icojs

A JavaScript library to use ICO. Works on both Node.js and the browser.

Install

npm install icojs

Node.js:

import { isICO, parseICO } from 'icojs';

Browser:

import { isICO, parseICO } from 'icojs/browser';

or

<script type="text/javascript" src="node_modules/icojs/dist/ico.js"></script>

To fully use this library, browsers must support JavaScript typed arrays, Canvas API and Promise. Chrome, Edge 12, Firefox and Safari 9 support these functions.

Example

Node.js:

import { readFile, writeFile } from 'node:fs/promises';
import { parseICO } from 'icojs';

const buffer = await readFile('favicon.ico');
const images = await parseICO(buffer, 'image/png');
// save as png files
images.forEach(image => {
  const file = `${image.width}x${image.height}-${image.bpp}bit.png`;
  const data = Buffer.from(image.buffer);
  writeFile(file, data);
});

Browser:

<input type="file" id="input-file" />
<script>
  document.getElementById('input-file').addEventListener('change', evt => {
    // use FileReader for converting File object to ArrayBuffer object
    var reader = new FileReader();
    reader.onload = async e => {
      const images = await ICO.parseICO(e.target.result);
      // logs images
      console.dir(images);
    };
    reader.readAsArrayBuffer(evt.target.files[0]);
  }, false);
</script>

Demo

https://egy186.github.io/icojs/#demo

API

ICO

• ICO
  • isICO(source) ⇒ boolean ⏏
  • parseICO(buffer, [mime]) ⇒ Promise.<Array.<ParsedImage>> ⏏

isICO(source) ⇒ boolean ⏏

Check the ArrayBuffer is valid ICO.

Kind: global method of ICO
Returns: boolean - True if arg is ICO.

| Param | Type | Description | | --- | --- | --- | | source | ArrayBuffer | Buffer | ICO file data. |

parseICO(buffer, [mime]) ⇒ Promise.<Array.<ParsedImage>> ⏏

Parse ICO and return some images.

Kind: global method of ICO
Returns: Promise.<Array.<ParsedImage>> - Resolves to an array of ParsedImage.

| Param | Type | Default | Description | | --- | --- | --- | --- | | buffer | ArrayBuffer | Buffer | | ICO file data. | | [mime] | string | "image/png" | MIME type for output. |

Typedefs

ParsedImage : object

Kind: global typedef
Properties

| Name | Type | Description | | --- | --- | --- | | width | number | Image width. | | height | number | Image height. | | bpp | number | Image color depth as bits per pixel. | | buffer | ArrayBuffer | Image buffer. |

License

MIT license