US 6,661,844 B2 · Adaptive method of encoding and decoding a series of pictures by transformation, and devices for implementing this method

Abstract

A method and a device for coding and decoding a sequence of images or pictures is disclosed. One exemplary embodiment disclosed codes by dividing each picture into blocks of picture elements. Each element of a block being represented by a digital value. Two types of coding are utilized in order to reduce the amount of data; inter-coding, which takes into account a corresponding block in a previous picture and intra coding, which is independent from a previous picture. Blocks being thus coded so that a further reduction of data is obtained by transmitting high spatial frequencies with less weight than low spatial frequencies. This is accomplished with the use of weighting coefficients. Weighting coefficients are variable as a function of the quantity of information to be transmitted.

Claims1

Dependent claims

A method for coding a sequence of pictures wherein each picture is divided into blocks of picture elements and a cosine transform is performed on the picture blocks to provide blocks of coefficients, the coding using a zigzag path to define the order to code the coefficients of each block and a variable length, or Huffman code, wherein the variable length or Huffman code comprises at least coding for coefficients which are preceded by a sequence of zero values;

for each block, the last sequence of zeros is not encoded and an inter-block word is inserted;
and between encoded data corresponding to two consecutive pictures, a picture separator word is inserted, each picture separator comprised of a pattern which cannot be imitated by licit concatenations of encoded data.

Dependencies are inferred from the claim text.

Facts

Application

10/071,686Filed 8 Feb 2002 · division

Priority

FR 87 1837130 Dec 1987

Published

US 2002/0039387 A11 Aug 2002

Granted

9 Dec 2003

Term ends

Not estimatedThe source records don’t support an estimate.

Classification11 codes

H04N 11/044
Codec means: involving transform coding
H04N 19/117
Characterised by the element, parameter or selection affected or controlled by the adaptive coding: filters, e.g. for pre-processing or…
H04N 19/124
Characterised by the element, parameter or selection affected or controlled by the adaptive coding: quantisation
H04N 19/15
Data rate or code amount at the encoder output: by monitoring actual compressed data size at the memory before deciding storage at the…

Family

PCT/FR88/00649Parent of this continuation · filed 30 Dec 1988

Application09/978,376Parent of this division · filed 17 Oct 2001

US 2002/0101928 A1Pre-grant publication · published 1 Aug 2002

US 6,563,875 B2Parent of this division

Application09/978,376Parent of this continuation

Application07/408,515Parent of this continuation

US 2002/0039387 A1Published application

US 6,661,844 B2This patent

From the US filing history. Foreign family members aren’t listed.

Adaptive method of encoding and decoding a series of pictures by transformation, and devices for implementing this method

Life of this patent

Adaptive method of encoding and decoding a series of pictures by transformation, and devices for implementing this method

Life of this patent

Abstract

Claims1