System for transmitting television picture information using an error-protection code

Claim 1

In a system for transmitting, over a transmission medium, data for reconstructing a television picture constituted by a plurality of subpicture, said system comprising means for generating subpicture data for reconstructing each of said subpictures, transformation means for receiving subpicture data and transforming said data into a series of a coefficient bits including a most significant bit of respective transformation functions, said transformation functions having associated frequencies including a lowest frequency, said transformation means further comprising encoding means interconnected between said transformation means and said transmission medium for encoding a first subset of k bits of said coefficient bits into a larger group of n bits by a predetermined code having predetermined error detection capabilities for said k bits, said k bits containing at least one bit constituting said most significant bit of said coefficient associated with said transformation function having said lowest frequency: improved encoding means wherein said predetermined code has a first minimum Hamming distance of four for allowing at least single error correction, double-error detection within said k bits, said code further having a second minimum Hamming distance of at least five for allowing double-error correction within an error protected subset of at least two of said k bits.