I\'ve seen this in a number of apps but can\'t find anything in the documentation or online samples.
When you invoke the PhotoChooserTask some apps enable you to res
You can set the width and height of the desired image and the PhotoChooserTask will automatically create the crop mechanism.
photoChooser.PixelHeight = 500;
photoChooser.PixelWidth = 500;
There are some known issues with this method in the pre-nodo emulator; using the 7.1.1 tools I have not had any problems with this method.
Go to this MSDN site and download Photos Sample
.It describes in detail How to crop. Hope this helps.
Those apps will be doing the cropping themselves. There is not built in way to crop images.