Keying Graphics in GenCG

Sometimes we get asked how a graphic key (superimposition or layer) works and how a TV graphic can be keyed (superimposed or layered) on top of live video.

Video and graphics you see on your TV screen are made up of red, green, and blue (RGB) colors that combine to make all visible colors. Shown is the fill video which you see on TV.

In still graphics, a key is referred to as an alpha.  A TV graphics system cuts a key hole for the fill video to fit into. The key hole is black and white, not visible on TV, and behind the fill. This allows the fill video to have transparency over the background video. Targa (.tga) files made in software like Adobe Photoshop™ make these alpha or key layers.

Here is a key for the above fill:

Here is a background with no fill or key:

Here is the final output with the foreground fill from picture #1 and the invisible key in picture #2 combined with the background from picture #3.  Notice the transparency of the fill. You can see through it to the background. This is made possible by the alpha, or key.

This is a very quick overview of the concept of keying graphics over video. Until next time!

RSS on TV using NewsScroll

We get a lot of interest from folks about how to include RSS feeds to be part of their web-based or video project.

Compix has made this process really easy. It used to require a lot of custom coding and fancy data translators – it was usually a science project that most users did not want to get involved with.

One of our customers has a popular cable channel that uses the RSS feed function to turn their cable feed into money. They have folks send messages to their cable channel and, for a fee, birthday, anniversary, or graduation messages can be included in the scroll that goes over the video feed for all of their cable subscribers to see.

Adding an RSS feed to your project is as easy as 1,2,3!

1. Find a website that has the RSS feed you need. Let’s use CNN as an example. The RSS feeds are generally on the bottom of the page. Find it and then open the RSS page.
2. Copy the RSS feed you want to use in your scroll. In this case, we have chosen Top Stories.
3. In the Compix NewsScroll software, open the RSS dialog box and paste the RSS URL to use in the scroll.

And voilà! It really is that easy. The RSS feed is now available to put over your video feed.Hope this gives you some great ideas about getting your message out there.