Multipoint Cropping

[CACohenDVM]

Occasionally I would like to crop an image along non-parallel lines or along polygonal lines, etc. Is there an app that allows for this type of multipoint cropping? Otherwise, I must import an image into an art app and layer in changes. One of the problems I run into when layering is wrapping text around my final image. Layering effects still results, I think, in the underlying image (perhaps a typical rectangle or square) defining limits on a Pages for iPad page vs the limits of the polygonal shape allowing text to wrap neatly around the polygonal limits created. Thanks much.