Vectric aspire is a great program with a really great price but when it comes to 3D you really need to be more specific.
Example there are lots of programs that will convert a jpeg into a 3dish lithopane image.
However if you are looking for something more like where the image stands up off the surface a good ways (.75" or more) then there really isnt any easy way to do this (you will need to make a bump map) this is an image with black, whites and greys (which the lithopane type software aspire does) but there is usually way to much information/noise in a jpeg type image and you get very bad high relief images.
The only real way to get a great image that is capable of being carved several inches high is to build it as a 3D model and then export the bumpmap info(almost every 3D program has the ability to export the bump map info) then use this bump map in Vectric aspire and you will have a great high depth capable 3D image.
The big problem is 3D design software has a huge learning curve and to get the detail takes time (and time is money).
Good Luck
if you find a point and click way to do it for tall relief carving please let us know I am sure most of us would love to know how to do it quick and ease.