In a baseband television signal, the DC level (nominally 0 volts) from which the amplitudes of the various components of the signal are measured. Conventionally, the viewable parts of the signal (except subcarriers) are positive with respect to blanking, while the synchronizing pulses are negative with respect to blanking. In North American NTSC signals, the darkest portions of the image… (Read More →)

Transmission without obtaining a receipt, i.e., acknowledgement of reception, from the intended receiving station.
Note: Blind transmission may occur or be necessary when security constraints, such as radio silence, are imposed, when technical difficulties with a sender's receiver or receiver's transmitter occur, or when lack of time precludes the delay caused by waiting for receipts.

In graphic display devices, an intentional periodic change in the intensity of one or more display elements or display segments.

1. A group of bits or digits that is transmitted as a unit and that may be encoded for error-control purposes.
2. A string of records, words, or characters, that for technical or logical purposes are treated as a unit.
Note 1: Blocks (a) are separated by interblock gaps, (b) are delimited by an end-of-block signal, and (c) may contain… (Read More →)

See end-of-transmission-block character.

In the processing or transmission of digital data, an error-control procedure that is used to determine whether a block of data is structured according to given rules.

A character added to a transmission block to facilitate error detection.
Note: In longitudinal redundancy checking and cyclic redundancy checking, block check characters are computed for, and added to, each message block transmitted. This block check character is compared with a second block check character computed by the receiver to determine whether the transmission is error free.

An error detection and/or correction code in which the encoded block consists of N symbols, containing K information symbols (K<N) and N-K redundant check symbols, such that most naturally occurring errors can be detected and/or corrected.

A diagram of a system, a computer, or a device in which the principal parts are represented by suitably annotated geometrical figures to show both the basic functions of the parts and their functional relationships.

In the received image in video systems, distortion characterized by the appearance of an underlying block encoding structure.