FastImage

FastImage 2.0 is an Swift port of the Ruby project by Stephen Sykes. It's directive is to request as little data as possible (usually just the first batch of bytes returned by a request) to determine the size and type of a remote image.

This means you can get the size of a large image (say 2MB), by only downloading around 8KB - 32KB

Fairly simple to use:

let fastImage = FastImage()
let imageURL = URL("http://i.imgur.com/7GLI90s.jpg")!

fastImage.imageSizeAndType(for: url, completion: { result in
  switch result {
  case .success(let (size, type)):
    // `size` would be 1600 x 1200
    // `type` would be .jpg
    ...
  case .failure(let error):
    // Get a URLError here (timed out, etc.) or a SizeNotFoundError (just couldn't get a size based on data)
  }
})

Currently supports JPEG, PNG, BMP, GIF, TIFF, ICO, CUR, and PSD.

Compatability

2.0 was built with Xcode 10.1 with a deployment target of 11.0 but could likely be set lower

License

MIT, see LICENSE file