IMAGE ENCODING DEVICE, IMAGE DECODING DEVICE, IMAGE ENCODING METHOD AND IMAGE DECODING METHOD

• US 20090003441A1
• Filed: 10/30/2007
• Published: 01/01/2009
• Est. Priority Date: 06/28/2007
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: YAMAGISHI, Shuichi, MORIYA, Yoshimi, IDEHARA, Yuichi, YAMADA, Yoshihisa, MURAKAMI, Tokumichi, SEKIGUCHI, Shunichi, ASAI, Kohtaro
• Granted Patent: US 8,139,875 B2
• Time in Patent Office: Days
• US Class Current: 375/240.130
• CPC Class Codes: H04N 19/107 between spatial and temporal predictive coding, e.g. picture refresh
• CPC Class Codes: H04N 19/109 among a plurality of temporal predictive coding modes
• CPC Class Codes: H04N 19/11 among a plurality of spatial predictive coding modes
• CPC Class Codes: H04N 19/117 Filters, e.g. for pre-processing or post-processing sub-band filter banks H04N19/635
• CPC Class Codes: H04N 19/147 according to rate distortion criteria rate-distortion as a criterion for motion estimation H04N19/567
• CPC Class Codes: H04N 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/186 the unit being a colour or a chrominance component
• CPC Class Codes: H04N 19/19 using optimisation based on Lagrange multipliers
• CPC Class Codes: H04N 19/436 using parallelised computational arrangements
• CPC Class Codes: H04N 19/517 by encoding
• CPC Class Codes: H04N 19/523 with sub-pixel accuracy
• CPC Class Codes: H04N 19/593 involving spatial prediction techniques
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/91 Entropy coding, e.g. variable length coding [VLC] or arithmetic coding

Abstract

An encoding device includes a color component separating unit for separating an input bit stream for the respective color components, a block dividing unit for dividing an input color component signal into blocks to generate a signal of an encoding unit area, a predicted image generating unit for generating a predicted image for the signal, a determining unit for determining a prediction mode used for encoding according to a prediction efficiency of the predicted image, a prediction error encoding unit for encoding a difference between the predicted image corresponding to the prediction mode determined by the determining unit and the input color component signal, and an encoding unit for variable length-coding the prediction mode, an output from the prediction error encoding unit, and a color component identification flag indicating the color component to which the input bit stream belongs as a result of the color component separation.

Claims

1. An image decoding device for receiving a bit stream obtained by compression-encoding a color moving image signal composed of a plurality of color components as an input and selectively applying one of intra decoding and motion compensation prediction decoding for each of the plurality of color components of the color moving image signal to decode the color moving image signal, comprising:

a color component identifying unit for decoding a color component identification flag for identifying the color component to which the input bit stream belongs and determining the color component whose encoded information is contained in the bit stream;

a decoding unit for decoding information obtained by encoding a prediction mode indicating a predicted image generating method used for encoding each encoding unit area, corresponding prediction overhead information and a prediction error from the bit stream for each color component determined by the color component identifying unit according to a predetermined syntax for the encoding unit area;

a predicted image generating unit for generating a predicted image for a signal of the encoding unit area based on the decoded prediction mode and the corresponding prediction overhead information;

a prediction error decoding unit for decoding a prediction error signal based on the information obtained by encoding the prediction error; and

an adder unit for adding an output from the predicted image generating unit and an output from the prediction error decoding unit, wherein the decoding unit decodes a prediction information encoding indication flag indicating one of use of the prediction mode used for encoding and corresponding prediction overhead information in an area to be encoded of another color component constituting the same screen at the same image position and use of its own prediction mode and corresponding prediction overhead information for the color component to determine the prediction mode used in the predicted image generating unit and the corresponding prediction overhead information based on a value of the prediction information encoding indication flag.