MarkdownToImageLibrary 1.1.0

Markdown to Image Converter

A .NET application that processes markdown files to extract HTML/CSS sections and converts them to images using wkhtmltoimage.exe.

Features

• Extracts HTML sections from markdown files (content within html blocks)
• Converts each HTML section to a PNG image using wkhtmltoimage
• Handles CSS styles embedded within HTML sections
• Creates complete HTML documents with proper structure
• Saves generated images in an images folder
• Supports multiple HTML sections per markdown file

Prerequisites

1. .NET 8.0 SDK - Download from https://dotnet.microsoft.com/download
2. wkhtmltoimage - Download from https://wkhtmltopdf.org/downloads.html

Installing wkhtmltoimage

1. Download the wkhtmltopdf installer for Windows
2. Install it (default location: C:\Program Files\wkhtmltopdf\bin\wkhtmltoimage.exe)
3. Optionally add the installation directory to your PATH environment variable

Build and Run

1. Restore dependencies:

   dotnet restore
   

2. Build the application:

   dotnet build
   

3. Run the application:

   dotnet run --project MarkdownToImageConverter.csproj sample.md
   

   Or specify the path to wkhtmltoimage.exe if it's not in PATH:

   dotnet run --project MarkdownToImageConverter.csproj sample.md "C:\Program Files\wkhtmltopdf\bin\wkhtmltoimage.exe"
   

4. Check system status:

   dotnet run --project MarkdownToImageConverter.csproj --check
   

Usage

MarkdownToImageConverter <markdown-file-path> [wkhtmltoimage-path]
MarkdownToImageConverter --check

Examples

# Check system status
dotnet run --project MarkdownToImageConverter.csproj --check

# Using wkhtmltoimage from PATH
dotnet run --project MarkdownToImageConverter.csproj example.md

# Specifying wkhtmltoimage path
dotnet run --project MarkdownToImageConverter.csproj example.md "C:\Program Files\wkhtmltopdf\bin\wkhtmltoimage.exe"

Input Format

The application looks for HTML sections in markdown files marked with html code blocks:

# My Document

Some regular markdown content...

## HTML Section

```html
<style>
    .my-class {
        color: blue;
        font-family: Arial;
    }
</style>
<div class="my-class">
    <h1>Hello World</h1>
    <p>This will be converted to an image!</p>
</div>
\```

More markdown content...

Output

• Images are saved in the images folder
• Each HTML section becomes a separate PNG file
• Files are named: {markdown-filename}_section_{number}.png
• Example: sample_section_1.png, sample_section_2.png

How It Works

1. Parse Markdown: Reads the markdown file and extracts all html blocks
2. Process HTML: Creates complete HTML documents with proper structure
3. Extract Styles: Separates CSS styles and HTML content
4. Generate Images: Uses wkhtmltoimage to render HTML to PNG images
5. Save Results: Outputs images to the images folder

Dependencies

• Markdig: For markdown processing
• HtmlAgilityPack: For HTML parsing and manipulation
• wkhtmltoimage: External tool for HTML to image conversion

Error Handling

The application handles various error conditions:

• Missing markdown files
• Invalid HTML content
• wkhtmltoimage execution failures
• File system errors

Sample File

A sample.md file is included that demonstrates the expected input format with working HTML/CSS examples.