FieldCure.DocumentParsers.Pdf.Ocr 1.0.1

.NET 8.0 This package targets .NET 8.0. The package is compatible with this framework or higher.
Suggested Alternatives

FieldCure.DocumentParsers.Ocr 1.0.0

Additional Details

Renamed to FieldCure.DocumentParsers.Ocr 1.0. Same functionality, new namespace FieldCure.DocumentParsers.Ocr.*; AddPdfOcrSupport() → AddOcrSupport(). Windows only.

dotnet add package FieldCure.DocumentParsers.Pdf.Ocr --version 1.0.1
                    


                    

                
NuGet\Install-Package FieldCure.DocumentParsers.Pdf.Ocr -Version 1.0.1
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package. 
<PackageReference Include="FieldCure.DocumentParsers.Pdf.Ocr" Version="1.0.1" />
For projects that support PackageReference, copy this XML node into the project file to reference the package. 
<PackageVersion Include="FieldCure.DocumentParsers.Pdf.Ocr" Version="1.0.1" />
                    


                            Directory.Packages.props
                        

                    

                
<PackageReference Include="FieldCure.DocumentParsers.Pdf.Ocr" />
                    


                            Project file
For projects that support Central Package Management (CPM), copy this XML node into the solution Directory.Packages.props file to version the package. 
paket add FieldCure.DocumentParsers.Pdf.Ocr --version 1.0.1
                    


                    

                
#r "nuget: FieldCure.DocumentParsers.Pdf.Ocr, 1.0.1"
#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package. 
#:package FieldCure.DocumentParsers.Pdf.Ocr@1.0.1
#:package directive can be used in C# file-based apps starting in .NET 10 preview 4. Copy this into a .cs file before any lines of code to reference the package. 
#addin nuget:?package=FieldCure.DocumentParsers.Pdf.Ocr&version=1.0.1
                    


                            Install as a Cake Addin
                        

                    

                
#tool nuget:?package=FieldCure.DocumentParsers.Pdf.Ocr&version=1.0.1
                    


                            Install as a Cake Tool

FieldCure.DocumentParsers.Pdf.Ocr

Tesseract OCR fallback for scanned PDFs in FieldCure.DocumentParsers.Pdf.

Quick Start

using FieldCure.DocumentParsers.Pdf.Ocr;

// Register PDF parser with OCR fallback (call once at startup)
using var ocrEngine = DocumentParserFactoryOcrExtensions.AddPdfOcrSupport();

// Use as usual — scanned pages are automatically OCR'd
var parser = DocumentParserFactory.GetParser(".pdf")!;
var text = parser.ExtractText(File.ReadAllBytes("scanned.pdf"));

How It Works

  1. Text extraction is attempted via PdfPig (same as the base PDF package).
  2. If a page yields no meaningful text (< 5% non-whitespace or < 10 chars), it is rendered at 300 DPI.
  3. The rendered image is processed by Tesseract OCR.
  4. Korean text is post-processed to remove spurious inter-character spaces.

Included Languages

  • English (eng.traineddata)
  • Korean (kor.traineddata)

Languages are auto-discovered from embedded traineddata files.

Thread Safety

Uses an engine pool (default size: min(ProcessorCount, 4)) for concurrent OCR processing.

Product Compatible and additional computed target framework versions.
.NET net8.0 is compatible.  net8.0-android was computed.  net8.0-browser was computed.  net8.0-ios was computed.  net8.0-maccatalyst was computed.  net8.0-macos was computed.  net8.0-tvos was computed.  net8.0-windows was computed.  net9.0 was computed.  net9.0-android was computed.  net9.0-browser was computed.  net9.0-ios was computed.  net9.0-maccatalyst was computed.  net9.0-macos was computed.  net9.0-tvos was computed.  net9.0-windows was computed.  net10.0 was computed.  net10.0-android was computed.  net10.0-browser was computed.  net10.0-ios was computed.  net10.0-maccatalyst was computed.  net10.0-macos was computed.  net10.0-tvos was computed.  net10.0-windows was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.

NuGet packages

This package is not used by any NuGet packages.

GitHub repositories

This package is not used by any popular GitHub repositories.

Version Downloads Last Updated
1.0.1 155 4/8/2026 1.0.1 is deprecated because it is no longer maintained.
1.0.0 130 4/8/2026 1.0.0 is deprecated because it is no longer maintained.

# Release Notes — FieldCure.DocumentParsers.Pdf.Ocr

## [1.0.1] - 2026-04-08

### Fixed
- Tesseract native DLLs (`leptonica-1.82.0.dll`, `tesseract50.dll`) now included in NuGet package with `build/` and `buildTransitive/` targets, fixing `DllNotFoundException` in `PackAsTool` consumers (e.g., MCP servers)

## [1.0.0] - 2026-04-08

### Added
- `TesseractOcrEngine` — Tesseract OCR fallback for scanned PDFs with no text layer
- Embedded traineddata (tessdata_fast): English + Korean
- Automatic language discovery from tessdata directory
- Korean post-processing: removes spurious inter-character spaces from Tesseract output
- Engine pool via `ConcurrentBag` + `SemaphoreSlim` for concurrent OCR (default: `min(ProcessorCount, 4)`)
- `DocumentParserFactoryOcrExtensions.AddPdfOcrSupport()` — one-line factory registration with OCR