Multiple technique entropy coding system and method

• US 8,947,271 B2
• Filed: 06/07/2011
• Issued: 02/03/2015
• Est. Priority Date: 04/17/2003
• Status: Expired due to Fees

• Current Assignee: Straight Path IP Group, Inc. (Verizon Communications Inc.)
• Original Assignee: Soryn IP Capital Management, LLC
• Inventors: Lynch, William C., Kolarov, Krasimir D., Saunders, Steven E.
• Primary Examiner(s): NGUYEN, LINH V
• Application Number:
  US13/155,280
• Publication Number:
  US 20110234431A1
• Time in Patent Office: 1,337 Days
• Field of Search: 341/51, 341/65, 341/67, 341/106, 341/107
• US Class Current: 341/51
• CPC Class Codes: H03M 7/40 Conversion to or from variable length codes, e.g. Shannon-Fano code, Huffman code, Morse code
• CPC Class Codes: H03M 7/4075 Golomb codes
• CPC Class Codes: H04N 19/12 Selection from among a plurality of transforms or standards, e.g. selection between discrete cosine transform [DCT] and sub-band transform or selection between H.263 and H.264
• 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 19/134 characterised by the element, parameter or criterion affecting or controlling the adaptive coding
• CPC Class Codes: H04N 19/136 Incoming video signal characteristics or properties
• CPC Class Codes: H04N 19/18 the unit being a set of transform coefficients
• CPC Class Codes: H04N 19/1887 the unit being a variable length codeword
• CPC Class Codes: H04N 19/60 using transform coding
• CPC Class Codes: H04N 19/91 Entropy coding, e.g. variable length coding [VLC] or arithmetic coding

Abstract

A system, method and computer program product having optimal matching to a known or measured probability distribution encodes data without the use of an excessively large lookup table. An encoder constructed according to the present invention uses two or more different encoding methods in combination. In one embodiment, Huffman coding by table lookup is combined with computational generation, such as by using an exponential Golomb equation. The most commonly occurring elements are looked up in a small Huffman table, while the remaining elements are coded with the equation. In another embodiment, data is encoded using two or more equations. In yet another embodiment, data is encoded using multiple tables in conjunction with one or more equations.

Claims

1. A method of compressing data, comprising:

calculating from an incoming data stream binary representations of magnitudes of symbols for each portion of the incoming data stream according to an algorithmic analysis;

selectively applying a first coding technique to symbols of the portions of the incoming data stream that have binary representations of magnitudes greater than a first threshold value;

selectively applying a second coding technique to portions of the incoming data stream that have binary representations of magnitudes less than the first threshold value but greater than a second threshold value; and

selectively applying a third coding technique to portions of the incoming data stream that have binary representations of magnitudes less than the second threshold value.

3. The method as claimed in claim 1, wherein the first coding technique comprises an exponential Golumb encoding method encoding the portions of the incoming data stream that have binary representations of magnitudes greater than the first threshold value.

6. The method as claimed in claim 3, wherein the third coding technique comprises Huffman encoding any portion of the incoming data stream having a binary representation of a magnitude that is less than the second threshold value.

2. A system comprising:

means for assigning from an incoming data stream binary representations of magnitudes of symbols to each of the portions of the incoming data stream;

means for applying a first coding technique when binary representations of the magnitudes of symbols of any portion of the incoming data stream is greater than a first threshold value;

means for applying a second coding technique when the binary representations of magnitude of any portion of the incoming data stream is less than the first threshold value but greater than a second threshold value; and

means for applying a third coding technique when the binary representations of magnitude of any portion of the incoming data stream is less than the second threshold value.

4. The system as claimed in claim 2, wherein the means for applying the first coding technique comprises an exponential Golumb encoder encoding any portion of the incoming data stream having a binary representation of a magnitude that is greater than the first threshold value.

5. The system as claimed in claim 4, wherein the means for applying the third coding technique comprises a Huffman encoder for encoding any portion of the incoming data stream having a binary representation of a magnitude that is less than the second threshold value.