US 6,687,296 B1Granted

Apparatus and method for transforming picture information

AssigneeSony Corporation

InventorsKazushi Sato, Yu Liu, Naofumi Yanagihara

Life of this patent

Estimating the term…

Loading patent…

Abstract

An apparatus and a method for transforming picture information can significantly reduce the bit rate. A picture information transform apparatus for receiving as input the compressed picture information obtained by coding the picture information of a plurality of picture type images by ways of orthogonal transform and motion compensation includes a variable length decoder 4 for performing a variable length decoding operation on the input compressed picture information, an inverse quantizer 5 for inversely quantizing the decoded information, a band limiter 7 for limiting the bandwidth, a quantizer 8 and a bit rate controller 9 for computationally determining the target bits for the coded images of each picture type by adaptively using a plurality of parameters operating as coefficients for the contents of the coded images of the picture type on the bais of the contents of the coded images of the picture type.

Claims10

Dependent claims

A picture information transform apparatus for receiving as input the compressed picture information of a plurality of picture type obtained by coding the picture information by means of orthogonal transform and motion compensation, said apparatus comprising:

a decoding means for decoding the input compressed picture information to the picture information;
a coding means for coding the picture information obtained by the decoding of said decoding means;
and
a control means for controlling the target coding quantity of each of the coded pictures of respective picture type by adaptively using a plurality of parameters to be used as coefficients of the contents of each of the coded pictures of respective picture type on the basis of the contents of each of the coded pictures of respective picture type at the time of coding by said coding means, wherein, said compressed picture information is prepared on the basis of a unit of group of pictures including Intra-coded pictures, Predictive-coded pictures forwardly predictively coded in the display sequence and Bidirectionally predictive-coded pictures bi-directionally predictively coded in the display sequence, and said plurality of parameters include a first parameter KP operating as the coefficient for the contents of said Predictive-coded picture as determined on the basis of ratio XP/XI of the complexity XP of said Predictive-coded picture to the complexity XI of said Intra-coded picture and a second parameter KB operating as the coefficient for the contents of said Bidirectionally predictive-coded picture as determined on the basis of the ratio XB/XI of the complexity XB of said Bidirectionally predictive-coded picture to the complexity XI of said Intra-coded picture, provided that the coefficient of the contents of the Intra-coded picture is equal to 1, where XI represents the complexity of said Intra-coded picture, XP represents the complexity of said Predictive-coded picture and XB represents the Bidirectionally predictive-coded picture.

1 more element

A picture information transform method for receiving as input the compressed picture information of a plurality of picture type obtained by coding the picture information by means of orthogonal transform and motion compensation, said method comprising:

a decoding step for decoding the input compressed picture information to the picture information;
a coding step for coding the picture information obtained by the decoding of said decoding step;
and
a control step for controlling the target coding quantity of each of the coded pictures of respective picture type by adaptively using a plurality of parameters to be used as coefficients of the contents of each of the coded pictures of respective picture type on the basis of the contents of each of the coded pictures of respective picture type at the time of coding by said coding means, wherein, said compressed picture information is prepared on the basis of a unit of group of pictures including Intra-coded pictures, Predictive-coded pictures forwardly predictively coded in the display sequence and Bidirectionally predictive-coded pictures bi-directionally predictively coded in the display sequence, and said plurality of parameters include a first parameter KP operating as the coefficient for the contents of said Predictive-coded picture as determined on the basis of ratio XP/XI of the complexity XP of said Predictive-coded picture to the complexity XI of said Intra-coded picture and a second parameter KB operating as the coefficient for the contents of said Bidirectionally predictive-coded picture as determined on the basis of the ratio XB/XI of the complexity XB of said Bidirectionally predictive-coded picture to the complexity XI of said Intra-coded picture, provided that the coefficient of the contents of the Intra-coded picture is equal to 1, where XI represents the complexity of said Intra-coded picture, XP represents the complexity of said Predictive-coded picture and XB represents the Bidirectionally predictive-coded picture.

1 more element

Dependencies are inferred from the claim text.

Facts

Application: 09/708,255Filed 7 Nov 2000
Priority: JP P11-32726317 Nov 1999
Granted: 3 Feb 2004
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

H04N 19/40
Methods or arrangements for coding, decoding, compressing or decompressing digital video signals: using video transcoding, i.e. partial or full…
H04N 19/132
Characterised by the element, parameter or selection affected or controlled by the adaptive coding: sampling, masking or truncation of coding…
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
H04N 19/152
Data rate or code amount at the encoder output: by measuring the fullness of the transmission buffer