Chromakey

ChristerTX wrote on 11/29/2003, 9:22 PM
Hello,
Can someone give me a short tutorial on how to do Chromakey in Screenblast.

The effect I'm after is someone holding an object in their hand. The object would be in a separete still and the hand would be in the video event.
There might be other ways of doing this, but I dont know how.

Can I create a still picture with part of the image transparent ?

Comments

IanG wrote on 11/30/2003, 4:26 AM
Put the clip with the person on the video track and align the clip that's going to be chromakeyed on the overlay track. Select chromakey from the Video FX, choose the one that's most suitable and drag it onto the FX icon on the overlay clip. If the background colour isn't there, there's an eye dropper you can use to select the colour to be made transparent. You can use pan and crop on the clips to resize and reposition them.

This works with stills, too.

Ian G.
JohnnyRoy wrote on 11/30/2003, 5:58 AM
In order for Chromakey to work for you, your object must be on a solid color background that can be keyed out. If it isn’t, you’ll have to process your still image in an image editor and add an alpha channel to make the background transparent or paint the background a solid color that can be keyed out.

If you want to make the background transparent and don’t know how to do this I would recommend you download a trial copy of Paint Shop Pro 8 because it has a background eraser tool, which will allow you to manually erase the background. Then export it as a PNG or TGA file with an alpha channel.

~jr