Systems and methods for coding

Patent metadata

Field	Value
Publication number	US-11967119-B2
Application number	US-202117643837-A
Country	US
Kind code	B2
Filing date	Dec 12, 2021
Priority date	Jul 22, 2019
Publication date	Apr 23, 2024
Grant date	Apr 23, 2024

Abstract

The present disclosure relates to systems and methods for coding. The methods may include receiving at least two contexts, for each of the at least two contexts, obtaining at least one coding parameter corresponding to the context from at least one lookup table, determining a probability interval value corresponding to the context based on a previous probability interval value and the at least one coding parameter, determining a normalized probability interval value corresponding to the context by performing a normalization operation on the probability interval value, determining a probability interval lower limit corresponding to the context based on a previous probability interval lower limit and the at least one coding parameter, determining a normalized probability interval lower limit corresponding to the context by performing the normalization operation on the probability interval lower limit, and outputting at least one byte based on the normalized probability interval lower limit.

First claim

We claim:

1. A system for coding, comprising:
at least one storage medium including a set of instructions; and
at least one processor in communication with the at least one storage medium, wherein when executing the set of instructions, the at least one processor is directed to cause the system to:
receive at least two contexts including a first context and a second context;
for each of the at least two contexts,
obtain, from at least one lookup table, at least one coding parameter corresponding to the context;
determine a probability interval value corresponding to the context based on a previous probability interval value and the at least one coding parameter;
determine a normalized probability interval value corresponding to the context by performing a normalization operation on the probability interval value;
determine a probability interval lower limit corresponding to the context based on a previous probability interval lower limit and the at least one coding parameter;
determine a normalized probability interval lower limit corresponding to the context by at least performing the normalization operation on the probability interval lower limit; and
output at least one byte corresponding to the context based on the normalized probability interval lower limit.

2. The system of claim 1 , wherein the at least one coding parameter includes at least one of a context probability, a next less probable symbol (NLPS) index, a next more probable symbol (NIPS) index, a more probable symbol (MPS) index, a interval switch flag, or a count of leading zeros (LZs).

3. The system of claim 1 , wherein to obtain, from the at least one lookup table, the at least one coding parameter corresponding to the context, the at least one processor is directed to cause the system to:
determine whether the first context is not equal to the second context;
in response to a determination that the first context is not equal to the second context, retrieve at least one first coding parameter corresponding to the first context and at least one second coding parameter corresponding to the second context from the at least one lookup table with the first context and the second context as indexes respectively.

4. The system of claim 3 , wherein to obtain, from the at least one lookup table, the at least one coding parameter corresponding to the context, the at least one processor is directed to cause the system to:
in response to a determination that the first context is equal to the second context, retrieve the at least one first coding parameter corresponding to the first context from a first lookup table of the at least one lookup table with the first context as index;
determine whether a first MPS index in the at least one first coding parameter is not equal to a first decision corresponding to the first context; and
in response to a determination that the first MPS index is not equal to the first decision, retrieve the at least one second coding parameter corresponding to the second context from a second lookup table of the at least one lookup table with a first NLPS index in the at least one first coding parameter as index.

5. The system of claim 4 , wherein to obtain, from the at least one lookup table, the at least one coding parameter corresponding to the context, the at least one processor is directed to cause the system to:
in response to a determination that the first MPS index is equal to the first decision, determine whether the previous probability interval value is less than an OR operation result of a first context probability in the at least one first coding parameter and a predetermined value;
in response to a determination the previous probability interval value is less than the OR operation result of the first context probability and the predetermined value, retrieve the at least one second coding parameter from the second lookup table with a first NMPS index in the at least one first coding parameter as index; and
in response to a determination the previous probability interval value is larger than or equal to the OR operation result of the first context probability and the predetermined value, determine the at least one second coding parameter based on the at least one first coding parameter.

6. The system of claim 1 , wherein the at least one processor is directed to cause the system further to:
determine whether a decision corresponding to the context, an MPS index in the at least one coding parameter, a context probability in the at least one coding parameter, and the previous probability interval value satisfy a preset condition.

7. The system of claim 6 , wherein to determine the probability interval value corresponding to the context based on the previous probability interval value and the at least one coding parameter, the at least one processor is directed to cause the system to:
in response to a determination that the decision, the MPS index, the context probability, and the previous probability interval value satisfy the preset condition, determine the probability interval value equal to the context probability; and
in response to a determination that the decision, the MPS index, the context probability, and the previous probability interval value do not satisfy the preset condition, determine the probability interval value equal to the previous probability interval value minus the context probability.

8. The system of claim 6 , wherein to determine the normalized probability interval value corresponding to the context by performing the normalization operation on the probability interval value, the at least one processor is directed to cause the system to:
in response to a determination that the decision, the MPS index, the context probability, and the previous probability interval value satisfy the preset condition, determine a shift digit corresponding to the context equal to a count of LZs in the at least one coding parameter;
in response to a determination that the decision, the MPS index, the context probability, and the previous probability interval value do not satisfy the preset condition, determine the shift digit corresponding to the context based on the previous probability interval value and a context probability in the at least one coding parameter; and
determine the normalized probability interval value corresponding to the context by performing the normalization operation on the probability interval value based on the shift digit.

9. The system of claim 6 , wherein to determine the probability interval lower limit corresponding to the context based on a previous probability interval lower limit and the at least one coding parameter, the at least one processor is directed to cause the system to:
in response to a determination that the decision, the MPS index, the context probability, and the previous probability interval value satisfy the preset condition, determine the probability interval lower limit equal to the previous probability interval lower limit plus a context probability in the at least one coding parameter; and
in response to a determination that the decision, the MPS index, the context probability, and the previous probability interval value do not satisfy the preset condition, determine the probability interval lower limit equal to the previous probability interval lower limit.

10. The system of claim 1 , wherein to determine the normalized probability interval lower limit corresponding to the context by at least performing the normalization operation on the probability interval lower limit, the at least one processor is directed to cause the system to:
determine an intermediate probability interval lower limit corresponding to the context by performing the norm

Assignees

• Zhejiang Dahua Technology Co

Inventors

• Yu Pan
• Zhu Zhuqing
• Chen Qi
• Fang Wei
• Yang Yinchang

Classifications

• G06T9/00 Primary

  Image coding (bandwidth or redundancy reduction for static pictures H04N1/41; coding or decoding of static colour picture signals H04N1/64; methods or arrangements for coding, decoding, compressing or decompressing digital video signals H04N19/00) · CPC title

• G06F1/03

  working, at least partly, by table look-up (G06F1/025 takes precedence) · CPC title

• H03M7/3079 Primary

  Context modeling · CPC title

• H03M7/6011

  Encoder aspects · CPC title

• H03M7/3084

  using adaptive string matching, e.g. the Lempel-Ziv method · CPC title