CompuServe Thread

Hi, Alex I too would like to know this, I am just starting work on some ID's for a local TV station and they like to "key" lower 3rd ID's over their on Video. To know what Color and if it is better to use the Alpha CH. or not would be a great help. Rick Smith

With a targa+ you can do it with Tips. Feed your video signal to the input of the targa+ and get a composite of graphics and video on the output. You can key out any color. When I did this I used black RGB 0,0,0. I only ever set up once to do this because I really didn't like working in Tips. The other way is to use 3DS and rotoscope the video into the graphic as a background. This procedure has a lot more flexibility for graphics but requires rendering and is slow. Tips is faster but less control over movements. Both seem equal in output quality.

The answer Don gave will work if you are going to overlay in your own computer, or one that has a targa+ board. However, if you are planning to send these graphics off with a client you may need to comply with the needs of an editing suite. Depending on the editing suite you may want to supply the graphics on a blue background but you may find more suites would prefer black. What they will do is key out the color you use for the background and then fill that area with the live video. Just like Don's method in the Targa card. Another method would require you to prepare a cut reel. A cut reel is simply a pure white representation of what ever you created. This reel will be used to cut the key hole for the graphics. You can think of the key hole as a cookie cutter in the video which will be filled with your graphic. Usually this method will be used if you have a full spectrum of colors in your graphic and some detail would be missed by using the graphic image to do the cutting. It is best to check with your client first. Fred