Motion blur is used as a "low-pass filter" to avoid temporal aliasing. The Nyquist theorem says that you have to sample at twice the rate of the highest frequency. Basically, this says that you have to sample fast enough to get both the high and the low amplitude of the highest-frequency sine wave. When this is translated into sequences of frames, this means that the highest frequency representable sine wave (every other dot) can't move as much as 1 pixel per frame, else it could be interpreted as moving in the opposite direction (e.g., backwards wagon wheels in western movies). In order to avoid this problem, you have to consider the speed of motion of an object in the scene. If the object is moving at (say) 5 pixels per frame, then you will have to filter the image of the object to eliminate all its frequencies with a period higher than 10 pixels. This is pretty severe filtering, and is probably considered unreasonably harsh by the computer graphics folks. ---------------------------------------------------------------------- You can UNSUBSCRIBE from the OpenDTV list in two ways: - Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org - By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word unsubscribe in the subject line.