Display, modify and save image

Hi,

I'm trying to write app, which can
   1. load an image (such as jpg)
   2. display this image on the screen
   3. modify the image - bitmap (low level, operations such as filters)
   4. display image ...
   5. ...

What is the easiest way? What classes I should use?

I tried class CPAlbImageViewerBasic, which can open and display image.
It's great to rotate, scroll, zoom image.
But it can return only visible part of bitmap.
I need the whole of bitmap.
Also I didn't find way to give a bitmap to be displayed by this class.

So I need to get bitmap from a file (jpg).
This bitmap I want to modify and display.
(Also scroll and zoom...)
At the end save into jpg file.

What classes and function do you recommend?

Thanks a lot for response