This pattern tests the effectiveness of the MPEG compression. MPEG works by only encoding the parts of the picture that are changing from one frame to the next, and uses some predicting algorithms to predict the next frame.
There is some white noise on the test pattern which completely flummoxes the encoding procedure because white noise is random and takes up a lot of bandwidth to encode. The outcome of this is that the rotating circles at the bottom, which are moving from side to side, flicker quite badly.
Most of the chart moves in some way, to try and catch out the MPEG, but there are some familiar parts of the chart, notably the greyscale (which moves) and the gratings (which are stationary).
There is also a small box which changes between "IfN" whatever that stands for) and what looks like a really old Radio Spares (RS) logo.
Click on the chart to see a movie of this in action! However, as it is encoded in MPEG and it looks slightly corrupted on a Digibox, you can't expect much!
Taken: 1999
