US 10,257,516 B2 · Encoding device, decoding device, encoding method, and decoding method for coding efficiency

Abstract

According to an embodiment, an encoding device includes a deriving unit and an encoding unit. The deriving unit is configured to derive a first reference value based on fixed point precision representing roughness of a weighting factor that is used for multiplying a reference image. The encoding unit is configured to encode a first difference value that is a difference value between the weighting factor and the first reference value and the fixed point precision. The weighting factor is included in a first range of predetermined bit precision having the first reference value at approximate center. The first difference value is in the predetermined range.

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Claims25

Dependent claims

An electronic apparatus, comprising

input circuitry configured to input encoded data;
and
decoder circuitry coupled to the input circuity and configured to:
decode a first denom for a luma weighting factor of a target image from the encoded data;
derive a first reference value of the luma weighting factor according to the first denom, wherein the first reference value is equal to a value obtained by left shift of “1” by at least one binary digit specified by the first denom;
decode a first difference value of the luma weighting factor from the encoded data, wherein the first difference value is equal to a value of a difference between the luma weighting factor and the first reference value, wherein the first difference value is in a fixed range of −128 to +127 regardless of the first denom;
derive the luma weighting factor by adding the first reference value and the first difference value, wherein the luma weighting factor is in a range of (the first reference value −128) to (the first reference value +127);
derive a second reference value of a chroma offset of the target image by subtracting a value obtained by both multiplying a median value of a maximum pixel value by a chroma weighting factor and shifting to right for at least one binary digit specified by a second denom for the chroma weighting factor, from the median value;
decode a second difference value of the chroma offset from the encoded data, wherein the second difference value is equal to a value of a difference between the chroma offset and the second reference value, wherein the second difference value is in a fixed range of −2n to +2n−1;
and
derive the chroma offset by adding the second reference value and the second difference value, wherein the chroma offset is in a range of (the second reference value −2n) to (the second reference value +2n−1).

8 more elements

A decoding method, comprising

inputting encoded data;
decoding, by decoder circuitry, a first denom for a luma weighting factor of a target image from the encoded data;
deriving, by the decoder circuitry, a first reference value of the luma weighting factor according to the first denom, wherein the first reference value is equal to a value obtained by left shift of “1” by at least one binary digit specified by the first denom;
decoding, by the decoder circuitry, a first difference value of the luma weighting factor from the encoded data, wherein the first difference value is equal to a value of a difference between the luma weighting factor and the first reference value, and the first difference value is in a fixed range of −128 to +127 regardless of the first denom;
deriving, by the decoder circuitry, the luma weighting factor by adding the first reference value and the first difference value, wherein the luma weighting factor is in a range of (the first reference value −128) to (the first reference value +127);
deriving, by the decoder circuitry, a second reference value of a chroma offset of the target image by subtracting a value obtained by both multiplying a median value of a maximum pixel value by a chroma weighting factor and shifting to right for at least one binary digit specified by a second denom for the chroma weighting factor, from the median value;
decoding, by the decoder circuitry, a second difference value of the chroma offset from the encoded data, wherein the second difference value is equal to a value of a difference between the chroma offset and the second reference value, wherein the second difference value is in a fixed range of −2n to +2n−1;
and
deriving, by the decoder circuitry, the chroma offset by adding the second reference value and the second difference value, wherein the chroma offset is in a range of (the second reference value −2n) to (the second reference value +2n−1).

6 more elements

A non-transitory computer readable medium storing computer executable instructions that, when executed by decoder circuitry, cause the decoder circuitry to:

decode a first denom for a luma weighting factor of a target image from encoded data;
derive a first reference value of the luma weighting factor according to the first denom, wherein the first reference value is equal to a value obtained by left shift of “1” by at least one binary digit specified by the first denom;
decode a first difference value of the luma weighting factor from the encoded data, wherein the first difference value is equal to a value of a difference between the luma weighting factor and the first reference value, and the first difference value is in a fixed range of −128 to +127 regardless of the first denom;
derive the luma weighting factor by adding the first reference value and the first difference value, wherein the luma weighting factor is in a range of (the first reference value −128) to (the first reference value +127);
derive a second reference value of a chroma offset of the target image by subtracting a value obtained by both multiplying a median value of a maximum pixel value by a chroma weighting factor and shifting to right for at least one binary digit specified by a second denom for the chroma weighting factor, from the median value;
decode a second difference value of the chroma offset from the encoded data, wherein the second difference value is equal to a value of a difference between the chroma offset and the second reference value, wherein the second difference value is in a fixed range of −2n to +2n−1;
and
derive the chroma offset by adding the second reference value and the second difference value, wherein the chroma offset is in a range of (the second reference value −2n) to (the second reference value +2n−1).

5 more elements

Dependencies are inferred from the claim text.

Description23,288 words

Summary346 words

#Embodiments described herein relate generally to an encoding method, a decoding method, an encoding device, and a decoding device.

#In recent years, a method of encoding an image with markedly improved coding efficiency is recommended as ITU-T REC. H.264 and ISO/IEC 14496-10 (hereinafter, referred to as “H.264”) in cooperation of ITU-T (International Telecommunication Union Telecommunication Standardization Sector) and ISO (International Organization for Standardization)/IEC (International Electrotechnical Commission).

#In H.264, an inter-prediction coding system is disclosed in which redundancy in the time direction is eliminated to achieve high coding efficiency by making a motion compensation prediction of fractional precision using a coded image as a reference image.

Brief description of the drawings37 figures

#FIG. 1 is a block diagram that illustrates an example of an encoding device according to a first embodiment;

#FIG. 2A is an explanatory diagram that illustrates an example of a predicted coding sequence for a pixel block according to the first embodiment;

#FIG. 2B is an explanatory diagram that illustrates another example of a predicted coding sequence for a pixel block according to the first embodiment;

Detailed description22,145 words

#According to an embodiment, an encoding device includes a deriving unit and an encoding unit. The deriving unit is configured to derive a first reference value based on fixed point precision representing roughness of a weighting factor that is used for multiplying a reference image. The encoding unit is configured to encode a first difference value that is a difference value between the weighting factor and the first reference value and the fixed point precision. The weighting factor is included in a first range of predetermined bit precision having the first reference value at approximate center. The first difference value is in the predetermined range.

#Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. An encoding device and a decoding device according to each embodiment presented below may be implemented by hardware such as an LSI (Large-Scale Integration) chip, a DSP (Digital Signal Processor), or an FPGA (Field Programmable Gate Array). In addition, an encoding device and a decoding device according to each embodiment presented below may be implemented by causing a computer to execute a program, in other words, by software. In description presented below, a term “image” may be appropriately replaced by a term such as a “video”, a “pixel”, an “image signal”, a “picture”, or “image data”.

#First Embodiment

Facts

Application

15/438,333Filed 21 Feb 2017 · continuation

Priority

27 Jun 2012

Published

US 2017/0163984 A18 Jun 2017

Granted

9 Apr 2019

Term ends

27 Jun 2032

Estimated · how

20 years from earliest known nonprovisional domestic filing plus recorded patent term adjustment. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification18 codes

H04N 19/13
Characterised by the element, parameter or selection affected or controlled by the adaptive coding: adaptive entropy coding, e.g. adaptive…
H04N 19/105
Selection of coding mode or of prediction mode: selection of the reference unit for prediction within a chosen coding or prediction mode, e.g.…
H04N 19/147
Data rate or code amount at the encoder output: according to rate distortion criteria
H04N 19/15
Data rate or code amount at the encoder output: by monitoring actual compressed data size at the memory before deciding storage at the…

Family

PCT/JP2012/066410Parent of this continuation · filed 27 Jun 2012

Application14/026,727Parent of this continuation · filed 13 Sep 2013

Application14/725,941Parent of this continuation · filed 29 May 2015

US 2017/0163984 A1Pre-grant publication · published 8 Jun 2017

US 9,621,914 B2Parent of this continuation

US 9,462,291 B2Parent of this continuation

Application14/725,941Parent of this continuation

Application14/026,727Parent of this continuation

US 2014/0079125 A1Published application

US 2015/0264388 A1Published application

US 10,257,516 B2This patent

From the US filing history. Foreign family members aren’t listed.

Encoding device, decoding device, encoding method, and decoding method for coding efficiency

Life of this patent

Encoding device, decoding device, encoding method, and decoding method for coding efficiency

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims25

Description23,288 words

Drawings

Classification18 codes

Life of this patent

Description23,288 words