distance-transform

distance-transform

Distance transforms for Lp metrics on binary ndarrays. This code is based on Meijster's algorithm. For more information see:

• https://github.com/parmanoir/Meijster-distance
• http://dissertations.ub.rug.nl/FILES/faculties/science/2004/a.meijster/c2.pdf

Example

//Generate some shape as a binary voxel image
var x = require("zeros")([256, 256])
x.set(128, 128, 1)

//Distance transform x in the Euclidean metric
require("distance-transform")(x)

//Save result
require("save-pixels")(x, "png").pipe(process.stdout)

Output

Install

Install using npm:

npm install distance-transform

API

require("distance-transform")(array[, p])

Performs a distance transform of array in place using Meijster's algorithm.

• array is the array to transform
• p is the exponent for the metric. (Default 2)

For different values of p you get different transforms

• p = 1 gives the Manhattan/taxicab distance metric
• p = 2 gives the Euclidean distance metric
• p = Infinity gives the Chebyshev/chessboard distance metric
• Other values of p give various interpolants

array is updated in place and gets the distance values.

License

(c) 2013 Mikola Lysenko. MIT License.