wcslight

WCSLight is a TypeScript library designed to manipulate data projections in standard FITS format and implements the standard WCS functions pix2world and world2pix. It offers a cutout functionality on single FITS files and entire HiPS, using parameters in input such as central Right Ascension (RA) and Declination (Dec), pixel size, radius, and the desired output projection (Cartesian or HiPS). Future updates will include additional projections.

Licensing

wcslight is dual-licensed under:

• the GNU Affero General Public License version 3 (AGPL-3.0); or
• a separate commercial license.

The AGPL-3.0 option is open source and permits both commercial and non-commercial use, subject to its terms.

The commercial license is an alternative for organizations that need to use wcslight in proprietary products, closed-source services, or other contexts where the AGPL-3.0 requirements are not suitable.

See:

• LICENSE.md for an overview of the dual-license model
• LICENSE-AGPL.md for the complete AGPL-3.0 license text
• LICENSE-COMMERCIAL.md for commercial licensing information

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Known limitations:

At the moment tested with HiPS tiles of 512x512. With other tile size it might fail.

How to use the generated library available in Nodejs repository

Include the following dependency into package.json file in your project:

"dependencies": {
        "wcslight": "^1.0.19"
    },

Installing as Javascript external file in a web page

Download the file "wcslight.js" under _bundle directory and include it in your web page.

Deployment as Node module

• Prerequisites: Node.js v<=16 (see installation instructions)

• Clone repo:

git clone https://github.com/fab77/wcslight.git

• Move into the wcslight folder:

cd wcslight

• Install the required dev modules:

npm i

• Compile the project:

npm run start:dev

Using WCSLight in another Node project

import { WCSLight, HiPSProjection, MercatorProjection, Point, CoordsType, NumberType } from 'wcslight';

const hipsBaseUri = "https://skies.esac.esa.int/Herschel/normalized/PACS_hips160/"
const center = {"ra": 306.40, "dec": 40};
const radius = 0.01;
const pxsize = 0.0005;

let inproj = new HiPSProjection(null, hipsBaseUri, null, 8);
let outproj = new MercatorProjection();

WCSLight.cutout(center, radius, pxsize, inproj, outproj).then( (result) => {
    const fitsheader = result.fitsheader;
    console.log(fitsheader);    
    const fitsdata = result.fitsdata;
    const canvas2d = result.canvas2d;
    const img = canvas2d.getCanvas2DBrowse();
    let encodedData = WCSLight.writeFITS(fitsheader, fitsdata, './output/test.fits');

}).catch(function(err){
    console.log(err);
});