Image Encoding Device

• US 20080247461A1
• Filed: 09/05/2005
• Published: 10/09/2008
• Est. Priority Date: 09/22/2004
• Status: Active Grant

• Current Assignee: Sovereign Peak Ventures, LLC (Dominion Harbor Enterprises, LLC)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Nishida, Hideshi
• Granted Patent: US 8,073,053 B2
• Time in Patent Office: Days
• US Class Current: 375/240.03
• CPC Class Codes: H04N 19/127 Prioritisation of hardware or computational resources
• CPC Class Codes: H04N 19/137 Motion inside a coding unit, e.g. average field, frame or block difference
• CPC Class Codes: H04N 19/157 Assigned coding mode, i.e. the coding mode being predefined or preselected to be further used for selection of another element or parameter
• CPC Class Codes: H04N 19/172 the region being a picture, frame or field
• CPC Class Codes: H04N 19/51 Motion estimation or motion compensation
• CPC Class Codes: H04N 19/57 Motion estimation characterised by a search window with variable size or shape
• CPC Class Codes: H04N 19/58 Motion compensation with long-term prediction, i.e. the reference frame for a current frame not being the temporally closest one H04N19/23 takes precedence
• CPC Class Codes: H04N 19/61 in combination with predictive coding

Abstract

In an image encoding device (100) that compression encodes moving pictures, a moving picture count acquisition unit (110) acquires a moving picture count of encoding target moving pictures corresponding to an arbitrary number of input moving pictures, a moving picture acquisition unit (120) acquires one or plural encoding target moving pictures, a processing method designation unit (130), in accordance with the acquired count, designates processing methods relating to encoding processing that affect a computation amount, for example, processing methods relating to a reference image frame count upper limit or a motion vector range, such that the greater the moving picture count is, the smaller the computation amount is, and an encoding processing unit (140) performs encoding processing with respect to the acquired one or plural moving pictures, using time division when the plural moving pictures are plural. The encoding unit (140) performs encoding processing using the designated methods.

Claims

1. An image encoding device that performs encoding processing that is for compressing one or more moving pictures and includes motion estimation processing, comprising:

a moving picture count acquisition unit operable to acquire a moving picture count that shows how many moving pictures are an encoding target;

a moving picture acquisition unit operable to acquire one or plural moving pictures that are the encoding target;

a motion estimation processing method designation unit operable to designate, in accordance with the acquired moving picture count, a motion estimation processing method that affects a computation amount in the motion estimation processing, such that the greater the moving picture count is, the smaller the computation amount is; and

an encoding unit operable to perform encoding processing with respect to the acquired one or plural moving pictures, and in a case that the plural moving pictures are acquired, perform the encoding processing by time division,

wherein the encoding unit includes a motion estimation sub-unit operable to perform, as part of the encoding processing, motion estimation processing using the designated motion estimation processing method.

2. The image encoding device of claim 1, wherein

the motion estimation processing designation unit (a) includes a storage sub-unit operable to store in advance a table that associates a plurality of moving picture count values and parameters for designating the motion estimation processing method, the moving picture count values and the parameters being associated so as to have a relationship whereby the greater the moving picture count is, the less the computation amount of the motion estimation processing is, and (b) designates the motion estimation processing method by transferring, to the motion estimation sub-unit, a parameter that, among the parameters in the table, corresponds to the acquired moving picture count, and

the motion estimation sub-unit performs the motion estimation processing using the designated motion estimation processing method, based on the parameter transferred from the motion estimation processing method designation unit.

3. The image encoding device of claim 1, wherein

the motion estimation processing designation unit designates, in accordance with the acquired moving picture count, the motion estimation processing method in relation to an upper limit value of a total number of reference image frames in motion estimation processing, such that the greater the moving picture count is, the smaller the upper limit value of the total number of reference frames is, and

the motion estimation sub-unit, in the motion estimation processing performs, with respect to each of processing target blocks in each of image frames that are a target of the motion estimation processing, a search for a motion vector in a total number of reference image frames that is no greater than the upper limit value in the designated motion estimation processing method.

4. The image encoding device of claim 1, wherein

the motion estimation processing method designation unit designates, in accordance with the acquired moving picture count, the motion estimation processing method in relation to a motion vector search range in the motion estimation search processing, such that the greater the moving picture count is, the smaller the search range is, and

the motion estimation sub-unit, with respect to each of processing target blocks in each of image frames that are a target of the motion estimation processing, searches within the search range in the designated motion estimation processing method for a reference image block that is similar to said processing target block, and determines a motion vector that indicates said reference image block.

5. The image encoding device of claim 1, wherein

the motion estimation processing method designation unit designates, in accordance with the acquired moving picture count, the motion estimation processing method in relation to shape patterns of reference image blocks in motion estimation processing, such that the greater the moving picture count is, the fewer the shape patterns are, and

the motion estimation unit, with respect to each of processing target blocks in each of image frames that are a target of the motion estimation processing, uses the shape patterns in the designated motion estimation processing method to search for a reference image block similar to said processing target block, and determines a motion vector that indicates said reference image block.

6. The image processing device of claim 1, wherein

the moving picture acquisition unit acquires a new moving picture while the encoding unit is performing the encoding,

the moving picture count acquisition unit newly acquires the moving picture count while the encoding unit is performing the encoding, and

the motion estimation processing designation unit newly designates the motion estimation processing method each time the moving picture count acquisition unit newly acquires the moving picture count.

7. The image encoding device of claim 1, wherein

the moving picture acquisition unit acquires the plural moving pictures that are encoding targets, and

the image encoding device further comprises:

a reception unit operable to receive, from an external device that is capable of executing encoding processing, capability information that shows computation processing capability of the external device;

a determination unit operable to determine, based on the capability information, a moving picture count of encoding target moving pictures whose encoding is to be delegated to the external device, from among the acquired moving pictures; and

a transmission unit operable to transmit, from among the acquired moving pictures, moving pictures equivalent in number to the moving picture count determined by the determination unit, wherein

the motion estimation processing method designation unit designates the motion estimation processing method in accordance with a difference between the moving picture count acquired by the moving picture count acquisition unit and the moving picture count determined by the determination unit, such that the greater the difference is, the less the computation amount is.

8. The image encoding device of claim 7, wherein

the determination unit, based on the capability information, determines a motion estimation processing method to be used in encoding processing that is delegated to the external device, in addition to determining the moving picture count of moving pictures whose encoding is to be delegated to the external device, and

the transmission unit further transmits, to the external device, information showing the motion estimation processing method determined by the determination unit.

9. The image encoding device of claim 1, further comprising:

a quantization step size designation unit operable to designate a quantization step size in accordance with the acquired moving picture count, such that the greater the moving picture count is, the smaller the quantization step size is, wherein

the encoding unit includes a quantization sub-unit operable to perform quantization using the determined quantization step size to quantize difference data obtained as a result of the motion estimation processing.

10. An image encoding device that performs encoding processing for compressing one or more moving pictures, comprising:

a moving picture count acquisition unit operable to acquire a moving picture count that shows how many moving pictures are an encoding target;

a moving picture acquisition unit operable to acquire one or plural moving pictures that are the encoding target;

a processing method designation unit operable to designate, in accordance with the acquired moving picture count, an encoding processing method that affects a computation amount in the encoding processing, such that the greater the moving picture count is, the smaller the computation amount is; and

an encoding unit operable to perform the encoding processing with respect to the acquired one or plural moving pictures using the designated encoding processing method, and in a case that the plural moving picture being acquired, perform the encoding processing by time division.

11. The image encoding device of claim 10, wherein

the processing method designation unit (a) includes a storage sub-unit operable to store in advance a table that associates a plurality of moving picture count values and parameters for designating the encoding processing method, the moving picture count values and the parameters being associated so as to have a relationship whereby the greater the moving picture count is, the less the computation amount of the encoding processing is, and (b) designates the encoding processing method by transferring, to the encoding unit, a parameter that, among the parameters in the table, corresponds to the acquired moving picture count, and

the encoding unit performs the encoding processing using the designated encoding processing method, based on the parameter transferred from the processing method designation unit.

12. The image encoding device of claim 10, wherein

the encoding unit includes an intra-encoding sub-unit operable to perform, as part of the encoding processing, image intra-frame encoding processing with respect to some or all image frames of the moving pictures that are the encoding target,

the processing method designation unit designates, in accordance with the acquired moving picture count, the processing method in relation to directions in which to search for an estimation value in image intra-frame encoding, such that the greater the moving picture count is, the fewer the search directions are, and

the intra-encoding specification unit, with respect to each of processing target blocks in an image frame, searches in each direction in the designated encoding processing method to search for an estimation value that is most similar to image data of said processing target block.

13. The image encoding device of claim 10, wherein

the processing method designation unit designates, in accordance with the acquired moving picture count, the encoding processing method in relation to whether or not to use inter-image frame encoding, such that inter-image frame encoding is used if the acquired moving picture count is fewer than a predetermined moving picture count, and inter-image frame encoding is not used if the acquired moving picture count is equal to or greater than the predetermined moving picture count,

the encoding unit

(a) performs inter-image frame encoding and intra-image frame encoding with respect to the moving pictures if the designated encoding processing method is the encoding processing method that uses inter-frame encoding, and

(b) performs intra-image frame encoding with respect to the moving pictures, without performing inter-image frame encoding, if the designated encoding processing method is the encoding processing method that does not use inter-image frame encoding.

14. The image encoding device of claim 10, wherein

the encoding unit includes a variable length encoding sub-unit operable to perform variable length encoding as part of the encoding processing,

the processing method designation unit designates, in accordance with the acquired moving picture count, a variable length processing method such that arithmetic coding is used if the acquired moving picture count is fewer than the predetermined moving picture count, and arithmetic coding is not used if the acquired moving picture count is equal to or greater than the predetermined moving picture count, and

the variable length encoding sub-unit

(a) performs the variable length encoding using arithmetic coding if the designated variable length encoding method is the variable length encoding method that uses arithmetic coding, and

(b) performs the variable length encoding using a comparative table of predetermined code words, without using arithmetic coding, if the designated variable length encoding method is the variable length encoding method that does not use arithmetic coding.

15. The image encoding device of claim 10, wherein

the moving picture acquisition unit acquires a new moving picture while the encoding unit is performing the encoding,

the moving picture count acquisition unit newly acquires the moving picture count while the encoding unit is performing the encoding, and

the processing method designation unit newly designates the encoding processing method each time the moving picture count acquisition unit newly acquires the moving picture count.

16. The image encoding device of claim 10, wherein

the moving picture acquisition unit acquires the plural moving pictures that are encoding targets, and

the image encoding device further comprises:

a reception unit operable to receive, from an external device that is capable of executing encoding processing, capability information that shows computation processing capability of the external device;

a determination unit operable to determine, based on the capability information, a moving picture count of moving pictures whose encoding is to be delegated to the external device, from among the acquired moving pictures; and

a transmission unit operable to transmit, from among the acquired moving pictures, moving pictures equivalent in number to the moving picture count determined by the determination unit, wherein

the processing method designation unit designates the encoding processing method in accordance with a difference between the moving picture count acquired by the moving picture count acquisition unit and the moving picture count determined by the determination unit, such that the greater the difference is, the less the computation amount is.

17. The image encoding device of claim 10, further comprising:

a picture quality information acquisition unit operable to acquire picture quality information showing a requested picture quality, wherein

the processing method designation unit designates the encoding processing method in accordance with the acquired motion picture count and the acquired picture quality information.

18. The image encoding device of claim 10, further comprising:

a decoding unit operable to decode a compressed moving picture, using part of circuits of the encoding unit, wherein

the processing method designation unit designates the encoding processing method further in accordance with an amount of the moving picture to be decoded by the decoding unit, such that the greater the amount of the moving picture is, the less the computation amount is.

19. An image encoding method that performs encoding processing that is for compressing one or more moving pictures and includes motion estimation processing, comprising:

a moving picture count acquisition step of acquiring a moving picture count that shows how many moving pictures are an encoding target;

a moving picture acquisition step of acquiring one or plural moving pictures that are the encoding target;

a motion estimation processing method designation step of designating, in accordance with the acquired moving picture count, a motion estimation processing method that affects a computation amount in the motion estimation processing, such that the greater the moving picture count is, the smaller the computation amount is; and

an encoding step of performing encoding processing with respect to the acquired one or plural moving pictures, and in a case that the plural moving pictures are acquired, performing the encoding processing by time division,

wherein the encoding step includes a motion estimation sub-step of performing, as part of the encoding processing, motion estimation processing using the designated motion estimation processing method.

20. An image encoding method that performs encoding processing for compressing one or more moving pictures, comprising:

a moving picture count acquisition step of acquiring a moving picture count that shows how many moving pictures are an encoding target;

a moving picture acquisition step of acquiring one or plural moving pictures that are the encoding target;

a processing method designation step of designating, in accordance with the acquired moving picture count, an encoding processing method that affects a computation amount in the encoding processing, such that the greater the moving picture count is, the smaller the computation amount is; and

an encoding step of performing the encoding processing with respect to the acquired one or plural moving pictures using the designated encoding processing method, and in a case that the plural moving pictures are acquired, performing the encoding processing by time division.

21. A control program that causes encoding control processing for compressing one or more moving pictures to be executed by an device that is capable of executing a computer program, the encoding control processing comprising:

a moving picture count acquisition step of acquiring a moving picture count that shows how many moving pictures are an encoding target;

a moving picture acquisition step of acquiring one or plural moving pictures that are the encoding target;

a motion estimation processing method designation step of designating, in accordance with the acquired moving picture count, a motion estimation processing method that affects a computation amount in the motion estimation processing, such that the greater the moving picture count is, the smaller the computation amount is; and

an encoding step of performing encoding processing with respect to the acquired one or plural moving pictures, and in a case that the plural moving pictures are acquired, performing the encoding processing by time division,

wherein the encoding step includes a motion estimation sub-step of performing, as part of the encoding processing, motion estimation processing using the designated motion estimation processing method.

22. A control program that causes encoding control processing for compressing one or more moving pictures to be executed by an device that is capable of executing a computer program, the encoding control processing comprising:

a moving picture count acquisition step of acquiring a moving picture count that shows how many moving pictures are an encoding target;

a moving picture acquisition step of acquiring one or plural moving pictures that are the encoding target;

a processing method designation step of designating, in accordance with the acquired moving picture count, an encoding processing method that affects a computation amount in the encoding processing, such that the greater the moving picture count is, the smaller the computation amount is; and

an encoding step of performing the encoding processing with respect to the acquired one or plural moving pictures using the designated encoding processing method, and in a case that the plural moving pictures are acquired, performing the encoding processing by time division.