Picture coding and decoding

• US 8,861,587 B2
• Filed: 06/29/2011
• Issued: 10/14/2014
• Est. Priority Date: 07/21/2010
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Sjoberg, Rickard, Priddle, Clinton
• Primary Examiner(s): Ortiz Criado, Jorge L
• Assistant Examiner(s): MYERS III, PAUL W
• Application Number:
  US13/144,369
• Publication Number:
  US 20130003868A1
• Time in Patent Office: 1,203 Days
• Field of Search: 375/240.12, 375/E8.243, 375/E7.027, 375/240.26, 375/240.02
• US Class Current: 375/240
• CPC Class Codes: A63B 2053/0491 with added weights, e.g. changeable, replaceable
• CPC Class Codes: A63B 53/04 Heads
• CPC Class Codes: A63B 53/0408 characterised by specific dimensions, e.g. thickness
• CPC Class Codes: A63B 53/0433 with special sole configurations
• CPC Class Codes: A63B 53/0454 Strengthening ribs on the rear surface of the impact face plate
• CPC Class Codes: A63B 53/0458 with non-uniform thickness of the impact face plate
• CPC Class Codes: A63B 53/047 iron-type
• CPC Class Codes: A63B 53/0475 with one or more enclosed cavities
• CPC Class Codes: A63B 60/02 Ballast means for adjusting the centre of mass A63B60/24, A63B60/54 take precedence
• CPC Class Codes: A63B 60/54 with means for damping vibrations
• CPC Class Codes: H04N 19/119 Adaptive subdivision aspects, e.g. subdivision of a picture into rectangular or non-rectangular coding blocks
• CPC Class Codes: H04N 19/174 the region being a slice, e.g. a line of blocks or a group of blocks
• CPC Class Codes: H04N 19/182 the unit being a pixel
• CPC Class Codes: H04N 19/196 being specially adapted for the computation of encoding parameters, e.g. by averaging previously computed encoding parameters processing of motion vectors H04N19/513
• CPC Class Codes: H04N 19/30 using hierarchical techniques, e.g. scalability H04N19/63 takes precedence
• CPC Class Codes: H04N 19/31 in the temporal domain
• CPC Class Codes: H04N 19/33 in the spatial domain
• CPC Class Codes: H04N 19/436 using parallelised computational arrangements
• CPC Class Codes: H04N 19/46 Embedding additional information in the video signal during the compression process H04N19/517, H04N19/68, H04N19/70 take precedence
• CPC Class Codes: H04N 19/70 characterised by syntax aspects related to video coding, e.g. related to compression standards
• CPC Class Codes: H04N 19/91 : Entropy coding, e.g. variable length coding [VLC] or arithmetic coding

Abstract

A picture (1) with multiple slices (2-5) is encoded by generating a coded slice representation for each of the slices. A slice flag is set to a first value for the first slice (2) in the picture (1) and corresponding slice flags of the remaining slices (3-5) are set to a second defined value. A respective slice address is generated for each remaining slice (3-5) to enable identification of the slice start position within the picture (1) for the slice. A coded picture representation (50) of the picture (1) comprises the coded slice representations, the slice addresses and the slice flags. The slice flags enable differentiation between slices (3-5) for which slice addresses are required and the slice (2) per picture (1) for which no slice address is needed to identify its slice start position.

Claims

1. A method of coding a picture comprising N≧

2 slices, said method comprising;

generating, for each slice of said N slices, a coded slice representation based on pixel values of pixels in said slice;

setting a slice flag associated with a first slice of said N slices to a first defined value;

setting, for each slice of N−

1 remaining slices of said N slices, a slice flag associated with said slice to a second defined value;

generating, for each slice of said N−

1 remaining slices, a slice address allowing identification of a position of a first coding unit of said slice within said picture;

generating a coded picture representation of said picture comprising said N coded slice representations, said N−

1 slice addresses and said N slice flags; and

determining a length of said N−

1 slice addresses in terms of number of bits as one of ceil (log₂(P)) and ceil (log₂(P−

1)), wherein ceil( ) denotes the ceiling function defined as ceil(x)=┌

x┐ and

outputs the smallest integer not less than x, and P denotes a total number of possible slice addresses in said picture.

2. The method according to claim 1, wherein said picture comprises multiple largest coding units, which have a selected size in terms of number of pixels and can be hierarchically split into multiple coding units having respective sizes that are smaller than said selected size, said method further comprising determining a length of said N−

1 slice addresses in terms of number of bits based on a hierarchical granularity selected for said picture, said hierarchical granularity defines a hierarchical level for slice border alignment within said picture, where said hierarchical level defines a size of a smallest possible addressable coding unit at which a start of a slice in said picture can be aligned.

3. The method according to claim 2, wherein determining said length of said N−

1 slice addresses comprises determining said length of said N−

1 slice addresses based on said hierarchical granularity and based on a total number of largest coding units in said picture.

4. A method of decoding a coded picture representation of a picture comprising N≧

2 slices, said method comprising;

retrieving, from said coded picture representation, a slice flag associated with a slice of said N slices;

generating a decoded representation of pixel values of pixels in said slice based on a coded slice representation associated with said slice and retrieved from said coded picture representation;

assigning said pixel values to pixels in a first portion of said picture in response to when a slice flag associated with said slice and retrieved from said coded picture representation has a first defined value;

retrieving, in response to when said slice flag associated with said slice has a second defined value, a slice address from said coded picture representation;

assigning, in response to when said slice flag associated with said slice has said second defined value, said pixel values to pixels in a portion of said picture identified based on said slice address; and

determining, in response to when said slice flag associated with said slice has said second defined value, a length of said slice address in terms of number of bits as one of ceil (log₂(P)) and ceil(log₂(P−

1)), wherein ceil( ) denotes the ceiling function defined as ceil(x)=┌

x┐ and

outputs the smallest integer not less than x , and P denotes a total number of possible slice addresses in said picture.

5. The method according to claim 4, wherein said picture comprises multiple largest coding units, which have a selected size in terms of number of pixels and can be hierarchically split into multiple coding units having respective sizes that are smaller than said selected size, said method further comprising:

retrieving, in response to when said slice flag associated with said slice has said second defined value, information of a hierarchical granularity associated with said coded picture presentation, said hierarchical granularity defining a hierarchical level for slice border alignment within said picture, said hierarchical level defining a size of a smallest possible addressable coding unit at which a start of a slice in said picture can be aligned; and

determining a length of said slice address in terms of number of bits based on said information of said hierarchical granularity.

6. The method according to claim 5, further comprising retrieving information of a total number of largest coding units in said picture from said coded picture representation, wherein determining said length of said slice address comprises determining said length of said slice address based on said information of said hierarchical granularity and based on said total number of largest coding units.

7. The method according to claim 4, further comprising:

determining, in response to when said slice flag associated with said slice has said second defined value, a first representation of the coordinates of a position of a largest coding unit within said picture based on said slice address;

determining, in response to when said slice flag associated with said slice has said second defined value, a second representation of the coordinates of a position of a first coding unit of said slice within said largest coding unit; and

identifying said portion of said picture based on said first representation and said second representation.

8. The method according to claim 7, wherein said picture comprises multiple largest coding units, which have a selected size in terms of number of pixels and can be hierarchically split into multiple coding units having respective sizes that are smaller than said selected size, said method further comprising:

retrieving, in response to when said slice flag associated with said slice has said second defined value, information of a hierarchical granularity associated with said coded picture presentation, said hierarchical granularity defining a hierarchical level for slice border alignment within said picture, said hierarchical level defining a size of a smallest possible addressable coding unit at which a start of a slice in said picture can be aligned; and

determining a length of said slice address in terms of number of bits based on said information of said hierarchical granularity, wherein determining said first representation comprises determining, in response to when said slice flag associated with said slice has said second defined value, said first representation based on said slice address and said information of said hierarchical granularity.

9. The method according to claim 7, wherein said picture comprises multiple largest coding units, which have a selected size in terms of number of pixels and can be hierarchically split into multiple coding units having respective sizes that are smaller than said selected size, said method further comprising:

retrieving, in response to when said slice flag associated with said slice has said second defined value, information of a hierarchical granularity associated with said coded picture presentation, said hierarchical granularity defining a hierarchical level for slice border alignment within said picture, said hierarchical level defining a size of a smallest possible addressable coding unit at which a start of a slice in said picture can be aligned; and

determining a length of said slice address in terms of number of bits based on said information of said hierarchical granularity, wherein determining said second representation comprises determining, in response to when said slice flag associated with said slice has said second defined value, said second representation based on said slice address, said information of said hierarchical granularity and said first representation.

10. A device for coding a picture comprising N≧

2 slices, said device comprising;

a representation generator configured to generate, for each slice of said N slices, a coded slice representation based on pixel values of pixels in said slice;

a flag setter configured to set a slice flag associated with a first slice of said N slices to a first defined value and set, for each slice of N−

1 remaining slices of said N slices, a slice flag associated with said slice to a second defined value;

an address generator configured to generate, for each slice of said N−

1 remaining slices, a slice address that identifies a position of a first coding unit of said slice within said picture;

a representation manager configured to generate a coded picture representation of said picture comprising said N coded slice representations, said N−

1 slice addresses and said N slice flags; and

a length determiner configured to determine a length of said N−

1 slice addresses in terms of number of bits as one of ceil(log₂(P)) and ceil(log₂(P−

1)), wherein ceil( ) denotes the ceiling function defined as ceil(x)=┌

x┐ and

outputs the smallest integer not less than x, and P denotes a total number of possible slice addresses in said picture.

11. The device according to claim 10, wherein said picture comprises multiple largest coding units, which have a selected size in terms of number of pixels and can be hierarchically split into multiple coding units having respective sizes that are smaller than said selected size, said device further comprising a length determiner configured to determine a length of said N−

1 slice addresses in terms of number of bits based on a hierarchical granularity selected for said picture, said hierarchical granularity defines a hierarchical level for slice border alignment within said picture, where said hierarchical level defines a size of a smallest possible addressable coding unit at which a start of a slice in said picture can be aligned.

12. The device according to claim 11, wherein said length determiner is configured to determine said length of said N−

1 slice addresses based on said hierarchical granularity and based on a total number of largest coding units in said picture.

13. A device for decoding a coded picture representation of a picture comprising N≧

2 slices, said device comprising;

a representation retriever configured to retrieve, from said coded picture representation, a slice flag associated with a slice of said N slices;

a representation generator configured to generate a decoded representation of pixel values of pixels in said slice based on a coded slice representation associated with said slice and retrieved from said coded picture representation;

an address retriever configured to retrieve, in response to when a slice flag associated with said slice and retrieved from said coded picture representation has a second defined value, a slice address associated with said slice from said coded picture representation;

a value assigner configured to assign said pixel values to pixels in a first portion of said picture in response to when said slice flag associated with said slice has a first defined value and assign, in response to when said slice flag associated with said slice has said second defined value, said pixel values to pixels in a portion of said picture identified based on said slice address; and

a length determiner configured to determine, in response to when said slice flag associated with said slice has said second defined value, a length of said N−

1 slice addresses in terms of number of bits as one of ceil(log₂(P)) and ceil(log₂(P−

1)), wherein ceil( ) denotes the ceiling function defined as ceil(x)=┌

x┐ and

outputs the smallest integer not less than x, and P denotes a total number of possible slice addresses in said picture.

14. The device according to claim 13, wherein said picture comprises multiple largest coding units, which have a selected size in terms of number of pixels and can be hierarchically split into multiple coding units having respective sizes that are smaller than said selected size, said device further comprising:

a granularity information retriever configured to retrieve, in response to when said slice flag associated with said slice has said second defined value, information of a hierarchical granularity associated with said coded picture presentation, said hierarchical granularity defining a hierarchical level for slice border alignment within said picture, said hierarchical level defining a size of a smallest possible addressable coding unit at which a start of a slice in said picture can be aligned; and

a length determiner configured to determine a length of said slice address in terms of number of bits based on said information of said hierarchical granularity.

15. The device according to claim 14, further comprising a coding unit information retriever configured to retrieve information of a total number of largest coding units in said picture from said coded picture representation, wherein said length determiner is configured to determine said length of said slice address based on said information of said hierarchical granularity and based on said total number of largest coding units.

16. The device according to claim 13, wherein said address retriever is configured to:

i) determine, in response to when said slice flag associated with said slice has said second defined value, a first representation of the coordinates of a position of a largest coding unit within said picture based on said slice address,

ii) determine, in response to when said slice flag associated with said slice has said second defined value, a second representation of the coordinates of a position of a first coding unit of said slice within said largest coding unit, and

iii) identify said portion of said picture based on said first representation and said second representation.

17. The device according to claim 16, wherein said picture comprises multiple largest coding units, which have a selected size in terms of number of pixels and can be hierarchically split into multiple coding units having respective sizes that are smaller than said selected size, said device further comprising:

a granularity information retriever configured to retrieve, in response to when said slice flag associated with said slice has said second defined value, information of a hierarchical granularity associated with said coded picture presentation, said hierarchical granularity defining a hierarchical level for slice border alignment within said picture, said hierarchical level defining a size of a smallest possible addressable coding unit at which a start of a slice in said picture can be aligned; and

a length determiner configured to determine a length of said slice address in terms of number of bits based on said information of said hierarchical granularity,

wherein said address retriever is configured to determine, in response to when said slice flag associated with said slice has said second defined value, said first representation based on said slice address and said information of said hierarchical granularity.

18. The device according to claim 16, wherein said picture comprises multiple largest coding units, which have a selected size in terms of number of pixels and can be hierarchically split into multiple coding units having respective sizes that are smaller than said selected size, said device further comprising:

a granularity information retriever configured to retrieve, in response to when said slice flag associated with said slice has said second defined value, information of a hierarchical granularity associated with said coded picture presentation, said hierarchical granularity defining a hierarchical level for slice border alignment within said picture, said hierarchical level defining a size of a smallest possible addressable coding unit at which a start of a slice in said picture can be aligned; and

a length determiner configured to determine a length of said slice address in terms of number of bits based on said information of said hierarchical granularity,

wherein said address retriever is configured to determine, in response to when said slice flag associated with said slice has said second defined value, said second representation based on said slice address, said information of said hierarchical granularity and said first representation.

19. A media terminal comprising:

a memory storing a coded representation of a picture comprising multiple slices and being composed of multiple largest coding units having a selected size in terms of number of pixels; and

a device for decoding said coded representation of the picture according to claim 13.