PDF Data Extraction and Storage in SQL with OCR and Password Removal

Overview
This project aims to develop a comprehensive C# application that can read PDF files from a specified location, extract data, implement OCR techniques for image-based files, remove password protection, and store the extracted data in an SQL database. A Web API will be created to facilitate these activities.

Objectives

Read PDF files from a specific location
Extract data from PDF files
Implement OCR techniques for image-based PDFs
Remove password protection from PDF files
Store extracted data in an SQL database
Develop a Web API to perform these activities
Implement a user authentication and authorization system for the Web API
Create logging and error handling mechanisms
Develop a monitoring system for the application
Required Libraries and Tools
Visual Studio 2019 or later
.NET Core 3.1 or later
iText 7 for .NET (PDF processing)
Tesseract OCR (OCR processing)
Microsoft.EntityFrameworkCore (Entity Framework Core for SQL)
Microsoft.AspNetCore.Mvc (Web API)
Microsoft.Extensions.Logging (Logging)
Microsoft.Extensions.Diagnostics.HealthChecks (Health monitoring)
IdentityServer4 (Authentication and Authorization)
Project Structure
4.1. PDFDataExtractor

Program.cs
App.config
4.2. PDFDataExtractor.Models

PdfFile.cs
ExtractedData.cs
ApplicationUser.cs
4.3. PDFDataExtractor.Services

IPdfService.cs
PdfService.cs
IOcrService.cs
OcrService.cs
IDataStorageService.cs
DataStorageService.cs
IUserService.cs
UserService.cs
4.4. PDFDataExtractor.WebAPI

Startup.cs
Controllers
PdfController.cs
UsersController.cs
Implementation Steps
5.1. Read PDF files from a specific location

Implement a method that reads PDF files from a specified location using iText 7.
5.2. Extract data from PDF files

Implement a method to extract text from PDF files using iText 7.
5.3. Implement OCR techniques for image-based PDFs

Implement a method to recognize text from image-based PDF files using Tesseract OCR.
5.4. Remove password protection from PDF files

Implement a method to remove password protection from PDF files using iText 7.
5.5. Store extracted data in an SQL database

Use Entity Framework Core to store the extracted data in an SQL database.
5.6. Develop a Web API to perform these activities

Create a Web API using .NET Core and expose endpoints to perform the data extraction and storage process.
5.7. Implement a user authentication and authorization system for the Web API

Use IdentityServer4 to create an authentication and authorization system for the Web API.
5.8. Create logging and error handling mechanisms

Implement logging using Microsoft.Extensions.Logging and create custom error handling middleware.
5.9. Develop a monitoring system for the application

Implement health checks using Microsoft.Extensions.Diagnostics.HealthChecks.
Testing
Unit tests for service classes
Integration tests for Web API endpoints
Load testing for the application
Deployment
Deploy the Web API to a hosting provider (e.g., Azure, AWS, or Heroku)
Implement CI/CD pipelines using Azure DevOps, GitHub Actions, or other similar tools
Documentation
Write comprehensive documentation for the project, including how to use the Web API, any limitations, and authentication/authorization details.