@khoohaoyit/image-size v0.0.2

@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

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