How do we convert image into a shape

Hi,

When we convert a design from photoshop to flash ie animated it we import a particular image as png or jpg format and then animated it and all.

But i have just been through some fla files where the image is in the form of shape. We can change the shape of the image by the curve or strech the corners by the corner angle that we get. Here the image doesn’t get destracted by the bg do gets streched or curves as we want. I wanted to know how do we convert an image to a shape in flash.

Attacehd is an image for what i’m trying to know

rgds
bn