jsfitsio

v1.1.15

Published

7 months ago

FITS I/O javascript library.

Downloads

0High
0Medium
0Low

fab77

FITS FITS I/O FITS in a browser

jsFITS I/O library

Project available in github at https://github.com/fab77/FITSParser#readme

Library used to handle FITS files as defined in the "Definition of the Flexible Image Transport System (FITS)" document defined by internation Astronomical Union (IAU)

This library is capable to read and write FITS files where the data are represented in the following formats (BITPIX):

8 Character or unsigned binary integer 16 16-bit two’s complement binary integer 32 32-bit two’s complement binary integer 64 64-bit two’s complement binary integer −32 IEEE single-precision floating point −64 IEEE double-precision floating point

Only ImageHDU are supported at the moment.

jsFITS I/O can be used as standalone Node module or integrated in the browser.

Getting Started

Installing as node module

$ npm install jsfitio

Installing as Javascript external file in a web page

Download the file "jfitsio.js" and include it in your web page as below:

Running the tests (still manual)

First compile the code:

$ node start:dev

To test jsfitsio in node:

$ node test/test01.js
$ node test/test02.js

Deployment as Node module

reading FITS file available in the web:

import { FITSParser } from 'jsfitio';

const fileuri = "http://skies.esac.esa.int/Herschel/normalized/PACS_hips160//Norder8/Dir40000/Npix47180.fits";
const fp = new FITSParser(fileuri);
const promise = fp.loadFITS();
promise.then(function (fits) {
    if (fits !== null) {
        console.log(fits === null || fits === void 0 ? void 0 : fits.header);

        console.log(`BITPIX: ${fits.header.get('BITPIX')}`);
        console.log(`NAXIS1: ${fits.header.get('NAXIS1')}`);
        console.log(`NAXIS2: ${fits.header.get('NAXIS2')}`);
        console.log(`payload bytes length ${fits.data.length * fits.data[0].length}`);

    }
    else {
        console.log("Empty data");
    }
});

using FITS available in the local filesystem:

import { FITSParser } from 'jsfitio';
import { FITSHeader } from 'jsfitio';
import { FITSWriter } from 'jsfitio';
import { writeFITS } from 'jsfitio'
import { FITSHeaderItem } from 'jsfitio';

const fileuri: string = "./test/inputs/x0c70103t_c1f.fits";
const fp = new FITSParser(fileuri);
const fitsPromise = fp.loadFITS();
fitsPromise.then( (fitsProcessed) => {
    let fitsHeader = fitsProcessed.header;
    let fitsData = fitsProcessed.data;
    let fw = new FITSWriter();
    fw.run(fits.header, fits.data);
    writeFITS("./MyFITS.fits", fw._fitsData);
});

Deployment as a Javascript library

You need to include "jsfitsio.js" (take it from _bundles directory in git the repo https://github.com/fab77/FITSParser ) file in your HTML page. Below a sample.

<!doctype html>
<html>

<head>
    <meta charset="utf-8" />
    <title>Webpack App</title>
    <base href="."/>
</head>

<body>
    <h1>Hello world!</h1>
    <h2>jsFITS I/O web integration sample</h2>
    <script src="./jsfitsio.js"></script>
    <script>
        let fitsURL = "http://skies.esac.esa.int/Herschel/normalized/PACS_hips160//Norder8/Dir40000/Npix47180.fits"
        let fp = new jsfitsio.FITSParser(fitsURL);
        let promise = fp.loadFITS();
        promise.then( (fits) => {
            if (fits !== null) {
                console.log(fits?.header);
                const blobUrl = jsfitsio.FITSParser.generateFITS(fits.header, fits.data);
                console.log(blobUrl);
            } else {
                console.log("Empty data");
            }
        });
    </script>
</body>

</html>

Built With

Node: v16.17.0 webpack: 5.74.0

Contributing

Versioning

Authors

Fabrizio Giordano

License

This project is licensed under the MIT License - see the LICENSE.md file for details

Acknowledgments

Yago Ascasibar