Video coding and decoding

A method of video decoding a picture coded by a set of coding blocks, each coding block corresponding to at least one group of the elementary coding elements and the coding blocks having a predetermined alignment in relation to the area of the picture, the method comprising the steps of:

• determining at least one separate coding object corresponding to at least one subset of the coding blocks defining at least one part of a picture being decoded;
• determining as a background object the subset of the coding blocks that corresponds to the part of the picture that excludes the at least one separate coding object;
• decoding the at least one separate coding object;
• and
• decoding the background object.

A video encoder comprising:

• means for dividing a picture into a set of regular shaped coding blocks having a predetermined alignment in relation to the area of the picture, each coding block corresponding to at least one group of elementary coding elements;
• means for determining at least one shape within a picture;
• means for selecting at least one subset of the coding blocks defining at least one area covering the at least one determined shape;
• means for determining as at least one separate coding object the selected at least one subset of the coding blocks;
• means for determining as a background object the subset of the coding blocks that corresponds to the part of the picture that excludes the at least one separate coding object;
• means for encoding the at least one separate coding object;
• and
• means for encoding as one coding object the background object.

A video decoder for video decoding a picture coded by a set of coding blocks, each coding block corresponding to at least one group of the elementary coding elements and the coding blocks having a predetermined alignment in relation to the area of the picture, the video decoder comprising:

• means for determining at least one separate coding object corresponding to at least one subset of the coding blocks defining at least one part of a picture being decoded;
• means for determining as a background object the subset of the coding blocks that corresponds to the part of the picture that excludes the at least one separate coding object;
• means for decoding the at least one separate coding object;
• and
• means for decoding as one coding object the background object.

A computer program product comprising computer executable program means for causing an apparatus to video encode a picture, the program product comprising

• computer executable program code for causing the apparatus to divide a picture into a set of regular shaped coding blocks having a predetermined alignment in relation to the area of the picture, each coding block corresponding to at least one group of elementary coding elements;
• computer executable program code for causing the apparatus to determine at least one shape within a picture;
• computer executable program code for causing the apparatus to select at least one subset of the coding blocks defining at least one area covering the at least one determined shape;
• computer executable program code for causing the apparatus to determine as at least one separate coding object the selected at least one subset of the coding blocks;
• computer executable program code for causing the apparatus to determine as a background object the subset of the coding blocks that corresponds to the part of the picture that excludes the at least one separate coding object;
• computer executable program code for causing the apparatus to encode the at least one separate coding object;
• and
• computer executable program code for causing the apparatus to encode as one coding object the background object.

A computer program product comprising computer executable program means for causing an apparatus to video decode a picture coded by a set of coding blocks, each coding block corresponding to at least one group of the elementary coding elements and the coding blocks having a predetermined alignment in relation to the area of the picture, the program product comprising

• computer executable program code for causing the apparatus to determine at least one separate coding object corresponding to at least one subset of the coding blocks defining at least one part of a picture being decoded;
• computer executable program code for causing the apparatus to determine as a background object the subset of the coding blocks that corresponds to the part of the picture that excludes the at least one separate coding object;
• computer executable program code for causing the apparatus to decode the at least one separate coding object;
• and
• computer executable program code for causing the apparatus to decode as one coding object the background object.

A video signal comprising:

• a plurality of compressed video coding blocks corresponding to at least one separate coding object corresponding to a part of a video encoded picture, the part of the video encoded picture having a variable size and position;
• an identifier for each of the at least one separate coding object;
• position and size information of the at least one separate coding object;
• and
• a plurality of compressed video coding blocks corresponding to a background object that corresponds to a set of the coding blocks that corresponds to the video encoded picture excluding the at least one separate coding object.