FastImage

FastImage finds the size or type of an image given its uri by fetching as little as needed

The problem

Your app needs to find the size or type of an image. But the image is not locally stored – it’s on another server, or in the cloud – at Amazon S3 for example.

You don’t want to download the entire image, which could be many tens of kilobytes, or even megabytes just to get this information. For most image types, the size of the image is simply stored at the start of the file. For JPEG files it’s a little bit more complex, but even so you do not need to fetch most of the image to find the size.

FastImage does this minimal fetch for image types GIF, JPEG, PNG and BMP.

You only need supply the uri, and FastImage will do the rest.

Examples

require 'fastimage'

FastImage.size("http://stephensykes.com/images/ss.com_x.gif")
=> [266, 56]  # width, height
FastImage.type("http://stephensykes.com/images/pngimage")
=> :png

Installation

Gem

Documentation

http://rdoc.info/projects/sdsykes/fastimage

© 2009 Stephen Sykes (sdsykes)