Abstract: A high-resolution television system in which color fidelity is preserved while allowing the use of frame-store type noise elimination techniques, by inverting one of the color axes at a first rate, and the other color axis at a second, different rate. While reversal of the second axis at a frame rate is preferred because it permits effective use of noise reduction techniques, reversal at other rates such as the field rate is also beneficial because it allows the filtering of the color subcarrier pattern with less degradation in image quality. In a preferred embodiment of the invention, the color subcarrier frequency is chosen as twice the standard NTSC frequency to reduce horizontal sweep harmonic interference and make the inventive equipment easily compatible with NTSC equipment. Apparatus for achieving such compatibility is described.

Abstract: Noise in a video picture is sharply reduced using the redundancy of information present in those portions of the picture which remain unchanged through several successive frames. A number of successive frames are compared to determine which portions of the picture are in motion and which are stationary. The moving portions of the image are separated from the stationary portions and are processed in a conventional manner. The stationary portions, however, are combined on a frame-by-frame basis to produce a highly noise-free averaged signal. In color systems, the conventional luminance-chroma separation methods used for the moving portions of the picture are replaced, in the stationary portions, by an opposite-phase frame comparison method which provides 100% separation regardless of the nature of the image.