Image Converter

A command-line tool for converting images between JPG, PNG and WebP.

Image Converter is a simple .NET CLI project to practice good OOP principles.

It is a first attempt at creating a useful CLI tool with .NET. It will serve as a foundation for a more advance project in the future.

The program places special focus on extensibility, allowing developers to add new menu options and image formats without modifying the existing code.

To add a new image format see Adding a new image format. To add a new menu option see Adding a new menu option.

Technology

• .NET 10 with C#
• ImageSharp to read and convert the images
• Spectre.Console for the CLI menus
• YoloDotNet to run the YOLO11s classification model from Ultralytics

Features

• Convert one image. You can browse your system for an image file and convert it to a chosen format.
• Convert all images in a folder. Browse your system for a folder and convert all images in it to a chosen format.
• AI naming. Uses an image classification model to tag your converted images with contextual information. For example, dog.jpg converted to WebP gets saved as dog-golden-retriever.webp (provided there is a golden retriever in the image!).
• Show image stats. Choose a folder to see stats of all images within it.

Settings

The app saves its settings in a file settings.json inside a folder in your application data folder. Use Settings in the menu to see or change them.

OS	Path
Windows	%APPDATA%\ImageConverter\settings.json
Linux	~/.config/ImageConverter/settings.json
Mac	~/Library/Application Support/ImageConverter/settings.json

Local development

You need the .NET 10 SDK.

To run the app:

dotnet run --project src/ImageConverter.Cli

To create a build:

dotnet build

The app is built as imgconv in src/ImageConverter.Cli/bin/.

Adding a new image format

Each format is a subclass of FormatConverter.

To add a format:

1. Add the format to ImageFormat.
2. Create a new converter in src/ImageConverter.Core/Models/Converters/ that inherits from FormatConverter.
3. Register the converter in ServiceCollectionExtensions.cs with services.AddSingleton<FormatConverter, YourConverter>().

Adding a new menu option

Each menu option is a class that implements IMenuOption.

To add a menu option:

1. Create a new class in src/ImageConverter.Cli/Options/ that implements IMenuOption.
2. Set DisplayText to the text shown in the menu, and put the option's logic in Run().
3. Register the class in ServiceCollectionExtensions.cs with services.AddSingleton<IMenuOption, YourOption>().

Options appear in the menu in the order they are registered, so add yours before MenuExit.

Limitations and opportunities for improvement

• Converting a folder does not include its subfolders, and it's not clear to the user if it will
• The app needs to facilitate adding settings to all image encoders
• AI functionality is very basic at the moment. Labels are not specific enough to truly be useful

License

See LICENSE.