Abstract: In an extended television signal having signalling bits for conveying control information to control an extended decoder, the signalling bits include a start code and data bits. The start code's main lobe of spectral energy resides in the lower spectral area of a baseband television signal below 2 MHz and preferably below 1.7 MHz. The start code is preferably (almost) DC-free, and the start code has good aperiodic correlation properties and a predetermined minimum bit Hamming distance to the data bits when shifted in the direction of the data bits following the start code.

Abstract: An arrangement for encoding a television signal including a video signal, comprising a circuit for producing an encoded television signal in accordance with a number of possible processing operations on the video signal, each processing operation providing a different distribution of spatial and/or temporal resolution, a circuit for obtaining a provisional selection for one processing operation on the video signal from the number of possible processing operations and for controlling a spatial and/or temporal consistency of said provisional selection for a processing operation on a portion of a picture of the video signal compared with selections for processing operations on spatially and/or temporally adjacent portions, to obtain a consistent selection, said consistency control comprising a spatial/temporal consistency control and a spatial consistency control, to obtain a television signal encoding with an improved consistency control, and a circuit for selecting one processing operation on the video signal

Abstract: In a method of encoding a television signal having a video signal, the method comprising producing an encoded television signal in accordance with a motion-compensated processing of the video signal, determining vectors in a first picture period of two consecutive picture periods of the video signal, and, in a second picture period of the said two consecutive picture periods, determining pointers to the vectors determined in the first picture period, a substitute pointer pointing to a vector which is indeed to be transmitted is searched if a pointer thus determined does not point to a vector to be transmitted, so that a television signal encoding with an improved picture quality can be obtained.

Abstract: A simple and reliable interpolation filter can be provided by a median filter 9 to which signals of the pixels x.sub.1, x.sub.2 and x.sub.3 are applied and which can supply incorrect output values at high spatial frequencies perpendicular to a connection line of pixels x.sub.3 and x.sub.4 located diametrically with respect to a pixel (.) to be interpolated, in conjunction with an averaging circuit 25 to which signals of the pixels x.sub.3 and x.sub.4 are applied and which will not be disturbed at the said frequencies, but will cause disturbances at high spatial frequencies in the direction of this connection line x.sub.3 -x.sub.4, at which last-mentioned frequencies the median filter 9 will function correctly again.