CN103260018A - Intra-frame image predictive encoding and decoding method and video codec - Google Patents

Abstract

The invention discloses an intra-frame image predictive encoding and decoding method and a video codec. The intra-frame image predictive encoding and decoding method comprises the following steps that intra-frame image predictive encoding is conducted by the adoption of an chromaticity intra-frame prediction mode; a reconstruction value of a luminance component Y of a transformation unit (TU) is acquired; a chromaticity component U of the current TU is predicted by the means of the reconstruction value of the luminance component Y of the current TU; a reconstruction value of the chromaticity component U of the current TU is acquired; a chromaticity component V of the current TU is predicted by the means of the reconstruction value of the chromaticity component U of the current TU. According to the intra-frame image predictive encoding and decoding method and the video codec, relevance between the chromaticity component V and the chromaticity component U can be fully used, and therefore predictive encoding and decoding efficiency of intra-frame images is improved.

Description

I picture prediction decoding method and Video Codec

Technical field

The present invention relates to image/video encoding and decoding and I picture electric powder prediction, relate in particular to I picture prediction decoding method and Video Codec.

Background technology

YUV is the color space that colour television standard adopts by a kind of colour coding method that the eurovision system is adopted.Wherein, Y is luminance component, expression lightness (Luma), just GTG value; And U and V are chromatic components, expression then be colourity (Chroma), effect is to describe colors of image and saturation, is used to specify color of pixel.The importance that adopts the YUV color space is that its luminance component Y separates with calibration component V with chromatic component U.Do not have chromatic component U and chromatic component V if having only luminance component Y, the image of expression is exactly the black and white gray level image so like this.Color TV adopts YUV color space available brightness component Y to solve the compatible problem of color television set and black and white television set, makes black and white television set also can receive colour TV signal.

The image/video compression coding and decoding is divided into inter frame image prediction encoding and decoding and two kinds of predictions of I picture prediction encoding and decoding encoding and decoding technique generally.The I picture predictive coding be used to from present frame the information of coded image unit the current encoded image unit is carried out predictive coding; The I picture prediction decoding be used to from present frame the information of decoded picture unit current decoded picture unit is carried out prediction decoding.

In the existing I picture prediction decoding method, be to adopt LM (Luma-based chroma intra prediction Mode is based on the chrominance frames inner estimation mode of brightness) to carry out I picture prediction encoding and decoding.Between LM hypothesis chromatic component U and chromatic component V and the luminance component Y linear relationship is arranged, based on this hypothesis, when coding colourity, LM predicts chromatic component U and chromatic component V with the reconstruction value of luminance component Y.

In HM4.0, LM predicts chromatic component U and chromatic component V with the reconstruction value of luminance component Y, and is chromatic component U and chromatic component V difference design factor α _LAnd β _LIn LM, adopt following linear model to predict chromatic component U and chromatic component V:

Pred _C[x，y]＝α _L·Rec′ _L[x，y]+β _L

Wherein, Pred _C[x, y] is the predicted value of current TU (Transform Unit, converter unit) chromatic component U or chromatic component V, Rec _L[x, y] is the reconstruction value of current TU luminance component Y, Rec ' _L[x, y] is the reconstruction value of filtered current TU luminance component Y, x, and y=0 ..., N-1, the width of current TU chrominance block and highly be N.

Be used for design factor α _LAnd β _LSample point as shown in Figure 1.Among Fig. 1, Rec ' _LBe the reconstruction value of filtered current TU luminance block adjacent left-hand one row and upside one-row pixels luminance component Y, Rec _CIt is the reconstruction value of current TU chrominance block adjacent left-hand one row and upside one-row pixels chromatic component U or chromatic component V.

But, when existing I picture prediction decoding method adopts LM to carry out I picture prediction encoding and decoding, do not take full advantage of the correlation between chromatic component V and the chromatic component U, make that I picture prediction encoding-decoding efficiency is lower.

Summary of the invention

The embodiment of the invention provides a kind of inage predicting encoding method in frame, and in order to improve I picture predictive coding efficient, this method comprises that the following chrominance frames inner estimation mode of employing carries out the I picture predictive coding:

Obtain the reconstruction value of current converter unit TU luminance component Y;

With the reconstruction value of current TU luminance component Y, current TU chromatic component U is predicted;

Obtain the reconstruction value of current TU chromatic component U;

With the reconstruction value of current TU chromatic component U, current TU chromatic component V is predicted.

The embodiment of the invention provides a kind of I picture prediction decoding method, and in order to improve I picture prediction decoding efficient, this method comprises:

Determine to adopt above-mentioned chrominance frames inner estimation mode to carry out the I picture prediction decoding;

Obtain the reconstruction value of current TU luminance component Y;

With the reconstruction value of current TU luminance component Y, current TU chromatic component U is predicted;

Obtain the reconstruction value of current TU chromatic component U;

With the reconstruction value of current TU chromatic component U, current TU chromatic component V is predicted.

The embodiment of the invention also provides a kind of video encoder, in order to improve I picture predictive coding efficient, this video encoder comprises that adopting following chrominance frames inner estimation mode to carry out first of I picture predictive coding obtains module, first prediction module, second acquisition module and second prediction module:

First obtains module, is used for obtaining the reconstruction value of current TU luminance component Y;

First prediction module is used for the reconstruction value with current TU luminance component Y, and current TU chromatic component U is predicted;

Second obtains module, is used for obtaining the reconstruction value of current TU chromatic component U;

Second prediction module is used for the reconstruction value with current TU chromatic component U, and current TU chromatic component V is predicted.

The embodiment of the invention also provides a kind of Video Decoder, and in order to improve I picture prediction decoding efficient, this Video Decoder comprises:

The pattern determination module is used for determining to adopt above-mentioned chrominance frames inner estimation mode to carry out the I picture prediction decoding;

First obtains module, is used for obtaining the reconstruction value of current TU luminance component Y;

First prediction module is used for the reconstruction value with current TU luminance component Y, and current TU chromatic component U is predicted;

Second obtains module, is used for obtaining the reconstruction value of current TU chromatic component U;

Second prediction module is used for the reconstruction value with current TU chromatic component U, and current TU chromatic component V is predicted.

The I picture prediction decoding method of the embodiment of the invention and the chrominance frames inner estimation mode that Video Codec adopts, be with the reconstruction value of current TU luminance component Y current TU chromatic component U to be predicted, reconstruction value with current TU chromatic component U is predicted current TU chromatic component V, current TU chromatic component U is compared with the technical scheme that chromatic component V predicts with the reconstruction value of current TU luminance component Y with existing LM, take full advantage of the correlation between chromatic component V and the chromatic component U, can improve I picture prediction encoding-decoding efficiency.

Description of drawings

In order to be illustrated more clearly in the embodiment of the invention or technical scheme of the prior art, to do to introduce simply to the accompanying drawing of required use in embodiment or the description of the Prior Art below, apparently, accompanying drawing in describing below only is some embodiments of the present invention, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain other accompanying drawing according to these accompanying drawings.In the accompanying drawings:

Fig. 1 is for being used for design factor α in the prior art _LAnd β _LThe schematic diagram of sample point;

Fig. 2 is the schematic diagram of inage predicting encoding method in frame in the embodiment of the invention;

The schematic diagram of Fig. 3 for the reconstruction value of current TU chromatic component U current TU chromatic component V being predicted in the embodiment of the invention;

Fig. 4 calculates factor alpha in the embodiment of the invention _VAnd β _VThe schematic diagram of the sample point that uses;

Fig. 5 is the schematic diagram of I picture prediction decoding method in the embodiment of the invention;

Fig. 6 is the structural representation of video encoder in the embodiment of the invention;

Fig. 7 is the structural representation of an instantiation of video encoder in the embodiment of the invention;

Fig. 8 is the structural representation of Video Decoder in the embodiment of the invention.

Embodiment

For the purpose, technical scheme and the advantage that make the embodiment of the invention is clearer, below in conjunction with accompanying drawing the embodiment of the invention is described in further details.At this, illustrative examples of the present invention and explanation thereof are used for explanation the present invention, but not as a limitation of the invention.

In order to take full advantage of the correlation between chromatic component V and the chromatic component U, improve I picture prediction encoding-decoding efficiency, the embodiment of the invention is revised existing LM.Between existing LM hypothesis chromatic component U and chromatic component V and the luminance component Y linear relationship is arranged, based on this hypothesis, when coding colourity, LM predicts chromatic component U and chromatic component V with the reconstruction value of luminance component Y.And the chrominance frames inner estimation mode that the I picture of embodiment of the invention prediction decoding method and Video Codec adopt, still supposing has linear relationship between chromatic component U and chromatic component V and the luminance component Y, and chromatic component U is predicted with the reconstruction value of luminance component Y this is identical with existing LM; Different with LM is, the embodiment of the invention also supposes between chromatic component V and the chromatic component U linear relationship is arranged also, this linear relationship is stronger than the linear relationship between colourity component V and the luminance component Y, and when considering prediction chromatic component V, chromatic component U reconstruct finishes, and therefore predicts chromatic component V with the reconstruction value of chromatic component U rather than the reconstruction value of luminance component Y.

For ease of describing, the I picture prediction decoding method of the embodiment of the invention and the chrominance frames inner estimation mode that Video Codec adopts, can be referred to as LUM (luma-based U and U-based V chroma intra prediction mode, the chrominance frames inner estimation mode of prediction V from luma prediction U from U).

Fig. 2 is the schematic diagram of the inage predicting encoding method in frame of the embodiment of the invention.As shown in Figure 2, the inage predicting encoding method in frame of the embodiment of the invention comprises that the following chrominance frames inner estimation mode of employing (LUM) carries out the I picture predictive coding:

The reconstruction value of step 201, the current converter unit TU luminance component Y of acquisition;

Step 202, with the reconstruction value of current TU luminance component Y, current TU chromatic component U is predicted;

The reconstruction value of step 203, the current TU chromatic component U of acquisition;

Step 204, with the reconstruction value of current TU chromatic component U, current TU chromatic component V is predicted.

Can be learnt by flow process shown in Figure 2, in the chrominance frames inner estimation mode (LUM) that the embodiment of the invention adopts, the Forecasting Methodology of chromatic component U is identical with existing LM, and different with existing LM be to predict chromatic component V with the reconstruction value of chromatic component U rather than the reconstruction value of luminance component Y.

During concrete enforcement, with the reconstruction value of current TU chromatic component U, current TU chromatic component V is predicted, can comprise:

With the reconstruction value of current TU chromatic component U, by linear relationship current TU chromatic component V is predicted.

During concrete enforcement, can with the reconstruction value of current TU chromatic component U, by linear relationship current TU chromatic component V be predicted by following formula:

Pred _V[x，y]＝α _V·Rec _U[x，y]+β _V

Wherein, Pred _V[x, y] is the predicted value of current TU chromatic component V, Rec _U[x, y] is the reconstruction value of current TU chromatic component U, x, and y=0 ..., N-1, the width of current TU chrominance block and highly be N, design factor α _VAnd β _VThe sample point that uses is current TU chrominance block adjacent left-hand one row and the reconstruction value of upside one-row pixels chromatic component U and the reconstruction value of chromatic component V.

The schematic diagram of Fig. 3 for the reconstruction value of current TU chromatic component U current TU chromatic component V being predicted in the embodiment of the invention.

Fig. 4 calculates factor alpha in the embodiment of the invention _VAnd β _VThe schematic diagram of the sample point that uses.Among Fig. 4, Rec _UBe the reconstruction value of current TU chrominance block adjacent left-hand one row and upside one-row pixels chromatic component U, Rec _VIt is the reconstruction value of current TU chrominance block adjacent left-hand one row and upside one-row pixels chromatic component V.

During concrete enforcement, can be by following formula, design factor α _VAnd β _V:

${\mathrm{\α}}_V=\frac{2N\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_V\left(i\right)\·\mathrm{Re}{c}_U\left(i\right)-\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_V\left(i\right)\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)}{2N\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)\·\mathrm{Re}{c}_U\left(i\right)-{\left(\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)\right)}^2}$

${\mathrm{\β}}_V=\frac{\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_V\left(i\right)-{\mathrm{\α}}_V\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)}{2N}$

Wherein, Rec _U(i) be the reconstruction value of current TU chrominance block adjacent left-hand one row and upside one-row pixels chromatic component U, Rec _V(i) be the reconstruction value of current TU chrominance block adjacent left-hand one row and upside one-row pixels chromatic component V, i=0 ..., 2N-1 travels through current TU chrominance block adjacent left-hand one and is listed as and the upside one-row pixels, the width of current TU chrominance block and highly be N.

Design factor α _VAnd β _VDetailed process can be referring to the newly-increased part 8.3.3.1.19 trifle of working draft (working draft) JCTVC-G1103_d4 hereinafter.

The chrominance frames inner estimation mode (LUM) that the inage predicting encoding method in frame of the embodiment of the invention adopts can carry out rate-distortion optimization with existing LM and select.

During concrete enforcement, can on the basis of implementing flow process shown in Figure 2, adopt existing LM to carry out the I picture predictive coding again: the reconstruction value that obtains current TU luminance component Y; With the reconstruction value of current TU luminance component Y, current TU chromatic component U and chromatic component V are predicted.The follow-up rate-distortion optimization that carries out is again selected, and namely in LUM and LM, selects the chrominance frames inner estimation mode of minimum rate distortion costs correspondence to carry out the I picture predictive coding.

During concrete enforcement, the inage predicting encoding method in frame of the embodiment of the invention can also comprise: which kind of chrominance frames inner estimation mode (as LUM or LM etc.) is the code word of coding colourity intra prediction mode, adopt carry out the I picture predictive coding with indication.Table 1 is the code word of chrominance frames inner estimation mode among the HM4.0:

The code word of chrominance frames inner estimation mode among the table 1:HM4.0

After introducing LUM, need adjust the code word of colourity intra prediction mode, as shown in table 2.

Table 2: the code word of the chrominance frames inner estimation mode after the adjustment

The chrominance frames inner estimation mode	Code word
		DM	0
LM	10
		LUM	110
Planar	1110
		Vertical	11110

Horizontal	111110
		DC	111111

Contrast table 1 and table 2 as can be seen, when the code word of coding colourity intra prediction mode, change has taken place on the basis of HM4.0 in the code word of chrominance frames inner estimation mode, and the maximum length of code word has been increased to 6 from 5.

Based on same inventive concept, also provide a kind of I picture prediction decoding method in the embodiment of the invention, as described in the following examples.Because the principle that I picture prediction decoding method is dealt with problems is similar to inage predicting encoding method in frame, so the enforcement of I picture prediction decoding method can repeat part and repeat no more referring to the enforcement of inage predicting encoding method in frame.

Fig. 5 is the schematic diagram of the I picture prediction decoding method of the embodiment of the invention.As shown in Figure 5, the I picture prediction decoding method of the embodiment of the invention can comprise:

Step 501, definite LUM that adopts carry out the I picture prediction decoding;

The reconstruction value of step 502, the current TU luminance component Y of acquisition;

Step 503, with the reconstruction value of current TU luminance component Y, current TU chromatic component U is predicted;

The reconstruction value of step 504, the current TU chromatic component U of acquisition;

Step 505, with the reconstruction value of current TU chromatic component U, current TU chromatic component V is predicted.

During concrete enforcement, determine to adopt LUM to carry out the I picture prediction decoding, can comprise:

The code word of decoding chrominance frames inner estimation mode;

According to the code word of chrominance frames inner estimation mode, determine to adopt LUM to carry out the I picture prediction decoding.

Among the HM4.0, the code word of chrominance frames inner estimation mode is as shown in table 1.The I picture prediction decoding method of the embodiment of the invention has increased LUM, and variation has taken place the code word of chrominance frames inner estimation mode, and is as shown in table 2.Therefore contrast table 1 and table 2 as can be seen, when the code word of decoding chrominance frames inner estimation mode, at first, the maximum length of decodes codeword has been increased to 6 from 5; Secondly, variation has also taken place in the chrominance frames inner estimation mode of code word representative, need obtain the chrominance frames inner estimation mode of code word correspondence according to table 2.

During concrete enforcement, with the reconstruction value of current TU chromatic component U, current TU chromatic component V is predicted, can comprise:

With the reconstruction value of current TU chromatic component U, by linear relationship current TU chromatic component V is predicted.

During concrete enforcement, can with the reconstruction value of current TU chromatic component U, by linear relationship current TU chromatic component V be predicted by following formula:

Pred _V[x，y]＝α _V·Rec _U[x，y]+β _V

Wherein, Pred _V[x, y] is the predicted value of current TU chromatic component V, Rec _U[x, y] is the reconstruction value of current TU chromatic component U, x, and y=0 ..., N-1, the width of current TU chrominance block and highly be N, design factor α _VAnd β _VThe sample point that uses is current TU chrominance block adjacent left-hand one row and the reconstruction value of upside one-row pixels chromatic component U and the reconstruction value of chromatic component V.

During concrete enforcement, can be by following formula, design factor α _VAnd β _V:

${\mathrm{\α}}_V=\frac{2N\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_V\left(i\right)\·\mathrm{Re}{c}_U\left(i\right)-\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_V\left(i\right)\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)}{2N\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)\·\mathrm{Re}{c}_U\left(i\right)-{\left(\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)\right)}^2}$

${\mathrm{\β}}_V=\frac{\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_V\left(i\right)-{\mathrm{\α}}_V\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)}{2N}$

Wherein, Rec _U(i) be the reconstruction value of current TU chrominance block adjacent left-hand one row and upside one-row pixels chromatic component U, Rec _V(i) be the reconstruction value of current TU chrominance block adjacent left-hand one row and upside one-row pixels chromatic component V, i=0 ..., 2N-1 travels through current TU chrominance block adjacent left-hand one and is listed as and the upside one-row pixels, the width of current TU chrominance block and highly be N.

Design factor α _VAnd β _VDetailed process can be referring to the newly-increased part 8.3.3.1.19 trifle of working draft JCTVC-G1103_d4 hereinafter.

During concrete enforcement, the I picture prediction decoding method of the embodiment of the invention is introduced LUM also to be needed working draft JCTVC-G1103_d4 is made amendment, concrete modification is as follows, revises part and is marked by underscore in table 8-1 and table 8-4, revises part and also comprises the 8.3.3.1.19 trifle.

8.3.1 Derivation process for luma intra prediction mode (luminance frame inner estimation mode derivation)

……

The Table 8-1 Specification of intra prediction mode and associated names explanation of corresponding title (the table 8-1 intra prediction mode with)

……

8.3.2 Derivation process for chroma intra prediction mode (chrominance frames inner estimation mode derivation)

……

Table 8-4 Specification of IntraPredModeC according to the values of intra_chroma_pred_mode and IntraPredMode[xB] [yB] when chroma_pred_from_luma_enabled_flag is equal to 1 (table 8-4 when the chroma_pred_from_luma_enabled_flag flag bit of luma prediction colourity (permission from) while equaling 1, utilize intra_chroma_pred_mode (colourity intra-frame prediction method) and IntraPredMode (intra prediction mode) [xB] [yB] to determine the explanation of IntraPredModeC (chrominance frames inner estimation mode))

……

8.3.3.1.19 the explanation of Intra_FromLumaAndU (being predicted by brightness and colourity U in the frame) predictive mode

As intraPredMode (intra prediction mode) when equaling 36, carry out following steps:

1, the interior pixel prediction process of carrying out in the 8.3.3.1.18 trifle of frame is predicted U;

2, carry out after the 8.3.3 reconstruct U, the pixel prediction process is predicted V in the frame below carrying out then:

The input of this process is:

The reconstruction value recSamples of adjacent U _U[x, y], x wherein, y=-1..nS-1, x=0 wherein, y=0 represents the position, the upper left corner of current block;

The reconstruction value recSamples of adjacent V _V[x, y], y=-1 wherein, x=0..nS-1 or x=-1, y=0..nS-1, x=0 wherein, y=0 represents the position, the upper left corner of current block;

Variable nS is used to refer to the current block size.

The output of this process is:

The predicted value predSamples of V _V[x, y], x, y=0..nS-1, x=0 wherein, y=0 represents the position, the upper left corner of current block;

The predicted value predSamples of V _V[x, y], x, y=0..nS-1 obtains by following steps:

1), calculates variable k3 and sample p _U, p _VAs follows:

k3＝Max(0，BitDepth _c+log ₂(nS)-14)

p _U[x，y]＝recSamples _U[x，y]，x，y＝-1..nS-1

p _V[x, y]=recSamples _V[x, y], y=-1, x=0..nS-1 or x=-1, y=0..nS-1

2), calculate variables L, C, LL, LC and k2 are as follows:

$L=\left(\underset{y=0}{\overset{\mathrm{nS}-1}{\mathrm{\Σ}}}{p}_U\right[-1,y]+\underset{x=0}{\overset{\mathrm{nS}-1}{\mathrm{\Σ}}}{p}_U[x,-1\left]\right)>>k3$

$C=\left(\underset{y=0}{\overset{\mathrm{nS}-1}{\mathrm{\Σ}}}{p}_V\right[-1,y]+\underset{x=0}{\overset{\mathrm{nS}-1}{\mathrm{\Σ}}}{p}_V[x,-1\left]\right)>>k3$

$\mathrm{LL}=(\underset{y=0}{\overset{\mathrm{nS}-1}{\mathrm{\Σ}}}{p}_U{[-1,y]}^2+\underset{x=0}{\overset{\mathrm{nS}-1}{\mathrm{\Σ}}}{p}_U{[x,-1]}^2)>>k3$

$\mathrm{LC}=\left(\underset{y=0}{\overset{\mathrm{nS}-1}{\mathrm{\Σ}}}{p}_U\right[-1,y]*p_V[-1,y]+\underset{y=0}{\overset{\mathrm{nS}-1}{\mathrm{\Σ}}}{p}_U[x,-1]*p_V[x,-1\left]\right)>>k3$

k2＝log ₂((2*nS)＞＞k3)

3), calculate variable a, b and k are as follows:

a1＝(LC＜＜k2)-L*C

a2＝(LL＜＜k2)-L*L

k1＝Max(0，log ₂(abs(a2))-5)-Max(0，log ₂(abs(a1))-14)+2

a1s＝a1＞＞Max(0，log ₂(abs(a1))-14)

a2s＝abs(a2＞＞Max(0，log ₂(abs(a2))-5))

a3＝a2s＜1？0:Clip3(-2 ¹⁵，2 ¹⁵-1，a1s*lmDiv+(1＜＜(k1-1))＞＞k1)

a＝a3＞＞Max(0，log ₂(abs(a3))-6)

k＝13-Max(0，log ₂(a))-6)

b＝(L-((a*C)＞＞k1)+(1＜＜(k2-1)))＞＞k2

Wherein lmDiv obtains by the 8-10 that tables look-up with a2s.

4), at last, calculate the predicted value predSamples of V _V[x, y] is as follows:

predSamples _V[x，y]＝Clip1 _C(((p _U[x，y]*a)＞＞k)+b)，x，y＝0..nS-1

Based on same inventive concept, a kind of video encoder and Video Decoder are also provided in the embodiment of the invention, as described in the following examples.Because video encoder is similar with coding/decoding method to the I picture predictive coding with the principle that Video Decoder is dealt with problems, therefore the enforcement of video encoder and Video Decoder can repeat part and repeat no more referring to the enforcement of I picture predictive coding and coding/decoding method.

Fig. 6 is the structural representation of video encoder in the embodiment of the invention.As shown in Figure 6, video encoder can comprise in the embodiment of the invention:

Adopt following chrominance frames inner estimation mode (LUM) to carry out first of I picture predictive coding and obtain module 601, first prediction module 602, second acquisition module 603 and second prediction module 604:

First obtains module 601, is used for obtaining the reconstruction value of current TU luminance component Y;

First prediction module 602 is used for the reconstruction value with current TU luminance component Y, and current TU chromatic component U is predicted;

Second obtains module 603, is used for obtaining the reconstruction value of current TU chromatic component U;

Second prediction module 604 is used for the reconstruction value with current TU chromatic component U, and current TU chromatic component V is predicted.

Among the embodiment, second prediction module 604 specifically can be used for:

With the reconstruction value of current TU chromatic component U, by linear relationship current TU chromatic component V is predicted.

Among the embodiment, second prediction module 604 specifically can be used for:

By following formula, with the reconstruction value of current TU chromatic component U, by linear relationship current TU chromatic component V is predicted:

Pred _V[x，y]＝α _V·Rec _U[x，y]+β _V

Wherein, Pred _V[x, y] is the predicted value of current TU chromatic component V, Rec _U[x, y] is the reconstruction value of current TU chromatic component U, x, and y=0 ..., N-1, the width of current TU chrominance block and highly be N, design factor α _VAnd β _VThe sample point that uses is current TU chrominance block adjacent left-hand one row and the reconstruction value of upside one-row pixels chromatic component U and the reconstruction value of chromatic component V.

Among the embodiment, second prediction module 604 specifically can be used for:

By following formula, design factor α _VAnd β _V:

${\mathrm{\α}}_V=\frac{2N\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_V\left(i\right)\·\mathrm{Re}{c}_U\left(i\right)-\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_V\left(i\right)\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)}{2N\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)\·\mathrm{Re}{c}_U\left(i\right)-{\left(\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)\right)}^2}$

${\mathrm{\β}}_V=\frac{\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_V\left(i\right)-{\mathrm{\α}}_V\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)}{2N}$

Wherein, Rec _U(i) be the reconstruction value of current TU chrominance block adjacent left-hand one row and upside one-row pixels chromatic component U, Rec _V(i) be the reconstruction value of current TU chrominance block adjacent left-hand one row and upside one-row pixels chromatic component V, i=0 ..., 2N-1.

As shown in Figure 7, among the embodiment, video encoder shown in Figure 6 can also comprise:

Pattern-coding module 701 for the code word of coding colourity intra prediction mode, adopts LUM to carry out the I picture predictive coding with indication.

Fig. 8 is the structural representation of Video Decoder in the embodiment of the invention.As shown in Figure 8, Video Decoder can comprise in the embodiment of the invention:

Pattern determination module 801 is used for determining to adopt LUM to carry out the I picture prediction decoding;

First obtains module 802, is used for obtaining the reconstruction value of current TU luminance component Y;

First prediction module 803 is used for the reconstruction value with current TU luminance component Y, and current TU chromatic component U is predicted;

Second obtains module 804, is used for obtaining the reconstruction value of current TU chromatic component U;

Second prediction module 805 is used for the reconstruction value with current TU chromatic component U, and current TU chromatic component V is predicted.

Among the embodiment, determination module 801 specifically can be used for:

The code word of decoding chrominance frames inner estimation mode;

According to the code word of chrominance frames inner estimation mode, determine to adopt LUM to carry out the I picture prediction decoding.

Among the embodiment, second prediction module 805 specifically can be used for:

With the reconstruction value of current TU chromatic component U, by linear relationship current TU chromatic component V is predicted.

Among the embodiment, second prediction module 805 specifically can be used for:

By following formula, with the reconstruction value of current TU chromatic component U, by linear relationship current TU chromatic component V is predicted:

Pred _V[x，y]＝α _V·Rec _U[x，y]+β _V

Wherein, Pred _V[x, y] is the predicted value of current TU chromatic component V, Rec _U[x, y] is the reconstruction value of current TU chromatic component U, x, and y=0 ..., N-1, the width of current TU chrominance block and highly be N, design factor α _VAnd β _VThe sample point that uses is current TU chrominance block adjacent left-hand one row and the reconstruction value of upside one-row pixels chromatic component U and the reconstruction value of chromatic component V.

Among the embodiment, second prediction module 805 specifically can be used for:

By following formula, design factor α _VAnd β _V:

${\mathrm{\α}}_V=\frac{2N\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_V\left(i\right)\·\mathrm{Re}{c}_U\left(i\right)-\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_V\left(i\right)\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)}{2N\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)\·\mathrm{Re}{c}_U\left(i\right)-{\left(\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)\right)}^2}$

${\mathrm{\β}}_V=\frac{\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_V\left(i\right)-{\mathrm{\α}}_V\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)}{2N}$

Wherein, Rec _U(i) be the reconstruction value of current TU chrominance block adjacent left-hand one row and upside one-row pixels chromatic component U, Rec _V(i) be the reconstruction value of current TU chrominance block adjacent left-hand one row and upside one-row pixels chromatic component V, i=0 ..., 2N-1.

The I picture prediction decoding method of the embodiment of the invention and the chrominance frames inner estimation mode of Video Codec employing are integrated among the HM4.0 (LM bug-fixed version), and compare with HM4.0.Experiment is to carry out according to the universal test condition among the JCTVC-F900.The test environment of experiment is: Intel (R) Xeon (R) CPU X56702.93GHz, and 6 nuclears,, internal memory 12GB, 7,32 compilers of Windows.

Experimental result is as shown in table 3.As can be seen, the embodiment of the invention code check that can reduce chromatic component V under " high efficiency intraframe coding (All Intra HE) " and " low complex degree intraframe coding (All Intra LC) " situation respectively reaches 0.72% and 1.33%.Luminance component Y and chromatic component U code check under " high efficiency intraframe coding " situation does not increase, and code check slightly increases (luminance component Y average bit rate increase by 0.03%, worst case code check increase by 0.11% under " low complex degree intraframe coding " situation; Chromatic component U average bit rate reduces by 0.07%, and the worst case code check increases by 0.88%).Code check increase under " low complex degree intraframe coding " situation mainly ascribes the increase of Planar, Vertical, Horizontal and four kinds of pattern code words of DC to (with the HM4.0 ratio, these four kinds of pattern code words have all increased by 1) and the poor efficiency during LCEC (low complexity entropy coder, low complex degree entropy coder) coding codeword.When the selected likelihood ratio of LUM was low, the performance raising that it brings is not enough to compensate above-mentioned four kinds of pattern code words increased the performance decline that causes, and at this moment bulking property will descend slightly.

Table 3: experimental result :-xx% represents that code check reduces xx%

In sum, the I picture prediction decoding method of the embodiment of the invention and the chrominance frames inner estimation mode that Video Codec adopts, be with the reconstruction value of current TU luminance component Y current TU chromatic component U to be predicted, reconstruction value with current TU chromatic component U is predicted current TU chromatic component V, current TU chromatic component U is compared with the technical scheme that chromatic component V predicts with the reconstruction value of current TU luminance component Y with existing LM, can take full advantage of the correlation between chromatic component V and the chromatic component U, improve I picture prediction encoding-decoding efficiency, when especially the linear relationship specific luminance component Y between chromatic component U and chromatic component V and the linear relationship between the chromatic component V are stronger, can generate than the better predicted value of LM for chromatic component V.

Those skilled in the art should understand that embodiments of the invention can be provided as method, system or computer program.Therefore, the present invention can adopt complete hardware embodiment, complete software embodiment or in conjunction with the form of the embodiment of software and hardware aspect.And the present invention can adopt the form of the computer program of implementing in one or more computer-usable storage medium (including but not limited to magnetic disc store, CD-ROM, optical memory etc.) that wherein include computer usable program code.

The present invention is that reference is described according to flow chart and/or the block diagram of method, equipment (system) and the computer program of the embodiment of the invention.Should understand can be by the flow process in each flow process in computer program instructions realization flow figure and/or the block diagram and/or square frame and flow chart and/or the block diagram and/or the combination of square frame.Can provide these computer program instructions to the processor of all-purpose computer, special-purpose computer, Embedded Processor or other programmable data processing device to produce a machine, make the instruction of carrying out by the processor of computer or other programmable data processing device produce to be used for the device of the function that is implemented in flow process of flow chart or a plurality of flow process and/or square frame of block diagram or a plurality of square frame appointments.

These computer program instructions also can be stored in energy vectoring computer or the computer-readable memory of other programmable data processing device with ad hoc fashion work, make the instruction that is stored in this computer-readable memory produce the manufacture that comprises command device, this command device is implemented in the function of appointment in flow process of flow chart or a plurality of flow process and/or square frame of block diagram or a plurality of square frame.

These computer program instructions also can be loaded on computer or other programmable data processing device, make and carry out the sequence of operations step producing computer implemented processing at computer or other programmable devices, thereby be provided for being implemented in the step of the function of appointment in flow process of flow chart or a plurality of flow process and/or square frame of block diagram or a plurality of square frame in the instruction that computer or other programmable devices are carried out.

Above-described specific embodiment; purpose of the present invention, technical scheme and beneficial effect are further described; institute is understood that; the above only is specific embodiments of the invention; and be not intended to limit the scope of the invention; within the spirit and principles in the present invention all, any modification of making, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (20)

1. an inage predicting encoding method in frame is characterized in that, comprises adopting following chrominance frames inner estimation mode to carry out the I picture predictive coding:

Obtain the reconstruction value of current converter unit TU luminance component Y;

With the reconstruction value of current TU luminance component Y, current TU chromatic component U is predicted;

Obtain the reconstruction value of current TU chromatic component U;

With the reconstruction value of current TU chromatic component U, current TU chromatic component V is predicted.

2. the method for claim 1 is characterized in that, with the reconstruction value of current TU chromatic component U, current TU chromatic component V is predicted, comprising:

With the reconstruction value of current TU chromatic component U, by linear relationship current TU chromatic component V is predicted.

3. method as claimed in claim 2 is characterized in that, by following formula, with the reconstruction value of current TU chromatic component U, by linear relationship current TU chromatic component V is predicted:

Pred _V[x，y]＝α _V·Rec _U[x，y]+β _V

Wherein, Pred _V[x, y] is the predicted value of current TU chromatic component V, Rec _U[x, y] is the reconstruction value of current TU chromatic component U, x, and y=0 ..., N-1, the width of current TU chrominance block and highly be N, design factor α _VAnd β _VThe sample point that uses is current TU chrominance block adjacent left-hand one row and the reconstruction value of upside one-row pixels chromatic component U and the reconstruction value of chromatic component V.

4. method as claimed in claim 3 is characterized in that, by following formula, and design factor α _VAnd β _V:

${\mathrm{\α}}_V=\frac{2N\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_V\left(i\right)\·\mathrm{Re}{c}_U\left(i\right)-\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_V\left(i\right)\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)}{2N\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)\·\mathrm{Re}{c}_U\left(i\right)-{\left(\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)\right)}^2}$

${\mathrm{\β}}_V=\frac{\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_V\left(i\right)-{\mathrm{\α}}_V\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)}{2N}$

Wherein, Rec _U(i) be the reconstruction value of current TU chrominance block adjacent left-hand one row and upside one-row pixels chromatic component U, Rec _V(i) be the reconstruction value of current TU chrominance block adjacent left-hand one row and upside one-row pixels chromatic component V, i=0 ..., 2N-1.

5. as each described method of claim 1 to 4, it is characterized in that, also comprise:

The code word of coding colourity intra prediction mode adopts the described chrominance frames inner estimation mode of claim 1 to carry out the I picture predictive coding with indication.

6. an I picture prediction decoding method is characterized in that, comprising:

Determine to adopt the described chrominance frames inner estimation mode of claim 1 to carry out the I picture prediction decoding;

Obtain the reconstruction value of current TU luminance component Y;

With the reconstruction value of current TU luminance component Y, current TU chromatic component U is predicted;

Obtain the reconstruction value of current TU chromatic component U;

With the reconstruction value of current TU chromatic component U, current TU chromatic component V is predicted.

7. method as claimed in claim 6 is characterized in that, determines to adopt the described chrominance frames inner estimation mode of claim 1 to carry out the I picture prediction decoding, comprising:

The code word of decoding chrominance frames inner estimation mode;

According to the code word of chrominance frames inner estimation mode, determine to adopt the described chrominance frames inner estimation mode of claim 1 to carry out the I picture prediction decoding.

8. method as claimed in claim 6 is characterized in that, with the reconstruction value of current TU chromatic component U, current TU chromatic component V is predicted, comprising:

With the reconstruction value of current TU chromatic component U, by linear relationship current TU chromatic component V is predicted.

9. method as claimed in claim 8 is characterized in that, by following formula, with the reconstruction value of current TU chromatic component U, by linear relationship current TU chromatic component V is predicted:

Pred _V[x，y]＝α _V·Rec _U[x，y]+β _V

Wherein, Pred _V[x, y] is the predicted value of current TU chromatic component V, Rec _U[x, y] is the reconstruction value of current TU chromatic component U, x, and y=0 ..., N-1, the width of current TU chrominance block and highly be N, design factor α _VAnd β _VThe sample point that uses is current TU chrominance block adjacent left-hand one row and the reconstruction value of upside one-row pixels chromatic component U and the reconstruction value of chromatic component V.

10. method as claimed in claim 9 is characterized in that, by following formula, and design factor α _VAnd β _V:

${\mathrm{\α}}_V=\frac{2N\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_V\left(i\right)\·\mathrm{Re}{c}_U\left(i\right)-\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_V\left(i\right)\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)}{2N\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)\·\mathrm{Re}{c}_U\left(i\right)-{\left(\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)\right)}^2}$

${\mathrm{\β}}_V=\frac{\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_V\left(i\right)-{\mathrm{\α}}_V\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)}{2N}$

Wherein, Rec _U(i) be the reconstruction value of current TU chrominance block adjacent left-hand one row and upside one-row pixels chromatic component U, Rec _V(i) be the reconstruction value of current TU chrominance block adjacent left-hand one row and upside one-row pixels chromatic component V, i=0 ..., 2N-1.

11. a video encoder is characterized in that, comprises that adopting following chrominance frames inner estimation mode to carry out first of I picture predictive coding obtains module, first prediction module, second acquisition module and second prediction module:

First obtains module, is used for obtaining the reconstruction value of current TU luminance component Y;

First prediction module is used for the reconstruction value with current TU luminance component Y, and current TU chromatic component U is predicted;

Second obtains module, is used for obtaining the reconstruction value of current TU chromatic component U;

Second prediction module is used for the reconstruction value with current TU chromatic component U, and current TU chromatic component V is predicted.

12. video encoder as claimed in claim 11 is characterized in that, described second prediction module specifically is used for:

With the reconstruction value of current TU chromatic component U, by linear relationship current TU chromatic component V is predicted.

13. video encoder as claimed in claim 12 is characterized in that, described second prediction module specifically is used for:

By following formula, with the reconstruction value of current TU chromatic component U, by linear relationship current TU chromatic component V is predicted:

Pred _V[x，y]＝α _V·Rec _U[x，y]+β _V

Wherein, Pred _V[x, y] is the predicted value of current TU chromatic component V, Rec _U[x, y] is the reconstruction value of current TU chromatic component U, x, and y=0 ..., N-1, the width of current TU chrominance block and highly be N, design factor α _VAnd β _VThe sample point that uses is current TU chrominance block adjacent left-hand one row and the reconstruction value of upside one-row pixels chromatic component U and the reconstruction value of chromatic component V.

14. video encoder as claimed in claim 13 is characterized in that, described second prediction module specifically is used for:

By following formula, design factor α _VAnd β _V:

${\mathrm{\α}}_V=\frac{2N\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_V\left(i\right)\·\mathrm{Re}{c}_U\left(i\right)-\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_V\left(i\right)\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)}{2N\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)\·\mathrm{Re}{c}_U\left(i\right)-{\left(\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)\right)}^2}$

${\mathrm{\β}}_V=\frac{\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_V\left(i\right)-{\mathrm{\α}}_V\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)}{2N}$

Wherein, Rec _U(i) be the reconstruction value of current TU chrominance block adjacent left-hand one row and upside one-row pixels chromatic component U, Rec _V(i) be the reconstruction value of current TU chrominance block adjacent left-hand one row and upside one-row pixels chromatic component V, i=0 ..., 2N-1.

15. as each described video encoder of claim 11 to 14, it is characterized in that, also comprise:

The pattern-coding module for the code word of coding colourity intra prediction mode, adopts the described chrominance frames inner estimation mode of claim 11 to carry out the I picture predictive coding with indication.

16. a Video Decoder is characterized in that, comprising:

The pattern determination module is used for determining to adopt the described chrominance frames inner estimation mode of claim 11 to carry out the I picture prediction decoding;

First obtains module, is used for obtaining the reconstruction value of current TU luminance component Y;

First prediction module is used for the reconstruction value with current TU luminance component Y, and current TU chromatic component U is predicted;

Second obtains module, is used for obtaining the reconstruction value of current TU chromatic component U;

Second prediction module is used for the reconstruction value with current TU chromatic component U, and current TU chromatic component V is predicted.

17. Video Decoder as claimed in claim 16 is characterized in that, described determination module specifically is used for:

The code word of decoding chrominance frames inner estimation mode;

According to the code word of chrominance frames inner estimation mode, determine to adopt the described chrominance frames inner estimation mode of claim 11 to carry out the I picture prediction decoding.

18. Video Decoder as claimed in claim 17 is characterized in that, described second prediction module specifically is used for:

With the reconstruction value of current TU chromatic component U, by linear relationship current TU chromatic component V is predicted.

19. Video Decoder as claimed in claim 18 is characterized in that, described second prediction module specifically is used for:

By following formula, with the reconstruction value of current TU chromatic component U, by linear relationship current TU chromatic component V is predicted:

Pred _V[x，y]＝α _V·Rec _U[x，y]+β _V

Wherein, Pred _V[x, y] is the predicted value of current TU chromatic component V, Rec _U[x, y] is the reconstruction value of current TU chromatic component U, x, and y=0 ..., N-1, the width of current TU chrominance block and highly be N, design factor α _VAnd β _VThe sample point that uses is current TU chrominance block adjacent left-hand one row and the reconstruction value of upside one-row pixels chromatic component U and the reconstruction value of chromatic component V.

20. Video Decoder as claimed in claim 19 is characterized in that, described second prediction module specifically is used for:

By following formula, design factor α _VAnd β _V:

${\mathrm{\α}}_V=\frac{2N\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_V\left(i\right)\·\mathrm{Re}{c}_U\left(i\right)-\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_V\left(i\right)\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)}{2N\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)\·\mathrm{Re}{c}_U\left(i\right)-{\left(\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)\right)}^2}$

${\mathrm{\β}}_V=\frac{\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_V\left(i\right)-{\mathrm{\α}}_V\·\underset{i=0}{\overset{2N-1}{\mathrm{\Σ}}}\mathrm{Re}{c}_U\left(i\right)}{2N}$

Wherein, Rec _U(i) be the reconstruction value of current TU chrominance block adjacent left-hand one row and upside one-row pixels chromatic component U, Rec _V(i) be the reconstruction value of current TU chrominance block adjacent left-hand one row and upside one-row pixels chromatic component V, i=0 ..., 2N-1.

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