lntelvideo's Digital Impulse Noise Reducer Model INR^ES is a state of the art signal processing system that essentially removes all electrical or ignition-type impulse noise from NTSC color television signals. It is also effective in detecting and correcting satellite or FM link threshold noise that normally appears as "sparkles" or streaks. It is, in effect, a means of extending threshold in FM links. The system may also be used as a stand alone dropout corrector for composite NTSC color signals.

Aside from the standard analog-to-digital and digital to analog conversion operations, the system signal processing is all digital. Every video pixel is analyzed and a differentiation between video and noise is made based on the statistical characteristics of unwanted noise and errors. Sophisticated circuits are used to analyze the video signal and search for impulse noise and dropout errors using multidimensional correlation techniques.

To differentiate between impulse noise and moving video details motion is also detected using a number of video frames for temporal correlation detection. When the circuits determine that a particular video pixel has noise perturbation or is in error, and the motion circuits determine that there is no motion in the vicinity of the error, that pixel is replaced with a value predicted from spatio temporal neighboring pixels. All signal processing is performed on the composite color signal, thus avoiding the introduction of video impairments due to color decoding and re-encoding.

Operation of the system has been significantly improved and simplified from the earlier Model INR. Extended sensitivity "ES" means a more accurate differentiation between noise and motion. Operation consists of selecting either "Process ON" or "System Bypass". "Auto" select operation is also available in which the system automatically switches itself into Bypass when no impulse noise is detected in the video.

The unit is fully self contained. It takes a baseband NTSC color video signal at 1 volt peak to peak and it outputs a processed NTSC color video signal at the same level as the input. Hardwired bypass occurs in the event of power loss.