@khoohaoyit/image-size

A stream based image size extractor in Node

Features:

• Support variaty of formats
• Low memory footprint
• API compatible with image-size
• Fine control over when to stop parsing
• No dependancy

Installation

npm install @khoohaoyit/image-size

Usage

Processing buffer

import { SizeExtractor } from "@khoohaoyit/image-size";
import { finished } from 'stream/promises';

const extractor = new SizeExtractor({ passthrough: false });
await finished(
  extractor
    .end(buffer)
);
console.log(extractor.imageSize); // Compatable with `image-size`

Extract image size while writing to a file

import { SizeExtractor } from "@khoohaoyit/image-size";
import { pipeline } from 'stream/promises';
import { createWriteStream } from 'fs';

const extractor = new SizeExtractor({ passthrough: true });
await pipeline(
  await fetch('https://github.githubassets.com/assets/gc_banner_dark-b73fa80c5473.png')
    .then(res => res.body),
  extractor,
  createWriteStream('imageA.png'),
);
console.log(extractor.sizes);

Stop processing once it has done parsing all formats

import { SizeExtractor } from "@khoohaoyit/image-size";
import { pipeline } from 'stream/promises';
import { createReadStream } from 'fs';

const extractor = new SizeExtractor({ passthrough: false });
const controller = new AbortController;
await pipeline(
  createReadStream('imageA.png'),
  extractor
    .once('parseAllDone', () => controller.abort()),
  { signal: controller.signal },
).catch(err => {
  if (controller.signal.aborted)
    return;
  throw err;
});
console.log(extractor.sizes);

Library Comparison

	@khoohaoyit/image-size	probe-image-size	image-size
Stream based	Yes	Yes	No
Support sync	No	Yes	Yes
dds	Yes	No	Yes
icns	Yes	No	Yes
j2c	Yes	No	Yes
jp2	Yes	No	Yes
ktx	Yes	No	Yes
pnm	Yes	No	Yes
tga	Yes	No	Yes
avif	Yes	Yes	No
heic	Yes	Yes	No
heif	Yes	Yes	No

The listed library on top all supports ico, cur, bmp, gif, jpg, png, psd, svg, tiff, and webp

Documentation

new SizeExtractor(options)

• options.passthrough: boolean
  • Passes the input to output if true
• options.whitelistFormats?: string[]
  • Whitelist specific formats
• options.blacklistFormats?: string[]
  • Blacklist specific formats, ignored if whitelistFormats is set

SizeExtractor.imageSize

The API compatible of image-size result

SizeExtractor.sizes

The extracted sizes emitted from 'size'

Event: 'size'

• data: { width: number, height: number }
• format: string

Emitted when a format has successfully extracted the image size

Event: 'parseError'

• error: unknown
• format: string

Emitted when a format encountered unexpected error while parsing

Event: 'parseDone'

• format: string

Emitted when a format has ended parsing

Event: 'parseAllDone'

Emitted when all formats has ended parsing