US 5,510,787 AGranted

System comprising at least one encoder for coding a digital signal and at least one decoder for decoding a digital signal, and encoder and decoder for use in the system according to the invention

AssigneeKoninklijke PTT Nederland N.V.

InventorArian Koster

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Abstract

Known systems based on layered coding and decoding do not take account of the greater surface area of an HDTV picture, which is to be coded with high resolution, compared with the smaller surface area of a conventional picture, to be derived therefrom, which is to be coded with low resolution. An improvement in the efficiency of the coding and decoding is achieved by actually taking account of this with the system according to the invention and maintaining the coupling between the two layers in the encoder and the decoder if a picture element is situated in a corresponding section of the two pictures and interrupting the coupling if a picture element is situated outside the corresponding section of the two pictures.

Claims10

Dependent claims

An encoder for coding a digital signal, said encoder comprising:

an encoder-input for receiving the digital signal;
first data processing means for generating a first coded digital signal at a first output of the first data processing means and having an input coupled to the encoder-input;
first encoder feedback means, having a first encoder memory means, for feeding-back at least a portion of the first coded digital signal wherein an output of the first encoder memory means is coupled to an input of the first data processing means and an input to the first encoder memory means is coupled to a second output of the first data processing means;
reduction means, having an input coupled to the encoder-input, for filtering and subsampling the received digital signal;
second data processing means for generating a second coded digital signal at a first output of the second data processing means and having an input coupled to an output of the reduction means;
second encoder feedback means, having a second encoder memory means, for feeding-back at least a portion of the second coded digital signal wherein an output of the second encoder memory means is coupled to the input of the second data processing means and an input to the second encoder memory means is coupled to a second output of the second data processing means;
and
encoder coupling means for coupling the second data processing means to the first data processing means, said encoder coupling means comprising an encoder prediction means for generating an encoder prediction signal;
wherein the encoder further comprises:
means for deriving a position code from the digital signal, comparing the position code with at least one adjustable code, and transmitting a control signal to the encoder coupling means thereby decoupling, operative as a result of a comparison, the second data processing means and the first data processing means, wherein said deriving, comparing and transmitting means has an input coupled to the encoder input and an output coupled to a control input of the encoder coupling means.

7 more elements

A coding/decoding system comprising at least one encoder for coding a digital signal and at least one decoder for decoding a coded digital signal wherein said encoder comprises:

an encoder-input for receiving the digital signal;
first data processing means for generating a first coded digital signal at a first output of the first data processing means data and having an input coupled to the encoder-input;
first encoder feedback means, having a first encoder memory means, for feeding back at least a portion of the first coded digital signal such that an output of the first encoder memory means is coupled to the input of the first data processing means and an input to the first encoder memory means is coupled to a second output of the first data processing means;
reduction means for filtering and subsampling the received digital signal having an input coupled to the encoder input;
second data processing means for generating a second coded digital signal at a first output of the second data processing means having an input coupled to an output of the reduction means;
second encoder feedback means, having a second encoder memory means, for feeding-back at least a portion of the second coded digital signal such that an output of the second encoder memory means is coupled to the input of the second data processing means and an input to the second encoder memory means is coupled to a second output of the second data processing means;
and
encoder coupling means for coupling the second data processing means to the first data processing means;
wherein said decoder further comprises:
first data reprocessing means for reprocessing a first coded digital signal;
first decoder memory means coupled to the first data reprocessing means;
second data reprocessing means for reprocessing a second coded digital signal;
second decoder memory means coupled to the second data reprocessing means;
and
decoder coupling means for coupling the second data reprocessing means to the first data reprocessing means having a decoder prediction means for generating a decoder prediction signal;
wherein the encoder further comprises:
means for deriving a position code from the digital signal, comparing the position code with at least one adjustable code, and transmitting a control signal to the encoder coupling means thereby decoupling, operative as a result of a comparison, the second data processing means and the first data processing means, wherein said deriving, comparing and transmitting means has an input coupled to the encoder input and an output coupled to a control input of the encoder coupling means.

14 more elements

Dependencies are inferred from the claim text.