Image Contours in Pure C#

Image Contours is a pure C# implementation of the Suzuki-Abe border following algorithm for Unity. It analyzes images and extracts both outer contours and inner holes, including their hierarchical relationships.

In addition to contour detection, the package provides a way to convert contour pixels into pixel-aligned boundary vertices, which can be useful when working with pixel art or grid-based geometry.

This package is intended for developers who need direct access to image shape data for rendering, tooling, or geometry generation.

This package focuses on

• Pure C# implementation: No native plugins or platform-specific dependencies
• Contour hierarchy support: Detects both outer contours and holes, with parent-child relationships
• Pixel boundary reconstruction: Convert contour pixels into corner-based boundary vertices
• Configurable detection behavior: Supports 4-connected and 8-connected neighborhoods
• Flexible foreground definition: Use alpha threshold or provide a custom predicate

Typical Use Cases

• Visualizing outlines of sprites or textures
• Generating boundaries for pixel art assets
• Building editor tools that operate on image shapes
• Preparing data for mesh generation or collision approximation
• Extracting regions for gameplay or AI systems

What's Included

• Core contour detection implementation
• Pixel boundary reconstruction
• Example components for visualization:
• LineRenderer-based drawing
• Pixel-based drawing
• Sample scene with configurable parameters
• Full source code with XML documentation
• NUnit test cases