SWFUpload - how to resize image by filling in whitespace if size does not match fixed size

I need to have full original image of any size, resized in to a fixed sized area.

I'm using SWFUpload for this. I haven't figured out how is this possible?

Example

I have image sized 200 X 500 px.

It has to fit to fixed sized image area of 500 X 500 px.

In the end image I'd like to have e开发者_C百科mpty area which is sized of 300 X 0 px to show white background.

Any ideas if this is actually possible?

This is not possible using the current flash api. The latest (beta) version allows only resizing.