Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

https://github.com/sindresorhus/image-type

Detect the image type of a Buffer/Uint8Array
https://github.com/sindresorhus/image-type

Last synced: about 1 month ago
JSON representation

Detect the image type of a Buffer/Uint8Array

Lists

README 

        
# image-type



> Detect the image type of a Buffer/Uint8Array



See the [`file-type`](https://github.com/sindresorhus/file-type) module for more file types and a CLI.



## Install



```sh

npm install image-type

```



## Usage



##### Node.js



```js

import {readChunk} from 'read-chunk';

import imageType, {minimumBytes} from 'image-type';



const buffer = await readChunk('unicorn.png', {length: minimumBytes});



await imageType(buffer);

//=> {ext: 'png', mime: 'image/png'}

```



Or from a remote location:



```js

import https from 'node:https';

import imageType, {minimumBytes} from 'image-type';



const url = 'https://upload.wikimedia.org/wikipedia/en/a/a9/Example.jpg';



https.get(url, response => {

	response.on('readable', () => {

		(async () => {

			const chunk = response.read(minimumBytes);

			response.destroy();

			console.log(await imageType(chunk));

			//=> {ext: 'jpg', mime: 'image/jpeg'}

		})();

	});

});

```



##### Browser



```js

const xhr = new XMLHttpRequest();

xhr.open('GET', 'unicorn.png');

xhr.responseType = 'arraybuffer';



xhr.onload = () => {

	(async () => {

		await imageType(new Uint8Array(this.response));

		//=> {ext: 'png', mime: 'image/png'}

	})();

};



xhr.send();

```



## API



### imageType(input)



Returns an `Promise` with:



- `ext` - One of the [supported file types](#supported-file-types)

- `mime` - The [MIME type](https://en.wikipedia.org/wiki/Internet_media_type)



Or `undefined` when there is no match.



#### input



Type: `Buffer | Uint8Array`



It only needs the first `minimumBytes` amount of bytes.



### minimumBytes



Type: `number`



The minimum amount of bytes needed to detect a file type. Currently, it's 4100 bytes, but it can change, so don't hardcode it.



## Supported file types



- [`jpg`](https://en.wikipedia.org/wiki/JPEG)

- [`png`](https://en.wikipedia.org/wiki/Portable_Network_Graphics)

- [`gif`](https://en.wikipedia.org/wiki/GIF)

- [`webp`](https://en.wikipedia.org/wiki/WebP)

- [`flif`](https://en.wikipedia.org/wiki/Free_Lossless_Image_Format)

- [`cr2`](https://fileinfo.com/extension/cr2)

- [`tif`](https://en.wikipedia.org/wiki/Tagged_Image_File_Format)

- [`bmp`](https://en.wikipedia.org/wiki/BMP_file_format)

- [`jxr`](https://en.wikipedia.org/wiki/JPEG_XR)

- [`psd`](https://en.wikipedia.org/wiki/Adobe_Photoshop#File_format)

- [`ico`](https://en.wikipedia.org/wiki/ICO_(file_format))

- [`bpg`](https://bellard.org/bpg/)

- [`jp2`](https://en.wikipedia.org/wiki/JPEG_2000) - JPEG 2000

- [`jpm`](https://en.wikipedia.org/wiki/JPEG_2000) - JPEG 2000

- [`jpx`](https://en.wikipedia.org/wiki/JPEG_2000) - JPEG 2000

- [`heic`](https://nokiatech.github.io/heif/technical.html)

- [`cur`](https://en.wikipedia.org/wiki/ICO_(file_format))

- [`dcm`](https://en.wikipedia.org/wiki/DICOM#Data_format) - DICOM Image File



*SVG isn't included as it requires the whole file to be read, but you can get it [here](https://github.com/sindresorhus/is-svg).*



## Related



- [file-type](https://github.com/sindresorhus/file-type) - Detect the type of a file

- [image-dimensions](https://github.com/sindresorhus/image-dimensions) - Get the dimensions of an image