https://github.com/image-js/fast-png

PNG image decoder and encoder written entirely in JavaScript
https://github.com/image-js/fast-png

hacktoberfest image image-decoder image-encoder javascript nodejs png

Last synced: about 2 months ago
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PNG image decoder and encoder written entirely in JavaScript

• Host: GitHub
• URL: https://github.com/image-js/fast-png
• Owner: image-js
• License: mit
• Created: 2015-09-24T07:57:54.000Z (almost 9 years ago)
• Default Branch: main
• Last Pushed: 2024-02-13T12:31:02.000Z (7 months ago)
• Last Synced: 2024-07-19T14:36:24.226Z (2 months ago)
• Topics: hacktoberfest, image, image-decoder, image-encoder, javascript, nodejs, png
• Language: TypeScript
• Homepage:
• Size: 477 KB
• Stars: 327
• Watchers: 8
• Forks: 17
• Open Issues: 7
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • License: LICENSE

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README

        
# fast-png

PNG image decoder and encoder written entirely in JavaScript.



  

    

  

  


    Maintained by Zakodium

  


[![NPM version][npm-image]][npm-url]

[![build status][ci-image]][ci-url]

[![npm download][download-image]][download-url]

## Installation

`$ npm install --save fast-png`

## Usage

### `decode(png[, options])`

#### Arguments

- `png` - A TypedArray or Buffer that contains the PNG data.

- `options` - An object of options

#### Options

- `checkCrc` - If set to `true`, the CRC will be checked for each chunk and an error will be thrown in case it's wrong (default: false).

### `encode(image)`

#### Arguments

- `png` - An object representing the image. You can pass an ImageData from the Canvas API or an object with the following properties:

  - `width` - The width of the image

  - `height` - The height of the image

  - `data` - An array or TypedArray with the image data

  - `depth` - A number indicating the color depth (only 8 and 16 are supported now). Default: `8`.

  - `channels` - Number of channels, including alpha (1, 2, 3 and 4 are supported). Default: `4`.

  - `text` - An object with key-value pairs representing `tEXt` chunks. The keys must have less than 80 characters.

             The keys and values must have only characters in the latin1 charset (maximum code point of 255).

             Default: `undefined`.

### `hasPngSignature(array)`

Returns whether the array starts with the PNG signature (magic bytes).

## PNG standard

Spec can be found at: https://www.w3.org/TR/PNG/

## License

[MIT](./LICENSE)

[npm-image]: https://img.shields.io/npm/v/fast-png.svg?style=flat-square

[npm-url]: https://www.npmjs.com/package/fast-png

[ci-image]: https://github.com/image-js/fast-png/workflows/Node.js%20CI/badge.svg?branch=main

[ci-url]: https://github.com/image-js/fast-png/actions?query=workflow%3A%22Node.js+CI%22

[download-image]: https://img.shields.io/npm/dm/fast-png.svg?style=flat-square

[download-url]: https://www.npmjs.com/package/fast-png