ndarray-warp

Inverse image warping operations for ndarrays.

Example

//Load input image
var lena = require("luminance")(require("lena"))

//Allocate storage for result
var result = require("zeros")([512, 512])

//Apply warp
require("ndarray-warp")(result, lena, function(out, inp) {
  var dx = inp[0] - 256
  var dy = inp[1] - 256
  var r  = Math.sqrt(dx * dx + dy * dy)
  var theta = Math.atan2(dy, dx)
  
  out[0] = 0.9 * r * Math.cos(theta + 0.01 * r) + 256
  out[1] = 0.7 * r * Math.sin(theta + 0.01 * r) + 256
})

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

Which produces the following image:

Install

npm install ndarray-warp

require("ndarray-warp")(output, input, map(out_coord, in_coord))

Applies an inverse warp to an image

• output is an ndarray image that gets the result of applying the warp

• input is an ndarray iamge that is warped

• map(result, coord) is a mapping from the coordinates of out image to input image.

  • result gets the resulting coordinate in input
  • coord is the coordinate in output

Credits

(c) 2013 Mikola Lysenko. MIT License