bun-image-size

Identify image Mime types and dimensions in Bun

The processor can handle absolute file paths or URLs to remote images and ofcourse you can pass the image's raw data as an ArrayBuffer too.

Supported Mime types

Currently the package can only identify and measure the following image types:

• JPEG
• PNG
• SVG
• ICO
• WEBP
• GIF
• BMP

Getting started

Get image type and dimensions from a remote URLs

import {createProcessor} from 'bun-image-size';

const processor = createProcessor('https://picsum.photos/500/400')
  .onError((error) => console.log(error));

const result = await processor.process();

/** result
 * {
 *   type: "image/png", // Mime type
 *   size: 123009, // The byte length
 *   width: 500, // Pixels
 *   height: 400 // Pixels
 * }
 */

The example above registers the processor with the URL supplied immediately. The URL is optional on initialization. If ommitted and process is called without a location too, an error will be reported.

Get image type and dimensions from a local file

import {createProcessor} from 'bun-image-size';

const processor = createProcessor(import.meta.dir + '/image.png')
  .onError((error) => console.log(error));

const result = await processor.process();

/** result
 * {
 *   type: "image/png", // Mime type
 *   size: 123009, // The byte length
 *   width: 500, // Pixels
 *   height: 400 // Pixels
 * }
 */

Get image type and dimensions from an ArrayBuffer

import {createProcessor} from 'bun-image-size';

let imageBuffer; /* get the buffer from somewhere */;

const processor = createProcessor()
  .onError((error) => console.log(error));

const result = await processor.processArrayBuffer(imageBuffer);

/** result
 * {
 *   type: "image/png", // Mime type
 *   size: 123009, // The byte length
 *   width: 500, // Pixels
 *   height: 400 // Pixels
 * }
 */

Only need the mimetype and not size?

You can use the helper to identify an image's Mime type in Bun.

import {createMimeIdentifier} from 'bun-image-size';

let imageBuffer: ArrayBuffer; // Get the image buffer from somewhere.

const identifier = createMimeIdentifier(imageBuffer);
const mimeType: string = await identifier.identify(); // image/png

Get a copy of the buffer currently being processed

import {createProcessor} from 'bun-image-size';

const processor = createProcessor(import.meta.dir + '/image.png');
const buffer = processor.buffer // Undefined
await processor.process();
const bufferNow = processor.buffer // ArrayBuffer

Benchmarks vs. Node

All tests conducted on:

• Bun 0.1.10
• Node 16.14.2
• bun-image-size 0.1.4
• image-size 1.0.2
• 1.6 GHz Dual-Core Intel Core i5 CPU
• 4GB 1600MHz DDR3 RAM

Runtime + type	Test Duration	Number of iterations	Iterations per second
NodeJS + JPG	10,000ms	251,838	25,184
Bun + JPG	10,000ms	494,257	49,426 (1.96x faster)
NodeJS + PNG	10,000ms	237,057	23,706
Bun + PNG	10,000ms	1,212,458	121,246 (5.11x faster)
NodeJS + SVG	10,000ms	193,883	19,388
Bun + SVG	10,000ms	663,204	66,320 (3.42x faster)
NodeJS + ICO	10,000ms	252,128	25,213
Bun + ICO	10,000ms	1,037,482	103,748 (4.11x faster)

All tests were validated and 0% of the tests gave invalid results. The image sizes varied in the different formats, but they were exactly the same across Runtime tests. The NodeJS version uses image-size