The DynamicImage effects
The DynamicImage server control implements a few handy out-of-the-box effects: grayscale, sepia and rotateflip but check out the Evolutions section to see how you can extend the list.
<piece:DynamicImage ID="DynamicImage1" runat="server"
DrawSepia="True" RotateFlip="RotateNoneFlipXY">
</piece:DynamicImage>
It also handles the server-side image resizing; in this case the Width and Height property values are used
and they are interpreted as pixels.
<piece:DynamicImage ID="DynamicImage4" runat="server"
ResizeHandler="Server" Width="200px" >
</piece:DynamicImage>