METHOD AND APPARATUS FOR PACKAGING IMAGE DATA FOR TRANSMISSION OVER A NETWORK

• US 20160142737A1
• Filed: 10/20/2015
• Published: 05/19/2016
• Est. Priority Date: 08/26/2005
• Status: Active Grant

• Current Assignee: RGB Systems Incorporated
• Original Assignee: RGB Systems Incorporated
• Inventors: SMITH, PETER LIONEL
• Granted Patent: US 10,244,263 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04N 19/107 between spatial and temporal predictive coding, e.g. picture refresh
• CPC Class Codes: H04N 19/13 Adaptive entropy coding, e.g. adaptive variable length coding [AVLC] or context adaptive binary arithmetic coding [CABAC]
• CPC Class Codes: H04N 19/132 Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking
• CPC Class Codes: H04N 19/17 the unit being an image region, e.g. an object
• 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 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/182 the unit being a pixel
• CPC Class Codes: H04N 19/186 the unit being a colour or a chrominance component
• CPC Class Codes: H04N 19/1883 the unit relating to sub-band structure, e.g. hierarchical level, directional tree, e.g. low-high [LH], high-low [HL], high-high [HH]
• CPC Class Codes: H04N 19/33 in the spatial domain
• CPC Class Codes: H04N 19/42 characterised by implementation details or hardware specially adapted for video compression or decompression, e.g. dedicated software implementation H04N19/635 takes precedence
• CPC Class Codes: H04N 19/423 characterised by memory arrangements H04N19/433 takes precedence
• CPC Class Codes: H04N 19/507 using conditional replenishment
• CPC Class Codes: H04N 19/51 Motion estimation or motion compensation
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/63 using sub-band based transform, e.g. wavelets
• CPC Class Codes: H04N 19/635 characterised by filter definition or implementation details
• CPC Class Codes: H04N 19/645 by grouping of coefficients into blocks after the transform
• CPC Class Codes: H04N 19/647 using significance based coding, e.g. Embedded Zerotrees of Wavelets [EZW] or Set Partitioning in Hierarchical Trees [SPIHT]
• CPC Class Codes: H04N 19/66 involving data partitioning, i.e. separation of data into packets or partitions according to importance
• CPC Class Codes: H04N 19/68 : involving the insertion of resynchronisation markers into the bitstream
• CPC Class Codes: H04N 19/70 : characterised by syntax aspects related to video coding, e.g. related to compression standards
• CPC Class Codes: H04N 19/86 : involving reduction of coding artifacts, e.g. of blockiness
• CPC Class Codes: H04N 19/89 : involving methods or arrangements for detection of transmission errors at the decoder
• CPC Class Codes: H04N 19/91 : Entropy coding, e.g. variable length coding [VLC] or arithmetic coding
• CPC Class Codes: H04N 19/96 : Tree coding, e.g. quad-tree coding

Abstract

Methods of data encoding using trees formed with logic gates are described which lead to spatial compression of image data. Data encoding is achieved using a five-level wavelet transform, such as the Haar or the 2/10 transform. A dual transform engine is used, the first and engine being used for the first part of the first-level transform, the second part of the first-level transform and the subsequent-level transforms being performed by the second transform engine within a time interval which is less than or equal to the time taken by the first transform engine to effect the part-transform. Each bit plane of the resulting coefficients is then encoded by forming a tree structure from the bits and OR logical combinations thereof. Redundant data are removed from the resulting tree structure, and further data can be removed by using a predetermined compression profile. The resulting blocks of compressed data are of variable length and are packaged with sync words and index words for transmission so that the location and identity of the transformed data blocks can be determined from the received signal.

Claims

1. A method of configuring, by a codec, a plurality of data blocks into a data stream for transmission over a communications network comprising:

for each data block, forming a respective indexed data block comprising;

a sync word that is distinguishable from other data in said data stream and that is identical for all indexed data blocks;

an index number which uniquely identifies the data block within said plurality of data blocks; and

the respective data block.

3. The method of claim 1 wherein said sync word comprises a repeated sequence of identical bits.

4. The method of claim 3 wherein said identical bits are each equal to 1.

5. The method of claim 1 wherein said index number for each said indexed data block comprises a bit sequence having a first number of bits.

6. The method of claim 1 wherein said plurality of data blocks have a plurality of sizes.

7. The method of claim 5 wherein said first number of bits is 11 bits.

8. The method of claim 1 wherein said blocks comprise image data.

9. The method of claim 8 wherein said blocks comprise image data that has been transformed in accordance with a wavelet transform.

10. The method of claim 1 further comprising the step of packaging said data block into one or more data packets for transmission over said communications network.

11. The method of claim 10 wherein said data packets comprise a fixed size.

12. The method of claim 11 wherein said step of packaging said data block comprises adding padding to fill a partially filled of said data packets.

2. The method of claim 2, wherein each said indexed data block comprises, in sequence, said sync word, said index number and said respective data block.

13. A method of retrieving a plurality of data blocks from a data stream transmitted over a communications network by a codec, comprising the steps of:

locating within said data stream each sync word identifying a data block;

retrieving each said identified data block from said data stream.

14. The method of claim 13, wherein each of said data blocks comprises a characteristic that enables it to be verified as a valid data block, the method further comprising the steps of:

determining whether said characteristic of each said identified data block verifies said data block as a potentially valid data block;

determining whether each said potentially valid data block is followed by a sync word identifying a next sequential data block in said data stream;

validating said potentially valid data block as a valid data block only if said potentially valid data block is followed immediately within said data stream by said sync word identifying said next sequential data block in said data stream.

15. The method of claim 14 further comprising selecting for a subsequent processing step only those data blocks that have been validated as valid data blocks.

16. The method of claim 15 wherein said data blocks comprise data corresponding to sequence of image frames, and wherein said subsequent processing step comprises reconstructing said image frames from said data blocks.

17. The method of claim 16 wherein said data blocks comprise compressed data, and said subsequent processing step comprises decompressing said compressed data.

18. The method of claim 16 wherein each of said data blocks comprises an index number corresponding to a location within an image frame.

19. The method of claim 16 wherein said reconstruction of said image frames comprises replacing a data block comprising a first index number of a previous image frame with a validated data block of a subsequent image frame comprising said first index number.

20. The method of claim 17 wherein said subsequent processing step comprises transforming said decompressed data using a reverse wavelet transform.