KR20170125724A - Method for coding and decoding intra-prediction, and atparatus for the same - Google Patents

Abstract

A method for coding and decoding intra-prediction according to the present invention includes a step of setting a plurality of temporary prediction directions; a step of generating temporal prediction direction information corresponding to the plurality of temporal prediction directions; a step of setting at least one adaptive directional mode selected from the plurality of temporary prediction directions; and a step of performing intra-prediction on the intra-prediction modes including the at least one adaptive direction mode, and determining the intra-prediction mode of a current block. It is possible to reduce the number of encoding bits.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an intra prediction encoding method and an apparatus for performing the intra prediction encoding and decoding method,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video encoding and decoding method and apparatus, and more particularly, to a method and apparatus for intraprediction encoding and decoding.

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 used 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 using 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.

On the other hand, demand for high resolution images is increasing, and demand for stereoscopic image contents as a new image service is also increasing. Video compression techniques are being discussed to effectively provide high resolution and ultra-high resolution stereoscopic content.

The present invention can provide a method and apparatus for adaptively setting an intra prediction direction in consideration of a relatively large reference area in coding / decoding a video signal.

In addition, the present invention can provide a method and apparatus capable of setting an accurate intra prediction mode by setting the intra prediction direction adaptively and further reducing the number of encoding bits.

In addition, the present invention can provide a method and apparatus for adaptively setting an intra prediction direction in consideration of a hardware environment of an encoding apparatus and a decoding apparatus, a communication environment between the encoding apparatus and a decoding apparatus, and the like.

According to an aspect of the present invention, there is provided an intra prediction encoding method comprising: setting a plurality of temporary prediction directions; generating temporary prediction direction information corresponding to the plurality of temporary prediction directions; Setting at least one adaptive directional mode and performing intra prediction for intra prediction modes including the at least one adaptive directional mode to determine an intra prediction mode of the current block have.

According to another aspect of the present invention, there is provided an intra prediction decoding method comprising: setting a plurality of temporary prediction directions; generating temporary prediction direction information for the temporary prediction direction; Determining an intra prediction mode of the coded intra prediction mode, performing intra prediction on the intra prediction modes including the at least one adaptive direction mode, and restoring the prediction block .

According to another aspect of the present invention, there is provided an intra-prediction encoding apparatus including a temporary prediction direction information generation unit for setting a plurality of temporary prediction directions and generating temporary prediction direction information for the plurality of temporary prediction directions, Wherein the intra prediction mode comprises at least one adaptive directional mode setting unit configured to set at least one adaptive directional mode selected from a plurality of intra-prediction modes, and intra-prediction modes including the at least one adaptive directional mode, And an intra prediction mode determining unit for determining a mode.

According to another aspect of the present invention, there is provided an intra prediction decoding apparatus comprising: a temporary prediction direction information generation unit that sets a plurality of temporary prediction directions and generates temporary prediction direction information for the plurality of temporary prediction directions; And an intra prediction mode setting unit for setting at least one of the intra prediction modes for the intra prediction modes including the at least one adaptive direction mode, And an intra prediction mode reconstructing unit for reconstructing the prediction block.

According to the present invention, an intraprediction direction can be set adaptively according to a direction in which a reference picture located in a relatively-referenced area exists, thereby making it possible to set an accurate intra prediction mode and further reduce the number of encoding bits.

Further, according to the present invention, it is possible to adaptively set the intra prediction direction in consideration of the hardware environment of the coding apparatus and the decoding apparatus, the communication environment between the coding apparatus and the decoding apparatus, and realize efficient coding and decoding.

1 is a block diagram illustrating an image encoding apparatus according to an embodiment of the present invention.
2 is a block diagram illustrating an image decoding apparatus according to an embodiment of the present invention.
3 is a block diagram illustrating a detailed configuration of an intra predictor included in an image encoding apparatus according to an exemplary embodiment of the present invention.
4 is a diagram illustrating a current block and a reference block according to an embodiment of the present invention.
5 is a diagram illustrating a temporary prediction direction set by the temporary prediction direction information generation unit according to an embodiment of the present invention.
6 is a diagram illustrating an example of a temporary block generated by the temporary prediction direction information generation unit according to an embodiment of the present invention.
FIG. 7 is a diagram illustrating an adaptive direction mode that is determined stepwise by an adaptive directional mode setting unit according to an embodiment of the present invention.
8 is an example of an adaptive direction mode determined by the adaptive direction mode setting unit according to an embodiment of the present invention.
9 is a block diagram illustrating a detailed configuration of an intra predictor included in an image decoding apparatus according to an embodiment of the present invention.
10 is a flowchart illustrating an intra prediction encoding method according to an embodiment of the present invention.
11 is a flowchart illustrating an intra prediction decoding method according to an embodiment of the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for like elements in describing each drawing.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

The definitions of the terms used in the present disclosure are as follows.

The temporary prediction direction may be a direction in which the range of the entire prediction direction is divided into a predetermined number according to a predetermined rule.

The temporary block may include a block predicted based on reference pixel information existing in each temporary prediction direction.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Hereinafter, the same reference numerals will be used for the same constituent elements in the drawings, and redundant explanations for the same constituent elements will be omitted.

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

1, the image encoding apparatus 100 includes a picture division unit 110, prediction units 120 and 125, a transform unit 130, a quantization unit 135, a reordering unit 160, an entropy encoding unit An inverse quantization unit 140, an inverse transform unit 145, a filter unit 150, and a memory 155. [

Each of the components shown in FIG. 1 is shown independently to represent different characteristic functions in the image encoding apparatus, and does not mean that each component is composed of separate hardware or one software configuration 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 separate embodiments of the components are also included within the scope of the present invention, unless they depart from the essence of the present invention.

In addition, some of the components are not essential components to perform essential functions in the present invention, but may be optional components only to improve 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.

The picture division unit 110 may divide the input picture into at least one processing unit. At this time, the processing unit may be a prediction unit (PU), a transform unit (TU), or a coding unit (CU). The picture division unit 110 divides one picture into a plurality of coding units, a prediction unit, and a combination of conversion units, and generates a coding unit, a prediction unit, and a conversion unit combination So that the picture can be encoded.

For example, one picture may be divided into a plurality of coding units. In order to divide a coding unit in a picture, a recursive tree structure such as a quad tree structure can be used. In a coding or decoding scheme in which one picture or a largest coding unit is used as a root and divided into other coding units A unit can be divided with as many child nodes as the number of divided coding units. Under certain constraints, an encoding unit that is no longer segmented becomes a leaf node. That is, when it is assumed that only one square division is possible for one coding unit, one coding unit can be divided into a maximum of four different coding units.

Hereinafter, in the embodiment of the present invention, a coding unit may be used as a unit for performing coding, or may be used as a unit for performing decoding.

The prediction unit may be one divided into at least one square or rectangular shape having the same size in one coding unit, and one of the prediction units in one coding unit may be divided into another prediction Or may have a shape and / or size different from the unit.

If a prediction unit performing intra prediction on the basis of an encoding unit is not the minimum encoding unit at the time of generation, intraprediction can be performed without dividing the prediction unit into a plurality of prediction units NxN.

The prediction units 120 and 125 may include an inter prediction unit 120 for performing inter prediction and an intra prediction unit 125 for performing intra prediction. It is possible to determine whether to use inter prediction or intra prediction for a prediction unit and to determine concrete information (e.g., intra prediction mode, motion vector, reference picture, etc.) according to each prediction method. At this time, the processing unit in which the prediction is performed may be different from the processing unit in which the prediction method and the concrete contents are determined. For example, the method of prediction, the prediction mode and the like are determined as a prediction unit, and the execution of the prediction may be performed in a conversion unit. The residual value (residual block) between the generated prediction block and the original block can be input to the conversion unit 130. [ In addition, the prediction mode information, motion vector information, and the like used for prediction can be encoded by the entropy encoding unit 165 together with the residual value and transmitted to the decoder. When a particular encoding mode is used, it is also possible to directly encode the original block and transmit it to the decoding unit without generating a prediction block through the prediction units 120 and 125.

The inter-prediction unit 120 may predict a prediction unit based on information of at least one of a previous picture or a following picture of the current picture, and may predict a prediction unit based on information of a partially- Unit may be predicted. The inter prediction unit 120 may include a reference picture interpolation unit, a motion prediction unit, and a motion compensation unit.

In the reference picture interpolating unit, reference picture information is supplied from the memory 155 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 (DCT) based on a different filter coefficient may be used to generate pixel information of less than an integer number of pixels in quarter-pixel units. In the case of a color difference signal, a DCT-based 4-tap interpolation filter may be used that generates a pixel information of an integer number of pixels or less in units of 1/8 pixel.

The motion prediction unit may 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 as methods for calculating 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 motion prediction unit can predict the current prediction unit by making the motion prediction method different. Various methods such as a skip method, a merge method, an AMVP (Advanced Motion Vector Prediction) method, and an Intra Block Copy method can be used as the motion prediction method.

The intraprediction unit 125 may set a prediction unit based on reference pixel information around the current block, which is pixel information in the current picture, and perform intra prediction on the set prediction unit to generate a prediction block. In the case where the neighboring block of the current prediction unit is the block in which the inter prediction is performed so that the reference pixel is the pixel performing the inter prediction, the reference pixel included in the block in which the inter prediction is performed is referred to as the reference pixel Information. That is, when the reference pixel is not available, the reference pixel information that is not available may be replaced by at least one reference pixel among the available reference pixels.

In 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 direction information is not used in prediction. The mode for predicting the luminance information may be different from the mode for predicting the chrominance information and the intra prediction mode information or predicted luminance signal information used for predicting the luminance information may be utilized to predict the chrominance information.

When intraprediction is performed, when the size of the prediction unit is the same as the size of the conversion unit, intra prediction is performed on the prediction unit based on pixels existing on the left side of the prediction unit, pixels existing on the upper left side, Can be performed. However, when intra prediction is performed, when the size of the prediction unit differs from the size of the conversion unit, intraprediction can be performed using the reference pixel based on the conversion unit. It is also possible to use intra prediction using N x N divisions for only the minimum coding units.

In the intra prediction method, an adaptive intra-smoothing filter (AISFAdaptive Intra Smoothing Filter) may be applied to a reference pixel according to a prediction mode, and then a prediction block may be generated. The type of adaptive intra smoothing filter applied to the reference pixel may be different. In order to perform the intra prediction method, the intra prediction mode of the current prediction unit can be predicted from the intra prediction mode of the prediction unit existing around the current prediction unit. In the case where the prediction mode of the current prediction unit is predicted using the mode information predicted from the peripheral prediction unit, if the intra prediction mode of the current prediction unit is the same as the intra prediction mode of the current prediction unit, The prediction mode information of the current block can be encoded by performing entropy encoding if the prediction mode of the current prediction unit is different from the prediction mode of the neighbor prediction unit.

In addition, a residual block including a prediction unit that has been predicted based on the prediction unit generated by the prediction units 120 and 125 and a residual value that is a difference value from the original block of the prediction unit may be generated. The generated residual block may be input to the transform unit 130. [

The transforming unit 130 transforms the residual block including the residual information of the prediction unit generated through the original block and the predictors 120 and 125 into a DCT (Discrete Cosine Transform), a DST (Discrete Sine Transform), a KLT Karhunen-Loeve Transform). The decision to apply the DCT, DST, or KLT to transform the residual block may be based on the intra prediction mode information of the prediction unit used to generate the residual block.

The quantization unit 135 may quantize the values converted into the frequency domain by the conversion unit 130. [ The quantization factor may vary depending on the block or the importance of the image. The values calculated by the quantization unit 135 may be provided to the inverse quantization unit 140 and the reorder unit 160.

The reordering unit 160 can reorder the coefficient values with respect to the quantized residual values.

The reordering unit 160 may change the two-dimensional block type coefficient to a one-dimensional vector form through a coefficient scanning method. For example, the rearranging unit 160 may scan a DC coefficient to a coefficient in a high frequency region using a Zig-Zag scan method, and change the DC coefficient to a one-dimensional vector form. Instead of the jig-jag scan, a vertical scan may be used to scan two-dimensional block type coefficients in a column direction, and a horizontal scan to scan a two-dimensional block type coefficient in a row direction depending on the size of the conversion unit and the intra prediction mode. That is, it is possible to determine whether any scanning method among the jig-jag scan, the vertical direction scan and the horizontal direction scan is used according to the size of the conversion unit and the intra prediction mode.

The entropy encoding unit 165 may perform entropy encoding based on the values calculated by the reordering unit 160. 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 165 receives the residual value count information of the encoding unit, the block type information, the prediction mode information, the division unit information, the prediction unit information and the transmission unit information, and the motion information of the motion unit from the reordering unit 160 and the prediction units 120 and 125 Vector information, reference frame information, interpolation information of a block, filtering information, and the like.

The entropy encoding unit 165 can entropy-encode the coefficient value of the encoding unit input by the reordering unit 160. [

The inverse quantization unit 140 and the inverse transformation unit 145 inverse quantize the quantized values in the quantization unit 135 and inversely transform the converted values in the conversion unit 130. [ The residual value generated by the inverse quantization unit 140 and the inverse transform unit 145 is combined with the prediction unit predicted through the motion estimation unit, the motion compensation unit and the intra prediction unit included in the prediction units 120 and 125, A block (Reconstructed Block) can be generated.

The filter unit 150 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, horizontal filtering and vertical filtering may be performed concurrently in performing vertical filtering and horizontal filtering.

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 adaptive loop filter can be performed based on a value obtained by comparing the filtered reconstructed image with the original image. After dividing the pixels included in the image into a predetermined group, one filter to be applied to the group may be determined and different filtering may be performed for each group. Information related to whether to apply the adaptive loop filter may be transmitted for each coding unit (CU), and the shape and the filter coefficient of the adaptive loop filter to be applied to each block may be different. Also, an adaptive loop filter filter of the same type (fixed form) may be applied regardless of the characteristics of the application target block.

The memory 155 may store the reconstructed block or picture calculated through the filter unit 150 and the reconstructed block or picture stored therein may be provided to the predictor 120 or 125 when the inter prediction is performed.

2 is a block diagram illustrating an image decoding apparatus according to an embodiment of the present invention.

2, the image decoder 200 includes an entropy decoding unit 210, a reordering unit 215, an inverse quantization unit 220, an inverse transform unit 225, prediction units 230 and 235, 240, and a memory 245 may be included.

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

The entropy decoding unit 210 can perform entropy decoding in a procedure opposite to that in which entropy encoding is performed in the entropy encoding unit of the image encoder. For example, various methods such as Exponential Golomb, Context-Adaptive Variable Length Coding (CAVLC), and Context-Adaptive Binary Arithmetic Coding (CABAC) may be applied in accordance with the method performed by the image encoder.

The entropy decoding unit 210 may decode information related to intra prediction and inter prediction performed in the encoder.

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 215 can 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 an inverse DCT, an inverse DST, and an inverse KLT on the DCT, DST, and KLT transformations performed by the transform unit on the quantization result performed by the image encoder. The inverse transform can be performed based on the transmission unit determined by the image encoder. In the inverse transform unit 225 of the image decoder, a transform technique (e.g., DCT, DST, KLT) may be selectively performed according to a plurality of information such as a prediction method, a size of a current block, and a prediction direction.

The prediction units 230 and 235 can generate a prediction block based on the prediction block generation related information provided by the entropy decoding unit 210 and the previously decoded block or picture information provided in the memory 245. [

As described above, when intra prediction is performed in the same manner as in the image encoder, when the size of the prediction unit is the same as the size of the conversion unit, pixels existing on the left side of the prediction unit, pixels existing on the upper left side, However, when the size of the prediction unit differs from the size of the prediction unit in intra prediction, intraprediction is performed using a reference pixel based on the conversion unit . It is also possible to use intra prediction using N x N divisions for only the minimum coding unit.

The prediction units 230 and 235 may include a prediction unit determination unit, an inter prediction unit, and an intra prediction unit. The prediction unit determination unit receives various information such as prediction unit information input from the entropy decoding unit 210, prediction mode information of the intra prediction method, motion prediction related information of the inter prediction method, and identifies prediction units in the current coding unit. It is possible to determine whether the unit performs inter prediction or intra prediction. The inter prediction unit 230 predicts the current prediction 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 unit by using information necessary for inter prediction of the current prediction unit provided by the image encoder, Unit can be performed. Alternatively, the inter prediction may be performed on the basis of the information of the partial region previously reconstructed in the current picture including the current prediction unit.

In order to perform inter prediction, a motion prediction method of a prediction unit included in a corresponding encoding unit on the basis of an encoding unit includes a skip mode, a merge mode, an AMVP mode, and an intra block copy mode It is possible to judge whether or not it is any method.

The intra prediction unit 235 can generate a prediction block based on the pixel information in the current picture. If the prediction unit is a prediction unit that performs intra prediction, intra prediction can be performed based on intra prediction mode information of a prediction unit provided by the image encoder to generate a prediction block. The intraprediction unit 235 may include an Adaptive Intra Smoothing Filter (AISF), a reference pixel interpolator, and a DC filter. The adaptive intra-smoothing filter performs filtering on the reference pixels of the current block, and can determine whether to apply the filter according to the prediction mode of the current prediction unit. The adaptive intra-smoothing filtering can be performed on the reference pixels of the current block by using the prediction mode of the prediction unit provided in the image encoder and the adaptive intra-smoothing filter information. If the prediction mode of the current block is a mode in which adaptive intra-smoothing filtering is not performed, the adaptive intra-smoothing filter may not be applied.

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

The restored block or picture may be provided to the filter unit 240. The filter unit 240 may include a deblocking filter, an offset correction unit, and an adaptive loop filter.

When information on whether a deblocking filter is applied to a corresponding block or picture from the image encoder or a deblocking filter is applied, information on whether a strong filter or a weak filter is applied can be provided. In the deblocking filter of the video decoder, the deblocking filter related information provided by the video encoder is provided, and the video decoder can perform deblocking filtering for the corresponding block.

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 adaptive loop filter can be applied to an encoding unit based on adaptive loop filter application information provided from an encoder, adaptive loop filter coefficient information, and the like. Such adaptive loop filter information may be provided in a specific set of parameters.

The memory 245 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.

As described above, in the embodiment of the present invention, a coding unit (coding unit) is used as a coding unit for convenience of explanation, but it may be a unit for performing not only coding but also decoding.

3 is a block diagram illustrating a detailed configuration of an intra predictor included in an image encoding apparatus according to an exemplary embodiment of the present invention. 3, an intra-prediction unit 125 according to an embodiment of the present invention includes a temporary prediction direction information generation unit 31, an adaptive direction mode setting unit 33, and an intra-prediction mode determination unit 35. [ . ≪ / RTI >

The temporary prediction direction information generating unit 31 may set the temporary prediction directions as the basis for setting the intra prediction mode to a predetermined number and generate the temporary prediction direction information based on the predetermined number of temporary prediction directions have.

Specifically, the temporary prediction direction information generator 31 may set the number of temporary prediction directions that can be used for determining the intra prediction mode for the current block to N (where N is a natural number). Here, the temporary prediction direction information generator 31 may divide the range of the entire prediction direction that can be used for determining the intra prediction mode into a predetermined number (N) in accordance with a predetermined rule, and set the temporary prediction direction . The predetermined rule may be to evenly divide the range of the entire prediction direction.

Furthermore, the temporary prediction direction information generating unit 31 generates N temporary blocks based on the reference pixel information existing in each temporary prediction direction, and determines the pixel information of the generated N temporary blocks as temporary prediction direction information .

The adaptive direction mode setting unit 33 sets the adaptive direction mode by a predetermined number (e.g., M (M is a natural number)) using the temporary prediction direction information. The predetermined number in which the adaptive direction mode is set may be set to a fixed value in the designing stage of the encoding apparatus according to an embodiment of the present invention. As another example, the predetermined number in which the adaptive direction mode is set considers the hardware computing capability of the encoder and the decoder, the size of the storage capacity of the encoder and the decoder, the communication environment between the encoder and the decoder, and the like And can be set adaptively.

Although the method of setting the predetermined number (e.g., M (M is a natural number)) for setting the adaptive direction mode is illustrated in the adaptive direction mode setting unit 33 in the embodiment of the present invention, The present invention is not limited thereto. It suffices that the decoding apparatus can set the predetermined number to the same rule as the rule used by the encoding apparatus according to the embodiment of the present invention to set the predetermined number. Therefore, the rules used to set the predetermined number may be set in advance in the coding apparatus and the decoding apparatus as described above, or the rules used for setting the predetermined number in the process of coding the data by the coding apparatus And to confirm a rule used by the decoding apparatus to set the predetermined number in the process of decoding the data.

The adaptive direction mode setting unit 33 identifies the difference value between the temporary blocks and merges or splits the temporary blocks on the basis of the identified difference value to determine the adaptive direction mode as the predetermined The number can be set. For example, the adaptive direction mode setting unit 33 may set a threshold value for the difference value step by step, and may merge or split the temporary block based on the threshold value set in a stepwise manner . The adaptive direction mode setting unit 33 may use the directional mode corresponding to the temporary blocks merged or separated and used as the adaptive directional mode. As a result, the intra prediction direction can be adaptively set according to the value of the actual peripheral reference pixel, not in a direction divided by a fixed angle as in the conventional method. Therefore, it is possible to set a more accurate intra prediction mode than the intra prediction direction in the fixed angular direction according to the conventional method, and further, it can contribute to reduce the number of encoding bits.

The intraprediction mode determination unit 35 performs intraprediction on the current block based on the directional mode of the adaptive directional mode set by the adaptive directional mode setting unit 33 together with the planar mode and the DC mode, The prediction mode can be determined.

On the other hand, in the above-described embodiment, the temporary prediction direction information generating section 31 generates temporary blocks corresponding to the number (N) of temporary prediction directions, and stores the pixel information of the generated N temporary blocks as a temporary prediction Direction information, but the present invention is not limited thereto. It is sufficient that the temporary prediction direction information generating unit 31 can confirm the information on the pixels included in the current block based on the aforementioned temporary prediction direction. For example, the temporary prediction direction information generation unit 31 generates information (hereinafter referred to as " temporary block mapping ") by mapping pixels of a temporary block that can reflect a reference pixel corresponding to the temporary prediction direction, Information "), and may determine the temporary block mapping information as the temporary prediction direction information. In this case, the adaptive direction mode setting unit 33 processes a numerical operation on the relationship between the reference pixels included in the temporary block mapping information and the pixels of the temporary block, thereby quickly changing the adaptive direction mode out of the temporary prediction directions You can decide. As described above, if the adaptive direction mode is set based on the temporary block mapping information, the computation amount or hardware resources required to set the adaptive direction mode can be reduced, and effective processing can be performed.

Hereinafter, the operation of the intra-prediction unit according to an embodiment of the present invention will be described in detail with reference to the drawings.

4 is a diagram illustrating a current block and a reference block according to an embodiment of the present invention. FIG. 5 is a diagram illustrating a temporary prediction direction set by a temporary prediction direction information generation unit according to an embodiment of the present invention. 6 is a diagram illustrating an example of a temporary block generated by the temporary prediction direction information generation unit according to an embodiment of the present invention.

4 shows a case where the current block 40 has a plurality of pixels TP1 to TP16 arranged in a square and the reference pixels RP1 to RP17 referenced in generating a temporary block based on the current block 40 are arranged in the current block 40. [ The upper left portion of the current block 40, the upper right portion of the current block 40, the left portion of the current block 40, and the lower left portion of the current block 40. [ 5 illustrates the temporary prediction directions (V1 to Vn, H1 to Hn, VH0) set by the temporary prediction direction information generation unit 31. [

Referring to the above-mentioned drawings, the temporary prediction direction information generating unit 31 can first set the temporary prediction direction on which the intra prediction mode is set. The temporary prediction direction indicates a direction indicating a reference pixel located in the vicinity of the current block 40, and may be a direction obtained by dividing the range of the region where the reference pixel is located into a predetermined number (e.g., N). For example, when the reference pixels are distributed around the current block 40 as shown in FIG. 4, the range of the region in which the reference pixel is located is equally divided by a predetermined number (for example, N) (Fig. 5, V1 to Vn, H1 to Hn, and VH0).

In one embodiment of the present invention, the predetermined number in which the temporary prediction directions (V1 to Vn, H1 to Hn, VH0) are set can be exemplified by N. This is because the adaptive direction mode setting unit 33 finally determines The number of adaptive directional modes (M).

Next, the temporary prediction direction information generating unit 31 generates a temporary block (refer to FIG. 6, TB1 to TBn) corresponding to the N temporary prediction directions (V1 to Vn, H1 to Hn, VH0) set through the above- Can be generated. That is, the temporary prediction direction information generation unit 31 refers to the color difference information of the reference pixels existing in the region indicated by the N prediction directions (V1 to Vn, H1 to Hn, VH0) centering on the current block, So that a temporary block can be constructed. The N temporary blocks configured through the above operation can be provided to the adaptive direction mode setting unit 33 as the temporary prediction direction information.

The adaptive direction mode setting unit 33 identifies the provisional prediction direction information provided from the provisional prediction direction information generating unit 31 and sequentially integrates the N temporary prediction directions V1 to Vn and H1 to Hn and VH0 And determine M adaptive directional modes to be used for intra prediction.

FIG. 7 is a diagram illustrating an adaptive direction mode determined step by step by the adaptive direction mode setting unit according to an embodiment of the present invention, and FIG. 8 is a diagram illustrating an adaptive direction mode setting unit according to an embodiment of the present invention. Lt; RTI ID = 0.0 > directional < / RTI >

The adaptive direction mode setting unit 33 first confirms the difference value Dk between the N temporary blocks 71. [ The difference value Dk between the temporary blocks 71 can be confirmed by an operation of Equation 1 below.

Here, distance is a function for calculating a difference between prediction blocks, such as a Sum of Squared Difference (SSD), a Sum of Absolute Diffrence (SAD), or the like.

First, when the difference value Dk between the temporary blocks 71 is 0, the neighboring temporary blocks are merged into one temporary block. If the difference value between neighboring temporary blocks 71 is not 0 Maintain temporary blocks. For example, in FIG. 7, the first temporary block TB1 and the second temporary block TB2, the fourth temporary block TB4 and the fifth temporary block TB5, the sixth temporary block TB6, When the difference values Dk between the blocks TB7 and TB7 are 0, the temporary blocks having the difference value Dk = 0 are the same temporary blocks, and one temporary block is deleted from the corresponding blocks to process the primary merge . First, it is confirmed whether the number of temporary blocks 72 remaining after merging is equal to or smaller than a predetermined number (for example, M) which is a reference for setting the adaptive direction mode. If the number of temporary blocks 72 remaining after the merge processing is larger than M, the secondary merge proceeds as follows.

The adaptive direction mode setting unit 33 merges neighboring temporary blocks into one temporary block when the difference value Dk between neighboring temporary blocks is equal to or less than a predetermined threshold value, If the value Dk is greater than a predetermined threshold value, the temporary block is maintained. The adaptive direction mode setting unit 33 sets the adaptive direction mode until the number of temporary blocks 73 remaining after merging is equal to or smaller than a predetermined number (for example, M) The above-described merging process operation can be repeatedly performed while sequentially increasing the predetermined threshold value.

When the number of temporary blocks remaining after merging is equal to or smaller than a predetermined number (for example, M) that is a reference for setting the adaptive direction mode, the adaptive direction mode setting unit 33 sets the merging The direction corresponding to the remaining temporary blocks 74 may be determined as the adaptive direction mode (see FIG. 8).

Next, the intra-prediction mode determining unit 35 may assign an index of the intra-prediction mode including the directional mode of the adaptive directional mode set by the adaptive directional mode setting unit 33 together with the planar mode and the DC have. The intra prediction mode determination unit 35 can determine any intra prediction mode among a plurality of modes allocated to the index of the intra prediction mode.

The adaptive direction mode setting unit 33 may merge the N temporal prediction directions V1 to Vn and H1 to Hn and VH0 step by step while illustrating the operation of the intra prediction unit according to an embodiment of the present invention, (Where N > M) is determined, the present invention is not limited thereto. The number of temporal prediction directions is set to be different from the number of adaptive directional modes that are finally determined in consideration of the fact that the finally determined adaptive directional mode is variably set reflecting the relationship between the reference pixel and the pixels included in the prediction block Sufficient is enough.

As an example different from the above-described embodiment, the adaptive direction mode of M (where N < M) is determined by stepwise dividing N temporary prediction directions (V1 to Vn, H1 to Hn, VH0) It is also possible to do.

Specifically, the adaptive direction mode setting unit 33 sets a temporary prediction direction of a number (N) smaller than the number of adaptive directional modes (M) and generates temporary blocks 71 corresponding to the temporary prediction direction do. The adaptive direction mode setting unit 33 identifies the difference value Dk between the N temporary blocks according to the above-described Equation 1, and outputs the N temporary predictive directions V1- Vn, H1 to Hn, and VH0) can be stepwise divided (sprit).

The adaptive direction mode setting unit 33 provides the temporary prediction direction information generating unit 31 with information on the temporary blocks when the difference value Dk between neighboring temporary blocks is equal to or greater than a predetermined threshold value , And can request division into a plurality of blocks. In response to this, the temporary prediction direction information generating unit 31 generates at least one temporary block by spitting the temporary prediction direction formed by the temporary blocks, and temporarily converts the temporary prediction direction information corresponding to the generated temporary block Directional mode setting unit 33 as shown in FIG. The adaptive direction mode setting unit 33 confirms whether the number of temporary blocks existing after the division is the same as a predetermined number (for example, M) as a reference for setting the adaptive direction mode, and the number of temporary blocks It is possible to repeatedly perform the dividing processing operation described above while sequentially decreasing the predetermined threshold value until the number of the thresholds becomes equal to a predetermined number (for example, M) which is a reference for setting the adaptive direction mode. If the number of temporary blocks remaining after the division is equal to a predetermined number (for example, M) which is a reference for setting the intra prediction direction, the adaptive direction mode setting unit 33 sets the number of temporary blocks Can be determined as the adaptive direction mode.

Although it has been illustrated that the temporary prediction direction information generation unit 31 generates temporary blocks and constructs the temporary prediction direction information based on the generated temporary blocks while illustrating the operation of the intra prediction unit according to the embodiment of the present invention, It is not limited thereto. It is sufficient that the temporary prediction direction information can predict information on the pixels included in the current block based on the aforementioned temporary prediction direction. For example, the temporary prediction direction information generating unit 31 generates a temporary pixel of a temporary block (hereinafter, referred to as a 'temporary pixel') to which a reference pixel corresponding to the temporary prediction direction can be reflected Mapped information (hereinafter referred to as `temporary block mapping information`), and may determine the temporary block mapping information as the temporary prediction direction information. For example, referring to the temporary block illustrated in FIG. 4, the first reference pixel RP1 includes a first temporary pixel TP1, a fifth temporary pixel TP5, a ninth temporary pixel TP9 in the vertical direction, And the thirteenth temporary pixel TP13 and may be reflected in the second temporary pixel TP2, the seventh temporary pixel TP7, and the twelfth temporary pixel TP12 in the diagonal direction. The temporary block mapping information may be information that matches the information including the temporary prediction direction, the reference pixel, and the temporary pixel.

When the temporary prediction direction information is temporary block mapping information, the adaptive direction mode setting unit 33 performs a numerical calculation on the relationship between the reference pixel and the temporary pixel included in the temporary block mapping information, The adaptive direction mode can be quickly determined from the temporary prediction directions. For example, it is possible to calculate how many reference pixels are reflected in the temporary pixels, align the reference pixels based on the number of times the temporary pixels are reflected, and set the direction mode corresponding to the M reference pixels to the adaptive direction mode. As described above, if the adaptive direction mode is set based on the temporary block mapping information, the computation amount or hardware resources required to set the adaptive direction mode can be reduced, and effective processing can be performed.

9 is a block diagram illustrating a detailed configuration of an intra predictor included in an image decoding apparatus according to an embodiment of the present invention. 9, an intra predictor 235 included in an image decoding apparatus according to an exemplary embodiment of the present invention includes a temporary prediction direction information generation unit 91, an adaptive direction mode setting unit 93, And a mode recovery unit 95.

The temporal prediction direction information generating unit 91 and the adaptive directional mode setting unit 93 provided in the intra prediction unit 235 of the video decoding apparatus perform temporal prediction with respect to the temporal prediction direction included in the intra prediction unit 125 of the video encoding apparatus The information generating unit 31, and the adaptive direction mode setting unit 33 shown in FIG. Therefore, the concrete configuration of the temporary prediction direction information generation unit 91 and the adaptive direction mode setting unit 93 is the temporary prediction direction information generation unit 31 provided in the intra prediction unit 125 of the image encoding apparatus, The description of the configuration of the adaptive direction mode setting unit 33 will be referred to.

The temporary prediction direction information generation unit 91 sets a temporary prediction direction as a basis for setting an intra prediction mode to a predetermined number and generates temporary prediction direction information based on the predetermined number of temporary prediction directions have.

The adaptive direction mode setting unit 93 merges or splits the temporary blocks on the basis of the pixel information of the temporary blocks included in the temporary prediction direction information to determine the predetermined number of adaptive directional modes Can be set. As another example, the adaptive direction mode setting unit 93 may perform a numerical calculation on the relationship between the reference pixels and the pixels included in the temporary block based on the temporary block mapping information included in the temporary prediction direction information, The predetermined number of adaptive direction modes can be set.

The intraprediction mode restoration unit 95 may assign an index of an intra prediction mode including the adaptive direction mode set by the adaptive direction mode setting unit 33 together with the planer mode and the DC mode. The intra prediction mode determination unit 95 may process the intra prediction prediction for the block encoded in the intra prediction mode. For example, the intra prediction mode determination unit 95 confirms that the prediction unit block is coded in the intra prediction mode, and confirms the intra prediction mode of the block based on the index of the intra prediction mode. For example, when the intra-prediction mode determined by the intra-prediction mode determining unit 95 is the directional mode, the intra-prediction mode determining unit 95 determines the direction of the intra-prediction mode based on the adaptive direction mode, From the memory 245, the information of the reference pixel corresponding to the reference pixel. Such an operation may be repeatedly performed on at least one pixel included in the block of the prediction unit to restore the prediction block.

Since the image decoding apparatus includes the intra prediction unit as described above, it is possible to set a more accurate intra prediction mode than the intra prediction direction in the fixed angle direction according to the conventional method, and further, to reduce the number of encoding bits have. The intraprediction unit of the video decoding apparatus is provided to adaptively set a mode used for intraprediction in cooperation with the video encoding apparatus, and thus can be implemented in a hardware environment of the video encoding apparatus and the decode apparatus, or in a hardware environment of the video encoding apparatus and the decode apparatus The intra-prediction mode can be adaptively set in consideration of the communication environment of the terminal. Particularly, by setting the intra prediction mode adaptively, high-quality image encoding / decoding can be realized, image encoding data can be reduced, and efficient image data transmission can be realized.

10 is a flowchart illustrating an intra prediction encoding method according to an embodiment of the present invention. The intra prediction coding method can be processed by the intra prediction unit of the above-described coding apparatus.

In step S1001, the intra prediction unit may set a predetermined number of temporary prediction directions on which the intra prediction mode is set. Specifically, the intra-prediction unit can divide the range of the entire prediction direction that can be used for determining the intra-prediction mode into a predetermined number (e.g., N) according to a predetermined rule to set the temporary prediction direction. Here, the predetermined rule may be to evenly divide the range of the entire prediction direction into a predetermined number (N). For example, the temporary prediction direction may indicate a direction indicating a reference pixel located in the vicinity of the current block (see FIG. 4). The intra-prediction unit uniformly divides the range of the region in which the reference pixel is located by a predetermined number (for example, N) and divides the direction corresponding to the divided region into a temporary prediction direction (see FIG. 5, V1 to Vn, H1 to Hn, VH0). In the embodiment of the present invention, the predetermined number (N) in which the temporary prediction directions (V1 to Vn, H1 to Hn, VH0) are set is set to be larger than the number of the finally determined adaptive directional modes However, the present invention is not limited thereto, and may be variously set in consideration of the configuration and operation of steps S1002 and S1003 described later.

In step S1002, the intraprediction unit may generate a temporary block (see FIG. 6, TB1 to TBn) corresponding to the N temporary prediction directions (V1 to Vn, H1 to Hn, and VH0) set through the above operation. That is, the intra predictor refers to the chrominance information of the reference pixel existing in the region indicated by the N prediction directions (V1 to Vn, H1 to Hn, VH0) around the current block, and reflects the chrominance information on the pixels included in the temporary block , Temporary blocks can be constructed. N temporary blocks constructed through such operations can be used as temporary prediction direction information.

In step S1003, the intra predictor sets the adaptive direction mode by a predetermined number (e.g., M) using the temporary prediction direction information. The predetermined number in which the adaptive direction mode is set may be set to a fixed value in the designing stage of the encoding apparatus according to an embodiment of the present invention. As another example, the predetermined number in which the adaptive direction mode is set may be adaptively set in consideration of a hardware environment of the encoding apparatus and the decoding apparatus, a communication environment between the encoding apparatus and the decoding apparatus, and the like.

Although the exemplary embodiment of the present invention illustrates a method of setting a predetermined number (e.g., M) of the intra predictor to set the adaptive direction mode, the present invention is not limited thereto. It suffices that the decoding apparatus can set the predetermined number to the same rule as the rule used by the encoding apparatus according to the embodiment of the present invention to set the predetermined number. Therefore, the rules used to set the predetermined number may be set in advance in the coding apparatus and the decoding apparatus as described above, or the rules used for setting the predetermined number in the process of coding the data by the coding apparatus And to confirm a rule used by the decoding apparatus to set the predetermined number in the process of decoding the data.

In step S1003, the intraprediction unit may check the difference value between the temporary blocks, and may merge the temporary blocks step by step based on the determined difference value to set the adaptive direction mode to the predetermined number.

Specifically, the intra-prediction unit confirms the temporal prediction direction information and performs an operation of stepwise merging the N temporary prediction directions (V1 to Vn, H1 to Hn, VH0) to generate M adaptive directions Mode can be determined. That is, the intraprediction unit first confirms the difference value Dk between N temporary blocks (see FIG. 7, 71). The difference value Dk between the temporary blocks 71 can be confirmed through the operation of Equation (1). First, when the difference value Dk between the temporary blocks 71 is 0, the intra predictor merges the neighboring temporary blocks into one temporary block, and when the difference value between neighboring temporary blocks 71 is 0 If not, keep the temporary block. For example, in FIG. 7, the first temporary block TB1 and the second temporary block TB2, the fourth temporary block TB4 and the fifth temporary block TB5, the sixth temporary block TB6, When the difference values Dk between blocks TB7 and TB7 are 0, the temporary blocks having the difference value Dk = 0 are the same temporary blocks. Therefore, the intra-prediction unit deletes one temporary block among the corresponding blocks, Lt; / RTI &gt; The intraprediction unit first confirms whether the number of temporary blocks 72 remaining after the merge processing is equal to or smaller than a predetermined number (for example, M) which is a reference for setting the adaptive direction mode. If the number of temporary blocks 72 remaining after the merge processing is larger than M, the secondary merge proceeds as follows.

The intra predictor merges neighboring temporary blocks into one temporary block when the difference value Dk between neighboring temporary blocks is equal to or less than a predetermined threshold value, and when the difference value Dk between neighboring temporary blocks is smaller than a predetermined threshold value If it is larger than the threshold value, the temporary block is maintained. The adaptive direction mode setting unit 33 sets the adaptive direction mode until the number of temporary blocks 73 remaining after merging is equal to or smaller than a predetermined number (for example, M) It is possible to repeatedly proceed while increasing a predetermined threshold sequentially. If the number of temporary blocks remaining after merging is equal to or smaller than a predetermined number (for example, M) that is a reference for setting the adaptive direction mode, the intra predictor corresponds to the remaining temporary blocks 74 after merging (Refer to FIG. 8).

In this manner, the intraprediction unit may merge some of the temporary blocks generated based on the temporary prediction direction, and use the directional mode corresponding to the remaining temporary blocks after the merging as the adaptive directional mode. As a result, the intra prediction direction can be adaptively set according to the value of the actual peripheral reference pixel, not in a direction divided by a fixed angle as in the conventional method. Therefore, it is possible to set a more accurate intra prediction mode than the intra prediction direction in the fixed angular direction according to the conventional method, and further, it can contribute to reduce the number of encoding bits.

Meanwhile, in step S1004, the intraprediction unit may perform intraprediction on the current block based on the adaptive direction mode together with the planer mode and the DC mode, thereby determining the intra prediction mode.

(N > M) by merging the N temporal prediction directions (V1 to Vn, H1 to Hn, VH0) step by step by the intraprediction unit, while explaining the intra prediction method according to an embodiment of the present invention. The present invention is not limited to this. The intra prediction method according to the present invention sets the number of temporal prediction directions different from the number of adaptive directional modes finally determined in consideration of the fact that the intra prediction method according to the present invention is variably set reflecting the relationship between the reference pixels and the pixels included in the prediction block Sufficient is enough.

The intra prediction method differs from the above embodiment in that N temporary prediction directions (V1 to Vn, H1 to Hn, VH0) are stepwise divided into a plurality of M (where N < M) It is also possible to determine the direction mode. Specifically, in step S1001, the intra predictor sets a temporary prediction direction of a number N smaller than the number M of adaptive directional modes. In step S1002, the temporary blocks 71 corresponding to the temporary prediction direction, , And generates temporal prediction direction information on the temporal prediction direction information. In step S1003, the intra predictor determines the difference value Dk between the N temporary blocks according to the above-described equation (1), and generates N temporary prediction directions V1 to Vn, H1 ~ Hn, VH0) can be stepped (sprit). If the difference value Dk between the temporary blocks is equal to or greater than a predetermined threshold value, the intra predictor can process the corresponding temporary blocks into a plurality of blocks. Then, the intra-prediction unit confirms whether the number of temporary blocks existing after the division is the same as a predetermined number (for example, M) that is a reference for setting the adaptive direction mode, and if the number of temporary blocks is the adaptive direction mode It is possible to repeatedly perform the operation of dividing the threshold value sequentially decreasing until a predetermined number (for example, M number) of the thresholds to be set becomes equal to the predetermined number. If the number of temporary blocks existing after the partitioning is equal to a predetermined number (for example, M), which is a reference for setting the intra-prediction direction, the intra-prediction unit sets the direction mode corresponding to the remaining temporary blocks to An adaptive direction mode can be determined.

In the above-described embodiment, the intra prediction method has exemplified the generation of the temporary blocks corresponding to the number (N) of temporary prediction directions and the pixel information of the generated N temporary blocks as the temporary prediction direction information , But the present invention is not limited thereto. It is sufficient that the intra prediction method can confirm information on the pixels included in the current block based on the temporary prediction direction described above.

As another example, in step S1002, the intraprediction method configures information (i.e., temporary block mapping information) in which pixels of a temporary block that can reflect a reference pixel corresponding to the temporary prediction direction are mapped (i.e., temporary block mapping information) As the temporary prediction direction information. 4, the first reference pixel RP1 includes a first temporary pixel TP1, a fifth temporary pixel TP5, a ninth temporary pixel TP9 in the vertical direction, ), And the thirteenth temporary pixel TP13 and may be reflected in the second temporary pixel TP2, the seventh temporary pixel TP7, and the twelfth temporary pixel TP12 in the diagonal direction. The temporary block mapping information may be information that matches the information including the temporary prediction direction, the reference pixel, and the temporary pixel.

In consideration of the temporary block mapping information described above, the intra prediction method performs a numerical calculation on the relationship between the reference pixels included in the temporary block mapping information and the pixels of the temporary block in step S1003, You can process values quickly. For example, it is possible to calculate how many reference pixels are reflected in the temporary pixels, align the reference pixels based on the number of times the temporary pixels are reflected, and set the direction mode corresponding to the M reference pixels to the adaptive direction mode. As described above, if the adaptive direction mode is set based on the temporary block mapping information, the computation amount or hardware resources required to set the adaptive direction mode can be reduced, and effective processing can be performed.

11 is a flowchart illustrating an intra prediction decoding method according to an embodiment of the present invention. The intra prediction decoding method can be processed by the intra prediction unit of the above-described decoding apparatus.

Referring to FIG. 11, an intra prediction decoding method according to an exemplary embodiment of the present invention includes setting a temporary prediction direction (S1101), generating temporary prediction direction information (S1102), setting an adaptive direction mode (S1103), and restoring the intra prediction mode (S1104).

(S1101), generating the temporary prediction direction information (S1102), and setting the adaptive direction mode (S1103) included in the intraprediction decoding method, A step S1001 of setting a temporary prediction direction, a step S1002 of generating temporary prediction direction information, and a step S1003 of setting an adaptive direction mode, respectively, and the operation may also proceed in the same manner. Therefore, the concrete construction and operation (step S1102) of setting the temporary prediction direction included in the intra prediction decoding method (S1101), generating the temporary prediction direction information (S1102), and setting the adaptive direction mode (S1001, S1002, S1003) described in the intra prediction coding method.

The intraprediction unit may set a predetermined number of temporary prediction directions to be used for setting the intra prediction mode (S1101), and may generate temporary prediction direction information based on the predetermined number of temporary prediction directions (S1102 ).

In step S1103, the intra-prediction unit refers to the temporary prediction direction information to merge or split the temporary blocks, or to process the predetermined number of adaptive directional modes by processing the numerical operations based on the temporary block mapping information Can be set.

In step S1104, the intra prediction unit may assign an index for an intra prediction mode including a directional mode of a planer mode, a DC mode, and an adaptive directional mode. The intraprediction unit may process intraprediction reconstruction for the block encoded in the intra prediction mode. That is, the intra-prediction unit confirms that the block of the prediction unit is coded in the intra-prediction mode, and confirms the intra-prediction mode of the block based on the index of the intra-prediction mode. For example, when the identified intra prediction mode is the directional mode, the intra prediction unit confirms the direction of the intra prediction mode set based on the adaptive direction mode, and confirms the information of the reference pixels corresponding to the identified direction from the memory 245 . Such an operation may be repeatedly performed on at least one pixel included in the block of the prediction unit to restore the prediction block.

By performing the intra prediction decoding method described above, it is possible to set a more accurate intra prediction mode than the intra prediction direction in the fixed angular direction according to the conventional method, and further contribute to reduce the number of encoding bits. In addition, the intra prediction decoding method is adaptable to a mode used for intraprediction in conjunction with the intra prediction coding method. Therefore, the intra prediction decoding method can adaptively set the mode used for the intra prediction by adaptively setting the intra prediction mode in consideration of the hardware environment for performing image encoding and decoding, The intra prediction mode can be set. As a result, by setting the intra prediction mode adaptively, high-quality image encoding / decoding, optimization of encoded data, and efficient transmission of image data can be realized.

In the embodiments of the present invention described above, the units to be referred to or predicted in the description of the temporary prediction direction, the adaptive direction mode, and the intra prediction direction are exemplified in pixel units, but the present invention is not limited thereto. The units to be referred to or predicted can be variously changed, and it is needless to say that the temporary prediction direction, the adaptive direction mode, and the intra prediction direction can be set in consideration of this.

Although the exemplary methods of the present invention (i. E. Intraprediction coding method and intra prediction decoding method) are represented by a series of operations for clarity of explanation, they are not intended to limit the order in which the steps are performed, Each step may be performed simultaneously or in a different order. In order to implement the method according to the present invention, the illustrative steps may additionally include other steps, include the remaining steps except for some steps, or may include additional steps other than some steps.

The various embodiments of the present invention are not intended to be all-inclusive and are intended to illustrate representative aspects of the present invention, and the elements described in the various embodiments may be applied independently or in a combination of two or more.

Furthermore, various embodiments of the invention may be implemented by means of hardware, firmware, software, or a combination thereof. In the case of hardware implementation, one or more ASICs, Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs) A general processor, a controller, a microcontroller, a microprocessor, and the like.

The scope of the present invention includes software or machine-executable instructions (e.g., operating system, applications, firmware, programs, etc.) that cause an operation in accordance with the methods of the various embodiments to be performed on a device or computer, Instructions, and the like are stored and are non-transitory computer-readable medium executable on the device or computer.

Claims (20)

In the intra prediction coding method,
Setting a plurality of temporary prediction directions,
Generating temporary prediction direction information corresponding to the plurality of temporary prediction directions;
Setting at least one adaptive directional mode selected in the plurality of temporary prediction directions,
And performing intra prediction on the intra prediction modes including the at least one adaptive direction mode to determine an intra prediction mode of the current block. 2. The method of claim 1, wherein generating the temporary prediction direction information comprises:
Generating a plurality of temporary blocks each reflecting the reference pictures in the plurality of temporary prediction directions and generating temporary prediction direction information including information on the plurality of temporary blocks, . 3. The method of claim 2, wherein setting the adaptive direction mode comprises:
Merging the temporary blocks;
And setting at least one adaptive direction mode corresponding to a direction of the temporary block remaining after the merging process. 2. The method of claim 1, wherein generating the temporary prediction direction information comprises:
Generating temporal prediction direction information including temporal block mapping information matching a reference pixel corresponding to the plurality of temporal prediction directions and a relation between pixels included in the temporal block, Encoding method. 5. The method of claim 4, wherein the step of setting the adaptive direction mode comprises:
And setting the at least one adaptive direction mode by performing a numerical calculation on the relationship between the reference pixels included in the temporary block mapping information and the pixels included in the temporary block, . 5. The method of claim 4, wherein the step of setting the adaptive direction mode comprises:
And setting the at least one adaptive directional mode based on the reference pixels that are relatively frequently referred to pixels included in the temporary block. 2. The method of claim 1, wherein generating the temporary prediction direction information comprises:
And allocating an index for intra prediction modes including the at least one adaptive direction mode and performing the intra prediction based on the allocated index. In the intra prediction decoding method,
Setting a plurality of temporary prediction directions,
Generating temporary prediction direction information for the temporary prediction direction;
Setting at least one adaptive directional mode selected in the plurality of temporary prediction directions,
Determining a coded intra prediction mode, and performing intra prediction on intra prediction modes including the at least one adaptive direction mode to reconstruct a prediction block. 9. The method of claim 8, wherein generating the temporary prediction direction information comprises:
Generating the plurality of temporary blocks each reflecting the reference pictures in the plurality of temporary prediction directions;
And generating temporal prediction direction information including information on the plurality of temporal blocks. 10. The method of claim 9, wherein setting the adaptive direction mode comprises:
Merging the plurality of temporary blocks;
And setting the at least one adaptive direction mode corresponding to the temporary block remaining after the merging process. 9. The method of claim 8, wherein generating the temporary prediction direction information comprises:
Generating temporal prediction direction information including temporal block mapping information matching a reference pixel corresponding to the plurality of temporal prediction directions and a relation between pixels included in the temporal block, Decoding method. 12. The method of claim 11, wherein setting the adaptive direction mode comprises:
And setting the at least one adaptive direction mode by performing a numerical calculation on a relationship between the reference pixels included in the temporary block mapping information and the pixels included in the temporary block, . In the intra prediction coding apparatus,
A temporary prediction direction information generation unit that sets a plurality of temporary prediction directions and generates temporary prediction direction information for the plurality of temporary prediction directions,
An adaptive direction mode setting unit configured to set at least one adaptive directional mode selected from the plurality of temporary prediction directions,
And an intra prediction mode determiner for performing intra prediction on intra prediction modes including the at least one adaptive direction mode to determine an intra prediction mode of the current block. 14. The apparatus according to claim 13,
And generates temporary prediction direction information including information on the plurality of temporary blocks by generating a plurality of temporary blocks each reflecting the reference pictures in the plurality of temporary prediction directions. 15. The apparatus of claim 14, wherein the adaptive direction-
And the at least one adaptive direction mode corresponding to the remaining micro blocks is determined after the merging process. 14. The apparatus according to claim 13,
Wherein the temporal prediction direction information generating unit generates temporal prediction direction information including reference pixels corresponding to the plurality of temporal prediction directions and temporal block mapping information matching a relation between pixels included in the temporal block. 17. The apparatus as claimed in claim 16, wherein the adaptive direction-
Wherein the at least one adaptive directional mode is set by performing a numerical calculation on the relationship between the reference pixels included in the temporary block mapping information and the pixels included in the temporary block. 17. The apparatus as claimed in claim 16, wherein the adaptive direction-
Wherein the at least one adaptive directional mode is set based on the reference pixels that are relatively frequently referred to the pixels included in the plurality of temporary blocks. 14. The apparatus of claim 13, wherein the intra-
An index for intra prediction modes including the at least one adaptive direction mode is allocated, and the intra prediction is performed based on the allocated index. In the intra prediction decoding apparatus,
A temporary prediction direction information generation unit that sets a plurality of temporary prediction directions and generates temporary prediction direction information for the plurality of temporary prediction directions,
An adaptive direction mode setting unit configured to set at least one adaptive directional mode selected from the plurality of temporary prediction directions,
And an intra prediction mode reconstruction unit for reconstructing a prediction block by performing intra prediction on the intra prediction modes including the at least one adaptive direction mode.

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