Image Processing Reference
Figure 39-2 Shape-coded moving matte.
information, weather data, traffic, and news. Probably one of the most popular features of
this service is the live sports-results reporting. These are updated very rapidly as the
results come in.
Of course, much of this data is only useful during the broadcast and it is only guar-
anteed to be present at all in direct off-air signals. Video recorders do preserve some of the
data but the recording does not preserve all the available lines. The lack of sufficient band-
width seriously compromises the data and it may not contain any usable information at all.
The standards for transmitting Teletext data are widely known and available pub-
licly on the Internet. It is not complex, and a simple data slicer that works like a 50%