// Azure: endpoint URL + API key + async + nested block traversal — before a single character
var client = new ImageAnalysisClient(new Uri(endpoint), new AzureKeyCredential(apiKey));
using var stream = File.OpenRead(imagePath);
var result = await client.AnalyzeAsync(BinaryData.FromStream(stream), VisualFeatures.Read);
var text = string.Join("\n", result.Value.Read.Blocks.SelectMany(b => b.Lines).Select(l => l.Text));

// IronOCR: no endpoint, no key rotation, no async, no traversal
var text = new IronTesseract().Read(imagePath).Text;

// Azure: endpoint URL + API key + async + nested block traversal — before a single character
var client = new ImageAnalysisClient(new Uri(endpoint), new AzureKeyCredential(apiKey));
using var stream = File.OpenRead(imagePath);
var result = await client.AnalyzeAsync(BinaryData.FromStream(stream), VisualFeatures.Read);
var text = string.Join("\n", result.Value.Read.Blocks.SelectMany(b => b.Lines).Select(l => l.Text));

// IronOCR: no endpoint, no key rotation, no async, no traversal
var text = new IronTesseract().Read(imagePath).Text;

dotnet remove package Azure.AI.Vision.ImageAnalysis

dotnet remove package Azure.AI.Vision.ImageAnalysis

dotnet remove package Azure.AI.FormRecognizer

dotnet remove package Azure.AI.FormRecognizer

// Before (Azure Computer Vision)
using Azure;
using Azure.AI.Vision.ImageAnalysis;
// For PDF processing:
// using Azure.AI.FormRecognizer.DocumentAnalysis;

// After (IronOCR)
using IronOcr;

// Before (Azure Computer Vision)
using Azure;
using Azure.AI.Vision.ImageAnalysis;
// For PDF processing:
// using Azure.AI.FormRecognizer.DocumentAnalysis;

// After (IronOCR)
using IronOcr;

// appsettings.json binds to this class
public class AzureComputerVisionOptions
{
    public string Endpoint { get; set; }   // "https://your-resource.cognitiveservices.azure.com/"
    public string ApiKey   { get; set; }   // rotated periodically
}

// Program.cs / Startup.cs
services.Configure<AzureComputerVisionOptions>(
    configuration.GetSection("AzureComputerVision"));

services.AddSingleton<ImageAnalysisClient>(sp =>
{
    var opts = sp.GetRequiredService<IOptions<AzureComputerVisionOptions>>().Value;
    return new ImageAnalysisClient(
        new Uri(opts.Endpoint),
        new AzureKeyCredential(opts.ApiKey));
});

services.AddScoped<IOcrService, AzureOcrService>();

// appsettings.json binds to this class
public class AzureComputerVisionOptions
{
    public string Endpoint { get; set; }   // "https://your-resource.cognitiveservices.azure.com/"
    public string ApiKey   { get; set; }   // rotated periodically
}

// Program.cs / Startup.cs
services.Configure<AzureComputerVisionOptions>(
    configuration.GetSection("AzureComputerVision"));

services.AddSingleton<ImageAnalysisClient>(sp =>
{
    var opts = sp.GetRequiredService<IOptions<AzureComputerVisionOptions>>().Value;
    return new ImageAnalysisClient(
        new Uri(opts.Endpoint),
        new AzureKeyCredential(opts.ApiKey));
});

services.AddScoped<IOcrService, AzureOcrService>();

// AzureOcrService.cs
public class AzureOcrService : IOcrService
{
    private readonly ImageAnalysisClient _client;

    public AzureOcrService(ImageAnalysisClient client)
    {
        _client = client;
    }

    public async Task<string> ReadAsync(string imagePath)
    {
        using var stream = File.OpenRead(imagePath);
        var data = BinaryData.FromStream(stream);
        var result = await _client.AnalyzeAsync(data, VisualFeatures.Read);

        return string.Join("\n",
            result.Value.Read.Blocks
                .SelectMany(b => b.Lines)
                .Select(l => l.Text));
    }
}

// AzureOcrService.cs
public class AzureOcrService : IOcrService
{
    private readonly ImageAnalysisClient _client;

    public AzureOcrService(ImageAnalysisClient client)
    {
        _client = client;
    }

    public async Task<string> ReadAsync(string imagePath)
    {
        using var stream = File.OpenRead(imagePath);
        var data = BinaryData.FromStream(stream);
        var result = await _client.AnalyzeAsync(data, VisualFeatures.Read);

        return string.Join("\n",
            result.Value.Read.Blocks
                .SelectMany(b => b.Lines)
                .Select(l => l.Text));
    }
}

// Program.cs / Startup.cs
// One-time license key — no endpoint, no credential class, no options binding
IronOcr.License.LicenseKey = Environment.GetEnvironmentVariable("IRONOCR_LICENSE");

// Register IronTesseract as a singleton — it is thread-safe
services.AddSingleton<IronTesseract>();
services.AddScoped<IOcrService, IronOcrService>();

// Program.cs / Startup.cs
// One-time license key — no endpoint, no credential class, no options binding
IronOcr.License.LicenseKey = Environment.GetEnvironmentVariable("IRONOCR_LICENSE");

// Register IronTesseract as a singleton — it is thread-safe
services.AddSingleton<IronTesseract>();
services.AddScoped<IOcrService, IronOcrService>();

// IronOcrService.cs
public class IronOcrService : IOcrService
{
    private readonly IronTesseract _ocr;

    public IronOcrService(IronTesseract ocr)
    {
        _ocr = ocr;
    }

    public string Read(string imagePath)
    {
        return _ocr.Read(imagePath).Text;
    }
}

// IronOcrService.cs
public class IronOcrService : IOcrService
{
    private readonly IronTesseract _ocr;

    public IronOcrService(IronTesseract ocr)
    {
        _ocr = ocr;
    }

    public string Read(string imagePath)
    {
        return _ocr.Read(imagePath).Text;
    }
}

// DocumentAnalysisClient — separate from ImageAnalysisClient, separate resource
public class FormRecognizerPdfService
{
    private readonly DocumentAnalysisClient _client;

    public FormRecognizerPdfService(string endpoint, string apiKey)
    {
        _client = new DocumentAnalysisClient(
            new Uri(endpoint),
            new AzureKeyCredential(apiKey));
    }

    // Blocking wait — thread is held for the duration of cloud processing
    public async Task<string> ExtractPdfTextBlocking(string pdfPath)
    {
        using var stream = File.OpenRead(pdfPath);

        var operation = await _client.AnalyzeDocumentAsync(
            WaitUntil.Completed,  // blocks until Azure finishes
            "prebuilt-read",
            stream);

        var docResult = operation.Value;
        var sb = new StringBuilder();
        foreach (var page in docResult.Pages)
        {
            foreach (var line in page.Lines)
            {
                sb.AppendLine(line.Content);  // .Content, not .Text
            }
        }
        return sb.ToString();
    }

    // True async — manual polling loop required
    public async Task<string> ExtractPdfTextNonBlocking(string pdfPath)
    {
        using var stream = File.OpenRead(pdfPath);

        var operation = await _client.AnalyzeDocumentAsync(
            WaitUntil.Started,  // returns immediately, not complete yet
            "prebuilt-read",
            stream);

        // Poll every 500ms until the operation finishes
        while (!operation.HasCompleted)
        {
            await Task.Delay(500);
            await operation.UpdateStatusAsync();
        }

        var docResult = operation.Value;
        var sb = new StringBuilder();
        foreach (var page in docResult.Pages)
        {
            foreach (var line in page.Lines)
            {
                sb.AppendLine(line.Content);
            }
        }
        return sb.ToString();
    }
}

// DocumentAnalysisClient — separate from ImageAnalysisClient, separate resource
public class FormRecognizerPdfService
{
    private readonly DocumentAnalysisClient _client;

    public FormRecognizerPdfService(string endpoint, string apiKey)
    {
        _client = new DocumentAnalysisClient(
            new Uri(endpoint),
            new AzureKeyCredential(apiKey));
    }

    // Blocking wait — thread is held for the duration of cloud processing
    public async Task<string> ExtractPdfTextBlocking(string pdfPath)
    {
        using var stream = File.OpenRead(pdfPath);

        var operation = await _client.AnalyzeDocumentAsync(
            WaitUntil.Completed,  // blocks until Azure finishes
            "prebuilt-read",
            stream);

        var docResult = operation.Value;
        var sb = new StringBuilder();
        foreach (var page in docResult.Pages)
        {
            foreach (var line in page.Lines)
            {
                sb.AppendLine(line.Content);  // .Content, not .Text
            }
        }
        return sb.ToString();
    }

    // True async — manual polling loop required
    public async Task<string> ExtractPdfTextNonBlocking(string pdfPath)
    {
        using var stream = File.OpenRead(pdfPath);

        var operation = await _client.AnalyzeDocumentAsync(
            WaitUntil.Started,  // returns immediately, not complete yet
            "prebuilt-read",
            stream);

        // Poll every 500ms until the operation finishes
        while (!operation.HasCompleted)
        {
            await Task.Delay(500);
            await operation.UpdateStatusAsync();
        }

        var docResult = operation.Value;
        var sb = new StringBuilder();
        foreach (var page in docResult.Pages)
        {
            foreach (var line in page.Lines)
            {
                sb.AppendLine(line.Content);
            }
        }
        return sb.ToString();
    }
}

// One class handles both images and PDFs — no second client or second resource
public class IronOcrDocumentService
{
    private readonly IronTesseract _ocr;

    public IronOcrDocumentService(IronTesseract ocr)
    {
        _ocr = ocr;
    }

    // Synchronous — returns immediately when local processing completes
    public string ExtractPdfText(string pdfPath)
    {
        using var input = new OcrInput();
        input.LoadPdf(pdfPath);
        return _ocr.Read(input).Text;
    }

    // Specific page range — no per-page billing penalty
    public string ExtractPageRange(string pdfPath, int startPage, int endPage)
    {
        using var input = new OcrInput();
        input.LoadPdfPages(pdfPath, startPage, endPage);
        return _ocr.Read(input).Text;
    }

    // If an async signature is required by an interface or controller
    public Task<string> ExtractPdfTextAsync(string pdfPath)
    {
        return Task.Run(() => ExtractPdfText(pdfPath));
    }
}

// One class handles both images and PDFs — no second client or second resource
public class IronOcrDocumentService
{
    private readonly IronTesseract _ocr;

    public IronOcrDocumentService(IronTesseract ocr)
    {
        _ocr = ocr;
    }

    // Synchronous — returns immediately when local processing completes
    public string ExtractPdfText(string pdfPath)
    {
        using var input = new OcrInput();
        input.LoadPdf(pdfPath);
        return _ocr.Read(input).Text;
    }

    // Specific page range — no per-page billing penalty
    public string ExtractPageRange(string pdfPath, int startPage, int endPage)
    {
        using var input = new OcrInput();
        input.LoadPdfPages(pdfPath, startPage, endPage);
        return _ocr.Read(input).Text;
    }

    // If an async signature is required by an interface or controller
    public Task<string> ExtractPdfTextAsync(string pdfPath)
    {
        return Task.Run(() => ExtractPdfText(pdfPath));
    }
}

public async Task<List<WordResult>> ExtractWordPositionsAsync(string imagePath)
{
    using var stream = File.OpenRead(imagePath);
    var imageData = BinaryData.FromStream(stream);

    var response = await _client.AnalyzeAsync(imageData, VisualFeatures.Read);
    var words = new List<WordResult>();

    foreach (var block in response.Value.Read.Blocks)
    {
        foreach (var line in block.Lines)
        {
            foreach (var word in line.Words)
            {
                // BoundingPolygon is a list of ImagePoint — variable vertex count
                var polygon = word.BoundingPolygon;
                int minX = polygon.Min(p => p.X);
                int minY = polygon.Min(p => p.Y);
                int maxX = polygon.Max(p => p.X);
                int maxY = polygon.Max(p => p.Y);

                words.Add(new WordResult
                {
                    Text        = word.Text,
                    // Azure confidence: 0.0 to 1.0 — multiply by 100 for comparison
                    Confidence  = (double)word.Confidence * 100.0,
                    X           = minX,
                    Y           = minY,
                    Width       = maxX - minX,
                    Height      = maxY - minY
                });
            }
        }
    }
    return words;
}

public record WordResult(string Text, double Confidence, int X, int Y, int Width, int Height);

public async Task<List<WordResult>> ExtractWordPositionsAsync(string imagePath)
{
    using var stream = File.OpenRead(imagePath);
    var imageData = BinaryData.FromStream(stream);

    var response = await _client.AnalyzeAsync(imageData, VisualFeatures.Read);
    var words = new List<WordResult>();

    foreach (var block in response.Value.Read.Blocks)
    {
        foreach (var line in block.Lines)
        {
            foreach (var word in line.Words)
            {
                // BoundingPolygon is a list of ImagePoint — variable vertex count
                var polygon = word.BoundingPolygon;
                int minX = polygon.Min(p => p.X);
                int minY = polygon.Min(p => p.Y);
                int maxX = polygon.Max(p => p.X);
                int maxY = polygon.Max(p => p.Y);

                words.Add(new WordResult
                {
                    Text        = word.Text,
                    // Azure confidence: 0.0 to 1.0 — multiply by 100 for comparison
                    Confidence  = (double)word.Confidence * 100.0,
                    X           = minX,
                    Y           = minY,
                    Width       = maxX - minX,
                    Height      = maxY - minY
                });
            }
        }
    }
    return words;
}

public record WordResult(string Text, double Confidence, int X, int Y, int Width, int Height);

public List<WordResult> ExtractWordPositions(string imagePath)
{
    var result = new IronTesseract().Read(imagePath);
    var words = new List<WordResult>();

    foreach (var page in result.Pages)
    {
        foreach (var line in page.Lines)
        {
            foreach (var word in line.Words)
            {
                // Rectangle-based bounding box — no polygon math required
                // Confidence is already 0–100, matching the converted Azure scale
                words.Add(new WordResult
                {
                    Text       = word.Text,
                    Confidence = word.Confidence,   // 0–100, no conversion needed
                    X          = word.X,
                    Y          = word.Y,
                    Width      = word.Width,
                    Height     = word.Height
                });
            }
        }
    }
    return words;
}

// Filter to only high-confidence words — common post-processing pattern
public IEnumerable<string> ExtractHighConfidenceWords(string imagePath, double threshold = 80.0)
{
    var result = new IronTesseract().Read(imagePath);
    return result.Words
        .Where(w => w.Confidence >= threshold)
        .Select(w => w.Text);
}

public record WordResult(string Text, double Confidence, int X, int Y, int Width, int Height);

public List<WordResult> ExtractWordPositions(string imagePath)
{
    var result = new IronTesseract().Read(imagePath);
    var words = new List<WordResult>();

    foreach (var page in result.Pages)
    {
        foreach (var line in page.Lines)
        {
            foreach (var word in line.Words)
            {
                // Rectangle-based bounding box — no polygon math required
                // Confidence is already 0–100, matching the converted Azure scale
                words.Add(new WordResult
                {
                    Text       = word.Text,
                    Confidence = word.Confidence,   // 0–100, no conversion needed
                    X          = word.X,
                    Y          = word.Y,
                    Width      = word.Width,
                    Height     = word.Height
                });
            }
        }
    }
    return words;
}

// Filter to only high-confidence words — common post-processing pattern
public IEnumerable<string> ExtractHighConfidenceWords(string imagePath, double threshold = 80.0)
{
    var result = new IronTesseract().Read(imagePath);
    return result.Words
        .Where(w => w.Confidence >= threshold)
        .Select(w => w.Text);
}

public record WordResult(string Text, double Confidence, int X, int Y, int Width, int Height);

// Azure does not support multi-frame TIFF directly via ImageAnalysisClient
// Must split frames manually and upload each as a separate transaction
public async Task<string> ExtractMultiFrameTiffAsync(string tiffPath)
{
    // Load TIFF using System.Drawing or a third-party library
    using var bitmap = new System.Drawing.Bitmap(tiffPath);
    int frameCount = bitmap.GetFrameCount(
        System.Drawing.Imaging.FrameDimension.Page);

    var allText = new StringBuilder();

    for (int i = 0; i < frameCount; i++)
    {
        // Select frame, save to temporary PNG, upload to Azure
        bitmap.SelectActiveFrame(System.Drawing.Imaging.FrameDimension.Page, i);

        using var ms = new MemoryStream();
        bitmap.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
        ms.Position = 0;

        // Each frame = 1 Azure transaction = $0.001
        var imageData = BinaryData.FromStream(ms);
        var result = await _client.AnalyzeAsync(imageData, VisualFeatures.Read);

        foreach (var block in result.Value.Read.Blocks)
            foreach (var line in block.Lines)
                allText.AppendLine(line.Text);
    }

    return allText.ToString();
}

// Azure does not support multi-frame TIFF directly via ImageAnalysisClient
// Must split frames manually and upload each as a separate transaction
public async Task<string> ExtractMultiFrameTiffAsync(string tiffPath)
{
    // Load TIFF using System.Drawing or a third-party library
    using var bitmap = new System.Drawing.Bitmap(tiffPath);
    int frameCount = bitmap.GetFrameCount(
        System.Drawing.Imaging.FrameDimension.Page);

    var allText = new StringBuilder();

    for (int i = 0; i < frameCount; i++)
    {
        // Select frame, save to temporary PNG, upload to Azure
        bitmap.SelectActiveFrame(System.Drawing.Imaging.FrameDimension.Page, i);

        using var ms = new MemoryStream();
        bitmap.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
        ms.Position = 0;

        // Each frame = 1 Azure transaction = $0.001
        var imageData = BinaryData.FromStream(ms);
        var result = await _client.AnalyzeAsync(imageData, VisualFeatures.Read);

        foreach (var block in result.Value.Read.Blocks)
            foreach (var line in block.Lines)
                allText.AppendLine(line.Text);
    }

    return allText.ToString();
}

// IronOCR handles multi-frame TIFF natively — single call, no frame splitting
public string ExtractMultiFrameTiff(string tiffPath)
{
    using var input = new OcrInput();
    input.LoadImageFrames(tiffPath);  // all frames loaded automatically
    var result = new IronTesseract().Read(input);
    return result.Text;
}

// Access per-page data for frame-level reporting
public void ExtractTiffWithPageStats(string tiffPath)
{
    using var input = new OcrInput();
    input.LoadImageFrames(tiffPath);

    var ocr = new IronTesseract();
    var result = ocr.Read(input);

    Console.WriteLine($"Total frames processed: {result.Pages.Length}");
    foreach (var page in result.Pages)
    {
        Console.WriteLine($"Frame {page.PageNumber}: " +
            $"{page.Words.Length} words, " +
            $"confidence {page.Confidence:F1}%");
    }
}

// Combine with preprocessing for scanned TIFF archives
public string ExtractLowQualityTiffArchive(string tiffPath)
{
    using var input = new OcrInput();
    input.LoadImageFrames(tiffPath);
    input.Deskew();
    input.DeNoise();
    input.Contrast();

    var result = new IronTesseract().Read(input);
    return result.Text;
}

// IronOCR handles multi-frame TIFF natively — single call, no frame splitting
public string ExtractMultiFrameTiff(string tiffPath)
{
    using var input = new OcrInput();
    input.LoadImageFrames(tiffPath);  // all frames loaded automatically
    var result = new IronTesseract().Read(input);
    return result.Text;
}

// Access per-page data for frame-level reporting
public void ExtractTiffWithPageStats(string tiffPath)
{
    using var input = new OcrInput();
    input.LoadImageFrames(tiffPath);

    var ocr = new IronTesseract();
    var result = ocr.Read(input);

    Console.WriteLine($"Total frames processed: {result.Pages.Length}");
    foreach (var page in result.Pages)
    {
        Console.WriteLine($"Frame {page.PageNumber}: " +
            $"{page.Words.Length} words, " +
            $"confidence {page.Confidence:F1}%");
    }
}

// Combine with preprocessing for scanned TIFF archives
public string ExtractLowQualityTiffArchive(string tiffPath)
{
    using var input = new OcrInput();
    input.LoadImageFrames(tiffPath);
    input.Deskew();
    input.DeNoise();
    input.Contrast();

    var result = new IronTesseract().Read(input);
    return result.Text;
}

// Must throttle to 10 TPS to avoid 429 errors on S1 tier
public class ThrottledAzureBatchProcessor
{
    private readonly ImageAnalysisClient _client;
    // Semaphore limits concurrent Azure calls to stay under 10 TPS
    private readonly SemaphoreSlim _throttle = new SemaphoreSlim(10, 10);

    public async Task<Dictionary<string, string>> ProcessBatchAsync(
        IEnumerable<string> imagePaths)
    {
        var results = new ConcurrentDictionary<string, string>();
        var tasks = imagePaths.Select(async path =>
        {
            await _throttle.WaitAsync();
            try
            {
                using var stream = File.OpenRead(path);
                var data = BinaryData.FromStream(stream);
                var response = await _client.AnalyzeAsync(data, VisualFeatures.Read);

                var text = string.Join("\n",
                    response.Value.Read.Blocks
                        .SelectMany(b => b.Lines)
                        .Select(l => l.Text));

                results[path] = text;

                // Respect 1-second window for the 10 TPS ceiling
                await Task.Delay(100);
            }
            catch (RequestFailedException ex) when (ex.Status == 429)
            {
                // Rate limited despite throttling — back off and retry
                await Task.Delay(2000);
                // Re-queue or log failure — simplified here
                results[path] = string.Empty;
            }
            finally
            {
                _throttle.Release();
            }
        });

        await Task.WhenAll(tasks);
        return new Dictionary<string, string>(results);
    }
}

// Must throttle to 10 TPS to avoid 429 errors on S1 tier
public class ThrottledAzureBatchProcessor
{
    private readonly ImageAnalysisClient _client;
    // Semaphore limits concurrent Azure calls to stay under 10 TPS
    private readonly SemaphoreSlim _throttle = new SemaphoreSlim(10, 10);

    public async Task<Dictionary<string, string>> ProcessBatchAsync(
        IEnumerable<string> imagePaths)
    {
        var results = new ConcurrentDictionary<string, string>();
        var tasks = imagePaths.Select(async path =>
        {
            await _throttle.WaitAsync();
            try
            {
                using var stream = File.OpenRead(path);
                var data = BinaryData.FromStream(stream);
                var response = await _client.AnalyzeAsync(data, VisualFeatures.Read);

                var text = string.Join("\n",
                    response.Value.Read.Blocks
                        .SelectMany(b => b.Lines)
                        .Select(l => l.Text));

                results[path] = text;

                // Respect 1-second window for the 10 TPS ceiling
                await Task.Delay(100);
            }
            catch (RequestFailedException ex) when (ex.Status == 429)
            {
                // Rate limited despite throttling — back off and retry
                await Task.Delay(2000);
                // Re-queue or log failure — simplified here
                results[path] = string.Empty;
            }
            finally
            {
                _throttle.Release();
            }
        });

        await Task.WhenAll(tasks);
        return new Dictionary<string, string>(results);
    }
}

// Non rate limiting needed — throughput is hardware-bound
public Dictionary<string, string> ProcessBatch(IEnumerable<string> imagePaths)
{
    var results = new ConcurrentDictionary<string, string>();

    Parallel.ForEach(imagePaths, imagePath =>
    {
        // Each thread gets its own IronTesseract instance — fully thread-safe
        var ocr = new IronTesseract();
        var result = ocr.Read(imagePath);
        results[imagePath] = result.Text;
    });

    return new Dictionary<string, string>(results);
}

// With controlled parallelism for memory-constrained environments
public Dictionary<string, string> ProcessBatchControlled(
    IEnumerable<string> imagePaths, int maxDegreeOfParallelism = 4)
{
    var results = new ConcurrentDictionary<string, string>();
    var options = new ParallelOptions { MaxDegreeOfParallelism = maxDegreeOfParallelism };

    Parallel.ForEach(imagePaths, options, imagePath =>
    {
        var ocr = new IronTesseract();
        var result = ocr.Read(imagePath);
        results[imagePath] = result.Text;
    });

    return new Dictionary<string, string>(results);
}

// Non rate limiting needed — throughput is hardware-bound
public Dictionary<string, string> ProcessBatch(IEnumerable<string> imagePaths)
{
    var results = new ConcurrentDictionary<string, string>();

    Parallel.ForEach(imagePaths, imagePath =>
    {
        // Each thread gets its own IronTesseract instance — fully thread-safe
        var ocr = new IronTesseract();
        var result = ocr.Read(imagePath);
        results[imagePath] = result.Text;
    });

    return new Dictionary<string, string>(results);
}

// With controlled parallelism for memory-constrained environments
public Dictionary<string, string> ProcessBatchControlled(
    IEnumerable<string> imagePaths, int maxDegreeOfParallelism = 4)
{
    var results = new ConcurrentDictionary<string, string>();
    var options = new ParallelOptions { MaxDegreeOfParallelism = maxDegreeOfParallelism };

    Parallel.ForEach(imagePaths, options, imagePath =>
    {
        var ocr = new IronTesseract();
        var result = ocr.Read(imagePath);
        results[imagePath] = result.Text;
    });

    return new Dictionary<string, string>(results);
}

// Non client-side preprocessing API — must preprocess externally before upload
public async Task<string> ExtractFromLowQualityScanAsync(string imagePath)
{
    // Option 1: Accept whatever Azure returns (may be empty or low-quality)
    using var stream = File.OpenRead(imagePath);
    var imageData = BinaryData.FromStream(stream);

    var result = await _client.AnalyzeAsync(imageData, VisualFeatures.Read);

    // Non way to know if the server applied enhancement
    // Non confidence on the overall result — only per-word
    var text = string.Join("\n",
        result.Value.Read.Blocks
            .SelectMany(b => b.Lines)
            .Select(l => l.Text));

    if (string.IsNullOrWhiteSpace(text))
    {
        // Option 2: Apply external preprocessing using System.Drawing, SkiaSharp,
        // or ImageMagick, re-serialize to stream, re-upload — second billable transaction
        throw new Exception("Azure returned empty result; manual preprocessing needed");
    }

    return text;
}

// Non client-side preprocessing API — must preprocess externally before upload
public async Task<string> ExtractFromLowQualityScanAsync(string imagePath)
{
    // Option 1: Accept whatever Azure returns (may be empty or low-quality)
    using var stream = File.OpenRead(imagePath);
    var imageData = BinaryData.FromStream(stream);

    var result = await _client.AnalyzeAsync(imageData, VisualFeatures.Read);

    // Non way to know if the server applied enhancement
    // Non confidence on the overall result — only per-word
    var text = string.Join("\n",
        result.Value.Read.Blocks
            .SelectMany(b => b.Lines)
            .Select(l => l.Text));

    if (string.IsNullOrWhiteSpace(text))
    {
        // Option 2: Apply external preprocessing using System.Drawing, SkiaSharp,
        // or ImageMagick, re-serialize to stream, re-upload — second billable transaction
        throw new Exception("Azure returned empty result; manual preprocessing needed");
    }

    return text;
}

// Preprocessing is part of the same call — no re-upload, no second transaction
public string ExtractFromLowQualityScan(string imagePath)
{
    using var input = new OcrInput();
    input.LoadImage(imagePath);

    // Correct common scanning defects before OCR
    input.Deskew();           // Fix rotated documents
    input.DeNoise();          // Remove scanner noise
    input.Contrast();         // Improve contrast for faded documents
    input.Binarize();         // Convert to black and white

    var ocr = new IronTesseract();
    var result = ocr.Read(input);

    Console.WriteLine($"Confidence after preprocessing: {result.Confidence:F1}%");
    return result.Text;
}

// For severely degraded documents
public string ExtractFromDegradedDocument(string imagePath)
{
    using var input = new OcrInput();
    input.LoadImage(imagePath);
    input.DeepCleanBackgroundNoise();  // Deep learning-based noise removal
    input.Deskew();
    input.Scale(150);                  // Upscale for better character resolution

    var result = new IronTesseract().Read(input);
    return result.Text;
}

// Preprocessing is part of the same call — no re-upload, no second transaction
public string ExtractFromLowQualityScan(string imagePath)
{
    using var input = new OcrInput();
    input.LoadImage(imagePath);

    // Correct common scanning defects before OCR
    input.Deskew();           // Fix rotated documents
    input.DeNoise();          // Remove scanner noise
    input.Contrast();         // Improve contrast for faded documents
    input.Binarize();         // Convert to black and white

    var ocr = new IronTesseract();
    var result = ocr.Read(input);

    Console.WriteLine($"Confidence after preprocessing: {result.Confidence:F1}%");
    return result.Text;
}

// For severely degraded documents
public string ExtractFromDegradedDocument(string imagePath)
{
    using var input = new OcrInput();
    input.LoadImage(imagePath);
    input.DeepCleanBackgroundNoise();  // Deep learning-based noise removal
    input.Deskew();
    input.Scale(150);                  // Upscale for better character resolution

    var result = new IronTesseract().Read(input);
    return result.Text;
}

// Existing interface — do not change it
public interface IOcrService
{
    Task<string> ReadAsync(string imagePath);
}

// New IronOCR implementation — fulfills the contract
public class IronOcrService : IOcrService
{
    private readonly IronTesseract _ocr;

    public IronOcrService(IronTesseract ocr) => _ocr = ocr;

    public Task<string> ReadAsync(string imagePath)
    {
        // Task.Run offloads to thread pool — no await chain needed
        return Task.Run(() => _ocr.Read(imagePath).Text);
    }
}

// Existing interface — do not change it
public interface IOcrService
{
    Task<string> ReadAsync(string imagePath);
}

// New IronOCR implementation — fulfills the contract
public class IronOcrService : IOcrService
{
    private readonly IronTesseract _ocr;

    public IronOcrService(IronTesseract ocr) => _ocr = ocr;

    public Task<string> ReadAsync(string imagePath)
    {
        // Task.Run offloads to thread pool — no await chain needed
        return Task.Run(() => _ocr.Read(imagePath).Text);
    }
}

// Before: Azure threshold (0.0 - 1.0 scale)
var highConfidenceWords = azureWords
    .Where(w => w.Confidence > 0.85f)
    .Select(w => w.Text);

// After: IronOCR threshold (0 - 100 scale)
var result = new IronTesseract().Read(imagePath);
var highConfidenceWords = result.Words
    .Where(w => w.Confidence > 85.0)
    .Select(w => w.Text);

// Overall document confidence — also on 0-100 scale
if (result.Confidence < 70.0)
{
    // Document may need preprocessing or manual review
}

// Before: Azure threshold (0.0 - 1.0 scale)
var highConfidenceWords = azureWords
    .Where(w => w.Confidence > 0.85f)
    .Select(w => w.Text);

// After: IronOCR threshold (0 - 100 scale)
var result = new IronTesseract().Read(imagePath);
var highConfidenceWords = result.Words
    .Where(w => w.Confidence > 85.0)
    .Select(w => w.Text);

// Overall document confidence — also on 0-100 scale
if (result.Confidence < 70.0)
{
    // Document may need preprocessing or manual review
}

var ocr = new IronTesseract();

// Define extraction zones for a known invoice template
var headerZone    = new CropRectangle(50,  40,  400, 60);
var totalZone     = new CropRectangle(350, 600, 250, 50);
var dateZone      = new CropRectangle(400, 100, 200, 40);

string header, total, date;

using (var input = new OcrInput())
{
    input.LoadImage("invoice.jpg", headerZone);
    header = ocr.Read(input).Text.Trim();
}

using (var input = new OcrInput())
{
    input.LoadImage("invoice.jpg", totalZone);
    total = ocr.Read(input).Text.Trim();
}

using (var input = new OcrInput())
{
    input.LoadImage("invoice.jpg", dateZone);
    date = ocr.Read(input).Text.Trim();
}

var ocr = new IronTesseract();

// Define extraction zones for a known invoice template
var headerZone    = new CropRectangle(50,  40,  400, 60);
var totalZone     = new CropRectangle(350, 600, 250, 50);
var dateZone      = new CropRectangle(400, 100, 200, 40);

string header, total, date;

using (var input = new OcrInput())
{
    input.LoadImage("invoice.jpg", headerZone);
    header = ocr.Read(input).Text.Trim();
}

using (var input = new OcrInput())
{
    input.LoadImage("invoice.jpg", totalZone);
    total = ocr.Read(input).Text.Trim();
}

using (var input = new OcrInput())
{
    input.LoadImage("invoice.jpg", dateZone);
    date = ocr.Read(input).Text.Trim();
}

var result = new IronTesseract().Read("document.jpg");

// Write hOCR file — recognized by most document analysis tools
result.SaveAsHocrFile("document.hocr");

// Searchable PDF — alternative for archive and search indexing workflows
result.SaveAsSearchablePdf("document-searchable.pdf");

var result = new IronTesseract().Read("document.jpg");

// Write hOCR file — recognized by most document analysis tools
result.SaveAsHocrFile("document.hocr");

// Searchable PDF — alternative for archive and search indexing workflows
result.SaveAsSearchablePdf("document-searchable.pdf");

# Remove only the OCR-related Azure packages
dotnet remove package Azure.AI.Vision.ImageAnalysis
dotnet remove package Azure.AI.FormRecognizer

# Verify remaining Azure packages have no new conflicts
dotnet restore
dotnet build

# Remove only the OCR-related Azure packages
dotnet remove package Azure.AI.Vision.ImageAnalysis
dotnet remove package Azure.AI.FormRecognizer

# Verify remaining Azure packages have no new conflicts
dotnet restore
dotnet build

using var input = new OcrInput();
input.LoadImage("low-quality-scan.jpg");
input.Deskew();
input.DeNoise();
input.Scale(200);       // Upscale to improve character resolution
input.Contrast();
input.Sharpen();

var result = new IronTesseract().Read(input);
Console.WriteLine($"Extraction confidence: {result.Confidence:F1}%");

using var input = new OcrInput();
input.LoadImage("low-quality-scan.jpg");
input.Deskew();
input.DeNoise();
input.Scale(200);       // Upscale to improve character resolution
input.Contrast();
input.Sharpen();

var result = new IronTesseract().Read(input);
Console.WriteLine($"Extraction confidence: {result.Confidence:F1}%");

# Find all Azure OCR-related using statements
grep -r "Azure.AI.Vision.ImageAnalysis" --include="*.cs" .
grep -r "Azure.AI.FormRecognizer" --include="*.cs" .
grep -r "ImageAnalysisClient" --include="*.cs" .
grep -r "DocumentAnalysisClient" --include="*.cs" .
grep -r "AnalyzeAsync" --include="*.cs" .
grep -r "AnalyzeDocumentAsync" --include="*.cs" .
grep -r "VisualFeatures.Read" --include="*.cs" .
grep -r "WaitUntil.Completed" --include="*.cs" .
grep -r "UpdateStatusAsync" --include="*.cs" .
grep -r "AzureKeyCredential" --include="*.cs" .

# Find all Azure OCR-related using statements
grep -r "Azure.AI.Vision.ImageAnalysis" --include="*.cs" .
grep -r "Azure.AI.FormRecognizer" --include="*.cs" .
grep -r "ImageAnalysisClient" --include="*.cs" .
grep -r "DocumentAnalysisClient" --include="*.cs" .
grep -r "AnalyzeAsync" --include="*.cs" .
grep -r "AnalyzeDocumentAsync" --include="*.cs" .
grep -r "VisualFeatures.Read" --include="*.cs" .
grep -r "WaitUntil.Completed" --include="*.cs" .
grep -r "UpdateStatusAsync" --include="*.cs" .
grep -r "AzureKeyCredential" --include="*.cs" .

grep -r "cognitiveservices.azure.com" --include="*.json" .
grep -r "AzureComputerVision\|FormRecognizer" --include="*.json" .
grep -r "ComputerVision\|FormRecognizer" --include="appsettings*.json" .

grep -r "cognitiveservices.azure.com" --include="*.json" .
grep -r "AzureComputerVision\|FormRecognizer" --include="*.json" .
grep -r "ComputerVision\|FormRecognizer" --include="appsettings*.json" .