Changing backgrounds

[LauraRJC]

I know its possible, as I have seen it done, but I am wondering if someone could help me figure out how to do this.
I have gimp, and am wanting to do a super pic of a car, and would like to change the background to compliment the car and the lines.
Does anyone here have that kind of experience, and if you do could you give me leads on how to do this?
It would be taking the pic of the car and placing it on another picture making a whole new background.
Thanks for your help in advance,
Laura

[Japaslavian]

The action you want is not the difficult part.
All you would be doing is outlining the car with whatever the GIMP's equivalent to the pen tool is and cutting and pasting.
The problem with doing things like this is making the two images look natural together.
For instance the lighting is most likely going to be completely different, and the colors won't really mesh well together.
Another things is perspective. If you shot the car coming down a little bit, your new background will have to be shot taken coming down a little bit, otherwise you will have conflicting perspectives and it will look strange.
Also, because the car has a very reflective nature to it, you will see one thing in the car's reflections, but you won't see it in the new background. i.e. the car will be reflecting some trees on the door panel, and a mountain view through the windows, but the car is somehow inside a parking garage. Things like that are much more difficult to hide.

So if someone is familiar with GIMP and can explain how to trim things out (I don't know GIMP), and you are really ambitious you might be able to pull it off, but it's going to take a lot of work.