软考报名时发现可以进行头像区域裁剪功能，F12了一下，发现使用了imgAreaSelect控件。
控件官网：
http://odyniec.net/projects/imgareaselect/
控件说明：
imgAreaSelect is a jQuery plugin for selecting a rectangular area of an image. It allows web developers to easily implement image cropping functionality, as well as other user interface features, such as photo notes (like those on Flickr).
在线例子：
