I usually don't suggest software I haven't tried, but I'll make an exception, due to low cost ($49US or $19US - see below) of this program and the fact that it has a free trial. There is a program that works in Photoshop/Elements and and few other image editing programs, called EZlect: http://www.ezlect.com/
Based on skimming their tutorial
, it looks like you just put markers on your image to help the software determine what selection you want: one type of marker for parts your want; and another for other types you do not want. When you have enough markers in the right spots, you get your foreground image removed. I assume the more difficult the selection you want is to single out from the background, the more markers that you will need.
I haven't been able to use this software because the install doesn't appear to work on 64-bit versions of PhotoShop 5. It also doesn't seem to work on my old PhotoShop 3.0 install. I have asked the developer if he plans to support 64 bit PS any time soon. You'll notice on the developers web site that the cost of the product is $49US, but on Oct 27, Bits-du-Jour (a site that offers discounts on software that last usually just 1-day), will have EZelect for: $19UShttp://www.bitsdujour.com/software/ezlect/
(I am not sure if this link will work; you might need to register on the Bit-du-Jour site to see this page)
I hope this helps and if you or anyone else does try EZlect, please post here to let me know if it works well for you. Thanks.