muvipix Community

Hi All,

Say I have a video of a person, and I want to remove the original background, and place the person in another background.
Question would I be on the right track by thinking I would use a garbage mattee, replacement background on track 1, and video on track 2,
or is there another way. I will be using either PE7 or 10.
Any help greatly appreciated.
Thanks
B.G.

Garbage Mattes are rather crude. Even using the Garbage Matte with the most vertices will most likely still show some of the background you're trying to eliminate. If that's not objectional for your purpose, your approach will work.

It's better if you have a uniform background you can key out. Chromakey can work well if you don't have a greenscreen or bluescreen background. FYI, Garbage Mattes are often used to cut out unwanted areas or non-uniform areas when using the keying effects. You can also apply the keying effect more than once to remove more of the background that may not be removed by the first effect because the color is too different or too non-uniform.

Professional shops often use a technique called rotoscoping to remove backgrounds or objects where a screen wasn't used. You need a more advanced tool such as After Effects to do that.

We used to be able to do Rotoscoping using Premiere Elements and Photoshop Elements but the took away the export to Filmstrip file in Premiere Elements.

Hi Bob
Thanks very much for your quick reply. I just typed out a reply just before, and somehow it just disappeared, Oh well probably something silly I did.
Yes I did try greenscreen and chroma key, but it did not work very well.
Actually I will try and explain exactly what I am on about. Say I had a person in a video and I wanted to crop the person so that I just have the head, and replace
the head in another background, and have the head moving across the track, naturally I need to remove the background otherwise it looks like a little square box.
This is just a bit of fun L.N. has come up with , in a video we are doing for a friend. He is the comedy side of the two of us, but when he mentioned it, it got me
to thinking how we could achieve something like that. In this case I know I could take the easy way out and photograph him in front of a greenscreen, but figured there
could be away of achieving this, given at anytime I wanted to do this and the person was not available to just greenscreen.
Any thoughts would be great.

Yes to your question, you have a good memory. We actually leave Aus on the 12.2. and will be in Anaheim from the 12.2. to 25.4.12
Cheers
L.N. & B.G.

If there isn't a lot of motion, you can try using a track matte.

Export a typical frame from the "replacement" footage and edit it in Photoshop Elements. What you want is a silhouette of the head with what you want to show in white and what you want to hide in black. Save the edited frame to use as the matte. In premiere Elements, place the video of the original person on track 1, the video with the replacement head on track 2, and the matte on track 3 -- stretch it to the size of the video clip. Appy the track matte effect to track 2 and in the properties set the matte to track 3 and and use matte luma.

Now comes the tricky part. You can keyframe tracks 2 and 3 to have the head follow the footage on track 1. Keyframing track 2 allows you to position and scale the head to fit over the head on track 1. If the head on track 2 moves a little, keyframing track 3 will allow you to adjust the matte to fit the position and size of the head on track 2. It's easier to do than describe. Play with it a little and I'm sure you'll get it. The less motion in the two videos the easier it will be.

Hi Bob
Thanks for the help will give that ago.
BG