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@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