KR20110073263A - Method and apparatus for encoding and decoding for intra prediction - Google Patents

Abstract

PURPOSE: An intra prediction encoding and decoding method and an intra prediction encoding and decoding apparatus implementing the method are provided to reduce overhead related to mode bit with the selection of a prediction mode through peripheral blocks. CONSTITUTION: A first intra prediction unit(111) respectively calculates the degree of pixel correlation by intra prediction direction between a macroblock and the peripheral blocks of the macroblock. A second intra prediction unit(113) performs the intra prediction of the macroblock with the mode information of the peripheral block in the upper part of the macro block. A third intra prediction unit(115) performs the intra prediction of the brightness component of a current picture. A mode selection unit(117) selects an optimal intra prediction mode.

Description

An intra prediction encoding method and an encoding method, and an intra prediction encoding apparatus and an intra prediction decoding apparatus which perform the above-described method METHODS AND APPARATUS FOR ENCODING AND DECODING FOR INTRA PREDICTION

The present invention relates to an intra prediction encoding method and an encoding method for performing intra prediction, and to an encoding apparatus and a decoding device for performing the method. More specifically, the present invention relates to a current block using information of a neighboring block that is already encoded and transmitted. A method and apparatus for predicting modes.

In order to deliver moving images more quickly and easily in a portable multimedia device, a technique for compressing image information is required. In general, H.264 / AVC, one of the video compression standards, is used to compress a video. H.264 / AVC encodes a video using an intra prediction encoding method and an inter prediction encoding method. Among these, the intra prediction encoding method is a method of encoding using spatial correlation, and by generating prediction data using pixels decoded around, spatial redundancy can be removed. The intra prediction mode may include a 4 × 4 intra prediction mode of the luminance component, an 8 × 8 intra prediction mode, a 16 × 16 intra prediction mode, and an intra prediction mode of the chrominance component.

According to the intra prediction encoding method, in order to decode the bitstream encoded by the encoding apparatus in the decoding apparatus, the decoding apparatus must know information related to the intra prediction direction in advance. To this end, the encoding apparatus inserts information related to the intra prediction direction, which is a result of performing the intra prediction encoding, into a bitstream and transmits the information to the decoding apparatus.

In detail, the encoding apparatus for performing intra prediction predicts a most likely mode (MPM) that is likely to be a prediction mode of the current block by using neighboring reference blocks. A flag bit indicating whether or not the same can be transmitted to the decoding apparatus. If the prediction mode and the optimal mode are the same, the flag bit is 1 bit. However, when the prediction mode and the optimal mode are different, flag bits and additional n bits (n is a positive number) must be used to represent the prediction mode. In this case, as the size of the macro block increases, the number of bits to be used increases and overhead may occur.

Therefore, there is a demand for a technique for improving coding efficiency by reducing overhead associated with prediction mode.

The present invention provides an apparatus and method for determining a prediction mode of a current block by using neighboring neighboring blocks that are already coded and transmitted.

An encoding method according to an embodiment of the present invention includes determining an optimal intra prediction mode for the current block by using neighboring blocks adjacent to a current block to be encoded; And generating a bitstream by encoding the current block according to the optimal intra prediction mode.

A decoding method according to an embodiment of the present invention includes decoding a bitstream transmitted by an encoding apparatus; Determining a method of performing intra prediction based on a result of decoding the bitstream; And performing intra prediction on the current block according to the determined method, wherein the method may include a method of performing intra prediction using neighboring blocks adjacent to the current block that is already encoded and transmitted. .

An encoding apparatus according to an embodiment of the present invention includes an intra predictor configured to determine an optimal intra prediction mode for the current block by using neighboring blocks adjacent to a current block to be encoded; And an encoder which generates a bitstream by encoding the current block according to the optimal intra prediction mode.

A decoding apparatus according to an embodiment of the present invention includes a decoder which decodes a bitstream transmitted by an encoding apparatus; An intra prediction mode determiner configured to determine a method of performing intra prediction based on a result of decoding the bitstream; And an intra prediction unit configured to perform intra prediction on the current block according to the determined method, wherein the method may include a method of performing intra prediction using neighboring blocks adjacent to the current block that is already encoded and transmitted. have.

A recording medium according to an embodiment of the present invention may be read by a computer in which a bitstream encoded by an encoding apparatus by performing intra prediction on a current block is recorded. The bitstream may include macro block type, color difference block mode information, It may include a block pattern and a residue.

According to an embodiment of the present invention, by selecting a prediction mode indicating a prediction direction of a current block by using neighboring neighboring blocks that are already coded and transmitted, it is not necessary to transmit additional information related to the prediction mode, and thus the over the mode bit. The head can be reduced, thereby improving the compression rate.

1 is a block diagram illustrating an encoding apparatus according to an embodiment of the present invention.
FIG. 2 is a block diagram illustrating in detail the intra predictor of FIG. 1.
FIG. 3 is a diagram for describing an operation performed by the first intra predictor of FIG. 2.
FIG. 4 is a diagram for describing an operation performed by the second intra predictor of FIG. 2.
5 is a diagram illustrating a 4x4 intra prediction mode of luminance components.
6 is a diagram illustrating a process of selecting an optimal intra prediction mode according to an embodiment of the present invention.
FIG. 7 is a diagram illustrating a process of encoding an intra prediction direction predicted by the first intra predictor of FIG. 2.
8 is a diagram illustrating a grammar of a bitstream according to an embodiment of the present invention.
9 is a diagram illustrating a grammar of a bitstream according to another embodiment of the present invention.
FIG. 10 is a diagram illustrating a type of macroblock used when intra prediction of an image according to an embodiment of the present invention.
11 is a block diagram illustrating a decoding apparatus according to an embodiment of the present invention.
FIG. 12 is a block diagram illustrating an intra predictor of FIG. 10.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. When encoding or decoding an image, a coding unit or a decoding unit may mean a divided unit and may be expressed as a macro block. In the embodiments described below, the number of prediction modes, the size of prediction blocks, the number of mode bits, and the like are terms used in H.264 / AVC, and the terms using different compression schemes may be expressed differently. In addition, intra prediction encoding is an encoding method for predicting pixels constituting a macro block by referring to pixels already generated in a current picture without a reference picture.

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

Referring to FIG. 1, the encoding apparatus 100 may include an intra predictor 110, a motion estimator 120, a motion compensator 130, a first difference unit 140, an encoder 150, and inverse quantization. The inverse transform unit 160, the second difference unit 170, the filter 180, and the picture memory 190 are included. Here, the intra predictor 110 may correspond to an intra prediction encoding apparatus according to an embodiment of the present invention.

The intra predictor 110 predicts and encodes a macroblock, which is an encoding unit to be encoded, using spatially adjacent pixel values. In this case, the intra prediction unit 110 may receive the current block to be predictively encoded, and determine the intra prediction mode of the macro block by using information of neighboring neighboring blocks that are already encoded and transmitted.

That is, the intra predictor 110 may determine the prediction mode of the macro block using the current block constituting the current picture. In one example, the intra prediction unit 110 receives a current block to be predictively encoded, and selects an optimal intra prediction mode among 16 × 16 intra prediction modes of luminance components, 4 × 4 intra prediction modes, or 8 × 8 intra prediction modes of chrominance components. Can be determined. In addition, the intra prediction unit 110 may determine the intra prediction mode by using information of neighboring reference blocks that are already encoded and transmitted.

The motion estimation unit 120 estimates a motion vector of the current block in the current picture to be encoded, and the motion compensation unit 130 based on the motion vector estimated by the motion estimation unit 120. A prediction block that is a prediction value is generated. The motion estimator 120 may estimate the motion vector of the current block by using various motion estimation algorithms such as block matching algorithm (BMA), phase correlation, and HSBMA.

The switch S provides a prediction block output from the intra predictor 110 or the motion compensator 130 to the first difference unit 140. The first difference unit 140 generates a difference block by subtracting the prediction block from the current block.

The encoder 150 performs an intra prediction or inter prediction encoding on the current block based on one of the intra prediction direction determined by the intra prediction unit 110 or the inter prediction predicted by the motion compensator 130 to perform a bit stream. Create

To this end, the encoder 150 includes a transformer 151, a quantizer 153, a reordering unit 155, and an entropy coding unit 157.

The transform unit 151 performs a discrete cosine transform (DCT) on the difference block generated by the first difference unit 140, and the quantization unit 153 quantizes the discrete cosine transformed block to obtain a quantized transform coefficient. Create The quantized results are rearranged in reordering unit 155 for encoding.

The entropy coding unit 157 entropy encodes encoding information such as a quantized transform coefficient and a motion vector to generate a bitstream. In this case, the encoded transform coefficient, the filter structure information, and the final filter coefficient are inserted into the bitstream together with the motion vector and transmitted to the decoding apparatus 1000.

The inverse quantization and inverse transform unit 160 inversely quantizes the difference blocks quantized by the DCT and the quantization unit 153 for prediction of the next coded picture, and inverse discrete cosine transform to reconstruct the difference blocks before encoding. .

The second difference unit 170 adds the reconstructed differential block and the prediction block generated by the motion compensator 130 to reconstruct the current block before encoding. The reconstructed block or reconstructed picture is stored in the frame memory 190 via the filter 180 and used for inter prediction using the next block or the next picture.

FIG. 2 is a block diagram illustrating in detail the intra predictor of FIG. 1.

The intra prediction unit 110 shown in FIG. 2 performs intra prediction using a neighboring block to find a predicted value of a macro block in a current picture. Specifically, intra prediction means a method of determining an intra prediction value of a macroblock to be encoded using spatial correlation. That is, intra prediction may remove spatial redundancy by performing intra prediction on a macro block including a plurality of current blocks using neighboring neighboring blocks.

Referring to FIG. 2, the intra predictor 110 includes a first intra predictor 111, a second intra predictor 113, a third intra predictor 115, and a mode selector 117. The first intra predictor 111 and the second intra predictor 113 may receive the current block and perform intra prediction on a macroblock that is a coding unit by using information of neighboring neighboring blocks that are already encoded and transmitted. have.

The first intra predictor 111 performs an intra prediction direction between the macroblock in the M × M current block and the M × N neighboring blocks neighboring the upper part of the macroblock and the N × M neighboring blocks neighboring the left side of the macroblock. Each pixel correlation is calculated. The first intra predictor 111 may determine the intra prediction value of the neighboring block having a large pixel correlation as the intra prediction value of the macro block.

The second intra predictor 113 uses the mode information of the M × N neighboring blocks adjacent to the upper part of the macroblock and the mode information of the N × M neighboring blocks neighboring to the left of the macroblock. You can make predictions. In detail, mode information having the minimum value among mode information of M × N neighboring blocks neighboring the upper part of the macroblock and N × M neighboring blocks neighboring the left side of the macroblock is determined as an intra prediction value of the macroblock. Can be.

When the current picture Fn to be reconstructed is input, the third intra predictor 115 performs intra prediction with a macroblock including 4 × 4 and 16 × 16 current blocks with respect to the luminance component of the current picture Fn. can do. The third intra predictor 115 may perform intra prediction on a macroblock including 8 × 8 current blocks with respect to the color difference component of the current picture.

The mode selector 117 is an intra determined by the first intra predictor 111, the second intra predictor 113, and the third intra predictor 115 using a rate-distortion optimization technique. An optimal intra prediction mode may be selected based on the prediction value. That is, the mode selector 117 may obtain a cost function for the intra prediction result and select an optimal intra prediction mode based on the result of which the cost function has the lowest intra prediction value. In detail, the mode selector 117 may determine an optimal intra prediction mode for the macro block by calculating a difference and distortion between the original value and the predicted value according to a rate-distortion optimization technique. In this case, the intra prediction mode may include the number of current blocks constituting the macro block and the intra prediction direction. The encoder 150 generates a bitstream by encoding a macroblock including the current block according to an optimal intra prediction mode determined by the mode selector 117.

FIG. 3 is a diagram for describing an operation performed by the first intra predictor of FIG. 2.

The current block shown in FIG. 3 is a current block of any one of 16 × 16 current blocks, 4 × 4 current blocks, or 8 × 8 current blocks among the M × M current blocks constituting the image. Which corresponds to a macro block. The first intra predictor 111 may calculate a pixel correlation between the macro block and the neighboring block adjacent to the left side of the macro block and the neighboring block adjacent to the upper side of the macro block. In this case, the pixel correlation may be calculated according to prediction directions of nine intra prediction modes as illustrated in FIG. 3.

In this case, the first intra predictor 111 may calculate a pixel correlation based on the DC mode according to Equation 1.

Here, A, B, C, and D mean pixel values of neighboring blocks adjacent to the top of the current block, and I, J, K, and L mean pixel values of neighboring blocks adjacent to the left of the current block.

FIG. 4 is a diagram for describing an operation performed by the second intra predictor of FIG. 2.

The second intra predictor 113 uses the mode information of the M × N neighboring blocks adjacent to the upper part of the macroblock and the mode information of the N × M neighboring blocks neighboring to the left of the macroblock. You can make predictions.

Referring to FIG. 4, the second intra prediction unit 113 may include a neighboring block L adjacent to the left of 4 × 4 current blocks C and a neighboring block U adjacent to an upper portion of the current block C. FIG. Mode information having the minimum value of each mode information may be determined as an intra prediction value of the current block.

Referring to FIG. 4, the mode information of the neighboring block L adjacent to the left side of the current block C is 1, and the mode information of the neighboring block U adjacent to the upper part of the current block C is 2. . Then, the second intra predictor 113 may determine 1, which is mode information indicating the minimum value, as an intra prediction value of the current block.

5 is a diagram illustrating a 4x4 intra prediction mode of luminance components.

Referring to FIG. 5, the 4 × 4 intra prediction mode includes a vertical mode, a horizontal mode, a DC mode, a diagonal down-left mode, a diagonal down-right mode, and a vertical right side. A total of nine prediction modes may be included, such as (vertical right) mode, horizontal down mode, vertical left mode, and horizontal up mode.

The prediction mode numbers 0 to 8 are numbers determined according to the frequency with which each prediction mode is used. The vertical mode with the prediction mode number 0 means the prediction mode that is most frequently selected when performing probabilistic intra prediction coding. The horizontal upper mode with the prediction mode number 8 indicates the prediction mode that is selected the least when performing intra prediction coding. do.

In another example, the 16 × 16 intra prediction mode may include a total of four prediction modes of a vertical mode, a horizontal mode, a DC mode, and a plane mode.

According to the H.264 / AVC standard, macroblocks are encoded according to 4x4 intra prediction mode and 16x16 intra prediction mode when encoding luminance components of an image, and 8x8 intra when encoding color difference components of an image. The macroblock may be encoded according to the prediction mode.

In order for a decoding apparatus to decode a bitstream encoded through intra prediction, an intra prediction mode must be known. Thus, the encoding apparatus may insert an intra prediction mode into the bitstream and transmit the intra prediction mode to the decoding apparatus so that the decoding apparatus may perform intra prediction decoding.

6 is a diagram illustrating a process of selecting an optimal intra prediction mode according to an embodiment of the present invention.

Referring to FIG. 6, in steps 610 to 614, when the current picture Fn to be reconstructed is input by the third intra predictor 115, 4 × 4 of the luminance component of the current picture Fn is input. Intra prediction may be performed with a macroblock including pieces and 16 × 16 current blocks. The third intra predictor 115 may perform intra prediction on a macroblock including 8 × 8 current blocks with respect to the color difference component of the current picture.

In operation 616, the first intra predictor 111 may perform intra prediction on a macroblock including 4 × 4 current blocks using pixel correlation.

In operation 618, the second intra prediction unit 113 performs intra prediction on a macroblock including 4 × 4 current blocks using mode information.

In operation 620, the first intra predictor 111 may perform intra prediction on a macroblock including 8 × 8 current blocks using pixel correlation.

In operation 622, the second intra prediction unit 113 may perform intra prediction on a macroblock including 8 × 8 current blocks using mode information.

In operation 630, the mode selector 117 may perform rate-distortion optimization on the intra prediction result in each of operations 610 to 622 according to the rate-distortion optimization technique. In operation 640, the mode selector 117 may select an optimal intra prediction mode for the current picture according to the result of operation 630.

FIG. 7 is a diagram illustrating a process of encoding an intra prediction direction predicted by the first intra predictor of FIG. 2.

The intra prediction mode number of the current block 70 constituting the macroblock is called 'P', and the intra prediction mode number of the neighboring block 71 adjacent to the top of the current block is 'U' and adjacent to the left of the current block. Assume that the intra prediction mode number of the neighboring block 72 is 'L'.

For example, the encoding apparatus may intra-prediction-encode the current block by referring to the intra prediction directions of the neighboring block 71 and the neighboring block 72. In this case, the neighboring block 71 and the neighboring block 72 have intra prediction mode numbers indicating intra prediction directions, respectively, as neighboring blocks that have already been encoded before encoding the current block 70.

First, the intra prediction mode number of the current block 70 is compared with the minimum value of the intra prediction mode number of the neighboring block 71 and the intra prediction mode number of the neighboring block 72. If the intra prediction mode number of the current block matches the minimum value, the intra prediction direction of the current block 70 is encoded as '1' and inserted into the bitstream. Then, the decoding apparatus may determine the minimum value of the intra prediction mode numbers of the neighboring block 71 and the neighboring block 72 as the intra prediction mode number of the current block 70. Thereafter, the decoding apparatus may decode the current block 70 according to the intra prediction direction based on the determined intra prediction mode number.

As described above, the intra prediction mode number is determined according to the frequency with which each intra prediction mode is used. After all, since the current block 70 has a high probability of having an intra prediction direction similar to the neighboring block 71 and the neighboring block 72 by spatial correlation, the intra of the neighboring block 71 and the neighboring blocks 72 is high. There is a high probability that the minimum value of the prediction mode number will match the intra prediction mode number of the current block 70.

If the intra prediction mode number of the current block 70 does not match the minimum value, the intra prediction direction of the current block 70 is encoded as '0' and inserted into the bitstream. At this time, since the intra prediction mode numbers of the current block 70 do not coincide with the minimum values, the intra prediction mode numbers of the current block 70 cannot be determined from the neighboring blocks 71 and 72. Thus, the information on the intra prediction direction of the current block 70 is also encoded in a size of 'XXX', that is, 3 bits and inserted into the bitstream. There are nine intra prediction mode numbers from 0 to 8, and since the minimum value is not the prediction mode number of the current block, the remaining eight cases minus the minimum value are represented by 3 bits.

Specifically, if the intra prediction mode number of the current block 70 is smaller than the minimum value of the intra prediction mode number of the neighboring block 71 and the intra prediction mode number of the neighboring block 72, the intra prediction mode of the current block 70 is smaller. The number is the binary 'XXX' value. However, if the intra prediction mode number of the current block 70 is greater than the minimum value, the intra prediction mode number of the current block is a value obtained by subtracting '1' from the binary XXX value.

The foregoing description is applied to the third intra predictor 115. That is, when encoding the current block using the intra prediction direction predicted by the third intra prediction unit 115, whether the minimum value of the intra prediction mode numbers of the neighboring blocks and the intra prediction mode number of the current block match. The number of bits to be encoded varies.

In detail, when the minimum value of the intra prediction mode numbers of the neighboring blocks and the intra prediction mode number of the current block match, the intra prediction mode number of the current block is encoded by 1 bit, but when it does not match, the intra prediction mode number of the current block is It is represented by 4 bits in total. On the other hand, when the current block is encoded using the intra prediction direction predicted by the first intra predictor 111 or the second intra predictor 113, the encoding apparatus encodes the information of the intra prediction mode number of the current block. There is no need to send.

8 is a diagram illustrating a grammar of a bitstream according to an embodiment of the present invention.

The grammar of the bitstream generated by the encoding apparatus is shown in FIG. 8 or 9.

In the grammar of the bitstream shown in FIG. 8, if the intra prediction mode used by the first intra predictor 110 or the second intra predictor 113 for intra prediction is selected as the optimal intra prediction mode, the bitstream grammar is shown in FIG. It has the same format as 8.

Referring to FIG. 8, the bitstream grammar includes macroblock type, chrominance block mode information, coded block pattern (CBP), and residue. In the case of FIG. 7, since the first intra predictor 111 and the second intra predictor 113 perform intra prediction using neighboring blocks that have been encoded and transmitted, the first intra predictor 111 and the second intra predictor 113 predict the third intra predictor 115. Has a different format from the bitstream grammar of FIG.

9 is a diagram illustrating a grammar of a bitstream according to another embodiment of the present invention.

In the grammar of the bitstream shown in FIG. 9, when the intra prediction mode used by the third intra prediction unit 115 for intra prediction is selected as the optimal intra prediction mode, the bitstream grammar has the format as shown in FIG. 9.

Referring to FIG. 9, the bitstream grammar 900 includes macroblock type, luminance block mode information, chrominance block mode information, CBP, and residue. That is, when the intra prediction mode used by the third intra prediction unit 115 is determined to be the optimal intra prediction mode, the encoding apparatus should additionally transmit mode information of the luminance block through the bitstream.

FIG. 10 is a diagram illustrating a type of macroblock used when intra prediction of an image according to an embodiment of the present invention.

Referring to FIG. 10, according to an embodiment of the present invention, not only the third intra predictor 115 but also the first intra predictor 111 and the second intra predictor 113 together perform intra prediction to perform macro blocks. The macroblock type with the code number of type 1 is added. In FIG. 10, when the code number of the macroblock type is 1 and the flag is 0, the current block is encoded according to the intra prediction mode used by the first intra prediction unit 111. In addition, when the code number of the macroblock type is 1 and the flag is 1, the current block is encoded according to the intra prediction mode used by the second intra prediction unit 113.

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

Referring to FIG. 11, the intra predictor 210 of the decoding apparatus includes a first intra predictor 211, a second intra predictor 213, and a third intra predictor 215. The first intra predictor 211 and the second intra predictor 213 perform intra prediction on the current block to be predictively encoded using neighboring neighboring blocks that are already encoded and transmitted. The third intra predictor 215 decodes the bitstream transmitted by the encoding apparatus and performs intra prediction on the current block using an intra prediction mode included in the bitstream.

FIG. 12 is a block diagram illustrating an intra predictor of FIG. 10.

Referring to FIG. 12, the decoding apparatus 1000 may include a macroblock type determination unit 1100, a flag bit reception determination unit 1200, a first intra prediction execution unit 1300, an intra prediction mode determination unit 1400, and a first embodiment. And a two intra prediction performing unit 1500.

The macroblock type determiner 1100 determines the intra prediction mode of the current block to be decoded using the type information of the macroblock included in the bitstream. In this case, the bitstream may be a result of encoding a macroblock including an intra prediction mode of a luminance component and a macroblock including an intra prediction mode of a chrominance component.

As shown in FIG. 9, when the grammar of the bitstream includes mode information of the luminance block, the macroblock type determiner 1100 determines that the current block is determined according to the intra prediction mode used by the third intra predictor 115. Predictive encoding may be determined. In addition, as shown in FIG. 8, when the grammar of the bitstream does not include the mode information of the luminance block, the macroblock type determination unit 1100 provides the bitstream to the flag bit reception determination unit 1200. The flag bit reception determiner 1200 checks a flag bit included in the bitstream and intra-predicts the current block through the switch 1600 or the second intra prediction performer 1300. Through 1500, it is possible to switch whether to make intra prediction.

If the flag bit is 0, the intra prediction mode determiner 1400 may determine that the current block is encoded using the pixel correlation between the current block and the neighboring block. In addition, when the flag bit is 1, the intra prediction mode determiner 1400 may determine that the current block is encoded using mode information having the minimum value among the mode information of the neighboring blocks.

The first intra prediction performer 1300 may perform intra prediction on the current block according to the intra prediction mode obtained by decoding the bitstream. The second intra prediction performer 1500 may perform intra prediction on the current block according to the intra prediction mode of the current block determined by the intra prediction mode determiner 1400. The operation of the first intra prediction execution unit 1300 and the second intra prediction execution unit 1400 may be referred to the description of FIG. 2.

Methods according to an embodiment of the present invention can be implemented in the form of program instructions that can be executed by various computer means and recorded in a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains various modifications and variations from such descriptions. This is possible.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below but also by the equivalents of the claims.

110: intra prediction unit
111: the first intra prediction unit
113: second intra prediction unit
115: third intra prediction unit
117: mode selector

Claims (20)

In the encoding method for intra prediction performed by the encoding apparatus,
Determining an optimal intra prediction mode for the current block by using neighboring blocks adjacent to the current block to be encoded; And
Generating a bitstream by encoding the current block according to the optimal intra prediction mode
Encoding method comprising a. The method of claim 1,
Determining the optimal intra prediction mode,
Performing first intra prediction based on pixel correlation according to intra prediction directions between neighboring blocks adjacent to the current block and the current block; And
Calculating a cost function of a result of performing the first intra prediction
Encoding method comprising a. The method of claim 1,
Determining the optimal intra prediction mode,
Performing a second intra prediction based on mode information which is the minimum of mode information of neighboring blocks adjacent to the current block; And
Calculating a cost function of a result of performing the second intra prediction.
Encoding method comprising a. The method of claim 1,
Determining the optimal intra prediction mode,
Performing first intra prediction based on pixel correlation according to intra prediction directions between neighboring blocks adjacent to the current block and the current block;
Performing a second intra prediction based on mode information which is the minimum of mode information of neighboring blocks adjacent to the current block; And
Calculating a cost function of a result of performing the first intra prediction and the second intra prediction.
Encoding method comprising a. The method of claim 1,
Determining the optimal intra prediction mode,
Performing first intra prediction based on pixel correlation according to intra prediction directions between neighboring blocks adjacent to the current block and the current block;
Performing a second intra prediction based on mode information which is the minimum of mode information of neighboring blocks adjacent to the current block;
Performing a third intra prediction based on a luminance component or a chrominance component of the current block; And
Calculating a cost function of a result of performing the first intra prediction, the second intra prediction, and the third intra prediction.
Encoding method comprising a. In the decoding method for intra prediction performed by the decoding apparatus,
Decoding the bitstream transmitted by the encoding apparatus;
Determining a method of performing intra prediction based on a result of decoding the bitstream; And
Performing intra prediction on the current block according to the determined scheme
Including,
The method is
And a method of performing intra prediction using neighboring blocks adjacent to a current block that is already encoded and transmitted. The method of claim 6,
Performing the intra prediction,
Performing first intra prediction based on pixel correlation according to intra prediction directions between neighboring blocks adjacent to the current block and the current block;
Performing a second intra prediction based on mode information which is the minimum of mode information of neighboring blocks adjacent to the current block; or
Performing a third intra prediction based on a luminance component or a chrominance component of the current block
Decryption method comprising a. The method of claim 7, wherein
The performing of the third intra prediction may include:
And performing a third intra prediction on the luminance component or the chrominance component of the current block by using an intra prediction mode derived by decoding the bitstream. The method of claim 7, wherein
The bitstream,
And type information related to the first intra prediction or the second intra prediction for the macroblock which is a decoding unit to perform intra prediction. An intra predictor configured to determine an optimal intra prediction mode for the current block by using neighboring blocks adjacent to a current block to be encoded; And
An encoder which generates a bitstream by encoding the current block according to the optimal intra prediction mode.
Encoding apparatus comprising a. The method of claim 10,
The intra prediction unit,
A first intra prediction performer configured to perform first intra prediction based on pixel correlation for each intra prediction direction between neighboring blocks adjacent to the current block and the current block; And
Cost function calculation unit for calculating a cost function of the result of performing the first intra prediction
Encoding apparatus comprising a. The method of claim 10,
The intra prediction unit,
A second intra prediction performing unit configured to perform a second intra prediction based on mode information which is the minimum among mode information of neighboring blocks adjacent to the current block; And
Cost function calculation unit for calculating a cost function of the result of performing the second intra prediction
Encoding apparatus comprising a. The method of claim 10,
The intra prediction unit,
A first intra prediction performer configured to perform first intra prediction based on pixel correlation for each intra prediction direction between neighboring blocks adjacent to the current block and the current block;
A second intra prediction performing unit configured to perform a second intra prediction based on mode information which is the minimum among mode information of neighboring blocks adjacent to the current block; And
A cost function calculator for calculating a cost function of a result of performing the first intra prediction and the second intra prediction.
Encoding apparatus comprising a. The method of claim 10,
The intra prediction unit,
A first intra prediction performer configured to perform first intra prediction based on pixel correlation for each intra prediction direction between neighboring blocks adjacent to the current block and the current block;
A second intra prediction performing unit configured to perform a second intra prediction based on mode information which is the minimum among mode information of neighboring blocks adjacent to the current block;
A third intra prediction performing unit performing third intra prediction based on a luminance component or a chrominance component of the current block; And
A cost function calculator for calculating a cost function of a result of performing the first intra prediction, the second intra prediction, and the third intra prediction.
Encoding apparatus comprising a. A decoder which decodes the bitstream transmitted by the encoding apparatus;
An intra prediction mode determiner configured to determine a method of performing intra prediction based on a result of decoding the bitstream; And
Intra predictor for performing intra prediction on the current block according to the determined method
Including,
The method is
And a method of performing intra prediction using neighboring blocks adjacent to a current block that is already encoded and transmitted. 16. The method of claim 15,
The intra prediction unit,
A first intra prediction performer configured to perform first intra prediction based on pixel correlation for each intra prediction direction between neighboring blocks adjacent to the current block and the current block;
A second intra prediction performing unit configured to perform a second intra prediction based on mode information which is the minimum among mode information of neighboring blocks adjacent to the current block; or
A third intra prediction performing unit that performs a third intra prediction based on the luminance component or the chrominance component of the current block
Decoding apparatus comprising a. The method of claim 16,
The third intra prediction execution unit,
And performing a third intra prediction on the luminance component or the chrominance component of the current block by using the intra prediction mode derived by decoding the bitstream. The method of claim 16,
The bitstream,
And type information related to the first intra prediction or the second intra prediction with respect to a macroblock which is a decoding unit to perform intra prediction. A computer-readable recording medium on which a bitstream encoded by encoding by performing an intra prediction on a current block is recorded.
The bitstream,
And a macro block type, chrominance block mode information, a block pattern, and a residue. The method of claim 19,
The bitstream,
Mode information that is the minimum among first intra prediction that performs intra prediction based on pixel correlation for each intra prediction direction between neighboring blocks adjacent to the current block and the current block, and mode information of neighboring blocks adjacent to the current block. And a flag bit for distinguishing a second intra prediction that performs intra prediction based on the.

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