How to edit part of video and add image over it

[method]

Hi all. i wonder how i can edit part of video and add an image over it. For example if a female is dancing in video clip i want to change her head with different head(static head image). I have seen so many clips in youtube like this. Could any one tell me how to do this an easy way.Looking forward for your replies.Thanks

[guns1inger]

There is a filter for virtualdub that can do this. Even the most basic editors have something similar. Static is easy. If you want to track it to a moving body it becomes more difficult and requires more expensive software. Wrigley Video has a tutorial for tracking faces for blurring that can be used as a starting point for tracking a moving head for an overlay effect.

[method]

Thanks for your reply. could you tell me what is the name of that filter in virtualdub and also if i want to move that image when head is moving how to do that ? what program do i need. could you mention the name of those programs?