Images

These packages read and write image files in plain JavaScript, so they run in Workers and browsers, where native libraries such as sharp don't.

image-size reads an image's type and dimensions from its first bytes.
exif reads EXIF metadata, and removes EXIF and XMP metadata from JPEG, PNG, and WebP files.
png decodes PNG files to RGBA pixels and encodes pixels as PNG.

Check an upload and strip its metadata

import * as Exif from '@portable/exif';
import * as ImageSize from '@portable/image-size';
import * as Streams from '@portable/streams';
 
export default {
  async fetch(request: Request, env: { BUCKET: R2Bucket }) {
    const bytes = await Streams.toBytes(request.body!, {
      maxBytes: 20_000_000,
    });
    const { type, width, height } = ImageSize.parse(bytes);
    if (width > 8000 || height > 8000) {
      return new Response('Too large', { status: 413 });
    }
    await env.BUCKET.put(crypto.randomUUID(), Exif.strip(bytes), {
      httpMetadata: { contentType: `image/${type}` },
    });
    return new Response(null, { status: 201 });
  },
};

Exif.strip copies the image data byte for byte without re-encoding it, so the photo loses no quality.