PdfReader – PDF Structure Inspector

A lightweight C# console tool for inspecting PDF structure, detecting content, and comparing blank vs. filled PDFs. This tool is especially useful when debugging auto-generated PDFs where content may be invisible or empty.

🚀 Features

Automatically scans all PDF files in the Files/ directory

Prints, for each PDF:

• Total pages
• Text length
• Word & letter count
• Number of images
• Page text content
• Helps you detect PDFs that are effectively “blank”
• No command-line args needed — simple dotnet run
• Uses PdfPig (free & open-source)

📁 Project Structure

PdfReader/
│
├── Files/                   # Put your PDF files here
│   ├── sample1.pdf
│   ├── sample2.pdf
│
├── Program.cs               # Entry point – scans Files/ folder
├── PdfAnalyzer.cs           # Extracts PDF structure information
├── PdfReport.cs             # Formats and prints analysis results
├── PdfReader.csproj
└── README.md

🛠 Requirements

• .NET 8.0 or later

• Windows, Linux, or macOS

• NuGet package: UglyToad.PdfPig

• Install PdfPig:

  dotnet add package UglyToad.PdfPig

📦 Installation

• Restore dependencies:

dotnet restore

Build the project:

dotnet build

📂 Adding PDF Files

Inside the project directory, create a folder named:

• Files

Add any .pdf files you want to analyze:

PdfReader/Files/
    blank.pdf
    document1.pdf
    invoice.pdf

▶️ Running the Project

Run:

dotnet run

The app will:

Automatically detect all PDFs inside Files/

Process each PDF one by one

Print structured reports to the console

Example output:

📁 Found 3 PDF(s) in: .../PdfReader/bin/Debug/net8.0/Files

======================================================
📄 Processing: blank.pdf
======================================================
------------- PAGE 1 -------------
Text Length:   0
Letters Count: 0
Words Count:   0
Images:        0

Text Content:
[NO TEXT]

======================================================
📄 Processing: filled.pdf
======================================================
------------- PAGE 1 -------------
Text Length:   120
Letters Count: 145
Words Count:   18
Images:        1

Text Content:
Patient: John Doe...

⚙️ Ensuring Files/ Folder Is Copied to Output

The Files folder must be included in your build output so the app can find the PDFs when running from bin/.

Your PdfReader.csproj must contain:

<ItemGroup>
  <Content Include="Files\**\*">
    <CopyToOutputDirectory>Always</CopyToOutputDirectory>
  </Content>
</ItemGroup>

This ensures that files are available at runtime under:

bin/Debug/net8.0/Files/

📐 Code Overview PdfAnalyzer.cs

Responsible for analyzing each PDF and building a PdfAnalysisResult with:

Page text

Word count

Letter count

Images count

Example shape (simplified):

public class PdfPageInfo
{
    public int PageNumber { get; set; }
    public string Text { get; set; } = "";
    public int ImagesCount { get; set; }
    public int WordsCount { get; set; }
    public int LettersCount { get; set; }
}

PdfReport.cs

Formats and prints readable console output for each PdfAnalysisResult.

Program.cs

Locates the Files/ folder

Enumerates all *.pdf files

Uses PdfAnalyzer to analyze each PDF

Uses PdfReport to print the results

🧪 Detecting “Blank PDFs” (Optional Helper)

You can add a small helper method to classify a PDF as “basically empty”:

using System.Linq;

bool IsBasicallyEmpty(PdfAnalysisResult pdf)
{
    return pdf.Pages.All(p =>
        string.IsNullOrWhiteSpace(p.Text) &&
        p.ImagesCount == 0 &&
        p.LettersCount == 0 &&
        p.WordsCount == 0
    );
}

You can then call this per file after analysis to quickly decide if the PDF has meaningful content or not.

📈 Possible Future Enhancements

Export analysis results to JSON or CSV

Compare two PDFs side by side

Highlight structural differences between PDFs

Colored console output for better readability

Save reports into a /Reports directory

Heuristics to distinguish scanned-image PDFs vs. digital-text PDFs

📝 License

This project is intended for debugging, testing, and internal development use. You are free to modify or extend it according to your needs.