Smart Fill Segmentation for Expo & React Native

A high-performance React Native / Expo Native Module for "Smart Region Filling" (flood fill based image segmentation).

Ever wanted a "magic wand" tool or "paint bucket fill" that constraints shapes within an image? This module provides exactly that. It runs an optimized native algorithm directly on the device memory to process complex images and generate scalable SVG path masks in milliseconds.

Features

• True Native Implementation: Written in Kotlin with memory-safe coroutine concurrency via Dispatchers.Default.
• Intelligent Edge Tracing: Uses flood filling and Moore-Neighbor edge tracking to export the closed boundary of an object automatically.
• Expo Friendly: Operates as a pure Expo plugin. Easy to drop into any managed workflow app!
• Works offline: Does not require hefty AI models. It runs purely on mathematical pixel similarity calculation.

Installation

npm install architram-smart-fill-segmentation

Quick Start

import { getSmartFillMask } from "architram-smart-fill-segmentation";
import type { SmartFillConfig } from "architram-smart-fill-segmentation";

async function handleTapOnImage(x: number, y: number, imageLocalUri: string) {
  try {
    const config: SmartFillConfig = {
      imageUri: imageLocalUri, // Must be a local `file://` URI
      startX: Math.floor(x),   // X pixel coordinate of touch point against origin image resolution
      startY: Math.floor(y),   // Y pixel coordinate of touch point against origin image resolution
      tolerance: 20            // Default is 20, up it for wider selection (0-255).
    };
    
    // Returns a raw SVG path string "M 10 10 L ... Z"
    const svgPathMask = await getSmartFillMask(config);
    
    console.log("Segment Boundary Path:", svgPathMask);
  } catch (error) {
    console.error("Failed to generate segmentation mask.", error);
  }
}

API

getSmartFillMask(config: SmartFillConfig): Promise<string>

Returns a Promise that yields a calculated SVG path <Path d="..." /> string for the connected color region clicked upon. If no valid path was found, it returns "" empty string.

SmartFillConfig Configuration

| Property | Type | Required | Description | | --------- | -------- | -------- | ------------------------------------------------------------ | | imageUri| string | Yes | Internal file:/// location of the fully downloaded image. | | startX | number | Yes | The x coordinate starting seed pixel (unzoomed image coord). | | startY | number | Yes | The y coordinate starting seed pixel (unzoomed image coord). | | tolerance| number | Optional | Color variance threshold integer value (0 - 255). 20 Default.|

Use-cases

• Interactive Coloring Book constraints.
• Background removal (invert selection path mask).
• Smart touch magic wand tooling.

Support & Contributions

Feel free to open an issue or pull request!