高效的基于web的图片处理程序，可以对图片进行旋转，格式，缩放和灰度处理，程序使用C#编写。

一个ASP.NET可扩展的通用图片处理程序，使用了filter。五种filter可用：resize, zoom, rotate,
 greyscaling and formatting(jpg, gif, tif, png)

作者添加了2种编码库来处理小图。WPF内置的bitmap编码和 FreeImage library。在测试中

FreeImage 制作最小的图片并且为默认的bitmap编码，在demo中。

使用一个从IImageProvider接口中抽象出来的ImageProvider获得原始图像，例如从CMS，数据库，硬盘

或者其他任意位置。一个继承了IImageProvider接口的类实现了从硬盘读取文件。

默认会处理下面的URL参数:

src: Key to an image, can be a relative url, guid or whatever you want

width: Width in pixels without any unit specification

height: Height in pixels without any unit specification

format: 格式化输出图像: png, gif, jpg, tif

greyscale: any non empty value triggers grey scaling

rotate: Invariant Culture floating point number in degrees where 360 is a complete rotation.

zoom: Invariant Culture floating point number indicating scale value. If 2 is specified the output will be double the original size.

如果需要的话，参数可以组合使用。

示例Url(只做说明使用，并不能真正使用)

// Returns the image mapping to /bla.jpg resized to width of 100 pixels preserving aspect relative to height
http://webimageresizer.codeplex.com/ImageHandler.ashx?src=/bla.jpg&width=100

// Returns the image mapping to /bla.jpg resized to height of 100 pixels preserving aspect relative to width
http://webimageresizer.codeplex.com/ImageHandler.ashx?src=/bla.jpg&height=100

// Returns the image mapping to /bla.jpg resized to width 100 pixels and a height of 50 pixels
http://webimageresizer.codeplex.com/ImageHandler.ashx?src=/bla.jpg&width=100&height=50

// Returns the image mapping to /bla.jpg resized to 2.5 times the original size
http://webimageresizer.codeplex.com/ImageHandler.ashx?src=/bla.jpg&zoom=2.5

// Returns the image mapping to /bla.jpg resized to 2.5 times the original size and rotated 45 degrees,
http://webimageresizer.codeplex.com/ImageHandler.ashx?src=/bla.jpg&zoom=2.5&rotate=45

// Returns the image mapping to /bla.jpg resized to 2.5 times the original size, rotated 45 degrees and greyscaled
http://webimageresizer.codeplex.com/ImageHandler.ashx?src=/bla.jpg&zoom=2.5&rotate=45&greyscale=1