US 8,300,695 B2Granted

Image encoding apparatus and image encoding method

AssigneeSharp Kabushiki Kaisha

InventorKazuhito Nishida

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Abstract

Since a global motion vector detector is disposed on the same chip as, for example, an image converter utilizing spatial correlations, a first problem is that an original frame is not completely reproduced in an image, since the frame to be referred to when detecting the global motion vector is an image obtained by inverse-converting a nonreversibly compression-converted image. A second problem is that, upon high-efficient image encoding, the detection process of the global motion vector is performed even when it is not necessary to detect the global motion vector. An image encoding apparatus is equipped with a mechanism for detecting a global motion vector. The mechanism is located outside an image converter that utilizes spatial correlations, such as high-frequency component removal by a DCT and round-down by a quantization, and variable encoding.

Claims9

Dependent claims

An image coding apparatus, which carries out coding of an inputted image, of a plurality of inputted images including one or more previous inputted images as reference images and a current image, by means of motion vector, comprising:

a first detection unit, which is for detecting the motion vector by searching a predetermined search range in the inputted image based on macro block of transformation-inverse transformation-processed image;
a second detection unit, which is for detecting a global motion vector between the inputted images based on a global macro block, larger than said macro block;
a determination unit for search range, which can determine search range of the search by the first detection unit by means of the global motion vector detected by said second detection unit;
a determination unit for utilization of global motion vector, which determines whether or not said global motion vector is utilized;
and
an acquisition unit for image size, which acquires image size of said inputted image, wherein
said determination unit for utilization of global motion vector further comprises,
a determination means dependent on image size, which carries out said determination based on the image size acquired by said acquisition unit for image size.

5 more elements

An image coding method for causing a computer to carry out coding of an inputted image by means of motion vector detected by search based on macro block of transformation-inverse transformation-processed image, comprising:

a second detection step, which is for detecting a global motion vector between the inputted images based on a global macro block, larger than said macro block;
a determination step for search range, which can determine search range of the search by the first detection unit by means of the global motion vector detected by said second detection step;
a first detection step, which is for detecting said motion vector by searching said determined search range based on a macro block;
and
an acquisition step for image size, which acquires image size of said inputted image, wherein
said determination step for utilization of global motion vector further comprises,
wherein said determination step for utilization of further comprises steps for carrying out said determination based on the image size acquired by said acquisition step for image size.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/065,074Filed 17 Jan 2006
Priority: JP 2005-33518621 Nov 2005
Published: US 2009/0268820 A129 Oct 2009
Granted: 30 Oct 2012
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

H04N 19/57
Motion estimation or motion compensation: motion estimation characterised by a search window with variable size or shape
H04N 19/103
Characterised by the element, parameter or selection affected or controlled by the adaptive coding: selection of coding mode or of prediction mode
H04N 19/136
Characterised by the element, parameter or criterion affecting or controlling the adaptive coding: incoming video signal characteristics or properties
H04N 19/172
The unit being an image region, e.g. an object: the region being a picture, frame or field