Can I change the background when I use iMovie?

Question

Hi, I am a newcomer to Mac and iMovie.
I have been very pleased with the results. But what I would really like to do now is to change the background on family films.
Is this possible?
I am sure I have seen this done somewhere, perhaps one could buy additional software? Thanks fr any advice.
Cheers-Chatch.

Answer 1

It would be possible ..but long-winded and complicated.
Neither your Mac, nor iMovie, "knows" which parts of your picture are "background" and which are the interesting family members, or the "foreground".
So you'd have to change some characteristic of what you call the "background", so that iMovie - or some other program - can identify the "background" ..to iMovie it's all just "flat" moving smudges!
You might have to change what you call the "background" to all one colour, and then use iMovie, or a downloadable 'Plug-In' (..extra bit of program for iMovie..) to substitute another picture, or scene, for what you've coloured, say, blue.
(..In mainstream movies and TV, actors are often shot against a blank blue or green screen, and then a shot of other scenery may be substituted for that blank, empty, featureless colour. But without identifying which regions are "background" and which aren't, there's no way to substitute one thing for another..)
Various other movie-editing programs let you draw on an area of the picture, or fill a region with colour ..but not iMovie itself: it's really for editing, not "compositing" ..which is what you want to do!
Other people may suggest ways in which it might be done with QuickTime Pro - another Mac program - or by copying some of your movies' shots into 'PhotoShop' or 'Graphic Converter', and tweaking things there.
Some downloadable Plug-Ins can do some of the job, e.g; (click on these blue links) Stupendous Software, or GeeThree's Slick Plug-Ins, or cf/x. You can find others by typing "iMovie Plug-Ins" into Google.
Happy hunting..