Indicating regions within a picture

1. A method for indicating size, shape and location of a region within a digital picture, the picture being divided into a set of blocks, the method comprising:

defining, in an encoder, a value for at least one size parameter being indicative of a number of the blocks within said region, and

selecting, in the encoder, a value for at least one shape evolution parameter being indicative of a selection order of the blocks into said region, wherein

said at least one size parameter comprises a size change rate parameter (GRIR) and a sequence number parameter of size change (SNIR).

2. The method as claimed in claim 1 , further comprising:

encoding said values for said at least one size parameter and said at least one shape evolution parameter into a bitstream of a video sequence in order to indicate size, shape and location of the region within the picture.

3. The method as claimed in claim 1 , further comprising:

including said value for the at least one shape evolution parameter in a parameter set of said picture.

4. The method as claimed in claim 1 , further comprising:

determining the number of the coding blocks within said region on the basis of at least one of the following: the value for said size change rate parameter, the value for said sequence number parameter of size change.

5. The method as claimed in claim 1 , further comprising:

including said value for the size change rate parameter in the parameter set of said picture, and

including said value for the sequence number parameter of size change in a slice header belonging to said region.

6. The method as claimed in claim 1 , further comprising:

determining the location of the blocks of the region on the basis of the value for the shape evolution parameter.

7. The method as claimed in claim 1 , further comprising:

selecting the value for said at least one shape evolution parameter from at least one of the following: raster scan, reverse raster scan, box-out clockwise, box-out counter-clockwise, wipe left, wipe right.

8. The method as claimed in claim 1 , wherein

the region comprises at least one slice, the slice comprising blocks having no essential prediction dependencies across boundaries of the slice,

whereby the blocks are selected into the slice in scanning order inside the region.

9. An encoder for encoding digital pictures into a bitstream, the encoder being arranged to

divide at least one picture into a set of blocks, determine a region within a picture, said region comprising at least one block,

define a value for at least one size parameter being indicative of a number of the blocks within said region,

select a value for at least one shape evolution parameter being indicative of a selection order of the blocks into said region, and

encode said values for at least one size parameter and said at least one shape evolution parameter in said bitstream in order to indicate size, shape and location of the region within the picture, wherein

said at least one size parameter comprises a size change rate parameter (GRIR) and a sequence number parameter of size change (SNIR).

10. The encoder as claimed in claim 9 , wherein the encoder is further arranged to

include said value for the at least one shape evolution parameter in a parameter set of said picture.

11. The encoder as claimed in claim 9 , wherein the encoder is further arranged to

include said value for the size change rate parameter in the parameter set of said picture, and

include said value for the sequence number parameter of size change in a slice header belonging to said region.

12. The encoder as claimed in claim 9 , wherein the encoder is further arranged to

select the value for said at least one shape evolution parameter from at least one of the following: raster scan, reverse raster scan, box-out clockwise, box-out counter-clockwise, wipe left, wipe right.

13. The encoder as claimed in claim 9 , wherein the region comprises at least one slice, the slice comprising blocks having no essential prediction dependencies across boundaries of the slice,

whereby the encoder is further arranged to select the blocks into the slice in scanning order inside the region.

14. A computer readable medium comprising a computer program product stored thereon and executable in a data processing device, for encoding digital pictures into a bitstream, the computer program product comprising

a computer program code for dividing at least one picture into a set of blocks,

a computer program code for determining a region within a picture, said region comprising at least one block,

a computer program code for defining a value for at least one size parameter being indicative of a number of the blocks within said region,

a computer program code for selecting a value for at least one shape evolution parameter being indicative of a selection order of the blocks into said region, and

a computer program code for encoding said values for at least one size parameter and said at least one shape evolution parameter in said bitstream in order to indicate size, shape and location of the region within the picture, wherein

said at least one size parameter comprises a size change rate parameter (GRIR) and a sequence number parameter of size change (SNIR).

15. A decoder for decoding a bitstream comprising at least one encoded digital picture, said at least one picture being divided into a set of encoded blocks, the decoder being arranged to

decode, from said bitstream, a value for at least one size parameter being indicative of a number of the encoded blocks of a region within the picture and a value for at least one shape evolution parameter being indicative of a selection order of the encoded blocks into said region,

determine size, shape and location of the region within the picture on the basis of the values for said parameters, and

decode the region according to said at least one size, shape and location, wherein

said at least one size parameter comprises a size change rate parameter (GRIR) and a sequence number parameter of size change (SNIR).

16. The decoder as claimed in claim 15 , wherein the decoder is arranged to

decode said value for the at least one shape evolution parameter from a picture parameter set of said region.

17. The decoder as claimed in claim 15 , wherein the decoder is arranged to

determine the number of the coding blocks within said region on the basis of at least one of the following: the value for said size change rate parameter, the value for said sequence number parameter of size change.

18. The decoder as claimed in claim 15 , wherein the decoder is arranged to

decode the value for said size change rate parameter from the parameter set of said picture, and

decode the value for said sequence number parameter of size change from a slice header belonging to said region.

19. The decoder as claimed in claim 15 , wherein the decoder is arranged to

determine the location of the blocks of the region on the basis of the value for the shape evolution parameter.

20. The decoder as claimed in claim 15 , wherein the value for said at least one shape evolution parameter is at least one of the following: raster scan, reverse raster scan, box-out clockwise, box-out counter-clockwise, wipe left, wipe right.

21. The decoder as claimed in claim 15 , wherein

the region comprising at least one slice, the slice comprising blocks having no essential prediction dependencies across boundaries of the slice,

whereby the decoder is arranged to decode the blocks into the slice in scanning order inside the region.

22. A computer readable medium comprising a computer program product stored thereon and executable in a data processing device, for decoding a bitstream comprising at least one encoded digital picture, said at least one picture being divided into a set of encoded blocks, the computer program product comprising:

a computer program code for decoding, from said bitstream, a value for at least one size parameter being indicative of a number of the encoded blocks of a region within the picture and a value for at least one shape evolution parameter being indicative of a selection order of the encoded blocks into said region,

a computer program code for determining size, shape and location of the region within the picture on the basis of the values for said parameters, and

a computer program code for decoding the region according said at least one size, shape and location, wherein

said at least one size parameter comprises a size change rate parameter (GRIR) and a sequence number parameter of size change (SNIR).

23. A video signal comprising a bitstream comprising at least one encoded digital picture, said at least one picture being divided into a set of encoded blocks, the video signal further comprising:

at least one size parameter value being indicative of a number of the encoded blocks of a region within the picture; and

at least one shape evolution parameter value being indicative of a selection order of the encoded blocks into said region, said parameters enabling to determine size, shape and location of the region within the picture, wherein

said at least one size parameter comprises a size change rate parameter (GRIR) and a sequence number parameter of size change (SNIR).