcrNet: 4 paths required — any missing file throws at runtime
Dim engine = New RapidOcrEngine(New RapidOcrOptions With {
    .DetModelPath = "./models/det.onnx",      ' ~3 MB download
    .ClsModelPath = "./models/cls.onnx",      ' ~1 MB download
    .RecModelPath = "./models/rec_en.onnx",   ' ~2–10 MB depending on language
    .KeysPath = "./models/en_keys.txt"        ' ~100 KB character dictionary
})

' Text blocks returned — must be sorted and joined manually
Dim result = engine.Run(imagePath)
Dim text = String.Join(vbCrLf, result.TextBlocks _
    .OrderBy(Function(b) b.BoundingBox.Top) _
    .ThenBy(Function(b) b.BoundingBox.Left) _
    .Select(Function(b) b.Text))

<ItemGroup>
  <Content Include="models\**\*.*">
    <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
  </Content>
</ItemGroup>

// RapidOcrNet: Runtime validation needed because any missing file crashes the engine
public static bool ValidateModelFiles()
{
    var requiredFiles = new[]
    {
        Path.Combine(ModelDirectory, "det.onnx"),
        Path.Combine(ModelDirectory, "cls.onnx"),
        Path.Combine(ModelDirectory, "rec_en.onnx"),
        Path.Combine(ModelDirectory, "en_keys.txt")
    };

    var missingFiles = requiredFiles.Where(f => !File.Exists(f)).ToList();

    if (missingFiles.Any())
    {
        Console.WriteLine("ERROR: Missing required model files:");
        foreach (var file in missingFiles)
            Console.WriteLine($"  - {file}");
        return false;
    }

    return true;
}

Imports System
Imports System.IO
Imports System.Linq

Public Class RapidOcrNet
    Public Shared Function ValidateModelFiles() As Boolean
        Dim requiredFiles = {
            Path.Combine(ModelDirectory, "det.onnx"),
            Path.Combine(ModelDirectory, "cls.onnx"),
            Path.Combine(ModelDirectory, "rec_en.onnx"),
            Path.Combine(ModelDirectory, "en_keys.txt")
        }

        Dim missingFiles = requiredFiles.Where(Function(f) Not File.Exists(f)).ToList()

        If missingFiles.Any() Then
            Console.WriteLine("ERROR: Missing required model files:")
            For Each file In missingFiles
                Console.WriteLine($"  - {file}")
            Next
            Return False
        End If

        Return True
    End Function
End Class

// IronOCR: no model downloads, no path configuration, no validation boilerplate
IronOcr.License.LicenseKey = "YOUR-LICENSE-KEY";
var text = new IronTesseract().Read("document.jpg").Text;

' IronOCR: no model downloads, no path configuration, no validation boilerplate
IronOcr.License.LicenseKey = "YOUR-LICENSE-KEY"
Dim text = New IronTesseract().Read("document.jpg").Text

// RapidOcrNet:英語engine
var englishEngine = new RapidOcrEngine(new RapidOcrOptions
{
    DetModelPath = Path.Combine(modelPath, "det.onnx"),
    ClsModelPath = Path.Combine(modelPath, "cls.onnx"),
    RecModelPath = Path.Combine(modelPath, "en_rec.onnx"),   // English-specific
    KeysPath     = Path.Combine(modelPath, "en_keys.txt")    // English-specific
});

// RapidOcrNet: Chinese engine — different rec and keys files required
var chineseEngine = new RapidOcrEngine(new RapidOcrOptions
{
    DetModelPath = Path.Combine(modelPath, "det.onnx"),
    ClsModelPath = Path.Combine(modelPath, "cls.onnx"),
    RecModelPath = Path.Combine(modelPath, "ch_rec.onnx"),   // Different download
    KeysPath     = Path.Combine(modelPath, "ch_keys.txt")    // Different download
});

// Spanish? NotSupportedException — no model exists

' RapidOcrNet: English engine
Dim englishEngine = New RapidOcrEngine(New RapidOcrOptions With {
    .DetModelPath = Path.Combine(modelPath, "det.onnx"),
    .ClsModelPath = Path.Combine(modelPath, "cls.onnx"),
    .RecModelPath = Path.Combine(modelPath, "en_rec.onnx"),   ' English-specific
    .KeysPath = Path.Combine(modelPath, "en_keys.txt")        ' English-specific
})

' RapidOcrNet: Chinese engine — different rec and keys files required
Dim chineseEngine = New RapidOcrEngine(New RapidOcrOptions With {
    .DetModelPath = Path.Combine(modelPath, "det.onnx"),
    .ClsModelPath = Path.Combine(modelPath, "cls.onnx"),
    .RecModelPath = Path.Combine(modelPath, "ch_rec.onnx"),   ' Different download
    .KeysPath = Path.Combine(modelPath, "ch_keys.txt")        ' Different download
})

' Spanish? NotSupportedException — no model exists

// IronOCR: language switching is a property change, not a file swap
var ocr = new IronTesseract();

// English
ocr.Language = OcrLanguage.English;

// Chinese Simplified
ocr.Language = OcrLanguage.ChineseSimplified;

// Spanish — no model download needed
ocr.Language = OcrLanguage.Spanish;

// Arabic — just works
ocr.Language = OcrLanguage.Arabic;

// Russian — just works
ocr.Language = OcrLanguage.Russian;

var result = ocr.Read("document.jpg");

Imports IronOcr

Dim ocr As New IronTesseract()

' English
ocr.Language = OcrLanguage.English

' Chinese Simplified
ocr.Language = OcrLanguage.ChineseSimplified

' Spanish — no model download needed
ocr.Language = OcrLanguage.Spanish

' Arabic — just works
ocr.Language = OcrLanguage.Arabic

' Russian — just works
ocr.Language = OcrLanguage.Russian

Dim result = ocr.Read("document.jpg")

var ocr = new IronTesseract();
ocr.Language = OcrLanguage.ChineseSimplified;
ocr.AddSecondaryLanguage(OcrLanguage.English);
var result = ocr.Read("mixed-document.jpg");

Imports IronOcr

Dim ocr As New IronTesseract()
ocr.Language = OcrLanguage.ChineseSimplified
ocr.AddSecondaryLanguage(OcrLanguage.English)
Dim result = ocr.Read("mixed-document.jpg")

// RapidOcrNet: PDF processing requires external library + manual assembly
public async Task<string> ExtractTextFromPdf(string pdfPath)
{
    // Step 1: Requires PdfPig, Docotic, or similar external library
    var pageImages = await RenderPdfToImages(pdfPath);

    // Step 2: Initialize RapidOcr with 4 model files (must already be downloaded)
    using var engine = new RapidOcrEngine(new RapidOcrOptions
    {
        DetModelPath = "models/det.onnx",
        ClsModelPath = "models/cls.onnx",
        RecModelPath = "models/rec_en.onnx",
        KeysPath     = "models/en_keys.txt"
    });

    // Step 3: OCR each image individually
    var results = new List<string>();
    foreach (var pageImage in pageImages)
    {
        var result = engine.Run(pageImage);
        results.Add(string.Join("\n", result.TextBlocks.Select(b => b.Text)));
    }

    // Step 4: Combine manually — page structure not preserved
    return string.Join("\n\n", results);
}

Imports System.Threading.Tasks
Imports System.Collections.Generic
Imports System.Linq

Public Class PdfTextExtractor
    ' RapidOcrNet: PDF processing requires external library + manual assembly
    Public Async Function ExtractTextFromPdf(pdfPath As String) As Task(Of String)
        ' Step 1: Requires PdfPig, Docotic, or similar external library
        Dim pageImages = Await RenderPdfToImages(pdfPath)

        ' Step 2: Initialize RapidOcr with 4 model files (must already be downloaded)
        Using engine As New RapidOcrEngine(New RapidOcrOptions With {
            .DetModelPath = "models/det.onnx",
            .ClsModelPath = "models/cls.onnx",
            .RecModelPath = "models/rec_en.onnx",
            .KeysPath = "models/en_keys.txt"
        })

            ' Step 3: OCR each image individually
            Dim results As New List(Of String)()
            For Each pageImage In pageImages
                Dim result = engine.Run(pageImage)
                results.Add(String.Join(vbLf, result.TextBlocks.Select(Function(b) b.Text)))
            Next

            ' Step 4: Combine manually — page structure not preserved
            Return String.Join(vbLf & vbLf, results)
        End Using
    End Function

    ' Placeholder for the RenderPdfToImages method
    Private Async Function RenderPdfToImages(pdfPath As String) As Task(Of List(Of Object))
        ' Implementation goes here
        Return New List(Of Object)()
    End Function
End Class

// IronOCR: direct PDF OCR — no conversion, no external library
var text = new IronTesseract().Read("scanned-document.pdf").Text;

//受密碼保護的 PDF— one parameter
using var input = new OcrInput();
input.LoadPdf("encrypted.pdf", Password: "secret");
var result = new IronTesseract().Read(input);

//可搜尋的PDF— one method call on the result
var result = new IronTesseract().Read("scanned.pdf");
result.SaveAsSearchablePdf("searchable-output.pdf");

Imports IronOcr

' IronOCR: direct PDF OCR — no conversion, no external library
Dim text As String = New IronTesseract().Read("scanned-document.pdf").Text

' 受密碼保護的 PDF— one parameter
Using input As New OcrInput()
    input.LoadPdf("encrypted.pdf", Password:="secret")
    Dim result = New IronTesseract().Read(input)
End Using

' 可搜尋的PDF— one method call on the result
Dim result2 = New IronTesseract().Read("scanned.pdf")
result2.SaveAsSearchablePdf("searchable-output.pdf")

// Before: RapidOcrNet — engine needs all 4 paths populated
var engine = new RapidOcrEngine(new RapidOcrOptions
{
    DetModelPath = "models/det.onnx",
    ClsModelPath = "models/cls.onnx",
    RecModelPath = "models/rec_en.onnx",
    KeysPath     = "models/en_keys.txt"
});
var result = engine.Run(imagePath);
var text = string.Join("\n", result.TextBlocks
    .OrderBy(b => b.BoundingBox.Top)
    .Select(b => b.Text));

// After:IronOCR— no configuration required
IronOcr.License.LicenseKey = "YOUR-LICENSE-KEY";
var text = new IronTesseract().Read(imagePath).Text;

Imports System.Linq

' Before: RapidOcrNet — engine needs all 4 paths populated
Dim engine = New RapidOcrEngine(New RapidOcrOptions With {
    .DetModelPath = "models/det.onnx",
    .ClsModelPath = "models/cls.onnx",
    .RecModelPath = "models/rec_en.onnx",
    .KeysPath = "models/en_keys.txt"
})
Dim result = engine.Run(imagePath)
Dim text = String.Join(vbCrLf, result.TextBlocks _
    .OrderBy(Function(b) b.BoundingBox.Top) _
    .Select(Function(b) b.Text))

' After: IronOCR— no configuration required
IronOcr.License.LicenseKey = "YOUR-LICENSE-KEY"
Dim text = New IronTesseract().Read(imagePath).Text

using var input = new OcrInput();
input.LoadImage("low-quality-scan.jpg");
input.Deskew();           // Correct skewed scans
input.DeNoise();          // Remove scanner noise
input.Contrast();         // Enhance contrast
input.Binarize();         // Convert to black/white
input.EnhanceResolution(300);

var result = new IronTesseract().Read(input);
Console.WriteLine($"Confidence: {result.Confidence}%");

Imports IronOcr

Using input As New OcrInput()
    input.LoadImage("low-quality-scan.jpg")
    input.Deskew()           ' Correct skewed scans
    input.DeNoise()          ' Remove scanner noise
    input.Contrast()         ' Enhance contrast
    input.Binarize()         ' Convert to black/white
    input.EnhanceResolution(300)

    Dim result = New IronTesseract().Read(input)
    Console.WriteLine($"Confidence: {result.Confidence}%")
End Using