Method and apparatus for concealing errors in a digital television signal

US4464674A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Axel Schulz · Emmelshausen, DE
• Werner Staude · Reinheim, DE

Key dates

• Filing date: Apr 9, 1982
• Grant date: Aug 7, 1984
• Expiry date: Apr 9, 2002

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04N9/888
• WIPO field: Audio-visual technology
• WIPO sector: Electrical engineering

Abstract

The digital signals representing successive picture points of a digital television video signal is caused to pass through, in succession, two delay circuits each providing a delay of one television line interval. This makes three places available where shift registers may be connected for stepping the digital signals at picture point intervals, so that a two-dimensional array of neighboring picture points located on adjacent portions of three television lines can be made simultaneously available for correcting the signal of the central picture point if it is found to be defective. A defective picture point is caused to be represented by a null value of digital signals by an error-correcting circuit. Thus, at the same places where the video signal shift registers are connected, gates for detecting null signals may be connected, each of which is followed by one-bit shift registers for addressing a read-only memory for controlling the choice of digital signal pairs from the picture point array which will be averaged in an averaging circuit to provide the output signal. If the digital signal of the central point of the picture point array is not defective, duplicates of this signal are…