Thursday, April 19, 2007

HDTV Pixelization


There are two types of pixelization. The creative type that is purposely used to obscure license plates and peoples faces on TV shows to hide ones identity, and the type that is a signal problem. From above, we know that digital signals either come through or they don't. Well when you see pixelization as shown below, the signal is at the point where it has come through entirely but there is a delay in processing the information. In other words, the signal and video processing of your equipment can't keep up with one another. If the problem persists, eventually you'll see a black screen, until everything catches up again. Satellite TV and cable subscribers experience this in adverse weather conditions when the wind or rain is interfering with the signal and it can't get through entirely. First it will pixelize, then black out all together. Pixelization of this type also occurs in video games, and also in home movie formats for the same reason. Maybe the scene that you were watching at the time had a lot going on, which requires more information than normal to be processed. When the hardware can't keep up, you will get these symptoms. But its' important to note that it's not always the hardware's fault. If the movie studio, broadcast company or video game company didn't use the correct methods of development, then that too can contribute as to WHY the pixelisation is occurring.