I’ve just been having a look at the Nokia Imaging SDK (also available via NuGet). It looks like it really bridges the gap that a lot of developers have when they want to include image technologies in their apps. (for example, you can specify an image size that you want to use in the PhotoChooserTask, but you can’t let the user decise what aspect ratio to use. It’s even less flexible in the CameraCaptureTask where the user can’t do any manipulation at all.
Adding this SDK would allow you to give a lot more control to your users as it supports cropping, resizing, rotation, scaling, filters and other image enhancements.
There’s a tutorial application project in the full downloadable version of the SDK (not available via NuGet) that will quickly get you started. Give it a try! (I would highly recommend you read the Quick Start guide as well, though. ;))