initial readme and license

readme.md

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+# go-imageproxy #
+
+go-imageproxy is a caching image proxy server written in golang.  It supports
+dynamic image resizing and URL whitelisting.
+
+This project was inspired by, and is designed to be an alternative to,
+WordPress's [photon service][photon].  Photon is a great free service, but is
+limited to sites hosted on WordPress.com, or that use the [Jetpack
+plugin][jetpack].  If you don't want to use Jetpack, then you're asked to use a
+different service.  If you're looking for an alternative hosted service, I'd
+recommend [resize.ly][], [embed.ly][], or [cloudinary][].  I decided to try
+building my own for fun.
+
+[photon]: http://developer.wordpress.com/docs/photon/
+[jetpack]: http://jetpack.me/
+[resize.ly]: https://resize.ly/
+[embed.ly]: http://embed.ly/display
+[cloudinary]: http://cloudinary.com/
+
+
+## URL Structure ##
+
+go-imageproxy URLs are of the form `http://localhost/{options}/{remote_url}`.
+
+### Options ###
+
+Currently, the options path segment follows the same structure as
+[resize.ly][].  You can specify:
+
+ - square crop - one number, which is used as both the height and width.
+   (example: `500`)
+ - rectangular crop - two numbers, separated by an 'x', resizes to the exact
+   dimensions (width listed first).  (example: `250x125`)
+ - auto height (preserves aspect ratio) - one number to the left of the 'x',
+   resizes to a specific width, adjusting the height to preserve the
+   aspect ration (example: `160x`)
+ - auto width (preserves aspect ratio) - one number to the right of the 'x',
+   resizes to a specific height, adjusting the width to preserve the
+   aspect ration (example: `x200`)
+
+### Remote URL ###
+
+The URL of the original image to load is specified as the remainder of the
+path, without any encoding.  For example,
+`http://localhost/200/https://willnorris.com/logo.jpg`.
+
+In order to [optimize caching][], it is recommended that URLs not contain query
+strings.
+
+[optimize caching]: http://www.stevesouders.com/blog/2008/08/23/revving-filenames-dont-use-querystring/
+
+
+## License ##
+
+This application is distributed under the BSD-style license found in the
+[LICENSE](./LICENSE) file.