CN105306957A - Adaptive loop filtering method and device - Google Patents
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Abstract
Embodiments of the invention disclose an adaptive loop filtering method and device for encoding and decoding video images, and method and device for processing encoded video images by using adaptive loop filtering. For the adaptive loop filtering, a final filtering shape with a cross linear filtering shape and a square filtering shape overlapped at the center is constructed, wherein the number of sample windows of the cross linear filtering shape on a horizontal direction is larger than the number of the sample windows on a vertical direction. According to the adaptive loop filtering provided by the embodiments of the invention, while improving the image quality, the hardware consumption is the lowest.
Description
Technical field
The present invention relates to the technical field of the video image encoding and decoding in MultiMedia Field, particularly relate to the adaptive loop filter method and apparatus that uses in a kind of video image encoding and decoding and use adaptive loop filter to process the method and apparatus of the video image of coding.
Background technology
Modern video encoding and decoding technique all uses the block of block-based prediction and quantification to convert.Generally current encoded frame is divided into the coding unit do not overlapped mutually, this coding unit can be the macro block (MB in AVC/H.264 (Motion Picture Experts Group advanced video coding MPEG-4AVC) or AVS1 (internal video coding standard the 1st edition), macroblock), also can be HEVC/H.265 (HighEfficiencyVideoCoding; High efficiency coding and decoding video) or AVS2 (internal video coding standard the 2nd edition) in coding unit (CU, codingunit).Coding unit can also be divided into coded sub-units as son further.Utilize block-based prediction, the block of pixels of reconstruction can be used for predicting other block of pixels.The use of the block conversion of block-based prediction and quantification can cause the loss of the original image information such as noise along the blocking effect of block border and block inside.
In HEVC/H.265 and AVS2 standard, have employed the noise that adaptive loop filter (ALF) eliminates block inside further, improve the quality of rebuilding image, improve forecasting efficiency.ALF technology by encoded filter shape and filter factor, is carried out filtering at decoder place to reconstruction image, is reduced the compression artefacts in decoded picture, and provides high-quality prediction reference image for follow-up encoding and decoding image, thus improves compression efficiency further.The structure of filter factor makes the mean square deviation (MSE) of rebuilding between image and original image reach minimum.But ALF is the part that scramble time is the longest, amount of calculation is maximum, complexity is the highest in these coding/decoding systems.For this reason, existing ALF algorithm normally reconstructed image quality with carry out in the complexity, amount of calculation, compression efficiency etc. of ALF algorithm balanced.ALF in AVS2 standard has carried out certain simplification relative to the ALF in HEVC/H.265.
In addition, video encoder and decoder are normally by hard-wired, but existing various ALF algorithm does not carry out design and development towards being conducive to hard-wired direction.
Summary of the invention
Object of the present invention aims to provide a kind of adaptive loop filter method of improvement, and it is while raising picture quality, and when hardware implementing, cost is less.
According to a first aspect of the invention, a kind of adaptive loop filter method for video image encoding and decoding is provided.The method comprises: reconstruction image is divided into multiple block; And for each block in described multiple block, filtering is carried out according to certain filter shape and filter factor, described filter shape is made up of multiple sample window, each sample window is for selecting the pixel of correspondence position, and be provided with a filter factor, described filter factor is designed such that the mean square deviation between described reconstruction image and original image is minimum.For a block in described multiple block, build the final filter shape that cross line style filter shape superposes in center with square filter shape.Described cross line style filter shape sample window number is in the horizontal direction greater than the sample window number of in the vertical direction.
Further, the cross line style filter shape forming described final filter shape is 9 × 7 sizes, and the square filter shape forming described final filter shape is 3 × 3 sizes.
Further, the cross line style filter shape forming described final filter shape is 7 × 5 sizes, and the square filter shape forming described final filter shape is respectively 3 × 3 sizes.
Further, the cross line style filter shape forming described final filter shape is 11 × 9 sizes, and the square filter shape forming described final filter shape is 4 × 4 sizes.
Further, corresponding to the filter factor of the sample window of described final filter shape about described final filter shape Central Symmetry or quadrant symmetrical.
According to a second aspect of the invention, a kind of adaptive loop filter equipment for video image encoding and decoding is provided.This equipment comprises: divide module, for reconstruction image is divided into multiple block; And filtration module, for for each block in described multiple block, filtering is carried out according to certain filter shape and filter factor, described filter shape is made up of multiple sample window, each sample window is for selecting the pixel of correspondence position, and be provided with a filter factor, described filter factor is designed such that the mean square deviation between described reconstruction image and original image is minimum.For a block in described multiple block, build the final filter shape that cross line style filter shape superposes in center with square filter shape.Described cross line style filter shape sample window number is in the horizontal direction greater than the sample window number of in the vertical direction.
According to a third aspect of the invention we, provide a kind of adaptive loop filter that uses to process the method for the video image of coding.The method comprises: the reconstructed image data receiving the vedio data corresponding to coding; Adaptive loop filter is applied to the view data of described reconstruction to generate the vedio data through filtering; And video data through filtering is provided.The final filter shape that described adaptive loop filter uses to be superposed in center by cross line style filter shape and square filter shape and builds.Described cross line style filter shape sample window number is in the horizontal direction greater than the sample window number of in the vertical direction.
According to a forth aspect of the invention, provide a kind of adaptive loop filter that uses to process the equipment of the video image of coding.This equipment comprises: receiver module, for receiving the reconstructed image data of the vedio data corresponding to coding; Filtration module, for being applied to the view data of described reconstruction to generate the vedio data through filtering by adaptive loop filter; And provide module, for providing the video data through filtering.The final filter shape that described adaptive loop filter uses to be superposed in center by cross line style filter shape and square filter shape and builds.Described cross line style filter shape sample window number is in the horizontal direction greater than the sample window number of in the vertical direction.
The final filter shape that the cross line style filter shape proposed according to the various execution mode of the present invention superposes in center with square filter shape, this final filter shape is choose the unsymmetric structure design of the pixel in horizontal direction more relative to vertical direction.Thus, both improve ALF filter effect, achieve again spend when hardware implementing minimum.
Accompanying drawing explanation
By reference to the accompanying drawings and with reference to following detailed description, the feature of each execution mode of the present invention, advantage and other aspects will become more obvious.In the accompanying drawings:
Fig. 1 shows the schematic block diagram of the encoder according to HEVC/H.265 standard;
Fig. 2 shows the schematic block diagram of the decoder according to HEVC/H.265 standard;
The two-dimentional brilliant filter shape of 5 × 5,7 × 7 and 9 × 7 three kinds of sizes that the ALF that Fig. 3 shows HEVC/H.265 standard adopts;
The size that the ALF that Fig. 4 shows AVS2 standard adopts is the two-dimensional symmetric filter shape of 7 × 7;
The basic block unit that the reconstruction image that Fig. 5 shows AVS standard divides and label sequential schematic;
Fig. 6 shows the asymmetric filter shape of the two dimension adopted according to the ALF of an embodiment of the invention; And
Fig. 7 shows the asymmetric filter shape of two dimension that ALF according to another implementation of the invention adopts.
Embodiment
Hereafter with reference to some illustrative embodiments, principle of the present invention and spirit will be described by reference to the accompanying drawings.Should be appreciated that providing these execution modes is only used to enable those skilled in the art understand better and then realize the present invention, and not limit the scope of the invention by any way.
In HEVC/H.265 standard, image is divided into basic coding unit when encoding, i.e. maximum coding unit (LCU), such as 64 × 64 pixels.According to the difference of coding flow process, again LCU is divided into three parts, is respectively coding unit (CU), predicting unit (PU) and converter unit (TU).
HEVC/H.265 standard additionally uses infra-frame prediction and inter-frame prediction techniques, wherein utilize the room and time redundancy of vision signal to reach the object of Information Compression: when compressing current coding unit or coded sub-units, to utilize Pixel Information encoded around it to predict the pixel value in current coding unit or coded sub-units.Forecasting process is generally use certain several predefined prediction algorithm on the basis of neighborhood pixels, generates a predict pixel block of current coded unit/subelement.According to the assessment to distortion performance, the predictive mode that encoder efficiency of selection is the highest.The concrete operations of encoder relevant therewith comprise: the index of the predictive mode used of 1) encoding; 2) current coded unit/subelement and predict pixel block poor, obtain residual block; 3) residual block converted, quantize and entropy code.The respective operations of decoder comprises: the index of predictive mode of 1) decoding, obtains predictive mode according to index, and calculate corresponding intra-frame prediction block; 2) entropy decoded transform coefficients, re-quantization, inverse transformation obtain residual block; 3) addition prediction block and residual block obtain the block of pixels of reconstruction.
Fig. 1 shows the schematic block diagram of the encoder according to HEVC/H.265 standard, and Fig. 2 shows the schematic block diagram of the decoder according to HEVC/H.265 standard.As shown in Figure 1, given current prediction unit PU, represents with x, then can pass through infra-frame prediction (or interframe) prediction and first obtain prediction PU, represent with x '.Prediction PU, x ' then can be deducted by from current PU, x, produce PU residual error, represent with e.Then can be converted by conversion by the CU residual error of dividing into groups to the PU residual error be associated with coding unit CU, e and generating, often next converter unit TU, produce the PU residual error in transform domain, represent with E.Described conversion can such as use the block of square or non-square to convert.
Then PU residual error, E can device module 118 quantize by quantifying, thus convert high accuracy conversion coefficient to a limited number of probable value.As will be appreciated, quantification damages operation, and quantification loss cannot recover usually.
Then coefficient through quantizing can carry out entropy encoding/decoding by entropy encoding/decoding module 120, produces last compression bit.It should be noted that and depend on performed encoding and decoding standard, prediction described above, transform and quantization can perform for any block of video data, such as, for PU or TU of CU, or for LCU.
In order to promote that Time and place is predicted, also can take the conversion coefficient E through quantizing, and utilizing inverse quantization module 122 to carry out re-quantization to it, thus produce the conversion coefficient E ' through re-quantization.Then conversion coefficient through re-quantization carries out inverse transformation by inverse transform module 124, producing the PU residual error through rebuilding, representing with e '.PU residual error through rebuilding, e ' are then added in time or spatially and predict PU, x accordingly ', to form the PU through rebuilding, with x " represent.
In loop filter 126, can through rebuild predicting unit PU, x " on perform de-blocking filter (" DFB ") operation, first to reduce blocking effect.Can complete for performing self adaptation sampling point compensation (" SAO ") process after the de-blocking filter process of the image of decoding conditionally, this compensates and is biased through the pixel value between the pixel and original pixels of reconstruction.After DBF operation and SAO process, can also perform auto-adaptive loop filter ALF function, this adaptive loop filter ALF function can perform conditionally on the PU through rebuilding.Adaptive loop filter ALF is minimized in the encoding and decoding distortion between input and output image.In certain embodiments, loop filter module 126 works during inter picture prediction loop.If the image through rebuilding is reference picture, then they can be stored in reference buffer 128 for time prediction in the future.
As shown in Figure 2, it illustrates the schematic block diagram of the decoder according to HEVC/H.265 standard.The entropy decoder module 146 of decoder 145 can code stream after decoding and coding.Entropy decoder module 146 can perform the inverse process of described process in conjunction with entropy encoding/decoding module 120.Then coefficient can be provided to inverse quantization module 147 by entropy decoder module 146, and it carries out re-quantization to coefficient matrix, produces E '.Coefficient through re-quantization can be provided to inverse transform module 149 by inverse quantization module 147.Inverse transform module 149 can perform Transform operations to coefficient, produces e '.Then, the mode application loop filtering that can describe with composition graphs 1 and spatial prediction.
With regard to HEVC/H.265 standard, as previously mentioned, a complete loop filtering process comprises 3 links: block elimination filtering (DeblockingFilter, DBF), self adaptation sampling point compensates (SampleAdaptiveOffset, SAO), adaptive loop filter (AdaptiveLoopFilter, ALF).Rebuilding image after block elimination filtering and adaptive equalization, still there is noise in block inside.In HEVC/H.265 standard, adaptive loop filter (ALF) carries out after SAO or block elimination filtering, minimum to reach the mean square deviation (MSE) of rebuilding between image and original image for restoration and reconstruction image, to reduce the distortion of rebuilding between image and source images further.So just improve the picture quality of reconstruction frames further, thus provide the accuracy of motion compensation and estimation.ALF adopts two dimensional wiener filtering device, and filter shape adopts the two-dimentional brilliant filter construction of 5 × 5,7 × 7 and 9 × 7 three kinds of sizes, as shown in Figure 3.Filter shape defines the position needing the pixel considered around it when carrying out filtering to a pixel.Filter factor corresponding to the sample window of filter shape carries out adaptive polo placement according to local characteristics.At encoder place, ALF calculates one group of filter coefficient according to Wiener filtering principle and this group coefficient is sent to decoder.The filter factor of these filter constructions is calculated by adaptive wiener filter, can be obtained by adaptive training.
Rebuild image for every width, ALF can be used to a whole frame, also may be used for Partial Block wherein.According to the difference of filtering control mode, ALF can be divided three classes: the ALF based on frame, the ALF based on block, ALF based on quaternary tree.ALF based on frame is suggested the earliest, can for whole frame application ALF, and when only having a mark to be used for representing present frame, application ALF carries out filtering.After using the ALF based on frame likely can cause finishing filtering, in this two field picture, the picture quality in some regions can improve, but the pixel error in other regions increases on the contrary, image quality decrease, has thus developed the ALF based on block.ALF based on quaternary tree adopts meticulousr block division methods, uses less filtering block in image border and details place, and uses larger block for image flat region.The size of block regulates automatically according to the character of the zones of different of image, thus improves code efficiency.
What AVS2 standard adopted equally is block-based prediction and quantization scheme, have employed block elimination filtering DBF, SAO and adaptive loop filter ALF wherein equally.Fig. 4 show filter shape that AVS2 standard adopts and filter factor (C0, C1 ... C8) layout.AVS2 and HEVC/H.265 standard is compared, and the filter shape of ALF filter adopts more simple symmetrical structure, and filter factor is about central point Central Symmetry, thus greatly simplifies amount of calculation and the complexity of ALF filtering.
In AVS2 standard, present image is divided into 16 fundamental regions, as shown in Figure 5, the label order of fundamental region can be order as figure 5 illustrates.For a filter of the symmetric shape that each fundamental region can adopt 7 × 7 cross line styles as shown in Figure 4 and 3 × 3 squares to superpose.Filter factor (C0, C1 ... C8) symmetrical structure centered by, can train the filter factor of the filter of each fundamental region according to the principle that mean square error is minimum, namely the principle that wherein mean square error is minimum is the minimum principle of reconstructed pixel value and original pixel value distortion.
At encoder place, the filter shape that ALF function can be adopted and filter factor, as the ALF parameter coding of a fundamental region in code stream, are sent to decoder.At decoder place, decoder can resolve the ALF parameter transmitted from encoder, obtains filter shape and filter factor.When carrying out ALF filtering in encoding-decoding process, for each pixel in a fundamental region, select to carry out to this pixel the surrounding pixel that filtering uses according to the filter shape in this region, the pixel of the correspondence position new pixel that sum obtains that to be multiplied with corresponding filter factor is carried out alternative current pixel value, and wherein the center window of filter shape corresponds to this pixel.
Hereinafter, the ALF filter shape that various execution mode according to the present invention improves is specifically described.
Owing to being undertaken by raster scan order (rasterscan) in the encoding and decoding process of video image, when so getting vertical orientation data, necessary buffer memory full line data on hardware implementing, horizontal direction because of firm encoding and decoding out, in hardware, backup has corresponding pixel value, therefore, if when getting the neighbor pixel on the vertical direction of a pixel in the realization of ALF filtering, so employing is accessed a few row data and below a few row data above, then this needs the memory space resource of several rows.This consumption for hardware resource is very large, and particularly when the super clear image of 4K, the data volume that store is very large.Therefore, the pixel that can reduce on vertical direction is chosen, and the neighbor pixel more on selection level direction carries out ALF filtering.
For this reason, according to various execution mode of the present invention, build the final filter shape that cross line style filter shape superposes in center with square filter shape, or being called Filtering Template, wherein said cross line style filter shape sample window number is in the horizontal direction greater than the sample window number (corresponding to the square of in Fig. 6) of in the vertical direction.So, choosing of filtered samples window (for selecting the pixel of correspondence position) is increased by horizontal direction, not only increase the quality of image, and the cost of hardware implementing cost is little, also can be good at the quality and the filter effect that improve image.
Fig. 6 shows the Filtering Template of the two-dimentional unsymmetric structure of the ALF function according to one embodiment of the present invention.This Filtering Template is formed by stacking in center by the cross line style filter shape of 9 × 7 sizes and the square filter shape of 3 × 3 sizes.Filter factor (C0, C1 ... C9) have employed centrosymmetric structure.Alternatively, filter factor (C0, C1 ... C9) also asymmetrical structure can be adopted.
Fig. 7 shows the Filtering Template of the two-dimentional unsymmetric structure of the ALF function according to another embodiment of the present invention.This Filtering Template is formed by stacking in center by the cross line style filter shape of 7 × 5 sizes and the square filter shape of 3 × 3 sizes.
According to another execution mode of the present invention, the Filtering Template of the two-dimentional unsymmetric structure of ALF function can be formed by stacking in center by the square filter shape of the cross line style filter shape of 11 × 9 sizes and 3 × 3 sizes.
According to another execution mode of the present invention, the Filtering Template of the two-dimentional unsymmetric structure of ALF function can by being formed by stacking in center by the square filter shape of the cross line style filter shape of 11 × 9 sizes and 4 × 4 sizes.
Embodiment of the present invention by using the final asymmetric filter shape (or Filtering Template) of improvement between reconstruction frames and primitive frame, and such as 9 × 7 asymmetric templates as shown in Figure 6, optimize loop filter.Should be appreciated that the Filtering Template that embodiment of the present invention proposes can use in conjunction with the evolution version of HEVC/H.265 standard, AVS2 standard and above-mentioned standard, the appropriate section in them can be replaced.The filter factor corresponding to the ALF Filtering Template proposed more can be minimum according to the mean square error in such as HEVC/H.265 standard, AVS2 standard principle train.Additionally, the ALF filter shape that embodiment of the present invention proposes also can be applied in other coding and decoding video scheme.
Although in description above, after ALF is used in DBF and SAO, the present invention does not limit the relative position relation of itself and DBF and SAO.Such as, ALF between DBF and SAO, or can carry out filtering independent of DBF and SAO.
Be to be understood that, according to the embodiment of the present invention, the division of the fundamental region of present image as shown in Figure 5 and the label order of fundamental region are only a kind of examples, and the ALF Filtering Template of embodiment of the present invention can also be used in combination with other fundamental region dividing mode mod sum label order.
According to various execution mode of the present invention, propose a kind of adaptive loop filter method for video image encoding and decoding, comprising:
-reconstruction image is divided into multiple block; And
-for each block in described multiple block, filtering is carried out according to certain filter shape and filter factor, described filter shape is made up of multiple sample window, each sample window is for selecting the pixel of correspondence position, and be provided with a filter factor, described filter factor is designed such that the mean square deviation between described reconstruction image and original image is minimum.
For a block in described multiple block, build the final filter shape that cross line style filter shape superposes in center with square filter shape, wherein said cross line style filter shape sample window number is in the horizontal direction greater than the sample window number of in the vertical direction.
Such as, the block size that reconstruction image is divided into can be 64 × 64,32 × 32,16 × 16 and 8 × 8.The block rebuilding image can also be become sub-block based on quaternary tree by Further Division, to the application of such sub-block according to various execution mode ALF of the present invention.
According to various execution mode of the present invention, also propose a kind of adaptive loop filter equipment for video image encoding and decoding, comprising:
-divide module, for reconstruction image is divided into multiple block; And
-filtration module, for for each block in described multiple block, filtering is carried out according to certain filter shape and filter factor, described filter shape is made up of multiple sample window, each sample window is for selecting the pixel of correspondence position, and be provided with a filter factor, described filter factor is designed such that the mean square deviation between described reconstruction image and original image is minimum.
For a block in described multiple block, build the final filter shape that cross line style filter shape superposes in center with square filter shape, wherein said cross line style filter shape sample window number is in the horizontal direction greater than the sample window number of in the vertical direction.
According to various execution mode of the present invention, also proposed a kind of adaptive loop filter that uses to process the method for the video image of coding, comprising:
-receive the reconstructed image data corresponding to the vedio data of encoding;
-adaptive loop filter is applied to the view data of described reconstruction to generate the vedio data through filtering; And
-video data through filtering is provided.
The final filter shape that described adaptive loop filter uses to be superposed in center by cross line style filter shape and square filter shape and builds, and wherein said cross line style filter shape sample window number is in the horizontal direction greater than the sample window number of in the vertical direction.
According to various execution mode of the present invention, also proposed a kind of adaptive loop filter that uses to process the equipment of the video image of coding, comprising:
-receiver module, for receiving the reconstructed image data of the vedio data corresponding to coding;
-filtration module, for being applied to the view data of described reconstruction to generate the vedio data through filtering by adaptive loop filter; And
-provide module, for providing the video data through filtering.
The final filter shape that described adaptive loop filter uses to be superposed in center by cross line style filter shape and square filter shape and builds, and wherein said cross line style filter shape sample window number is in the horizontal direction greater than the sample window number of in the vertical direction.
According to various execution mode of the present invention, compared with the filter shape adopted in AVS2 standard, what change the filtered samples window (for selecting the pixel of correspondence position) on horizontal direction and vertical direction chooses number, sample window number is in the horizontal direction made to be greater than the sample window number of in the vertical direction, turn improve the quality (have selected more neighbor pixel) of filtering image, make again the cost recruitment when hardware implementing very little.Compared with traditional two-dimentional brilliant template, the window of focal selection Current central sample window periphery, reduces in filtering computational complexity.
For 9 × 7 of embodiment of the present invention as shown in Figure 6 asymmetric Filtering Templates, by carrying out the ALF filtering (7 × 7 templates as shown in Figure 4) of AVS2 standard and adopt the performance comparison of the ALF filtering of 9 × 7 asymmetric Filtering Templates of this execution mode to test on AVS2 reference software RD11.0, test result is as shown in the table.
In the test of upper table, have chosen 14 cycle testss altogether, comprising 4 image sequences of 2 image sequences of UHD resolution, 4 image sequences of 1080p resolution, 4 image sequences of WVGA resolution and 720p resolution.For these 14 test pattern sequences, have chosen respectively quantization parameter quantization step (QP) be followed successively by 27,32,38 and 45 build test cases test.
As seen from the above table, 9 × 7 asymmetric Filtering Templates are as shown in Figure 6 adopted to carry out ALF filtering, compared with carrying out ALF filtering with the filter shape adopted as shown in Figure 4, for the luminance component Y of image, RA on average has the lifting of 0.06%, LD on average has the lifting of 0.2%, and AI on average has the lifting of 0.02%; Chromatic component U and V of image, RA are on average had respectively to the lifting of 0.07% and 0.28%, LD on average has the lifting of 0.12% and 0.02% respectively, and AI on average has the lifting of 0.08% and 0.08% respectively.
Inventor also to the asymmetric Filtering Template in 9 × 7 as shown in Figure 6 and comprise 7 × 5 asymmetric Filtering Templates as shown in Figure 7 and aforesaid 11 × 9 two kinds of asymmetric Filtering Templates carried out contrast test, test result show the filter shape shown in Fig. 6 image quality improvement amount and computation complexity balanced in be that effect is optimum.
Although should be appreciated that the ALF scheme that embodiment of the present invention proposes is particularly suitable for hardware implementing, the program also may be implemented as the combination of software or hardware and software.Hardware realizes by being designed to perform the conversion integrated circuit (ASIC) of above-mentioned functions, digital signal processor (DSP), programmable logic device (PLD), field programmable gate array (FPGA), processor, controller, microprocessor, other electronic units or its combination.Software realizes by the module performing above-mentioned functions.Software can be stored in the memory unit and be run by processor.As memory cell or processor, can adopt and well known to a person skilled in the art various unit.
Give specification of the present invention for the object illustrated and describe, but it is not intended to be exhaustive or be limited to the invention of disclosed form.It may occur to persons skilled in the art that a lot of amendment and variant.Under the prerequisite not departing from spirit of the present invention, all modifications made and replacement all will fall in the scope of claims definition.
Claims (10)
1., for an adaptive loop filter method for video image encoding and decoding, comprising:
Reconstruction image is divided into multiple block; And
For each block in described multiple block, filtering is carried out according to certain filter shape and filter factor, described filter shape is made up of multiple sample window, each sample window is for selecting the pixel of correspondence position, and be provided with a filter factor, described filter factor is designed such that the mean square deviation between described reconstruction image and original image is minimum
It is characterized in that, for a block in described multiple block, build the final filter shape that cross line style filter shape superposes in center with square filter shape, wherein said cross line style filter shape sample window number is in the horizontal direction greater than the sample window number of in the vertical direction.
2. method according to claim 1, is characterized in that, the cross line style filter shape forming described final filter shape is 9 × 7 sizes, and the square filter shape forming described final filter shape is 3 × 3 sizes, as shown in Figure 6.
3. method according to claim 1, it is characterized in that, the cross line style filter shape forming described final filter shape is 7 × 5 sizes or 11 × 9 sizes, and the square filter shape forming described final filter shape is respectively 3 × 3 sizes or 4 × 4 sizes.
4. the method according to any one of claim 1-3, is characterized in that, corresponding to the filter factor of the sample window of described final filter shape about described final filter shape Central Symmetry or quadrant symmetrical.
5., for an adaptive loop filter equipment for video image encoding and decoding, comprising:
Divide module, for reconstruction image is divided into multiple block; And
Filtration module, for for each block in described multiple block, filtering is carried out according to certain filter shape and filter factor, described filter shape is made up of multiple sample window, each sample window is for selecting the pixel of correspondence position, and be provided with a filter factor, described filter factor is designed such that the mean square deviation between described reconstruction image and original image is minimum
It is characterized in that, for a block in described multiple block, build the final filter shape that cross line style filter shape superposes in center with square filter shape, wherein said cross line style filter shape sample window number is in the horizontal direction greater than the sample window number of in the vertical direction.
6. use adaptive loop filter to process a method for the video image of coding, comprising:
Receive the reconstructed image data of the vedio data corresponding to coding;
Adaptive loop filter is applied to the view data of described reconstruction to generate the vedio data through filtering; And
Video data through filtering is provided,
It is characterized in that, the final filter shape that described adaptive loop filter uses to be superposed in center by cross line style filter shape and square filter shape and builds, and wherein said cross line style filter shape sample window number is in the horizontal direction greater than the sample window number of in the vertical direction.
7. method according to claim 6, is characterized in that, the cross line style filter shape forming described final filter shape is 9 × 7 sizes, and the square filter shape forming described final filter shape is 3 × 3 sizes.
8. method according to claim 6, it is characterized in that, the cross line style filter shape forming described final filter shape is 7 × 5 sizes or 3 × 3 sizes, and the square filter shape forming described final filter shape is respectively 3 × 3 sizes or 4 × 4 sizes.
9. the method according to any one of claim 6-8, is characterized in that, corresponding to the filter factor of the sample window of described final filter shape about described final filter shape Central Symmetry or quadrant symmetrical.
10. use adaptive loop filter to process an equipment for the video image of coding, comprising:
Receiver module, for receiving the reconstructed image data of the vedio data corresponding to coding;
Filtration module, for being applied to the view data of described reconstruction to generate the vedio data through filtering by adaptive loop filter; And
Module is provided, for providing the video data through filtering,
It is characterized in that, the final filter shape that described adaptive loop filter uses to be superposed in center by cross line style filter shape and square filter shape and builds, and wherein said cross line style filter shape sample window number is in the horizontal direction greater than the sample window number of in the vertical direction.
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