Skeleton Tracing WASM

by Lingdong Huang

Usage

<script src="https://cdn.jsdelivr.net/npm/skeleton-tracing-wasm/build/trace_skeleton_wasm.js"></script>

const TraceSkeleton = require('skeleton-tracing-wasm')
 
import TraceSkeleton  from 'skeleton-tracing-wasm'

You first need to initiate/load the wasm module calling a static method load()

const tracer = await TraceSkeleton.load()

then you can use the API methods

 
const { polylines,rects } = tracer.fromCanvas(HTMLCANVAS)
 

Or instead of async/await you can do

 
TraceSkeleton.load().then(tracer => {
    // wasm module loaded
    // here is your code 
    const { polylines,rects } = tracer.fromCanvas(HTMLCANVAS)
 
})
 

The below API's take an image representation and returns an object holding the polylines as well as rects processed by the algorithm (the latter is mainly for visualization)

{
    "polylines": [[[x,y],[x,y]],[[x,y],[x,y],[x,y],...],...],
    "rects":     [[x,y,w,h],[x,y,w,h],...]
}

TraceSkeleton.fromCanvas(canv)

Takes in an HTML Canvas object and returns the skeleton as polyilnes as well as the rects.

TraceSkeleton.fromImageData(imgData)

Takes JavaScript ImageData object (e.g. document.createElement("canvas").getContext('2d').getImageData(0,0,100,100))

TraceSkeleton.fromBoolArray(arr,w,h)

Takes array of booleans (or truthy and falsy values), e.g. [0,1,0,1,1,1,0,0,...] or [0,255,255,0,...] or [true,false,true,false,...] or even [undefined, "ok", null, "yes", ...]

TraceSkeleton.fromCharString(str,w,h)

Takes in a (char*) such as "\0\1\0\0\1\1\0....". This is the fastest (though probably most obscure) API because it does not need to translate the input to C constructs.

TraceSkeleton.visualize(result, {scale, strokeWidth, rects, keypoints})

Conveniently visualize the result from the previous functions, returns a string holding an SVG (scalable vector graphics).

Options:

• scale: factor to scale the drawing
• rects: draw the rects?
• keypoints: draw the keypoints on the polylines?
• strokeWidth: weight of the polyline strokes.

See /index.html for more detailed usage example, with animation, interactivity, webcam, etc.

More info at

Github Original Project

https://skeleton-tracing.netlify.app/

Developed at Frank-Ratchye STUDIO for Creative Inquiry at Carnegie Mellon University.