transformation-models v1.0.2

Transformation Models

The library can be used for calculating transformation parameters using 2D Affine or Thin Plate Spline (TPS) transformations.

Install

You can install it with NPM (npm install transformation-models) or Yarn (yarn add transformation-models) and then:

import { Affine, TPS } from 'transformation-models';

Affine transformation example

Allows scaling, rotation and translation only and preserves collinearity.

import { Affine } from 'transformation-models';

const sourcePoints = [
  [4734563.812, 8602649.049],
  [4725349.627, 8610759.665],
  [4723443.326, 8616104.954],
  [4721845.431, 8622312.598],
  [4720159.801, 8603248.973],
  [4718040.498, 8608875.072],
  [4716553.179, 8620405.969],
  [4724628.766, 8631596.47],
  [4724538.865, 8629857.48],
  [4751688.217, 8617662.209],
  [4746994.861, 8621675.591],
  [4746480.919, 8608375.672],
  [4741551.591, 8615165.917],
  [4734308.135, 8616623.423],
  [4744231.665, 8630246.732],
  [4736133.859, 8630921.615],
  [4732346.726, 8627234.144]
];
const targetPoints = [
  [4733708.335, 479703.427],
  [4724353.409, 487647.473],
  [4722352.973, 492956.916],
  [4720645.585, 499133.77],
  [4719298.709, 480047.397],
  [4717080.395, 485633.91],
  [4715389.251, 497134.073],
  [4723263.059, 508463.146],
  [4723204.053, 506723.307],
  [4750559.251, 495015.878],
  [4745796.219, 498944.058],
  [4745519.337, 485640.022],
  [4740470.969, 492340.007],
  [4733204.376, 493668.131],
  [4742881.509, 507462.453],
  [4734775.168, 507992.948],
  [4731055.189, 504239.725]
];

const affine = new Affine(sourcePoints, targetPoints);

affine.forward([4734064.359, 8615839.411]);
// result is: [4732974.629, 492880.087]

affine.inverse([4732974.629, 492880.087]);
// result is: [4734064.359, 8615839.411]

TPS transformation example

Can introduce local deformations in the data, but does not preserves collinearity.

import { TPS } from 'transformation-models';

const sourcePoints = [
  [4734563.812, 8602649.049],
  [4725349.627, 8610759.665],
  [4723443.326, 8616104.954],
  [4721845.431, 8622312.598],
  [4720159.801, 8603248.973],
  [4718040.498, 8608875.072],
  [4716553.179, 8620405.969],
  [4724628.766, 8631596.47],
  [4724538.865, 8629857.48],
  [4751688.217, 8617662.209],
  [4746994.861, 8621675.591],
  [4746480.919, 8608375.672],
  [4741551.591, 8615165.917],
  [4734308.135, 8616623.423],
  [4744231.665, 8630246.732],
  [4736133.859, 8630921.615],
  [4732346.726, 8627234.144]
];
const targetPoints = [
  [4733708.335, 479703.427],
  [4724353.409, 487647.473],
  [4722352.973, 492956.916],
  [4720645.585, 499133.77],
  [4719298.709, 480047.397],
  [4717080.395, 485633.91],
  [4715389.251, 497134.073],
  [4723263.059, 508463.146],
  [4723204.053, 506723.307],
  [4750559.251, 495015.878],
  [4745796.219, 498944.058],
  [4745519.337, 485640.022],
  [4740470.969, 492340.007],
  [4733204.376, 493668.131],
  [4742881.509, 507462.453],
  [4734775.168, 507992.948],
  [4731055.189, 504239.725]
];

const tps = new TPS(sourcePoints, targetPoints);

tps.forward([4734064.359, 8615839.411]);
// result is: [4732974.629, 492880.087]

tps.inverse([4732974.629, 492880.087]);
// result is: [4734064.359, 8615839.411]

License

transformation-models is MIT License @ bojko108