US 2002/0118752 A1Published application

Moving picture encoding system

AssigneeNEC Corporation

InventorRyoma Oami

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Abstract

A moving picture encoding system capable of bit rate control, by which moving pictures are encoded while maintaining high quality even when there are substantial changes in the size of objects and the characteristics of texture is provided. A predictive area calculating parameter extracting means obtains a predictive area calculating parameter to describe a function that indicates temporal variations in the area based on the history of the area data of an object. Besides, a bit number model parameter calculating means finds a bit number model parameter to describe a parameter for a bit number model used in modeling the generated bit number per unit area. A target bit number calculating means estimates a predictive value of the generated bit number for the uncoded VOPs based on the predictive area calculating parameter and the predictive bit number calculating parameter, and accordingly, allocates the remaining allocatable bits to decide a target bit number for the next VOP to be encoded. A coding means encodes the VOP according to the target bit number.

Claims24

Dependent claims

A moving picture encoding system for encoding moving picture sequences with respect to each object, comprising:

a coding means for encoding object picture data consisting of time series sequences of video object planes (VOPs), each of which is a picture image of the object at a point of time, and shape information data indicating the shape of the object in each VOP while conducting bit rate control so that the number of generated bits for each VOP meets a target bit number, and outputting coding information including a quantization parameter used in encoding and the generated bit number along with obtained bit streams;
an area calculating means for calculating the area of the object in each VOP based on the shape information data, and outputting the result as area data;
a predictive area calculating parameter extracting means for obtaining a function that indicates temporal variations in the area of the object based on the history of the area data, and outputting a parameter specifying the function or a predictive value of the area obtained by the function as a predictive area calculating parameter;
a bit number model parameter calculating means for calculating a parameter used in modeling the generated bit number per unit area of the object based on the coding information, the generated bit number and the area data, and outputting the result as a bit number model parameter;
a predictive bit number calculating parameter extracting means for obtaining a function that indicates temporal variations in the bit number model parameter based on the history of the bit number model parameter, and outputting a parameter specifying the function or a predictive value of the bit number model parameter obtained by the function as a predictive bit number calculating parameter;
and
a target bit number calculating means which performs a series of processes:
calculating an uncoded VOP allocatable bit number that is the total number of allocatable bits for uncoded VOPs in a certain period of time based on allocatable bit number information indicating the total number of allocatable bits for the VOPs in the certain period of time and the number of generated bits for the encoded VOPs in the certain period of time, estimating the number of generated bits for the uncoded VOPs based on the predictive area calculating parameter and the predictive bit number calculating parameter, allocating the uncoded VOP allocatable bit number, calculating a target bit number for the next VOP to be encoded, and outputting the target bit number;
sequentially for each of VOPs in the certain period of time.

6 more elements

A moving picture encoding system for encoding moving picture sequences with respect to each object, comprising:

a storing means for temporarily storing object picture data consisting of time series sequences of video object planes (VOPs), each of which is a picture image of the object at a point of time, and shape information data indicating the shape of the object in each VOP;
a coding means which reads the object picture data and shape information data out of the storing means, encodes the data while conducting bit rate control so that the number of generated bits for each VOP meets a target bit number, and outputs coding information including a quantization parameter used in encoding and the generated bit number along with obtained bit streams;
an area calculating means for calculating the area of the object in each VOP based on the shape information data, and outputting the result as area data;
a bit number model parameter calculating means for calculating a parameter used in modeling the generated bit number per unit area of the object based on the coding information, the generated bit number and the area data, and outputting the result as a bit number model parameter;
a predictive bit number calculating parameter extracting means for obtaining a function that indicates temporal variations in the bit number model parameter based on the history of the bit number model parameter, and outputting a parameter specifying the function or a predictive value of the bit number model parameter obtained by the function as a predictive bit number calculating parameter;
and
a target bit number calculating means which performs a series of processes:
calculating an uncoded VOP allocatable bit number that is the total number of allocatable bits for uncoded VOPs in a certain period of time based on allocatable bit number information indicating the total number of allocatable bits for the VOPs in the certain period of time and the number of generated bits for the encoded VOPs in the certain period of time, estimating the number of generated bits for the uncoded VOPs based on the area data and the predictive bit number calculating parameter, allocating the uncoded VOP allocatable bit number, calculating a target bit number for the next VOP to be encoded, and outputting the target bit number;
sequentially for each of VOPs in the certain period of time.

6 more elements

A moving picture encoding system for encoding each frame of moving picture sequences while conducting bit rate control with respect to each section of the frame, comprising:

a coding means which is supplied with picture data, section information data indicating the sections in each frame of the picture data and a target bit number for each section, encodes the data with respect to each section while conducting bit rate control so that the number of generated bits for each section meets the target bit number, and outputs coding information including a quantization parameter used in encoding and the generated bit number along with obtained bit streams;
an area calculating means for calculating the area of the section in each frame based on the section information data, and outputting the result as area data;
a predictive area calculating parameter extracting means for obtaining a function that indicates temporal variations in the area of the section based on the history of the area data, and outputting a parameter specifying the function or a predictive value of the area obtained by the function as a predictive area calculating parameter;
a bit number model parameter calculating means for calculating a parameter used in modeling the generated bit number per unit area of the section based on the coding information, the generated bit number and the area data, and outputting the result as a bit number model parameter;
a predictive bit number calculating parameter extracting means for obtaining a function that indicates temporal variations in the bit number model parameter based on the history of the bit number model parameter, and outputting a parameter specifying the function or a predictive value of the bit number model parameter obtained by the function as a predictive bit number calculating parameter;
and
a target bit number calculating means which performs a series of processes:
calculating an uncoded frame allocatable bit number that is the total number of allocatable bits for uncoded frames in a certain period of time based on allocatable bit number information indicating the total number of allocatable bits for the frames in the certain period of time and the number of generated bits for the encoded frames in the certain period of time, estimating the number of generated bits for each section in the uncoded frames based on the predictive area calculating parameter and the predictive bit number calculating parameter, allocating the uncoded frame allocatable bit number, calculating a target bit number for each section in the next frame to be encoded, and outputting the target bit number;
sequentially for each of frames in the certain period of time.

6 more elements

A moving picture encoding system for encoding each frame of moving picture sequences while conducting bit rate control with respect to each section of the frame, comprising:

a storing means for temporarily storing picture data, section information data indicating the sections in each frame of the picture data;
a coding means which reads the picture data and section information data out of the storing means, encodes the data with respect to each section while conducting bit rate control so that the number of generated bits for each section meets a target bit number for the section, and outputs coding information including a quantization parameter used in encoding and the generated bit number along with obtained bit streams;
an area calculating means for calculating the area of the section in each frame based on the section information data, and outputting the result as area data;
a bit number model parameter calculating means for calculating a parameter used in modeling the generated bit number per unit area of the section based on the coding information, the generated bit number and the area data, and outputting the result as a bit number model parameter;
a predictive bit number calculating parameter extracting means for obtaining a function that indicates temporal variations in the bit number model parameter based on the history of the bit number model parameter, and outputting a parameter specifying the function or a predictive value of the bit number model parameter obtained by the function as a predictive bit number calculating parameter;
and
a target bit number calculating means which performs a series of processes:
calculating an uncoded frame allocatable bit number that is the total number of allocatable bits for uncoded frames in a certain period of time based on allocatable bit number information indicating the total number of allocatable bits for the frames in the certain period of time and the number of generated bits for the encoded frames in the certain period of time, estimating the number of generated bits for each section in the uncoded frames based on the area data and the predictive bit number calculating parameter, allocating the uncoded frame allocatable bit number, calculating a target bit number for each section in the next frame to be encoded, and outputting the target bit number;
sequentially for each of frames in the certain period of time.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/024,215Filed 21 Dec 2001
Priority: JP 395592/200026 Dec 2000
Published: 29 Aug 2002
Term ends: Not estimatedThe source records don’t support an estimate.

Classification10 codes

H04N 19/20
Methods or arrangements for coding, decoding, compressing or decompressing digital video signals: using video object coding
H04N 19/115
Characterised by the element, parameter or selection affected or controlled by the adaptive coding: selection of the code volume for a coding unit…
H04N 19/126
Quantisation: details of normalisation or weighting functions, e.g. normalisation matrices or variable uniform quantisers
H04N 19/149
Data rate or code amount at the encoder output: by estimating the code amount by means of a model, e.g. mathematical model or statistical model