KR20140092423A - Method for determining scalable video coding mode and apparatus for using the same - Google Patents

Abstract

Disclosed are a method for determining an encoding/decoding mode for a hierarchical video and an apparatus using the same. An intra-screen prediction method includes the steps of determining if intra-screen prediction is performed with respect to a first video processing unit of a basic layer; decoding information of a basic layer predictor if the intra-screen prediction is performed with respect to the first video processing unit; and performing intra-screen prediction with respect to a second video processing unit corresponding to the first video processing unit in an enhanced layer based on the information of the basic layer. Information of the basic layer predictor may be information used for determining whether a reference pixel of the basic layer is used or a reference pixel of the enhanced layer is used as a reference pixel used to perform the intra-screen prediction for the second image processing unit. Accordingly, the video encoding/decoding efficiency of the enhanced layer can be increased.

Description

[0001] METHOD FOR DETERMINING SCALABLE VIDEO CODING MODE AND APPARATUS FOR USING THE SAME [0002]

The present invention relates to a method and apparatus for hierarchical video coding / decoding, and more particularly to a method and apparatus for determining a hierarchical video coding / decoding mode.

Recently, the demand for high resolution and high quality images such as high definition (HD) image and ultra high definition (UHD) image is increasing in various applications. As the image data has high resolution and high quality, the amount of data increases relative to the existing image data. Therefore, when the image data is transmitted using a medium such as a wired / wireless broadband line or stored using an existing storage medium, The storage cost is increased. High-efficiency image compression techniques can be utilized to solve these problems caused by high-resolution and high-quality image data.

An inter picture prediction technique for predicting a pixel value included in a current picture from a previous or a subsequent picture of a current picture by an image compression technique, an intra picture prediction technique for predicting a pixel value included in a current picture using pixel information in the current picture, There are various techniques such as an entropy encoding technique in which a short code is assigned to a value having a high appearance frequency and a long code is assigned to a value having a low appearance frequency. Image data can be effectively compressed and transmitted or stored using such an image compression technique.

A first object of the present invention is to provide a hierarchical image coding and decoding method.

A second object of the present invention is to provide an apparatus for performing a hierarchical image coding and decoding method.

According to another aspect of the present invention, there is provided an intra-frame prediction method including: determining whether a first image processing unit of a base layer performs intra-frame prediction; A step of decoding the base layer predictor information when the processing unit performs intra prediction and a step of decoding the base layer predictor information based on the base layer predictor information, Wherein the base layer predictor information includes information on whether to use a reference pixel of the base layer as a reference pixel for performing intra prediction on the second image processing unit, And may be information for determining whether to use the reference pixel. Wherein the performing of intra prediction on a second image processing unit corresponding to the first image processing unit in the enhancement layer based on the base layer predictor information comprises: In-picture prediction is performed on the basis of the reference pixels of the first image processing unit to indicate that the reference pixels of the base layer are to be used as reference pixels for performing intra-prediction on the intra-frame prediction, And upsampling the intra-frame predicted block. Wherein the performing of intra prediction on a second image processing unit corresponding to the first image processing unit in the enhancement layer based on the base layer predictor information comprises: Sampling the reference pixels of the first image processing unit when instructing to use the reference pixels of the base layer as reference pixels for performing intra prediction on the first image processing unit, And performing intra-frame prediction based on the reference pixels of the frame. Wherein the performing of intra prediction on a second image processing unit corresponding to the first image processing unit in the enhancement layer based on the base layer predictor information comprises: In the case where it is instructed to use a reference pixel of the enhancement layer as a reference pixel for performing intra-prediction on the second enhancement layer, the enhancement layer acquires reference pixel information for performing intra- And performing intra-frame prediction based on the reference pixel information. The intra-frame prediction method may further include determining whether the second image processing unit performs a base prediction mode to perform prediction. The first image processing unit and the second image processing unit may be one of a coding block unit, a coding tree block unit, a slice unit, and a picture unit . Wherein the base layer predictor information is flag information, and when the flag value is 1, the base layer predictor information uses a reference pixel of the base layer as a reference pixel for performing intra-picture prediction on the second image processing unit , And when the flag value is 0, the base layer predictor information may indicate to use the reference pixel of the enhancement layer as a reference pixel for performing intra-picture prediction on the second image processing unit have.

According to another aspect of the present invention, there is provided an apparatus for performing intra-picture prediction, the intra-picture prediction apparatus comprising: An entropy decoding unit for determining whether the first image processing unit of the base layer performs intra-frame prediction, and an entropy decoding unit for decoding the first image processing unit in the enhancement layer based on the base layer predictor information, 2 prediction unit for performing intra prediction on the second image processing unit, wherein the base layer predictor information is a reference pixel for performing intra-frame prediction on the second image processing unit, Or information for determining whether to use the reference pixels of the enhancement layer. When the base layer predictor information indicates to use a reference pixel of the base layer as a reference pixel for performing intra-frame prediction on the second image processing unit, the predicting unit may include a reference of the first image processing unit Pixel prediction based on the pixels to generate intra-picture predicted blocks, and upsample the intra-picture predicted blocks. When the base layer predictor information indicates to use a reference pixel of the base layer as a reference pixel for performing intra-frame prediction on the second image processing unit, And perform intra-frame prediction based on the up-sampled reference pixels of the first image processing unit. Wherein if the base layer predictor information indicates that a reference pixel of the enhancement layer is to be used as a reference pixel for intra prediction on the second image processing unit, Acquiring reference pixel information for performing intra-frame prediction on a processing unit, and performing intra-frame prediction based on the reference pixel information. The prediction unit may be configured to determine whether the second image processing unit performs a base prediction mode to perform prediction. The first image processing unit and the second image processing unit may be one of a coding block unit, a coding tree block unit, a slice unit, and a picture unit . Wherein the base layer predictor information is flag information, and when the flag value is 1, the base layer predictor information uses a reference pixel of the base layer as a reference pixel for performing intra-picture prediction on the second image processing unit , And when the flag value is 0, the base layer predictor information may indicate to use the reference pixel of the enhancement layer as a reference pixel for performing intra-picture prediction on the second image processing unit have.

As described above, according to the hierarchical image decoding / decoding mode determination method and apparatus using the hierarchical image decoding / decoding mode according to the embodiment of the present invention, various hierarchical image decoding / decoding methods are used, And may be used to perform coding and decoding of the image of the layer. Therefore, it is possible to enhance the image coding / decoding efficiency of the enhancement layer.

1 is a block diagram illustrating an encoding apparatus according to an embodiment of the present invention.
2 is a block diagram illustrating a decoder according to another embodiment of the present invention.
3 is a conceptual diagram illustrating a hierarchical video encoding method according to an embodiment of the present invention.
4 is a conceptual diagram illustrating a hierarchical video decoding method according to an embodiment of the present invention.
5 is a conceptual diagram illustrating a hierarchical image decoding method using an encoding block skip mode according to an embodiment of the present invention.
6 is a flowchart illustrating a hierarchical image decoding method using an encoding block skip mode according to an embodiment of the present invention.
7 is a conceptual diagram illustrating a hierarchical image decoding method using a slice skip mode according to an embodiment of the present invention.
8 is a flowchart illustrating a hierarchical image decoding method using a slice skip mode according to an embodiment of the present invention.
9 is a conceptual diagram illustrating a method for indicating a slice using a slice skip mode according to an embodiment of the present invention.
10 is a conceptual diagram illustrating a hierarchical image decoding method using a texture prediction mode according to an embodiment of the present invention.
11 is a flowchart illustrating a hierarchical image decoding method using a texture prediction mode according to an embodiment of the present invention.
12 is a conceptual diagram illustrating a method of performing a texture prediction mode in units of slices according to an embodiment of the present invention.
13 is a flowchart illustrating a method of performing a texture prediction mode in units of slices according to an embodiment of the present invention.
14 is a conceptual diagram illustrating a hierarchical image decoding method using a base layer mode according to an embodiment of the present invention.
15 is a flowchart illustrating a hierarchical image decoding method using a base layer mode according to an embodiment of the present invention.
16 is a conceptual diagram illustrating a method of performing a base prediction mode on a slice basis according to an embodiment of the present invention.
17 is a flowchart illustrating a method of performing a base prediction mode in units of slices according to an embodiment of the present invention.
18 is a conceptual diagram illustrating a hierarchical image decoding method using a coding block skip mode and a texture prediction mode according to an embodiment of the present invention.
19 is a conceptual diagram illustrating a hierarchical image decoding method using a skip mode, a texture prediction mode, and a base prediction mode according to an embodiment of the present invention.
20 is a flowchart illustrating a hierarchical image prediction method using an encoding block skip mode, a texture prediction mode, and a base prediction mode according to an embodiment of the present invention.
FIG. 21 is a flowchart illustrating a method of performing intra prediction when a base prediction mode is used in units of encoding blocks according to an embodiment of the present invention.
22 is a conceptual diagram illustrating a method of performing intra prediction of a prediction block based on reference pixel information of a base layer according to an embodiment of the present invention.
23 is a flowchart illustrating a hierarchical video coding method for division information of a transform block according to an embodiment of the present invention.

The embodiments of the present invention and the respective components disclosed in the drawings disclose an independent configuration to represent different characteristic functions of the image encoding apparatus. It does not mean that each component is necessarily composed of separate hardware or a single software component unit. That is, each constituent unit is included in each constituent unit for convenience of explanation, and at least two constituent units of the constituent units may be combined to form one constituent unit, or one constituent unit may be divided into a plurality of constituent units to perform a function. The integrated embodiments and the separate embodiments of the components are also included in the scope of the present invention unless otherwise departing from the spirit of the present invention.

In addition, some of the components disclosed in the present invention are not essential components that perform essential functions in the present invention, but may be optional components only for improving performance. The present invention can be implemented only with components essential for realizing the essence of the present invention, except for the components used for the performance improvement, and can be implemented by only including the essential components except the optional components used for performance improvement Are also included in the scope of the present invention.

1 is a block diagram illustrating an encoding apparatus according to an embodiment of the present invention.

1, the encoding apparatus includes a division unit 100, a prediction unit 110, an intra prediction unit 103, an inter-picture prediction unit 106, a conversion unit 115, a quantization unit 120, An entropy encoding unit 130, an inverse quantization unit 135, an inverse transformation unit 140, a filter unit 145, and a memory 150. [

The encoding apparatus can be implemented by the image encoding method described in the embodiments of the present invention, but operations in some constituent units may not be performed for lowering the complexity of the encoder or for fast real-time encoding. For example, in performing intra-picture prediction in the prediction unit, it is not necessary to use a method of selecting an optimal intra-picture coding method using all the intra-picture prediction mode methods in order to perform coding in real time, The intra-picture prediction mode may be used as the final intra-picture prediction mode. As another example, it is also possible to restrictively use the type of the prediction block used in intra-picture prediction or inter-picture prediction.

The unit of the block processed in the encoding apparatus may be a coding block for performing encoding, a prediction block for performing prediction, and a transform block for performing conversion. A predetermined information unit including information used for encoding or decoding a coded block is referred to as a coding unit (CU), and a certain information unit including information used for performing prediction for a prediction block is referred to as a prediction unit (PU) , Prediction Unit), and a unit including information used for performing conversion on a conversion block can be expressed by the term conversion unit (TU).

Hereinafter, the current block used in the embodiment of the present invention may refer to a block to be predicted, transformed, or encoded. In the prediction, the current block may be a block that is the target of the current prediction. When performing the conversion, the current block may be a conversion block that is the subject of the current conversion. When encoding or decoding is performed, the current block may be an encoding block to be encoded or decoded. That is, the unit of the current block may be changed according to the image processing to be performed.

In the division unit 100, one picture is divided into a combination of a plurality of encoding blocks, a prediction block, and a transform block, and one of the encoded blocks, the prediction block, and the transform block It is possible to divide the picture by selecting the division combination.

For example, a recursive tree structure such as a quadtree structure can be used to divide a coded block in a picture. Hereinafter, in the embodiment of the present invention, the meaning of an encoding block may be used not only for a block for performing encoding but also for a block for performing decoding.

The prediction block may be a block that performs intra-picture prediction or inter-picture prediction. The block for performing the intra prediction can have a square shape such as 2Nx2N, NxN, or a rectangular block shape using SDIP (Short Distance Intra Prediction). As the blocks for performing inter-picture prediction, 2NxN or Nx2N, which is a divided form of a square block or square block such as 2Nx2N or NxN, or a prediction block division using asymmetric AMP (Asymmetric Motion Partitioning) There is a way. The method of performing the transform in the transform unit 115 may vary depending on the type of the prediction block.

The prediction unit 110 may include an intra prediction unit 103 for performing intra prediction and an inter prediction unit 106 for performing inter prediction. The prediction unit 110 can determine whether to use inter-picture prediction or intra-picture prediction for the prediction block. The processing unit in which the prediction is performed may differ from the processing unit in which the prediction method and the concrete contents are determined. For example, in performing intra prediction, the prediction mode may be determined on a prediction block basis, and the process of performing prediction may be performed based on a conversion block unit. The residual value (residual block) between the generated predicted block (or the predicted sample) and the original block (or the original sample) may be input to the transforming unit 115. In addition, the prediction mode information, motion vector information, and the like used for prediction can be encoded by the entropy encoding unit 130 and transmitted to the decoder along with the residual value.

When the PCM (Pulse Coded Modulation) coding mode is used, it is also possible to directly encode the original block and transmit it to the decoding unit without performing the prediction through the predicting unit 110. [

The intra-frame prediction unit 103 can generate a predicted block based on the reference pixels existing in the vicinity of the current block (the prediction block). In order to calculate an optimal intra-picture prediction mode for the current block, a plurality of intra-picture prediction modes are used for the current block, and one intra-picture prediction mode is used as an intra-picture prediction mode Can be used. In the intra prediction, the prediction mode may have a directional prediction mode in which reference pixel information is used according to a prediction direction, and a non-directional mode in which prediction information is not used. The mode for predicting the luminance information and the intra prediction mode for predicting the chrominance information may be different from each other and utilize intra prediction mode information or predicted luminance signal information in which luminance information is predicted to predict color difference information .

Hereinafter, in the embodiment of the present invention, a neighboring block used to calculate the intra prediction mode of the current block 650 is defined as a neighboring block. The neighboring block is a neighboring block A 660 having pixel values located at (x-1, y) and a pixel value (x, y-1) located at (x, y-1) May be referred to as a neighboring block.

Picture prediction mode information of the current block from the intra-picture prediction mode information of the neighboring block of the current block. That is, the intra-picture prediction mode of the current block can be predicted from the intra-picture prediction mode of the prediction block existing around the current block.

If the intra-frame prediction mode of the current block is the same as the intra-frame prediction mode of the current block, information indicating that the prediction mode of the current block and the neighboring block are the same can be indicated using the flag information. If the prediction mode of the current block is different from that of the neighboring block, intra-picture prediction mode information of the current block can be encoded by performing entropy coding.

If the prediction mode of the neighboring block is not available, the intra prediction mode of the current prediction block can be predicted by setting the preset intra prediction mode value to the intra prediction mode value.

The intra prediction unit 103 may generate a predicted block or a predicted sample based on the reference pixel information around the current block which is pixel information in the current picture. A block or a sample generated by referring to pixels around the current block can be expressed as a predicted block or a predicted sample.

When intra prediction is performed, when the size of the prediction block is equal to the size of the transform block, the intra prediction is performed on the basis of the pixel existing on the left side of the prediction block, the pixel existing on the upper left side, Prediction can be performed.

When the size of the prediction block differs from the size of the transform block in performing intra prediction, intra-picture prediction is performed using a pixel existing on the left side of the transform block, a pixel existing on the upper left side, . In addition, intra prediction using NxN division can be used for only the minimum coded block.

The intra prediction method can generate a predicted block (or a predicted sample) after applying an Adaptive Intra Smoothing (AIS) filter to a reference pixel according to a prediction mode. The type of the AIS filter applied to the reference pixel may be different. After intra prediction has been performed, additional filtering may be performed on the reference pixels and some pixels present in the predicted block. The filtering for some pixels existing in the reference pixel and the predicted block can be performed using different filtering coefficients depending on the direction of the intra prediction mode.

The inter-picture prediction unit 106 may generate a prediction block (e.g., a predicted block or a predicted sample) based on information of at least one of a previous picture or a following picture of the current picture. The inter-picture predicting unit 106 may include a reference picture interpolating unit, a motion predicting unit, and a motion compensating unit. In the reference picture interpolating unit, reference picture information is supplied from the memory 150 and pixel information of an integer pixel or less can be generated in the reference picture. In the case of a luminance pixel, a DCT-based interpolation filter having a different filter coefficient may be used to generate pixel information of an integer number of pixels or less in units of quarter pixels. In the case of a color difference signal, a DCT-based 4-tap interpolation filter having a different filter coefficient may be used to generate pixel information of an integer number of pixels or less in units of 1/8 pixel.

The inter-picture predicting unit 106 can perform motion prediction based on the reference picture interpolated by the reference picture interpolating unit. Various methods such as Full Search-based Block Matching Algorithm (FBMA), Three Step Search (TSS), and New Three-Step Search Algorithm (NTS) can be used to calculate motion vectors. The motion vector may have a motion vector value of 1/2 or 1/4 pixel unit based on the interpolated pixel. The inter-picture prediction unit 106 can predict a current prediction block by differently performing a motion prediction method. As the motion prediction method, various methods such as a skip method, a merge method, and an AMVP (Advanced Motion Vector Prediction) method can be used.

In performing hierarchical image coding, the prediction unit 110 may perform different prediction operations depending on whether the prediction unit 110 is included in a base layer or an enhancement layer. In the case where the prediction unit 110 is included in the base layer, it can operate in the same manner as the above-described embodiment. However, when the prediction unit 110 is included in the enhancement layer, the prediction unit does not perform inter-picture prediction and intra-picture prediction according to the hierarchical image encoding mode, Intra prediction mode, motion prediction related information, etc.), and perform prediction based on the information. Specific examples will be further described in detail.

A residual block including the predicted block or the predicted sample which has been predicted by the predictor 110 and the residual value which is a difference value from the original block or the original sample can be generated. The generated residual block may be input to the conversion unit 115. The transforming unit 115 can transform the residual block using a transform method such as DCT (Discrete Cosine Transform) or DST (Discrete Sine Transform). Whether to apply the DCT or the DST to transform the residual block can be determined based on the intra prediction mode information of the prediction block corresponding to the residual block and / or the size information of the prediction block. That is, the conversion unit can use the conversion method differently depending on the size of the prediction block.

The quantization unit 120 may quantize the values converted into the frequency domain by the conversion unit 115. [ The quantization factor may vary depending on the block or the importance of the image. The values calculated by the quantization unit 120 may be provided to the inverse quantization unit 135 and the reorder unit 125.

The reordering unit 125 may rearrange the coefficient values on the quantized residual values. The reordering unit 125 rearranges the two-dimensional block type coefficients into a one-dimensional vector form through a coefficient scanning method Can be changed. For example, the rearranging unit 125 may scan a DC coefficient to a coefficient of a high frequency region using a Zig-Zag scan method, and change the DC coefficient to a one-dimensional vector form. A vertical scanning method of scanning a two-dimensional block type coefficient in a column direction instead of a jig-jag scanning method according to a size of a conversion block and an intra-picture prediction mode, and a horizontal scanning method of scanning a two- Can be used. That is, it is possible to determine whether any scan method among the jig-jag scan, the vertical scan and the horizontal scan is used according to the size of the conversion block and the intra prediction mode.

The entropy encoding unit 130 may perform entropy encoding based on the values calculated by the reordering unit 125. For entropy encoding, various encoding methods such as Exponential Golomb, Context-Adaptive Variable Length Coding (CAVLC), and Context-Adaptive Binary Arithmetic Coding (CABAC) may be used.

The entropy encoding unit 130 receives the residual value coefficient information of the encoding block, the block type information, the prediction mode information, the split block information, the prediction block information, the transform block information, the motion vector information , Reference frame information, block interpolation information, filtering information, and the like, and performs entropy encoding based on a predetermined encoding method. In addition, the entropy encoding unit 130 can entropy encode the information of the encoding unit input by the reordering unit 125. [

The inverse quantization unit 135 and the inverse transformation unit 140 dequantize the quantized values in the quantization unit 120 and invert the converted values in the conversion unit 115. [ The residual value generated by the inverse quantization unit 135 and the inverse transform unit 140 is combined with a predicted block through a motion estimation unit, a motion compensation unit and an intra prediction unit included in the prediction unit 110, Block) can be generated.

The filter unit 145 may include at least one of a deblocking filter, an offset correction unit, and an adaptive loop filter (ALF).

The deblocking filter can remove block distortion caused by the boundary between the blocks in the reconstructed picture. It may be determined whether to apply a deblocking filter to the current block based on pixels included in a few columns or rows included in the block to determine whether to perform deblocking. When a deblocking filter is applied to a block, a strong filter or a weak filter may be applied according to the deblocking filtering strength required. In applying the deblocking filter, the horizontal filtering and the vertical filtering may be performed concurrently when the vertical filtering and the horizontal filtering are performed.

The offset correction unit may correct the offset of the deblocked image with respect to the original image in units of pixels. In order to perform offset correction for a specific picture, pixels included in an image are divided into a predetermined number of areas, and then an area to be offset is determined and an offset is applied to the area. Alternatively, Can be used.

The ALF (Adaptive Loop Filter) can perform filtering based on a value obtained by comparing the filtered restored image and the original image. After dividing the pixels included in the image into at least one group, one filter to be applied to the group may be determined and different filtering may be performed for each group. The information related to whether to apply the ALF may be transmitted for each coding unit (CU), and the size and the coefficient of the ALF to be applied may be changed according to each block. The ALF may have various forms, and the number of coefficients included in the filter may also vary. The filtering related information (filter coefficient information, ALF On / Off information, filter type information) of the ALF can be transmitted as a bit stream in the parameter set.

The memory 150 may store the reconstructed block or picture calculated through the filter unit 145 and the reconstructed block or picture stored therein may be provided to the predictor 110 when inter-picture prediction is performed.

2 is a block diagram illustrating a decoder according to another embodiment of the present invention.

2, the decoder includes an entropy decoding unit 210, a reordering unit 215, an inverse quantization unit 220, an inverse transform unit 225, a predicting unit 230, a filter unit 235, a memory 240, May be included.

When a bitstream is input in the encoder, the input bitstream can be decoded in a procedure opposite to that of the encoder.

The entropy decoding unit 210 may perform entropy decoding in a procedure opposite to that in which the entropy encoding unit of the encoder performs the entropy encoding.

Information for generating a predicted block (or a predicted sample) out of the information decoded by the entropy decoding unit 210 is provided to the predicting unit 230. The residual value obtained by performing entropy decoding in the entropy decoding unit is supplied to a reordering unit 215 ).

The entropy decoding unit 210 can decode information related to intra-picture prediction and inter-picture prediction performed by the encoder. In the case where there is a constraint such as when the intra-picture prediction and the inter-picture prediction are performed in the encoder, for example, when the surrounding prediction mode is not available, as described above, entropy decoding based on the constraint is performed, It is possible to receive information related to the intra prediction and inter prediction.

The reordering unit 215 can perform reordering based on a method in which the entropy decoding unit 210 rearranges the entropy-decoded bitstreams in the encoding unit. The coefficients represented by the one-dimensional vector form can be rearranged by restoring the coefficients of the two-dimensional block form again. The reordering unit may perform reordering by receiving information related to the coefficient scanning performed by the encoding unit and performing a reverse scanning based on the scanning order performed by the encoding unit.

The inverse quantization unit 220 can perform inverse quantization based on the quantization parameters provided by the encoder and the coefficient values of the re-arranged blocks.

The inverse transform unit 225 may perform inverse DCT and inverse DST on the DCT and DST performed by the transform unit on the quantization result performed by the encoder. The inverse transform can be performed based on the conversion unit determined in the encoder. In the transform unit of the encoder, DCT and DST can be selectively performed according to a plurality of information such as a prediction method, a size and a prediction direction of the current block, and the inverse transform unit 225 of the inverse transform unit transforms transform information The inverse transform can be performed.

The predictor 230 predicts the predicted block (or predicted sample) generated based on the predicted block (or predicted sample) generation related information provided by the entropy decoding unit 210 and the previously decoded block or picture information provided in the memory 240, Lt; / RTI > sample).

As described above, when intra prediction is performed in the same manner as in the encoder, when the size of the prediction block and the size of the transform block are the same, a pixel existing on the left side of the prediction block, a pixel existing on the upper left side, However, when intra prediction is performed, when the size of the prediction block is different from the size of the transform block, the intra-picture prediction is performed using the reference block based on the transform block, Can be performed. In addition, intra prediction using NxN division can be used only for the minimum size encoded block.

The prediction unit 230 may include a prediction block determination unit, an inter picture prediction unit, and an intra prediction unit. The prediction block discriminator receives various information such as the prediction block information input from the entropy decoding unit, the prediction mode information of the intra prediction method, the motion prediction related information of the inter picture prediction method, and separates the prediction blocks in the encoding block. It is possible to determine whether inter-picture prediction is performed or intra-picture prediction is performed. The inter picture prediction unit may perform inter picture prediction on the current prediction block based on the information included in at least one of the previous picture of the current picture or the following picture including the current prediction block using the information provided by the encoder.

In order to perform the inter-picture prediction, the motion prediction method of the prediction block included in the encoded block is based on a skip mode, a merge mode, or an AMVP mode Can be determined.

The intra prediction unit can generate a predicted block (or a predicted sample) based on the pixel information in the current picture. If the prediction block is a prediction block in which intra prediction is performed, the intra prediction can be performed on the basis of the intra prediction mode information of the prediction block provided by the encoder. The intra-frame prediction unit may include an AIS filter, a reference pixel interpolator, and a DC filter. The AIS filter performs filtering on the reference pixels of the current block and determines whether the filter is applied or not according to the prediction mode of the current prediction block. The AIS filtering can be performed on the reference pixel of the current block using the prediction mode and the AIS filter information of the prediction block provided by the encoder. When the prediction mode of the current block is a mode in which AIS filtering is not performed, the AIS filter may not be applied. In addition, the encoder may similarly generate a prediction block and perform additional filtering together with the reference pixel.

The reference pixel interpolator can interpolate the reference pixels to generate reference pixels in units of pixels less than an integer value when the prediction mode of the prediction block is a prediction block that performs intra-frame prediction based on the pixel value obtained by interpolating the reference pixels . The reference pixel may not be interpolated in the prediction mode in which the prediction mode of the current block generates the prediction block without interpolating the reference pixel. The DC filter can generate a predicted block (or a predicted sample) through filtering when the prediction mode of the current block is the DC mode.

In performing hierarchical image decoding, the prediction unit 110 may perform different prediction operations depending on whether the prediction unit 110 is included in a base layer or an enhancement layer. In the case where the prediction unit 110 is included in the base layer, it can operate in the same manner as the above-described embodiment. However, when the prediction unit 110 is included in the enhancement layer, the prediction unit 110 does not perform inter-picture prediction and intra-picture prediction according to the hierarchical image decoding mode, Intra prediction mode, motion prediction related information, etc.), and perform prediction based on the information. The restored block or picture may be provided to the filter unit 235. [ The filter unit 235 may include a deblocking filter, an offset correction unit, and an ALF.

Information on whether a deblocking filter has been applied to the block or picture from the encoder and information on whether a strong filter or a weak filter is applied can be provided when the deblocking filter is applied. In the deblocking filter of the decoder, information related to the deblocking filter provided by the encoder is provided, and the decoder can perform deblocking filtering for the corresponding block. The vertical deblocking filtering and the horizontal deblocking filtering are performed as in the encoder, and at least one of the vertical deblocking and the horizontal deblocking can be performed in the overlapping portion. Vertical deblocking filtering or horizontal deblocking filtering that has not been performed previously can be performed at the overlapping portions of the vertical deblocking filtering and the horizontal deblocking filtering. Parallel processing of deblocking filtering is possible through the deblocking filtering process.

The offset correction unit may perform offset correction on the reconstructed image based on the type of offset correction applied to the image and the offset value information during encoding.

The ALF can perform filtering based on the comparison between the reconstructed image and the original image after filtering. The ALF can be applied to the encoding block based on the ALF application information and the ALF coefficient information provided from the encoder. Such ALF information may be provided in a specific parameter set.

The memory 240 may store the reconstructed picture or block to be used as a reference picture or a reference block, and may also provide the reconstructed picture to the output unit.

Hereinafter, a scalable video coding method will be described in an embodiment of the present invention. The hierarchical video coding method is a method of predicting image information of an enhancement layer based on image information in a base layer. This hierarchical video coding method will be described below.

3 is a conceptual diagram illustrating a hierarchical video encoding method according to an embodiment of the present invention.

Referring to FIG. 3, an image may be encoded through a base layer 300 and an enhancement layer 350. In the hierarchical image coding method, the image prediction information generated in the base layer 300 according to the hierarchical image coding method can be used to perform image coding of the enhancement layer 350. For example, the image prediction information may be information generated by upsampling the pixels of the base layer, intra prediction mode information used for predicting the block in the base layer, and motion prediction related information.

The base layer 300 includes a mode determining unit 305, a predicting unit 310, a transforming and quantizing unit 325, an inverse transforming and inverse quantizing unit 330, an entropy coding unit 335, a restoring unit 315, (320). The operation of each part is similar to that disclosed in FIG. 1, and the mode determination unit 305 determines whether to use the intra picture prediction method or the inter picture prediction method in the image encoding method.

One of the inter-layer image encoding methods is to use the up-sampling of the pixel information of the block generated in the base layer and use it in the enhancement layer. The pixel information of the block of the base layer 300 is upsampled by the upsampling unit 340 and is input to the enhancement layer 350 after passing through the additional inter-layer filtering units 345 and 347. [ . Interpolation may be performed to perform the upsampling.

Intra-picture prediction mode information or motion prediction related information used for prediction of a block in a base layer may be transmitted to an enhancement layer using another inter-layer coding method, and such prediction related information may be used in an enhancement layer. The inter-layer video coding method can use various methods as well as inter layer prediction method for receiving prediction image information from the base layer and performing prediction in the enhancement layer.

Also, in the enhancement layer, the image prediction and encoding process may be performed using only the enhancement layer information without receiving the image prediction information from the base layer.

The enhancement layer 350 includes a mode determination unit 355, a prediction unit 360, a transform and quantization unit 375, an inverse transform and inverse quantization unit 380, an entropy encoding unit 385, A restoration unit 365, and a filter unit 370. [ The operation of each constituent unit may have the same configuration as that shown in Fig. The mode determination unit 355 of the enhancement layer 350 may perform various image encoding methods such as an image prediction method using image information in the enhancement layer 350 or an interlayer prediction method using image prediction information of a base layer And can be used as a component for selecting one prediction method.

That is, the mode determination unit 355 of the enhancement layer can select an image prediction method to be performed by the image encoding unit.

Information, base layer information, and enhancement layer information generated in the up-sampling and inter-layer filtering units 340, 345, and 347 are multiplexed 395 to be generated as a scalable bitstream, Lt; / RTI >

4 is a conceptual diagram illustrating a hierarchical video decoding method according to an embodiment of the present invention.

Referring to FIG. 4, the image information may be transmitted through a scalable bitstream generated from the image encoding unit. The hierarchical bit stream is demultiplexed 405 and input to the entropy decoding unit 410 of the base layer 400, the entropy decoding unit 455 and the filter coefficient entropy decoding unit 485 of the enhancement layer 450 .

Information input to the entropy decoding unit 410 of the base layer 400 may be input to the inverse quantization unit and the inverse transform unit 415 and the mode determination unit 420 . Based on the decoded information, the mode determination unit 420 may determine whether inter prediction or intra prediction is to be performed. The prediction unit 425 can perform prediction based on the prediction mode information output from the mode determination unit 420. [ The inverse quantization unit and inverse transform unit 415 can generate residual information by inversely transforming and inverse-quantizing the residual information generated by the entropy decoding unit 410. [ That is, image decoding can be performed in the same manner as the image decoding step of FIG.

If the enhancement layer 450 performs decoding using information obtained by upsampling the pixels included in the block of the base layer 400, the information generated after the image decoding process in the base layer 400 is completed, (440). ≪ / RTI > The upsampled information may be sent to enhancement layer 450 via inter-layer filtering 445 and 447. [

In the mode determination unit 465 of the enhancement layer 450 based on the information decoded by the entropy decoding unit 455 of the enhancement layer 450, the enhancement layer 450 in the image encoding step performs an image encoding method or an image prediction method It is possible to determine whether or not encoding has been performed.

The mode determination unit 465 of the enhancement layer 450 may perform image decoding using the same prediction method as the image prediction method used in the enhancement layer of the image encoding unit. The image prediction method performed in the image decoding step may be a method of performing image prediction with reference to information of the base layer 400 or a method of performing image prediction without using information of the base layer 400 . When the image prediction is performed without using the information of the base layer 400, the enhancement layer 450 does not receive image related information separately from the base layer 400. [

Hereinafter, a scalable video coding method will be described in an embodiment of the present invention. Among the hierarchical image decoding methods, the base prediction mode may mean a mode using image prediction information used for predicting a block of a base layer to predict a block of an enhancement layer. The image prediction information may be, for example, an intra prediction mode used in a block of a base layer, motion prediction related information, or the like.

5 is a conceptual diagram illustrating a hierarchical image decoding method using an encoding block skip mode according to an embodiment of the present invention.

FIG. 5 shows an image prediction method using a coded block skip mode among the hierarchical image decoding methods.

The encoded block skip mode upsampling the image information existing in the encoding block unit 500 of the base layer and compresses the image information existing in the upsampled base layer encoding block unit 520 to the encoding block unit of the enhancement layer (540). The image information may be a luminance pixel value or a color difference pixel value as pixel information.

In the enhancement layer, a restoration block may be generated by filtering the upsampled image information.

Various methods can be used to upsample the image information included in the encoding block unit 500 of the base layer. For example, the image can be up-sampled by interpolating values between samples existing in the base layer using discrete cosine transform-interpolation filtering (DCT-IF). Various filters can be used as filters. Depending on the components of the sample, the 8-tap DCT-IF can be applied to luminance samples and the 4-tap DCT-IF can be applied to color difference samples.

That is, the coding block unit 540 for performing prediction using the coding block skip mode updates the video information of the coding block unit 500 of the base layer existing at the position corresponding to the coding block unit 540 of the enhancement layer And the sampled value can be used as the information of the restoration block of the enhancement layer. That is, when the coded block skip mode is used for the enhancement layer coded block unit 540, at least one prediction block included in the enhancement layer coded block unit 540 does not need to perform the image prediction process separately The information obtained by upsampling the video information of the encoding block unit 500 of the base layer can be directly used as a reconstruction block of the encoding block unit 540 of the enhancement layer. It may mean that the relative positions of the image units are the same in the picture of each layer that the image unit of the base layer corresponds to the image unit of the enhancement layer and may have the meaning of an image unit referenced between layers It is possible.

Hereinafter, in the hierarchical image decoding method according to an embodiment of the present invention, a block of a base layer corresponding to a block of an enhancement layer in a base layer is referred to as a 'corresponding block in a base layer' , 'Corresponding block', or 'corresponding block'. The corresponding unit in the base layer may be a unit such as a coding tree block (CTB), a slice, a picture, etc., instead of a block unit.

In order to perform a decoding process using a coded block skip mode, a syntax element indicating that a coded block uses a coded block skip mode may be newly defined. For example, when a coded block skip mode is performed in units of coded blocks, a syntax element indicating that a specific coded block performs a coded block skip mode may be transmitted as header information of a bit stream for transmitting block information.

For example, a syntax element indicating a coding block skip mode may exist in a coding unit header in a bit-stream, and the name of such syntax element is defined as a coding block skip flag (CB_skip_flag) Can be used.

The names of the various syntax elements used in the embodiment of the present invention and definitions of the syntax elements may be used as another example of syntax element names to represent the same syntax elements. It is also possible for a function of the same syntax element to be included in another syntax element to perform the same role.

(For example, ON or '1') as a result of decoding the encoded block skip flag CB_skip_flag for each encoded block unit, a syntax for decoding the current encoded block is determined Syntax elements associated with a unit of syntax elements and / or units below a current encoding block (e.g., a prediction block, a transform block) may not be explicitly transmitted in a bit-stream. have. In this case, the image decoding unit may infer the values of some syntax elements to perform a decoding process, if necessary.

6 is a flowchart illustrating a hierarchical image decoding method using an encoding block skip mode according to an embodiment of the present invention.

FIG. 6 shows a method for determining whether to apply a prediction method using a coding block skip mode to a coding block unit of an enhancement layer on the basis of a coding block skip flag.

Referring to FIG. 6, the value of the encoded block skip flag CB_skip_flag is determined (step S600).

Information on whether a coded block skip mode is applied to each coded block can be obtained based on information on the decoded coded block skip flag. For example, when the value of the coded block skip flag is '1', it means that the coded block skip mode is applied to each coded block unit. If the value of the coded skip flag is '0' It can be instructed not to perform.

And restores the video information of each coded block unit using the coded block skip mode (step S610).

When decoding is performed using a coded block skip mode for each coded block unit, the reconstructed block for each coded block unit of the enhancement layer can be generated by upsampling the image information of the corresponding coded block unit of the base layer. That is, the video information of the corresponding encoding unit of the upsampled base layer can be restored block information in the enhancement layer in units of the encoding block. Various methods can be used as the upsampling method.

In the enhancement layer, it is also possible to generate a restoration block by additionally filtering the upsampled image information in order to reduce a step with neighboring blocks.

If the encoding block unit does not use the encoding block skip mode as the prediction method, the image information of each encoding block unit is predicted using another image prediction method (step S620).

It is possible to use a method of performing decoding using only the image information of the enhancement layer by another image prediction method for each encoding block unit. In addition, various inter-layer image prediction methods in an enhancement layer to be described below may be used, and these embodiments are also included in the scope of the present invention.

7 is a conceptual diagram illustrating a hierarchical image decoding method using a slice skip mode according to an embodiment of the present invention.

FIG. 7 shows an image prediction method using an inter-layer skip mode applied to a unit other than an encoding block. For convenience of explanation, a slice skip mode in which an inter-layer skip mode is performed in units of slices will be described. However, the inter-layer skip mode can be applied not only to a slice unit but also to a coding tree block (CTB) unit and a picture unit. In this case, various terms such as a CTB skip mode and a picture skip mode are used to specify a skip mode between layers .

The CTB is a basic unit for dividing a slice, and can have a square shape of NxN size. The encoded block can be generated by dividing the CTB as a root into a quad-tree structure. A set in which a plurality of CTBs are gathered based on a certain reference can be referred to as a slice, and a single picture can be generated by assembling slices.

Referring to FIG. 7, the image information of the corresponding slice unit 700 of the base layer is upsampled.

The image information of the slice unit 700 existing in the base layer region may be upsampled to restore the image information of the slice unit 740 of the enhancement layer. In the slice skip mode, the image information of the slice unit 720 obtained by upsampling the image information of the slice unit 700 corresponding to the base layer in the same manner as the above-described encoded block skip mode is restored to the slice unit 740 of the enhancement layer And can be used as image information.

That is, when using the slice skip method, it is not necessary to separately perform an image prediction process and an additional decoding process in the enhancement layer for all the CTBs included in the slice. That is, the image information 720 of the slice unit 720 in which the image information of the corresponding slice unit 700 of the base layer is upsampled can be the image information 740 reconstructed in the enhancement layer. In the enhancement layer, the reconstructed image information included in the slice unit 740 may be filtered.

A syntax element indicating that the slice unit 740 of the enhancement layer performs the slice may be newly defined and used. For example, a flag may be defined as to whether a particular slice is a slice that performs a prediction using slice skip mode. The flag information may be included in a slice header or transmitted as a NAL type information in units of a network abstraction layer (NAL), which is a data unit in which a slice is included.

8 is a flowchart illustrating a hierarchical image decoding method using a slice skip mode according to an embodiment of the present invention.

Referring to FIG. 8, it is determined whether a slice skip mode is used in a slice unit (step S800).

It is possible to decode information for determining whether or not a prediction using a slice skip mode is performed in a specific slice unit in a unit such as a slice unit or a NAL unit. For example, using the slice skip flag (slice_skip_flag) which is flag information defined in a slice unit, information on whether or not a slice skip mode is used and decoded can be determined. In the NAL unit, information on whether prediction using a slice skip mode is performed for a slice included in a NAL unit can be indicated using NAL type information.

The number of rows of the slice information and the number of remaining CTBs of the slice are decoded (step S810).

It is possible to determine the total number of CTBs in the slice that performs the prediction using the slice skip mode based on the number of rows of the slice and the number of remaining CTBs of the slice. The number of rows of slice information and the number of remaining CTBs of a slice are examples of variables used to indicate a slice unit using a slice skip mode. Therefore, it is also possible to determine a slice unit using a slice skip mode by using another variable.

9 is a conceptual diagram illustrating a method for indicating a slice using a slice skip mode according to an embodiment of the present invention.

9, two slices (a first slice 900 and a second slice 910 to 950) may exist in one picture. The second slice includes four rows of CTBs 910, 920, and 930 , 940) and three additional CTBs 950.

To indicate a specific slice, information on the number of slice rows and information on the number of remaining CTBs of a slice may be used to obtain information on a slice unit that performs a prediction using a slice skip mode. That is, the total number of CTBs in the slice can be known.

In the case of the second slice, the number of rows (num_rows_in slice) of slices corresponds to 4, and the number of remaining CTBs (num_extra_CTBs_in_Col) corresponds to 3. Based on this information, a slice skip mode can be used to indicate the total number of CTBs in the second slice that perform the prediction.

The slice skip mode is applied to restore slice-unit image information (step S820).

The image information of the slice unit generated using the slice skip mode for the slice unit indicated by using the slice skip mode can be outputted as the image information of the restored slice. That is, information obtained by upsampling the image information of the corresponding slice unit of the base layer can be generated as reconstruction image information of the slice unit. Filtering is applied to the reconstructed image information of the slice unit, and the filtered image information may be output as the image information of the final slice.

If the slice or the CTB uses the inter-layer skip mode, the enhancement layer determines whether the syntax element of the data portion for the current unit and / or the syntax element for the unit below the current unit It is possible to perform a decoding process by referring to syntax element values as needed without being transmitted in a bit-stream.

It is possible to perform a slice skip mode for the slice unit of the enhancement layer by decoding only the slice skip flag information of the slice header to indicate that the skip is performed in units of slices. It is also possible to perform prediction using the inter-layer skip mode by changing the flag information indicating the inter-layer skip mode of another decoding / decoding unit included in the slice according to the slice skip flag information. For example, when the slice skip flag (slice_skip_flag) is ON, the CTB skip flag (CTB_skip_flag) of all the CTBs in the slice unit or the coding block skip flag (CB_skip_flag) of the coding block is turned on to invert . The coded block skip flag (CB_skip_flag) is a flag for indicating that skipping is performed in units of coded blocks, and the CTB skip flag (CTB_skip_flag) is a flag for indicating that skipping is performed in units of CTBs. When this method is used, the same effect can be obtained as in the case of explicitly transmitting the values of the CTB skip flag (CTB_skip_flag) or the encoding block skip flag (CB_skip_flag) on the bit-stream to ON. When a specific flag is 'on', it means that the operation indicated by the flag is performed.

Referring back to FIG. 8, if it is determined in step S800 that the slice skip mode is not used in the slice, image decoding may be performed using another image prediction method (step S830).

For example, image decoding can be performed by performing a general decoding process in an enhancement layer without separately providing image information in the base layer. As another example, various inter-layer prediction methods using video information of the base layer can be used.

10 is a conceptual diagram illustrating a hierarchical image decoding method using a texture prediction mode according to an embodiment of the present invention.

FIG. 10 shows an image prediction method using a texture prediction mode in which residual information is additionally used.

Referring to FIG. 10, (1) video information of a corresponding encoding unit 1000 in the base layer is upsampled.

(2) The image information 1020 of the coding unit 1020 obtained by upsampling the corresponding coding unit in the base layer is added to the decoded residual signal 1040, and the reconstructed image information of the coding unit 1060 is calculated in the enhancement layer do.

The residual signal (or residual signal, difference signal) may be a value obtained by subtracting the image information of the encoding unit 1020 of the base layer upsampled in the image encoding step and the image information of the original block of the enhancement layer. The residual information may be entropy-encoded in the encoding step and transmitted to the image decoding unit to perform texture prediction.

In the image encoding step, the predicted signal may be subtracted from the original block, and only the residual information may be entropy encoded and transmitted. In the image decoding step, prediction is performed by performing the same method as the image prediction method performed in the image encoding step, The reconstructed image information can be calculated by adding the transmitted residual information.

In the image prediction method of the enhancement layer using the texture prediction mode, the image information included in the encoding block unit 1000 of the base layer corresponding to the enhancement layer encoding block unit 1060 is upsampled and upsampled, The decoded residual information 1040 may be added to the image information of the unit 1020 to decode the image.

A new syntax element may be defined and used to indicate that the texture prediction mode is to be performed for an encoding block unit in the enhancement layer. The encoding block texture prediction flag CB_texture_prediction_flag may be used as flag information for indicating whether the encoding block performs texture prediction.

For example, when the coding block texture prediction flag (CB_texture_prediction_flag) is 1, it indicates that texture prediction is performed in units of coding blocks. If the coding block texture prediction flag (CB_texture_prediction_flag) is 0, texture prediction is performed in units of coding blocks Can be indicated.

Since the enhancement layer does not perform prediction separately on the encoding block unit 1060 in which the texture prediction is performed, additional syntax element information for performing prediction may not be transmitted. If necessary, information necessary for performing decoding on the encoding block can be inferred and used.

11 is a flowchart illustrating a hierarchical image decoding method using a texture prediction mode according to an embodiment of the present invention.

Referring to FIG. 11, it is determined whether a skip mode is applied to a coding block unit of the enhancement layer (step S1100).

The skip flag may be flag information for determining whether to perform prediction using the skip mode in the enhancement layer. The skip mode used here differs from the above-described coding block skip mode and slice skip mode in that decoding is performed using only the image prediction information of the enhancement layer.

That is, when the skip mode is performed in the enhancement layer encoding block unit, the prediction blocks included in the enhancement layer encoding block unit can perform prediction without using the image information of the base layer. As an inter-picture prediction method performed in the enhancement layer, a skip (SKIP) mode, a merge mode, and an advanced motion vector prediction (AMVP) can be used. The skip flag is a flag for determining whether to perform the prediction using the skip mode among the inter-picture prediction modes. When the skip mode is used, prediction can be performed using the video prediction information (e.g., motion prediction-related information) of another block previously decoded in the enhancement layer. Information on other blocks previously decoded can be immediately used as a reconstruction block without coding / decoding the residual information with respect to the original block separately in the skip mode used in the enhancement layer.

If it is determined that the skip mode is applied to a coding block unit of the enhancement layer as a result of the skip flag determination, the prediction block included in the coding block unit is predicted using the skip mode to restore the video information in units of the coding block (step S1110 ).

For example, when the skip flag is 1, it is determined that the prediction block included in the encoding block unit is decoded using the skip mode. In the case of the prediction block using the skip mode, prediction is performed using only the prediction information of the enhancement layer (step S1120).

The texture prediction mode is decoded (step S1130).

If the skip flag is 0, the texture prediction mode flag is decoded to judge whether or not the texture prediction is applied to the encoding block unit. The texture prediction mode is a picture prediction mode disclosed in FIG. 10 as described above. In the texture prediction mode, a method of upsampling image information of a unit of a corresponding encoding block in the base layer and adding decoded residual information to restore the image information of the enhancement layer encoding unit Point.

It is determined whether the texture prediction mode is applied to each coding block (step S1130).

It may be determined in step S1130 whether the texture prediction mode is applied to the encoding block unit based on the result of decoding the texture prediction mode flag. The texture prediction mode flag is a flag indicating whether or not texture prediction is performed for each encoding block unit. For example, if the texture prediction mode flag is '1', it indicates that the texture prediction mode is applied to each coding block unit. If the texture prediction mode flag is '0', texture prediction is not applied to each coding block unit .

If the texture prediction mode is applied to each coded block unit, prediction is performed using the texture prediction mode for each coded block unit to perform decoding (step S1140).

When a texture prediction mode is applied to a coding block unit, the enhancement layer can generate a reconstruction block by adding image information obtained by upsampling image information of a corresponding encoding block unit in the base layer and residual information.

If the texture prediction mode is not applied to each coding block unit, the image prediction for each coding block unit may be performed using another image prediction method (step S1150).

For example, if the texture prediction mode is not applied to a coding block unit, the enhancement layer can perform image prediction only in the enhancement layer without receiving the image information transmitted from the base layer. Alternatively, it is also possible to perform prediction for an encoding unit using another inter-layer prediction method.

12 is a conceptual diagram illustrating a method of performing a texture prediction mode in units of slices according to an embodiment of the present invention.

In FIG. 12, a method of using a texture prediction mode in units of slices is described for convenience of description, but a CTB, not a slice unit, and a texture prediction mode may be used for a picture unit, and these embodiments are also included in the scope of the present invention.

Referring to FIG. 12, when the texture prediction mode is used in the enhancement layer slice unit 1200, the image information of the corresponding slice unit 1200 in the base layer is upsampled.

The residual information (the difference value between the original information and the prediction information) 1240 is added to the upsampled slice unit 1220 in the same manner as in the texture prediction in units of the coded blocks, and the image information of the slice unit 1260 of the enhancement layer is restored can do.

New syntax element information can be defined to convey information that texture prediction is applied in slice units. For example, information on whether or not the texture prediction mode is performed for a slice unit may be transmitted based on flag information such as a slice texture prediction flag (slice_texture_prediction_flag), or a type of texture-prediction slice Information can be newly defined and information indicating that the texture prediction mode is applied to the slice included in the corresponding NAL unit can be transmitted.

13 is a flowchart illustrating a method of performing a texture prediction mode in units of slices according to an embodiment of the present invention.

Referring to FIG. 13, it is determined whether the texture prediction mode is applied in units of slices (step S1300).

Whether or not the texture prediction mode is applied in units of slices is determined by using a slice texture prediction flag (slice_texture_prediction_flag) transmitted in slice units, or whether the transmitted NAL type information of the NAL unit is a texture-prediction slice .

The number information of the slice and the number of remaining CTBs of the slice are decoded (step S1320).

It is possible to determine the total number of CTBs in the slice using the texture prediction mode based on the number of rows of slices and the number of remaining CTBs of the slice. The number of rows of slice information and the number of remaining CTBs of a slice can be used as one variable for determining a slice using the slice texture prediction mode, and it is also possible to determine a slice using the slice texture prediction mode using another variable.

The texture prediction mode is applied to the slice to perform prediction (step S1330).

Prediction is performed using the texture prediction mode for a slice unit using the texture prediction mode.

A slice texture prediction flag slice_texture_prediction_flag is transmitted in units of slices so that encoding / decoding units included in the slice can perform texture prediction. Alternatively, when the texture prediction flag is transmitted in units of slices, the CTB texture prediction flag (CTB_texture prediction_flag) of all the CTBs in the slice is set to on or the coding block texture prediction flag (CB_texture_prediction_flag) of all the coding blocks in the slice is set to ON To perform a decoding process.

The encoded block texture prediction flag (CB_texture_prediction_flag) is a flag for indicating that texture prediction is performed in units of a coded block. The CTB texture prediction flag (CTB_texture_prediction_flag) is a flag for indicating that texture prediction is performed in units of CTB. Using this method can have the same effect as explicitly transmitting the value of the CTB texture prediction flag (CTB_texture_prediction_flag) or the encoding block texture prediction flag (CB_texture_prediction_flag) on the bit stream to ON.

Referring back to FIG. 13, if it is determined in step S1300 that the slice texture prediction mode is not applied in units of slices, prediction using another prediction method may be performed (step S1320).

For example, in the enhancement layer, a general decryption process can be performed to perform image decryption. In the general decoding process, intra-layer prediction methods or various inter-layer prediction methods for performing decoding using only information of the enhancement layer can be used.

As another example, prediction can be performed on the enhancement layer using an inter-layer prediction method.

14 is a conceptual diagram illustrating a hierarchical image decoding method using a base layer mode according to an embodiment of the present invention.

FIG. 14 illustrates a method of performing prediction for a coding block of an enhancement layer using the prediction information associated with the coding block information in the base layer with respect to the coding block of the enhancement layer.

14, when the intra-picture prediction or the inter-picture prediction is performed in the corresponding encoding block unit 1400 in the base layer, the information used for the intra-picture prediction (for example, intra-picture prediction mode) The information used for prediction (e.g., motion prediction related information) can be used to perform image prediction in the corresponding encoding block unit 1440 in the enhancement layer.

For example, when intra prediction is performed using intra prediction mode 7 in units of coding blocks of a base layer corresponding to a coding block unit of the enhancement layer, intra prediction is performed in units of coding blocks of the enhancement layer Intra prediction on the encoding block can be performed using the intra prediction mode.

For example, when inter-picture prediction is performed using a specific motion vector in a specific reference picture in a prediction block included in a base layer coding block unit corresponding to an enhancement layer, And perform inter-picture prediction for a prediction unit included in a coding block unit of the enhancement layer using the reference picture.

As an example, the above method can be used for image prediction for an encoding unit of an enhancement layer by deriving other intra-frame prediction related information and other inter-frame prediction related information from the encoding unit of the base layer. If there are a plurality of prediction blocks included in the base layer coding block unit, the prediction related information may be derived for the prediction blocks related to the prediction blocks in the enhancement layer coding block units corresponding to the respective prediction blocks to predict the blocks.

For example, when one encoding block (2Nx2N) is divided into four prediction blocks (NxN), and the divided four prediction blocks perform the intra-picture prediction modes 1, 2, 3 and 4, respectively, The prediction blocks of the encoding unit of the enhancement layer corresponding to the encoding block unit can also perform intra picture prediction using the intra picture prediction modes 1, 2, 3 and 4.

Referring back to FIG. 14, the intra prediction mode information used in the base layer 1400 is decoded and used to perform intra prediction in the enhancement layer 1440. The predicted block generated based on the intra prediction mode information may be combined with the residual information 1420 transmitted from the image encoder to generate a reconstruction block in the enhancement layer.

15 is a flowchart illustrating a hierarchical image decoding method using a base layer mode according to an embodiment of the present invention.

Referring to Fig. 15, the skip flag is decoded (step S1500).

The skip flag may be a flag for determining whether or not the prediction unit included in the enhancement layer encoding block unit uses the skip mode prediction method as described above.

If it is determined that the skip mode is applied to the encoded block unit, a prediction unit included in the encoded block unit is predicted using the skip mode to generate a restored block (step S1510).

For example, when the skip flag is 1, it can be determined that a skip mode is applied to a unit of a coded block so that a prediction block included in each coded block unit performs prediction using the skipped mode.

It is determined whether the base prediction mode is used (step S1520).

The base mode flag is a flag indicating whether prediction using a base prediction mode is to be performed for a prediction unit included in a unit of a coding block. If the skip flag is 0, the base mode flag can be decoded to determine whether the base prediction mode is applied to the encoding block unit.

Based on the decoded base mode flag value, whether or not the base prediction mode is applied to each encoding block unit. If the base mode flag is '1', the base prediction mode is applied in units of coded blocks to indicate whether prediction for the enhancement layer is performed based on the image prediction information of the base layer. If the base mode flag is '0', it can be indicated that the base decoding mode is not applied to the encoding block unit but the image decoding is performed using another image prediction mode. The image prediction information may be information used for performing intra-frame prediction or inter-frame prediction in the enhancement layer, such as intra-frame prediction mode information and motion prediction related information.

If the base prediction mode is applied to the encoding block unit, prediction is performed by deriving the image prediction information of the base layer (step S1530).

If the base prediction mode is applied in units of coding blocks, the intra-picture prediction mode information and the motion prediction-related information can be derived from the base layer. The image prediction information used in the prediction block included in the encoding block unit of the base layer corresponding to the encoding block unit of the enhancement layer can be used as information for predicting the prediction block included in the enhancement layer encoding block unit. The block generated by performing prediction in the enhancement layer based on the image prediction information of the base layer can be added to the residual information to generate a reconstruction block.

If the base prediction mode is not applied in units of encoding blocks, another image prediction method may be used (step S1540).

For example, if the base prediction mode is not applied to the encoding block, the enhancement layer can perform image prediction using only enhancement layer image information without receiving the image information transmitted from the base layer. For example, it is possible to perform prediction on an encoding block by using an intra prediction method, a merge mode among inter prediction methods, and an inter picture prediction method based on AMVP.

In addition, image prediction can be performed using the inter-layer image prediction method except for the base prediction mode.

16 is a conceptual diagram illustrating a method of performing a base prediction mode on a slice basis according to an embodiment of the present invention.

16 shows a method of using a slice base prediction mode in units of slices for convenience of explanation, but a CTB, not a slice unit, and a base prediction mode may be used for each picture, and these embodiments are also included in the scope of the present invention .

Referring to FIG. 16, when prediction is performed using the slice base prediction mode in the slice unit 1640 of the enhancement layer, prediction related information is derived from blocks included in the slice area 1600 corresponding to the base layer.

For example, information on a specific prediction block included in the slice 1640 of the enhancement layer may be predicted in prediction blocks included in the corresponding slice 1600 of the base layer (e.g., intra prediction mode information, Motion prediction related information) can be derived and used. In the slice unit 1640 of the enhancement layer, prediction is performed based on the prediction-related information of the base layer slice unit 1600, and then the reconstructed slice is added to the residual information 1620.

New syntax element information can be defined to convey information that the slice base prediction mode is applied in slice units. For example, based on flag information such as a slice base layer flag (slice_base_layer_flag), information on whether or not the slice base prediction mode is to be performed may be transmitted in the current slice, or a base-layer slice type may be used as type information in units of NAL. And information indicating that the slice included in the NAL unit uses the slice base prediction mode can be transmitted.

17 is a flowchart illustrating a method of performing a base prediction mode in units of slices according to an embodiment of the present invention.

Referring to FIG. 17, it is determined whether a slice base prediction mode is applied to a slice unit (step S1700).

Whether or not the slice base prediction mode is applied to the slice is determined using a slice base layer flag (slice_base_layer_flag) transmitted in slice units, or whether the transmitted NAL type information of the NAL unit is a base layer slice type (base_layer_slice type) .

The number of rows of the slice and the number of remaining CTBs of the slice are decoded (step S1710).

The number of total number of CTBs in a slice using the base prediction mode can be designated based on the number of rows of slice information and the number of remaining CTBs of the slice. The number of rows of the slice and the number of remaining CTBs of the slice can be used to indicate a slice unit to which the base prediction mode is applied by using another variable as one variable for indicating a slice using the base prediction mode.

The slice base prediction mode is used to predict the slice (step S1730).

For example, when the slice base layer flag (slice_base_layer_flag) is transmitted as 'on' in slice units, the CTB base layer flag (CTB_base_layer_flag) of all the CTBs in the slice may be 'on' (CB CB_base_layer_flag) to 'on', thereby performing a decoding process.

The coding block base layer flag (CB_base_layer_flag) is a flag for indicating that the base prediction mode is performed in units of coded blocks, and the CTB base layer flag (CTB_base_layer_flag) is a flag for indicating that the base prediction mode is performed in units of CTBs. When this method is used, the same effect can be obtained as when the CTB base layer flag (CTB_base_layer_flag) or the CB base layer flag (CB_base_layer_flag) on the bit stream is set to be ON .

As a result of the determination in step S1700, if the base prediction mode is not applied in units of slices, the intra prediction method or the inter-layer prediction method for performing decoding using only the enhancement layer information or various inter- Prediction can be performed (step S1720).

18 is a conceptual diagram illustrating a hierarchical image decoding method using a coding block skip mode and a texture prediction mode according to an embodiment of the present invention.

18, an image decoding method using the above-described encoding block skip mode and texture prediction mode will be described.

Referring to FIG. 18, it is determined whether a coded block skip mode is applied to a coded block unit by decoding a coded block skip mode flag (step S1800).

The coded block skip mode is a method of up-sampling image information of the base layer and performing image decoding without residual information as described above. The encoding block skip mode flag is preferentially decoded to determine whether the encoding block skip mode is applied to each encoding block.

When a coded block skip mode is applied to each coded block, the predicted block included in the coded block unit of the enhancement layer may be subjected to image prediction using a coded block skip (step S1810)

In the enhancement layer, an encoding block skip method refers to a method of generating image information of an enhancement layer by upsampling image information of a base layer.

If the coded block skip mode is not applied to each coded block, the skip flag is decoded and it is determined whether to decode the skip mode using the skip mode (step S1820).

As described above, the skip flag is a flag indicating whether or not decoding is performed using the skip mode with only the image prediction information in the enhancement layer for the encoding block. The skip mode is a method of performing an image prediction using only the enhancement layer image information. As a result, the residual information (the difference value information between the original block and the prediction block) is not restored but the image is reconstructed using only the motion prediction- Indicates how to restore.

The decoding is performed using the skip mode (step S1830).

When a skip mode is applied to a coded block unit, the enhancement layer decodes the coded block using motion prediction related information or intra prediction mode information without residual information.

If the skip mode is not applied to each coded block, the texture prediction mode flag is decoded to determine whether the texture prediction mode is applied to the coded block unit (step S1840).

If the skip mode is not applied, the texture prediction mode flag is decoded to determine whether the texture prediction mode is applied in units of encoding blocks.

The texture prediction mode is applied to each encoding block unit (step S1850).

As a result of the determination of the texture prediction mode flag through step S1840, if the texture prediction mode is applied to each coding block unit, the texture mode prediction can be applied to each coding block unit. The texture prediction mode refers to a method of performing decoding using a method of upsampling image information of a corresponding base layer encoding block unit and adding decoded residual information as described above.

If the texture prediction mode is not applied in units of encoding blocks, image decoding is performed using another image prediction method (step S1860).

For example, if it is determined in step S1840 that the texture prediction mode is not applied to the encoding block, the enhancement layer may perform image prediction using only enhancement layer image information without receiving the image information transmitted from the base layer . It is also possible to use another layer-to-layer image prediction method.

Although FIG. 18 exemplifies a method in which two prediction modes are used in the enhancement layer for each coded block, it may be determined whether the corresponding prediction mode is used in units of slices or CTBs as described above. And are included in the scope of the invention.

19 is a conceptual diagram illustrating a hierarchical image decoding method using a skip mode, a texture prediction mode, and a base prediction mode according to an embodiment of the present invention.

FIG. 19 shows a method in which prediction is performed by applying the skip mode, the texture prediction mode and the base prediction mode to the encoding block unit.

Referring to FIG. 19, a skip mode flag is decoded to determine whether a skip mode is applied to an encoding block (step S1900).

The skip mode flag is flag information for determining whether a skip mode is applied to an encoding block to perform image decoding. The skip mode is a method of performing image prediction using image information and separately restoring the image using only the motion prediction related information decoded in the enhancement layer without restoring the residual information (difference value information between the original block and the prediction block) Lt; / RTI >

The skip mode flag is preferentially decoded to determine whether or not the skip mode is applied to each coded block.

The coded block is decoded using the skip mode (step S1910).

When a skip mode is applied to a unit of a coded block, prediction can be performed for each coded block using only prediction related information of the enhancement layer for the coded block.

If the skip mode is not applied to each coded block, the texture prediction flag is decoded to determine whether to decode the texture block by applying the texture prediction mode to the coded block (step S1920).

The texture prediction flag is a flag indicating whether prediction is performed by applying a texture prediction mode to a unit of a coded block. For example, if the texture prediction flag is '1', the texture prediction mode can be performed. If the texture prediction flag is '0', it is possible to instruct that a prediction method other than the texture prediction have.

Texture prediction is performed (step S1930).

If the texture prediction mode is applied to the encoding block as a result of decoding the texture prediction mode flag, a reconstruction block can be generated based on the information obtained by upsampling the block of the base layer corresponding to the enhancement layer encoding block and the residual information .

The base mode flag is decoded to determine whether to decode the encoded block using the base mode (step S1940).

The base mode flag is a flag indicating whether to perform prediction using the base mode for each encoding block unit.

A restoration block is generated using the base mode (step S1950).

When the base mode is applied to the encoding block unit as a result of decoding the base mode flag, prediction related information of the prediction block included in the encoding block unit of the base layer corresponding to the encoding block unit of the enhancement layer (for example, Intra prediction mode information, and motion prediction related information) to predict the enhancement layer.

A restoration block is generated without using the base mode (step S1960).

If the base prediction mode is not applied to the encoding block unit, the enhancement layer can perform image prediction using only enhancement layer image information without receiving the image information transmitted from the base layer. For example, it is possible to perform prediction on an encoding block by using an intra prediction method, a merge mode among inter prediction methods, and an inter picture prediction method based on AMVP. It is also possible that prediction is performed for each encoding block unit of the enhancement layer using another inter-layer prediction method.

Although FIG. 19 illustrates a method in which two prediction modes are used in an enhancement layer for each coded block, it may be determined whether the corresponding prediction mode is used in units of slices or CTBs as described above. And are included in the scope of the invention.

20 is a flowchart illustrating a hierarchical image prediction method using an encoding block skip mode, a texture prediction mode, and a base prediction mode according to an embodiment of the present invention.

In FIG. 20, a method for deciding whether or not a CB skip mode, a texture prediction mode, and a base prediction mode are applied to an encoding block and performing decoding on the encoding block will be described.

Referring to FIG. 20, the encoding block skip mode flag is decoded to determine whether a skip mode is applied to a unit of a coded block (step S2000).

The encoded block skip mode is a method of performing image decoding by upsampling image information of a base layer in units of encoding blocks without residual information. The encoding block skip mode flag is preferentially decoded to determine whether the encoding block skip mode is applied to each encoding block.

If the encoding block skip mode is applied to the encoding block unit, an image obtained by upsampling the image information of the base layer is generated (step S2010).

If the encoding block does not use the encoding block skip mode, it is determined whether a skip mode is applied to each encoding block (step S2020).

The skip flag is a flag indicating whether or not decoding is performed using a skip mode for each encoding block unit as described above. The skip mode is a method of performing image prediction using image information and separately restoring the image using only the motion prediction related information decoded in the enhancement layer without restoring the residual information (difference value information between the original block and the prediction block) Lt; / RTI >

Decryption is performed using the skip mode (step S2030).

When a skip mode is applied to a coded block unit, the enhancement layer decodes the coded block using the motion prediction related information decoded in the enhancement layer, the intra prediction mode information, or the like without residual information.

If the skip mode is not applied, the texture prediction mode flag is decoded to determine whether the prediction block included in the encoding block unit performs prediction using the texture prediction mode (step S2040).

The encoding block unit is decoded using the texture prediction mode (step S2050).

As a result of determining the texture prediction mode flag through step S2040, when a texture block is applied to the texture prediction mode, texture mode prediction is applied to a unit of the encoding block to perform decoding. The texture prediction mode refers to a method of performing decoding using a method of upsampling the base layer encoding block information corresponding to the enhancement layer encoding block unit and adding the decoded residual information as described above.

If the texture prediction mode is not applied to a unit of a coded block, the base mode flag is decoded to determine whether the coded block should be decoded using the base mode (step S2060).

The base mode flag is a flag indicating whether prediction is to be performed using the base prediction mode in encoding block units.

A restoration block is generated using the base prediction mode (step S2070).

When the prediction mode flag is decoded and the encoding block unit performs prediction using the base prediction mode, prediction related information of the base layer encoding block corresponding to the enhancement layer encoding block (for example, intra prediction mode information , Motion prediction related information) to predict a prediction block included in an enhancement layer coding block.

A restoration block is generated without using the base prediction mode (step S2080).

When the encoding block does not perform prediction using the base prediction mode, the enhancement layer can perform image prediction using only enhancement layer image information without receiving the image information transmitted from the base layer. For example, it is possible to perform prediction on an encoding block by using an intra prediction method, a merge mode among inter prediction methods, and an inter picture prediction method based on AMVP. As another example, it is also possible to perform prediction using a different inter-layer prediction method.

Although FIG. 20 exemplifies a method in which three prediction modes are used in the enhancement layer for each coded block, it may be determined whether the corresponding prediction mode is used in units of slices or CTBs as described above. And are included in the scope of the invention.

FIG. 21 is a flowchart illustrating a method of performing intra prediction when a base prediction mode is used in units of encoding blocks according to an embodiment of the present invention.

FIG. 21 shows a case in which intra prediction is performed as a case of performing prediction by applying a base prediction mode to a unit of a coding block.

Referring to FIG. 21, when the base prediction mode is applied to a unit of a coded block, it is determined whether an intra prediction mode is used for each coded block of the base layer (step S2100).

According to the embodiment of the present invention, when the intra prediction mode is used in units of coding blocks of the base layer, it can be determined how to use the reference pixels of the base layer to perform intra prediction. Therefore, it can be determined whether or not the intra-picture prediction is performed with respect to the encoding block unit of the base layer in advance.

As a result of the determination in step S2100, if the intra-frame prediction is not performed in the base layer block, the image prediction may be performed using the base prediction mode in the corresponding block of the base layer (S2110).

If intra prediction is not performed, inter prediction may be performed in the corresponding block of the base layer, and motion prediction related information may be derived from the corresponding block of the base layer to perform prediction on the block of the enhancement layer have.

As a result of the determination in step S2100, when intraprediction is performed in the base layer block, the base layer predictor flag is decoded to determine whether to use the reference pixels of the base layer (step S2120).

The base layer predictor flag is used as a flag for determining whether the prediction blocks included in the enhancement layer encoding block unit use the reference pixels of the base layer or the reference pixels of the enhancement layer in performing intra prediction .

Intra prediction of the prediction block is performed based on the reference pixel information of the base layer (step S2130).

It may be determined that the prediction block included in the encoding block unit is a block that performs prediction using the reference pixels of the base layer as a result of the determination based on the base layer predictor flag.

As a method of performing in-frame prediction of the prediction block based on the reference pixel information of the base layer, two methods can be used. 22 shows two methods of performing intra prediction of a prediction block on the basis of reference pixel information of a base layer.

22 is a conceptual diagram illustrating a method of performing intra prediction of a prediction block based on reference pixel information of a base layer according to an embodiment of the present invention.

Referring to FIG. 22A, (1) the reference pixel information 2200 is restored in the base layer and the reference pixel information 2200 of the base layer block is up-sampled 2210.

The reference pixel information 2200 of the base layer block may be up-sampled 2210 to generate reference pixel information for performing intra-frame prediction of the block of the enhancement layer.

(2) generates a predicted block 2220 for a block of an enhancement layer based on the upsampled reference pixel information.

In the enhancement layer, the intra prediction mode used in the encoding block of the base layer corresponding to the encoding block of the enhancement layer is derived based on the generated predicted block to perform intra prediction.

22 (A), the reference pixel information 2200 of the base layer is up-sampled 2210 to generate a predicted block 2220 using upsampled reference pixel information, Intra prediction can be performed.

In FIG. 22B, a method of up-sampling information that has been predicted using the reference pixel 2250 in the base layer may be used.

(1) Intra prediction is performed using the intra prediction mode used in the base layer coding block corresponding to the coding block of the enhancement layer based on the reference pixel 2250 of the base layer.

Unlike (A) in FIG. 22, (B) can directly generate the predicted block 2260 using the reference pixel information 2250 of the base layer.

(2) Upsampling (2270) the generated predicted block 2260 to generate a predicted block for a block of the enhancement layer.

Performs in-frame prediction to upsample (2270) the generated predicted block (2260) of the base layer to generate a predicted block (2280) for the enhancement layer. 22 (B), in-picture prediction is performed based on the reference pixel information 2250 of the base layer, and up-sampling 2270 is performed based on the predicted block 2260, Lt; RTI ID = 0.0 > 2280 < / RTI >

In the two intraprediction methods using the reference pixel information of the base layer described in FIG. 22, the receiving end / the transmitting end can use the same or separate syntax elements.

Referring again to FIG. 21, intra prediction of a prediction block is performed based on reference pixel information of an enhancement layer (step S2140).

Based on the base layer predictor flag, it can be determined that the block is a block that performs prediction using the reference pixels of the enhancement layer (step S2140). The reference pixel of the enhancement layer may be pixel information existing in a block generated by decoding in the enhancement layer as reference pixel information existing in a block of the enhancement layer.

Although FIG. 21 shows a case where a base layer predictor flag is applied to a unit of a coded block, information about whether a base layer predictor is used for a block included in a CTB or a slice other than the unit of a coded block can be transmitted .

For example, when the base layer predictor flag transmitted from the slice header is turned on, the reference pixel information may be derived from the base layer and used for the blocks using the intra prediction mode among the blocks included in the slice of the enhancement layer have.

23 is a flowchart illustrating a hierarchical video coding method for division information of a transform block according to an embodiment of the present invention.

FIG. 23 is a flowchart showing a method for determining whether division information for a transform block is obtained in a base layer or in an enhancement layer.

Referring to FIG. 23, the base layer conversion flag (BL_transform_partition_flag) is decoded (step S2300).

The base layer conversion flag indicates whether the division information of the conversion block in the enhancement layer is derived from the division information of the conversion block of the base layer or whether the division information for the conversion block is separately determined in the enhancement layer .

It is determined whether or not the conversion block partition information of the base layer is used (step S2310).

When using the conversion block division information of the base layer, the conversion block division information (split_transform_flag) of the base layer is read (step S2320).

When using the conversion block partition information of the base layer, the conversion block partition information of the base layer can be read and used equally in the enhancement layer. That is, a transform block can be generated by dividing an enhancement layer encoded block in the same manner as a method in which a transform block included in a base layer encoded block corresponding to an enhancement layer encoded block is divided.

When the conversion block division information of the base layer is not used, the conversion block division information (split_transform_flag) of the enhancement layer is read (step S2330).

If the transform block division information of the base layer is not used, the transform block division information of the enhancement layer can be obtained by decoding the transform block division information of the enhancement layer.

Although FIG. 23 discloses a method of using conversion block division information of a base layer for each coding block unit, it is possible to determine whether conversion block division information of a base layer is used for a block included in a CTB or a slice, And can be decoded through the flag information.

For example, when the conversion block division information flag of the base layer transmitted from the slice header becomes 'on', the division of the conversion blocks included in the slice of the enhancement layer is the same as the conversion blocks included in the slice of the base layer Type information.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. It will be possible.

Claims (14)

In the intra prediction method,
Determining whether the first image processing unit of the base layer performs intra-frame prediction; And
Decoding the base layer predictor information when the first image processing unit performs intra prediction; And
Performing in-picture prediction on a second image processing unit corresponding to the first image processing unit in an enhancement layer based on the base layer predictor information,
The base layer predictor information is information for determining whether to use a reference pixel of the base layer or a reference pixel of the enhancement layer as a reference pixel for performing intra-picture prediction on the second image processing unit Intra prediction method. 2. The method of claim 1, wherein performing intra-frame prediction on a second image processing unit corresponding to the first image processing unit in the enhancement layer based on the base layer predictor information comprises:
When the base layer predictor information indicates to use a reference pixel of the base layer as a reference pixel for performing intra-frame prediction on the second image processing unit, Generating intra-picture predicted blocks by performing intra-frame prediction with the intra-frame prediction; And
And upsampling the in-picture predicted block. 2. The method of claim 1, wherein performing intra-frame prediction on a second image processing unit corresponding to the first image processing unit in the enhancement layer based on the base layer predictor information comprises:
When the base layer predictor information indicates to use a reference pixel of the base layer as a reference pixel for performing intra-frame prediction on the second image processing unit, the reference pixel of the first image processing unit is updated Sampling; And
And performing intra-picture prediction based on the upsampled reference pixels of the first image processing unit. 2. The method of claim 1, wherein performing intra-frame prediction on a second image processing unit corresponding to the first image processing unit in the enhancement layer based on the base layer predictor information comprises:
When the base layer predictor information indicates to use a reference pixel of the enhancement layer as a reference pixel for performing intra-frame prediction on the second image processing unit, Acquiring reference pixel information for performing intra-frame prediction on the intra-frame prediction; And
And performing intra prediction on the basis of the reference pixel information. The method according to claim 1,
Further comprising the step of determining whether the second image processing unit performs a base prediction mode to perform prediction. 2. The image processing apparatus according to claim 1, wherein the first image processing unit and the second image processing unit comprise:
Wherein the image processing unit is one of a coding block unit, a coding tree block unit, a slice unit, and a picture unit. The apparatus of claim 1, wherein the base layer predictor information comprises:
When the flag value is 1, indicates that the base layer predictor information uses the reference pixel of the base layer as a reference pixel for performing intra-frame prediction on the second image processing unit, Is 0, the base layer predictor information indicates to use a reference pixel of the enhancement layer as a reference pixel for performing intra-picture prediction on the second image processing unit. A video decoding apparatus for performing intra prediction, the apparatus comprising:
An entropy decoding unit decoding the base layer predictor information when the first image processing unit of the base layer performs intra prediction; And
Determining whether the first image processing unit of the base layer performs intra-frame prediction, and determining whether the first image processing unit of the base layer performs intra-frame prediction for the second image processing unit corresponding to the first image processing unit in the enhancement layer And a prediction unit for performing prediction,
The base layer predictor information is information for determining whether to use a reference pixel of the base layer or a reference pixel of the enhancement layer as a reference pixel for performing intra-picture prediction on the second image processing unit Image decoding apparatus. 9. The apparatus of claim 8,
When the base layer predictor information indicates to use a reference pixel of the base layer as a reference pixel for performing intra-frame prediction on the second image processing unit, And performs up-sampling on the in-picture predicted block. 9. The apparatus of claim 8,
When the base layer predictor information indicates to use a reference pixel of the base layer as a reference pixel for performing intra-frame prediction on the second image processing unit, the reference pixel of the first image processing unit is updated And performs intra-frame prediction based on the upsampled reference pixels of the first image processing unit. 9. The apparatus of claim 8,
When the base layer predictor information indicates to use a reference pixel of the enhancement layer as a reference pixel for performing intra-frame prediction on the second image processing unit, And performs intra-picture prediction on the basis of the reference pixel information. 9. The apparatus of claim 8,
Wherein the second image processing unit is configured to determine whether to perform prediction by performing a base prediction mode. The image processing apparatus according to claim 8, wherein the first image processing unit and the second image processing unit comprise:
Wherein the image processing unit is one of a coding block unit, a coding tree block unit, a slice unit, and a picture unit. 9. The apparatus of claim 8, wherein the base layer predictor information comprises:
When the flag value is 1, indicates that the base layer predictor information uses the reference pixel of the base layer as a reference pixel for performing intra-frame prediction on the second image processing unit, Is 0, the base layer predictor information indicates to use a reference pixel of the enhancement layer as a reference pixel for performing intra-picture prediction on the second image processing unit.

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