WO2016072745A1

WO2016072745A1 - Video encoding method and apparatus therefor that perform regularisation, and video decoding method and apparatus therefor

Info

Publication number: WO2016072745A1
Application number: PCT/KR2015/011797
Authority: WO
Inventors: 미카엘 미슈로브스키; 알쉰알렉산더
Original assignee: 삼성전자 주식회사
Priority date: 2014-11-04
Filing date: 2015-11-04
Publication date: 2016-05-12

Abstract

A video decoding method is disclosed, wherein the method includes: obtaining a coefficient from a bit stream; generating an inverse quantised block by performing inverse quantisation with respect to a quantised block including the obtained coefficient; generating a residual block by performing an inverse transformation with respect to the inverse quantised block; restoring the current block using the residual block and a prediction block; and generating a filtered current block by filtering with respect to the restored current block. To this end, regularisation can be performed with respect to one or more blocks of the inverse quantised block, the prediction block, the restored current block and the filtered current block.

Description

Video encoding method and apparatus therefor performing normalization, video decoding method and apparatus therefor

A video encoding method and apparatus therefor, and a video decoding method and apparatus for performing normalization to improve an image quality of an image.

With the development and dissemination of hardware capable of playing and storing high resolution or high definition video content, there is an increasing need for a video codec for efficiently encoding or decoding high resolution or high definition video content. According to the existing video codec, video is encoded according to a limited encoding method based on coding units having a predetermined size.

Image data in the spatial domain is transformed into coefficients in the frequency domain using frequency transformation. The video codec divides an image into blocks having a predetermined size for fast operation of frequency conversion, performs DCT conversion for each block, and encodes frequency coefficients in units of blocks. Compared to the image data of the spatial domain, the coefficients of the frequency domain are easily compressed. In particular, since the image pixel value of the spatial domain is expressed as a prediction error through inter prediction or intra prediction of the video codec, when frequency conversion is performed on the prediction error, much data may be converted to zero. The video codec reduces data volume by substituting data repeatedly generated continuously with small size data.

When the video encoding apparatus performs an operation such as quantization in the process of encoding an image, loss of image information occurs, and thus, a difference occurs between the encoded image and the original image, resulting in deterioration in image quality. In addition, since the video encoding apparatus encodes an image in units of blocks, there is a problem in that a blocking phenomenon occurs near a boundary of a block, causing deterioration in image quality.

According to an embodiment, a video decoding method includes: obtaining coefficients from a bitstream; Generating an inverse quantization block by performing inverse quantization on the quantization block including the obtained coefficients; Generating a residual block by performing inverse transform on the inverse quantization block; Reconstructing a current block using the residual block and the prediction block; And generating a filtered current block by performing filtering on the restored current block. In this case, normalization may be performed on at least one of the dequantization block, the prediction block, the reconstructed current block, and the filtered current block.

The normalization may be a process of determining the result values at which the difference between the original values and the result values and the difference between the result values are minimized.

When the inverse quantization block is normalized, a difference between pixel values included in the normalized inverse quantization block and pixel values of the inverse quantization block and pixels included in the normalization reconstruction blocks are minimized. Pixel values of the normalized inverse quantization block may be determined. The normalized inverse quantization block is a block including result values generated by performing normalization on the inverse quantization block, and a normalization restoration block includes a normalization residual block generated as a result of performing an inverse transform on the normalized inverse quantization block and the It may be a block generated by synthesizing the predictive block.

When the dequantization block is normalized, a difference between pixel values included in the normalized dequantization block and pixel values of the dequantization block is multiplied by a weight W, and a pixel value difference between pixels included in the normalized reconstruction block. The pixel values in the normalized dequantization block are minimized, and the weight W is the difference between the pixel values included in the normalized dequantization block and the pixel values of the dequantization block than T (T is a predetermined value). If the value is smaller than a predetermined threshold, and the difference between the pixel values included in the normalized dequantization block and the pixel values of the dequantization block is greater than or equal to the T, the value is greater than or equal to the predetermined threshold. Can be a value.

On the other hand, when the prediction block is normalized, the normalization prediction block minimizes the difference between the pixel values included in the prediction block and the pixel values of the normalization prediction block and the pixel value difference between the pixels included in the normalization prediction block. The pixel values of may be determined. The normalization prediction block may be a block including result values generated by performing normalization on the prediction block.

The prediction block is generated using pixel values of the first prediction block predicted from the first reference picture and pixel values of the second prediction block predicted from the second reference picture,

When the prediction block is normalized, the first prediction block and the second prediction block may be normalized.

When the reconstructed current block is normalized, the normalization minimizes a difference between pixel values included in the reconstructed current block and pixel values of the normalized reconstruction block, and a pixel value difference between pixels included in the normalized reconstruction block. Pixel values included in the reconstruction block may be determined. The normalized restoring block may be a block including result values generated by performing normalization on the restored current block.

When the reconstructed current block is normalized, a difference between pixel values included in the extended current block and pixel values of the normalized extended reconstruction block and pixels included in the normalized extended reconstruction block is determined. Pixel values of the normalized extended recovery block are minimized, and pixel values corresponding to positions of pixels included in the current block among the pixel values included in the normalized extended recovery block are determined. Can be determined by In this case, an extended current block including a previously decoded neighboring block and the restored current block may be generated, and a normalized extended restoration block is generated by performing normalization on the extended current block. It may be a block containing the resulting results.

When the filtered current block is normalized, a difference between pixel values included in the filtered current block and pixel values of the normalized filtering block is multiplied by a weight W and between pixels included in the normalized filtering block. Pixel values of the normalized filtering block that minimize the pixel value difference are determined, and the weight W may be less than or equal to a predetermined value for pixels adjacent to the boundary of the filtered current block. In this case, the normalized filtering block may be a block including result values generated by performing normalization on the filtered current block.

The normalization is a process of performing an iterative process to determine the difference between the original values and the result values and the difference between the result values. Number of iteration) may be determined according to a predetermined syntax.

The normalization is to perform a process of determining the result values in consideration of a trade-off parameter λ relating to the difference between the original values and the result values and the difference between the result values. It may be determined according to a type of the at least one block to be normalized.

According to an embodiment, a video encoding method may include encoding coefficients included in a current block; Generating an inverse quantization block by performing inverse quantization on the quantization block including the encoded coefficients; Generating a residual block by performing inverse transform on the inverse quantization block; Reconstructing the current block using the residual block and the prediction block; And generating a filtered current block by performing filtering on the restored current block. In this case, normalization may be performed on at least one of the dequantization block, the prediction block, the reconstructed current block, and the filtered current block.

According to an embodiment, a video decoding apparatus includes: an inverse quantization unit configured to obtain a coefficient from a bitstream and perform inverse quantization on a quantization block including the obtained coefficient to generate an inverse quantization block; An inverse transform unit generating a residual block by performing an inverse transform on the inverse quantization block; A reconstruction unit for reconstructing a current block by using the residual block and the prediction block; A filtering unit configured to perform filtering on the restored current block to generate a filtered current block; And a normalization unit performing normalization on at least one data unit. In this case, the normalizer may perform normalization on at least one of the dequantization block, the prediction block, the reconstructed current block, and the filtered current block.

According to another exemplary embodiment, a video decoding method includes: obtaining coefficients from a bitstream; Generating a normalized dequantization block by performing normalized de-quantization on the quantization block including the obtained coefficients; Generating a residual block by performing an inverse transform on the normalized inverse quantization block; And reconstructing a current block by using the residual block and the prediction block.

The generating of the normalized dequantization block may include: minimizing a difference between pixel values of the normalized quantization block and pixel values of the quantization block and a pixel value difference between pixels included in the normalized dequantization block. And generating the normalized dequantization block. In this case, the normalized quantization block may be a block generated by quantizing the normalized inverse quantization block generated by performing inverse quantization on the quantization block.

A recording medium according to an embodiment records a computer program for executing the video encoding and decoding methods, which can be read by a computer.

Normalization may be performed on the encoded data to improve image quality of a decoded image.

1A is a block diagram of a video encoding apparatus, according to an embodiment.

1B is a flowchart of a video encoding method, according to an embodiment.

1C is a block diagram of a video decoding apparatus, according to an embodiment.

1D is a flowchart of a video decoding method, according to an embodiment.

2A is a block diagram of a video encoding apparatus, according to another embodiment.

2B is a flowchart of a video encoding method according to another embodiment.

2C is a block diagram of a video decoding apparatus, according to another embodiment.

2D is a flowchart of a video decoding method according to another embodiment.

3 is a diagram for describing an environment of a video decoding apparatus.

4A is a diagram for describing a process of performing normalized-dequantization on an entropy decoded signal in a video decoding apparatus, according to an embodiment.

4B is a diagram for describing a process of performing normalization on a dequantized signal in a video encoding apparatus, according to an embodiment.

FIG. 4C is a diagram for describing a process of performing normalized-inverse transformation on a dequantized signal in a video encoding apparatus, according to an embodiment.

4D is a diagram illustrating a weight function for accuracy used in performing normalization on an inverse quantized signal.

5A is a diagram for describing a process of performing normalization on a predicted signal in a video encoding apparatus, according to an embodiment.

FIG. 5B is a diagram for describing a process of performing normalization on a bi-prediction signal in a video encoding apparatus, according to an embodiment.

6A is a diagram for describing a process of performing normalization on a reconstructed signal in a video decoding apparatus, according to an embodiment.

6B is a diagram for describing a process of performing normalization by extending a reconstructed block to include a previously reconstructed adjacent region in a video decoding apparatus, according to an embodiment.

6C is a diagram for describing a process of performing normalization on a filtered reconstruction signal in a video decoding apparatus, according to an embodiment.

7 is a block diagram of a video encoding apparatus based on coding units having a tree structure, according to various embodiments.

8 is a block diagram of a video decoding apparatus based on coding units having a tree structure, according to various embodiments.

9 illustrates a concept of coding units, according to various embodiments.

10 is a block diagram of an image encoder based on coding units, according to various embodiments.

11 is a block diagram of an image decoder based on coding units, according to various embodiments.

12 is a diagram illustrating deeper coding units according to depths, and partitions, according to various embodiments.

13 illustrates a relationship between a coding unit and transformation units, according to various embodiments.

14 is a diagram of deeper encoding information according to depths, according to various embodiments.

15 is a diagram of deeper coding units according to depths, according to various embodiments.

16, 17, and 18 illustrate a relationship between coding units, prediction units, and transformation units, according to various embodiments.

19 illustrates a relationship between a coding unit, a prediction unit, and a transformation unit, according to the encoding information information of Table 1. FIG.

20 is a diagram illustrating a physical structure of a disk in which a program is stored, according to various embodiments.

21 shows a disc drive for recording and reading a program by using the disc.

FIG. 22 illustrates the overall structure of a content supply system for providing a content distribution service.

23 and 24 illustrate an external structure and an internal structure of a mobile phone to which a video encoding method and a video decoding method according to various embodiments are applied.

25 illustrates a digital broadcasting system employing a communication system.

26 illustrates a network structure of a cloud computing system using a video encoding apparatus and a video decoding apparatus, according to various embodiments.

The terms "... unit", "module", and the like described herein refer to a unit for processing at least one function or operation, which may be implemented in hardware or software, or a combination of hardware and software.

As used herein, the term "one embodiment" or "an embodiment" refers to a particular feature, structure, feature, etc. described with an embodiment included in at least one embodiment. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” appearing in various places throughout this specification are not necessarily all referring to the same embodiment.

1 to 6C, a video encoding technique and a video decoding technique for performing normalization on an encoded signal according to various embodiments will be described.

7 to 26, a video encoding method and a video decoding method based on coding units having a tree structure according to various embodiments are disclosed. Hereinafter, the 'image' may be a still image of the video or a video, that is, the video itself.

First, referring to FIGS. 1 to 6C, a video encoding technique and a video decoding technique for performing normalization on an encoded signal are disclosed.

There is a problem in that loss of image information occurs during encoding of a video signal, or degradation of image quality, such as a blocking phenomenon appearing near a boundary of a block, as encoding of the image is performed in units of blocks.

In order to solve the above problem, the video decoding apparatus according to an embodiment may improve the image quality of the image by performing normalization on the image signal.

In this case, the normalization of the video signal is to introduce additional information for solving an ill-posed problem in which the information of the original image is not known and obtaining a result value close to the original image. Means the process of determining the optimal result value. In this case, the additional information may be a constraint on the solution, and the constraint may be the smoothness of the solution.

An ill-posed problem refers to a problem that is the opposite of a well-posed problem, where the obvious problem is a solution, a solution is unique, and a solution Means a problem that depends on observation data continuously.

According to an embodiment, the video decoding apparatus may determine a lossy coding problem as an unclear problem, and in order to solve this problem, normalize the encoded signal to determine a result value of an improved image signal.

Referring to FIG. 1A, the video encoding apparatus 10 includes an encoder 11, an inverse quantizer 12, an inverse transformer 13, a reconstructor 14, a filter 15, and a normalizer 16. do.

The encoder 11 may generate a block including encoded coefficients by encoding an image. In detail, the encoder 11 generates a residual block by using the prediction block of the current block generated by the predictor (not shown) and the current block in the original image, and performs transformation on the residual block. A block and a quantization block may be generated by performing quantization on the transform block. That is, the encoded coefficients may be coefficients included in the quantization block.

The inverse quantization unit 12 may generate an inverse quantization block by performing inverse quantization on a quantization block including coded coefficients.

The inverse transform unit 13 generates a residual block by performing an inverse transform on the inverse quantization block.

The reconstruction unit 14 reconstructs the current block by using the prediction block and the residual block generated by the prediction unit (not shown).

The filtering unit 15 may generate a filtered current block by performing filtering on the restored current block.

The normalizer 16 may perform normalization on at least one data unit. For example, the normalizer 16 may normalize at least one of a dequantization block, a prediction block, a reconstructed current block, and a filtered current block. In this case, the normalization means a process of determining the result values based on the difference between the original values and the result values and the difference between the result values. The difference between the original values and the result values and the difference between the result values are minimized. This may mean a process of determining values. Alternatively, the normalization may mean a process of determining the result values in which the difference between the result values is minimized under the condition that the difference between the original values and the result values is less than or equal to a certain value.

In more detail, the normalization unit 16 may determine result values by performing normalization on original values by Equation 1 below.

Equation 1

Here, X is an original value matrix, Y is a result matrix, and F (X, Y) is a function related to constraints of normalization and may be a fidelity function indicating how close X and Y are. J (X, Y) is a function that imposes a restriction on the result matrix Y as a regularization function. Here, the restriction may be the smoothness of the result matrix Y. In this case, the flatness may be expressed as a function of the difference between the elements in the result matrix Y. λ means a trade-off parameter that balances between fidelity and normalization. The argminY {K} function outputs the result matrix Y whose K value is minimum.

For example, the accuracy function F (X, Y) can be represented by the following equation (2).

Equation 2

Where X is the input matrix, Y is the result matrix, and Xi is the i th element in the X matrix. However, the accuracy function F (X, Y) is not limited thereto, and may be represented by various functions representing a difference between an input value and a result value.

The normalization function J (X, Y) may be expressed by Equation 3 below.

Equation 3

Here, TV (Y) denotes isotropic total variation of the result matrix Y, and Y (i, j) denotes an element located in the j-th column of the i-th row of the result matrix Y. Can mean. N is the number of rows of the result matrix Y, M is the number of columns of the result matrix Y.

For example, the normalization function J (X, Y) can be expressed by the following equation (4).

Equation 4

Here, TV (Y) denotes an anisotropic total variation of the result matrix Y, and Y (i, j) denotes an element located in the j th row of the i th row of the result matrix Y. Can mean. N is the number of rows of the result matrix Y, M is the number of columns of the result matrix Y.

However, the normalization function J (X, Y) is not limited thereto and may be represented by various functions indicating flatness (for example, difference between result values) with respect to the result values.

When the normalization unit 16 performs normalization on the inverse quantization block, the difference between the pixel values included in the normalized dequantization block and the pixel values of the inverse quantization block, and the pixel value difference between the pixels included in the normalized reconstruction blocks. Pixel values of the normalized inverse quantization block can be determined. Here, the normalized inverse quantization block is a block including result values generated by performing normalization on the inverse quantization block, and the normalization reconstruction block is a normalization residual block and a prediction block generated as a result of performing an inverse transform on the normalized inverse quantization block. Means a block generated by synthesizing

When normalizing the inverse quantization block, the normalization unit 16 multiplies the difference between the pixel values included in the normalized dequantization block and the pixel values of the inverse quantization block by a weight W and the pixels included in the normalized reconstruction block. The pixel values of the normalization block may be determined to minimize the pixel value difference between them. In this case, the weight W is a value smaller than a predetermined threshold when the difference between the pixel values included in the normalized dequantization block and the pixel values of the dequantization block is smaller than the predetermined value T, and the pixel value included in the normalized dequantization block. And the difference between the pixel values of the inverse quantization block may be greater than or equal to T, and greater than or equal to a predetermined threshold.

When the normalization unit 16 normalizes the prediction block, the normalization unit 16 normalizes the difference between the pixel values included in the prediction block and the pixel values of the normalized prediction block and the pixel value difference between the pixels included in the normalized prediction block. Pixel values of the prediction block may be determined. In this case, the normalization prediction block refers to a block including result values generated by performing normalization on the prediction block.

Meanwhile, the prediction block may be a block generated by bi-prediction. That is, the prediction block may be generated using pixel values of the first prediction block predicted from the first reference image using pixel values of the second prediction block predicted from the second reference image. In this case, the normalizer 16 may perform normalization on the first prediction block and the second prediction block.

When the reconstructed current block is normalized, the normalizer 16 minimizes a difference between pixel values included in the reconstructed current block and pixel values of the normalized reconstructed block, and a pixel value difference between pixels included in the normalized reconstructed block. Pixel values of the normalized reconstruction block may be determined. In this case, the normalized recovery block refers to a block including result values generated by performing normalization on the restored current block.

Meanwhile, the normalizer 16 may generate an extended current block by extending the current block to include a partial region of a previously decoded neighboring block. When the normalization unit 16 performs normalization on the restored current block, the pixels included in the extended current block and the pixel values included in the normalized extended recovery block are different from each other. The pixel values of the normalized extended recovery block may be determined to minimize the pixel value difference between them. In this case, the normalized extended recovery block may mean a block including result values generated by performing normalization on the extended current block. The normalization unit 16 may determine pixel values corresponding to positions of pixels included in the current block among pixel values included in the normalized extended reconstruction block, as pixel values included in the normalized reconstruction block.

When the normalization unit 16 performs normalization on the filtered current block, the pixel between the pixels included in the filtered current block and the pixel values of the normalized filtering block and the pixels included in the normalized filtering block is normalized. Pixel values included in the normalized filtering block minimizing the difference in values may be determined. In this case, the normalized filtering block refers to a block including result values generated by performing normalization on the filtered current block.

Specifically, when the normalization unit 16 performs normalization on the filtered current block, a value obtained by multiplying the difference between pixel values included in the filtered current block and pixel values of the normalized extended reconstruction block by the weight W and normalized Pixel values of the normalized filtering block may be determined to minimize the pixel value difference between the pixels included in the filtering block. In this case, the weight W may be less than or equal to a predetermined value for pixels adjacent to the boundary of the filtered current block. The weight W may be greater than a predetermined value for pixels that are at the boundary of the filtered current block among the pixels of the filtered current block. For example, the weight W may be greater than a predetermined value for pixels located near the center of the filtered current block.

Normalization is the process of performing an iterative process to determine the difference between the original values and the result values and the result values that minimize the difference between the result values. In this case, the iterative process may perform the process by a predetermined number of repetitions to determine the result values. Alternatively, the video encoding apparatus 10 may determine the number of repetitions, generate information about the determined number of repetitions, and include the information in the bitstream. In addition, the number of repetitions may be determined according to various syntaxes to be included in the bitstream. For example, various syntaxes include a quantization parameter (QP), a size of a coding unit (CU_Size), a size of a maximum transformation unit (Max_TU_Size), a size of a minimum transformation unit (Min_TU_Size), a prediction mode (PredMode), and a color channel. ) May be a syntax regarding a flag indicating a coded block.

Normalization is a process of determining the result values by considering a trade-off parameter λ relating to the difference between the original values and the result values and the difference between the result values, and the trade-off parameter λ is It may be determined according to the type. For example, the trade-off parameter λ may be determined differently depending on whether the normalized block is a block of a transform unit, a prediction unit, and a coding unit size.

The video encoding apparatus 10 according to an exemplary embodiment collectively includes an encoder 11, an inverse quantizer 12, an inverse transformer 13, a reconstructor 14, a filter 15, and a normalizer 16. It may include a central processor (not shown) to control. Alternatively, the encoder 11, the inverse quantizer 12, the inverse transformer 13, the decompressor 14, the filter 15 and the normalizer 16 operate by their own processors (not shown). As the processors (not shown) operate organically with each other, the video encoding apparatus 10 may operate as a whole. Alternatively, under the control of an external processor (not shown) of the video encoding apparatus 10, the encoder 11, the inverse quantizer 12, the inverse transform unit 13, the reconstruction unit 14, The filtering unit 15 and the normalization unit 16 may be controlled.

The video encoding apparatus 10 according to an embodiment may include the encoding unit 11, the inverse quantization unit 12, the inverse transform unit 13, the reconstruction unit 14, the filtering unit 15, and the normalization unit 16. It may include one or more data storage unit (not shown) that stores the input and output data. The video encoding apparatus 10 may include a memory controller (not shown) that controls data input / output of the data storage unit (not shown).

The video encoding apparatus 10 according to an embodiment may perform a video encoding operation including transformation by operating in conjunction with an internal video encoding processor or an external video encoding processor to output a video encoding result. .

The internal video encoding processor of the video encoding apparatus 10 according to an embodiment may implement a video encoding operation as a separate processor. In addition, the video encoding apparatus 10, the central computing unit, or the graphics processing unit may include a video encoding processing module to implement a basic video encoding operation.

1B is a flowchart of a video encoding method, according to an embodiment.

In operation 1110, the video encoding apparatus 10 encodes a coefficient included in the current block.

In operation 1120, the video encoding apparatus 10 generates an inverse quantization block by performing inverse quantization on a quantization block including encoded coefficients.

In operation 1130, the video encoding apparatus 10 may generate a residual block by inversely transforming the inverse quantization block.

In operation 1140, the video encoding apparatus 10 may reconstruct the current block by using the residual block and the prediction block.

In operation 1150, the video encoding apparatus 10 may generate a filtered current block by performing filtering on the reconstructed current block.

In operation 1160, the video encoding apparatus 10 may perform normalization on at least one block among an inverse quantization block, a prediction block, a reconstructed current block, and a filtered current block.

Referring to FIG. 1C, the video decoding apparatus 20 according to an embodiment includes an inverse quantizer 21, an inverse transformer 22, a reconstructor 23, a filter 24, and a normalizer 25. do.

The inverse quantization unit 21 may perform inverse quantization on a quantization block including coefficients obtained from a bitstream.

The inverse transform unit 22 may generate a residual block by performing an inverse transform on the inverse quantization block.

The reconstruction unit 23 may reconstruct the current block by using the residual block and the prediction block generated by the prediction unit (not shown). The reconstruction unit 23 may reconstruct the current block by determining the sample values of the current block by adding the sample value of the residual block and the sample value of the prediction block.

The filtering unit 24 may generate a filtered current block by performing filtering on the restored current block.

The normalization unit 25 performs normalization on at least one data unit. For example, the normalizer 25 may perform normalization on at least one block of an inverse quantization block, a prediction block, a reconstructed current block, and a filtered current block. In this case, normalization is a process of determining the result values in which the difference between the original values and the result values and the difference between the result values are minimized. However, the present invention is not limited thereto, and normalization may be a process of determining the result values in which the difference between the original values and the related values and the difference between the related values and the resultant values are minimized.

When the normalization unit 25 performs normalization on the dequantization block, the normalization unit 25 minimizes the difference between the pixel values included in the normalized dequantization block and the pixel values of the dequantization block, and the pixel value difference between the pixels included in the normalization reconstruction block. The pixel values of the normalized dequantization block may be determined. The normalized inverse quantization block may mean a block including result values generated by performing normalization on the inverse quantization block, and the normalization restoration block may include a normalization residual block generated as a result of performing an inverse transform on the normalized inverse quantization block. It may mean a block generated by synthesizing the prediction block.

When the normalization unit 25 performs normalization on the inverse quantization block, the difference between the pixel values included in the normalized inverse quantization block and the pixel values of the inverse quantization block is multiplied by the weight W, and the pixels included in the normalization reconstruction block. The pixel values in the normalized dequantization block can be determined to minimize the pixel value difference between them. In this case, the weight W is smaller than a predetermined threshold when the difference between the pixel values included in the normalized dequantization block and the pixel values of the dequantized block is less than T, and is inverse to the pixel values included in the normalized dequantization block. If the difference between pixel values of the quantization block is greater than or equal to T, it may be greater than or equal to a predetermined threshold.

When the normalization unit 25 performs normalization on the prediction block, the normalization unit 25 minimizes the difference between the pixel values included in the prediction block and the pixel values of the normalization prediction block and the pixel value difference between the pixels included in the normalization prediction blocks. Pixel values of the normalized prediction block may be determined. In this case, the normalization prediction block may be a block including result values generated by performing normalization on the prediction block.

Meanwhile, the prediction block may be generated using pixel values of the first prediction block predicted from the first reference picture and pixel values of the second prediction block predicted from the second reference picture. In this case, when the normalization unit 25 performs normalization on the prediction block, the normalization unit 25 may perform normalization on the first prediction block and the second prediction block.

When the normalization unit 25 performs normalization on the restored current block, the difference between the pixel values included in the restored current block and the pixel values of the normalized decompression block, and the pixel value difference between the pixels included in the normalized decompression block. The pixel values of the normalized reconstruction block may be determined to minimize the value.

Meanwhile, the normalization unit 25 may generate an extended current block by extending the current block to include a partial region of a previously decoded neighboring block. When the normalization unit 16 performs normalization on the restored current block, the pixels included in the extended current block and the pixel values included in the normalized extended recovery block are different from each other. The pixel values of the normalized extension block can be determined to minimize the pixel value difference between them. In this case, the normalized extended recovery block may mean a block including result values generated by performing normalization on the extended current block.

The normalization unit 25 may determine pixel values corresponding to positions of pixels included in the current block among pixel values included in the normalized extended reconstruction block, as pixel values included in the normalized reconstruction block.

When the normalization unit 25 performs normalization on the filtered current block, the pixel between the pixel values included in the filtered current block and the pixel values of the normalized filtering block and the pixels included in the normalized filtering block is normalized. Pixel values included in the normalized filtering block minimizing the difference in values may be determined. In this case, the normalized filtering block refers to a block including result values generated by performing normalization on the filtered current block.

In detail, when the normalization unit 25 performs normalization on the filtered current block, a value obtained by multiplying the difference between pixel values included in the filtered current block and pixel values of the normalized extended reconstruction block by the weight W and normalized Pixel values of the normalized filtering block may be determined to minimize the pixel value difference between the pixels included in the filtering block. In this case, the weight W may be less than or equal to a predetermined value for pixels adjacent to the boundary of the filtered current block. The weight W may be greater than a predetermined value for pixels that are at the boundary of the filtered current block among the pixels of the filtered current block. For example, the weight W may be greater than a predetermined value for pixels located near the center of the filtered current block.

Normalization may be a process of performing an iterative process to determine the difference between the original values and the result values and the difference between the result values. In this case, the iterative process may perform the process by a predetermined number of repetitions to determine the result values. The video decoding apparatus 20 may determine the number of repetitions by parsing information about the number of repetitions included in the bitstream or various syntaxes.

Normalization is a process of determining the result values by considering a trade-off parameter λ relating to the difference between the original values and the result values and the difference between the result values, and the trade-off parameter λ is It may be determined according to the type.

The video decoding apparatus 20 according to an embodiment may include a central processor that collectively controls the inverse quantization unit 21, the inverse transform unit 22, the reconstruction unit 23, the filtering unit 24, and the normalization unit 25. (Not shown). Alternatively, the inverse quantization unit 21, the inverse transform unit 22, the decompression unit 23, the filtering unit 24, and the normalization unit 25 are operated by their own processors (not shown), and the processor (not shown). The video decoding apparatus 20 may be operated as a whole as the? Alternatively, according to the control of an external processor (not shown) of the video decoding apparatus 20, the inverse quantizer 21, the inverse transformer 22, the reconstructor 23, the filter 24, and The normalization unit 25 may be controlled.

The video decoding apparatus 20 according to an embodiment includes one in which input and output data of an inverse quantizer 21, an inverse transformer 22, a decompressor 23, a filter 24, and a normalizer 25 are stored. The data storage unit (not shown) may be included. The video decoding apparatus 20 may include a memory controller (not shown) that controls data input / output of the data storage unit (not shown).

The video decoding apparatus 20 according to an embodiment may perform a video decoding operation by operating in conjunction with an internal video decoding processor or an external video decoding processor to reconstruct the video through video decoding. The internal video decoding processor of the video decoding apparatus 20 according to an embodiment may implement a basic video decoding operation as a separate processor. In addition, the video decoding apparatus 20, the central processing unit, or the graphics processing unit may include a video decoding processing module to implement a basic video decoding operation.

1D is a block diagram of a video decoding apparatus, according to an embodiment.

In operation 1210, the video decoding apparatus 20 may obtain a coefficient from the bitstream.

In operation 1220, the video decoding apparatus 20 may generate inverse quantization blocks by performing inverse quantization on a quantization block including the obtained coefficients.

In operation 1230, the video decoding apparatus 20 generates a residual block by performing inverse transform on the inverse quantization block.

In operation 1240, the video decoding apparatus 20 may reconstruct the current block by using the residual block and the prediction block.

In operation 1250, the video decoding apparatus 20 may generate a filtered current block by performing filtering on the restored current block.

In operation 1260, the video decoding apparatus 20 may perform normalization on at least one of a dequantization block, a prediction block, a reconstructed current block, and a filtered current block.

Referring to FIG. 2A, a video decoding apparatus 30 according to an embodiment includes an encoder 31, a normalized inverse quantizer 32, an inverse transformer 33, and a reconstructor 34.

The encoder 31 encodes an image to generate a block including the encoded coefficients. In detail, the encoder 11 generates a residual block by using the prediction block generated by the predictor (not shown) and the current block included in the original image. The encoder 11 may determine the sample value included in the residual block by subtracting the sample value of the prediction block from the sample value of the current block included in the original image.

The encoder 11 generates a transform block by performing transform on the residual block. The encoder 11 may generate a quantization block by performing quantization on the generated transform block. The coded coefficients may be coefficients included in the quantization block.

The normalized dequantization unit 32 generates a normalized dequantization block by performing normalized dequantization on a quantization block including coded coefficients. In more detail, the normalized dequantization unit 32 selects a normalized dequantization block that minimizes the difference between the pixel values of the normalized quantization block and the pixel values of the quantization block and the pixel value change between the pixels included in the normalized dequantization block. Can be generated. In this case, the normalized quantization block may mean a block generated by quantizing a normalized inverse quantization block generated by performing inverse quantization on the quantization block.

The inverse transform unit 33 may generate a residual block by performing an inverse transform on the normalized inverse quantization block.

The reconstruction unit 34 may reconstruct the current block by using the prediction block and the residual block predicted from the prediction unit (not shown). The reconstructor 34 may reconstruct the sample value of the current block by adding the sample value of the prediction block and the sample value of the residual block.

2B is a flowchart of a video encoding method according to another embodiment.

In operation 2110, the video encoding apparatus 30 may encode coefficients included in the current block.

In operation 2120, the video encoding apparatus 30 may generate a normalized dequantization block by performing normalized dequantization on a quantization block including the encoded coefficients. In detail, the video encoding apparatus 30 may generate a normalized inverse quantization block that minimizes the difference between the pixel values of the normalized quantization block and the pixel values of the quantization block and the pixel value change between the pixels included in the normalized inverse quantization block. Can be. In this case, the normalized quantization block refers to a block generated by quantizing a normalized inverse quantization block generated by performing inverse quantization on the quantization block.

In operation 2130, the video encoding apparatus 30 may generate a residual block by performing inverse transform on the normalized inverse quantization block.

In operation 2140, the video encoding apparatus 30 may reconstruct the current block using the prediction block and the residual block.

The video decoding apparatus 40 according to an embodiment includes a normalized inverse quantizer 41, an inverse transformer 42, and a reconstructor 43.

The bitstream obtainer (not shown) may obtain coefficients from the bitstream.

The normalized dequantization unit 41 may generate a normalized dequantization block by performing normalized dequantization on a quantization block including coefficients obtained by a bitstream obtainer (not shown). The normalized inverse quantization unit 41 generates a normalized inverse quantization block that minimizes the difference between the pixel values of the normalized quantization block and the pixel values of the quantization block and the pixel value difference between the pixels included in the normalized inverse quantization block. Can be. In this case, the normalized quantization block may mean a block generated by quantizing a normalized inverse quantization block generated by performing inverse quantization on the quantization block.

The inverse transform unit 42 may generate a residual block by performing an inverse transform on the normalized inverse quantization block.

The reconstruction unit 43 reconstructs the current block by using the prediction block generated by the prediction unit (not shown) and the residual block generated by the inverse transformer 42. The reconstructor 43 may reconstruct the sample value of the current block by adding the sample value of the prediction block and the sample value of the residual block.

2D is a flowchart of a video decoding method according to another embodiment.

In operation 2210, the video decoding apparatus 40 may obtain a coefficient from the bitstream.

In operation 2220, the video decoding apparatus 40 performs a normalized inverse quantization block that minimizes a difference between pixel values of the normalized quantization block and pixel values of the quantization block and pixels included in the normalized inverse quantization block. Can be generated. In this case, the normalized quantization block may mean a block generated by quantizing a normalized inverse quantization block generated by performing inverse quantization on the quantization block.

In operation 2230, the video decoding apparatus 40 may generate a residual block by performing inverse transform on the normalized inverse quantization block.

In operation 2240, the video decoding apparatus 40 may reconstruct the current block by using the residual block and the prediction block.

3 is a diagram for describing an environment of a video decoding apparatus.

Referring to FIG. 3, the video decoding apparatus 3000 may include an entropy decoder 3010, an inverse quantizer 3020, an inverse transformer 3030, an inter predictor 3040, an intra predictor 3050, and a filter ( 3060 and a reconstructed picture buffer 3070.

The entropy decoder 3010 may entropy decode coefficients received from the bitstream to obtain entropy decoded coefficients.

The inverse quantization unit 3020 may generate inverse quantized coefficients by inversely quantizing the entropy decoded coefficients. On the other hand, the inverse quantization unit 3020 is a difference from the original due to the quantization of the coefficients in the process of inverse quantization of the entropy decoded coefficients.

The video decoding apparatus 3000 according to an embodiment may include a normalizer 3080.

By normalizing the dequantized signal, the normalization unit 3080 may improve the quality of the dequantized signal by reducing a difference from the original compared to when no normalization is performed.

The inverse transform unit 3030 may generate a residual block by inversely transforming an inverse quantization block including an inverse quantized coefficient.

The inter prediction unit 3040 may generate a prediction block of the current block by using samples of the reference picture previously reconstructed and stored in the reconstructed picture buffer 3070.

The intra predictor 3050 may generate a prediction block of the current block by using samples in the current picture that have been previously reconstructed.

The video decoding apparatus 3000 according to an embodiment may include a normalizer 3085.

The normalization unit 3085 performs normalization on the signal predicted from the inter prediction unit 3040 or the intra prediction unit 3050, thereby reducing the difference from the original compared to when the normalization is not performed, thereby improving the quality of the prediction signal. Can be improved.

The current block may be reconstructed using the residual block obtained by the inverse transform unit 3030 and the prediction block obtained from the inter predictor 3040 or the intra predictor 3050. That is, the sample value of the current block may be reconstructed by adding the sample value of the residual block obtained by the inverse transformer 3030 and the sample value of the prediction block obtained from the inter predictor 3040 or the intra predictor 3050. .

The video decoding apparatus 3000 according to an embodiment may include a normalizer 3090. The normalization unit 3090 performs normalization on the restored current block. The result value generated by performing the normalization can improve the quality of the reconstruction signal by reducing the difference from the original compared to when the normalization is not performed.

The filtering unit 3060 may generate a filtered block by performing filtering on the restored current block. For example, the filtering unit 3060 may generate a filtered block by performing deblocking filtering or sample adaptive offset filtering on the restored current block.

The video decoding apparatus 3000 according to an embodiment includes a normalizer 3095.

By normalizing the filtered signal, the normalization unit 3095 may improve the quality of the filtered signal by reducing the difference from the original compared to when the normalization is not performed. That is, when the video decoding apparatus 3000 decodes on a block basis, a blocking distortion phenomenon occurs. When normalization is performed to reduce this phenomenon, the video decoding apparatus 3000 adaptively adapts the distance of pixels that are separated from the boundary of the block. Blocking distortion can be reduced by performing normalization.

Referring to FIG. 4A, the video decoding apparatus 4000 includes an entropy decoder 4010 and a normalized inverse quantizer 4020.

The video decoding apparatus 4000 obtains coefficients from the bitstream. The entropy decoder 4010 may obtain entropy decoded coefficients by entropy decoding coefficients obtained from the bitstream. In this case, the entropy decoded coefficient may be a quantized coefficient.

A general video decoding apparatus includes an inverse quantization unit 4015, and the inverse quantization unit 4015 may generate inverse quantized coefficients by performing inverse quantization on a quantization block including quantization coefficients.

However, since information loss may occur due to the quantization process, when the prior information on the structure of the inverse quantized signal is known, the quality of the dequantized signal may be improved by improving the inverse quantization process. . That is, by performing normalized dequantization on the quantized signal, the dequantization process may be improved to improve the quality of the dequantized signal.

The normalized dequantization unit 4020 according to an embodiment may normalize the quantized signal by Equation 5 below.

Equation 5

In this case, X is a quantization matrix and generally refers to an original value matrix including a quantization signal generated as a result of performing entropy decoding. Y means a result matrix generated by performing normalization. δ is a constraint of fidelity for each element and may be a predetermined value for each element. That is, δ means an upper limit on the difference between the quantized value and the original value of the result value. J (Y) means the normalization function for Y. For example, J (Y) may be total varization with Y as a variable. argminY {J (Y)} is a function for obtaining a result matrix Y whose value of J (Y) is minimized.

4B, the video encoding apparatus 4100 includes a transformer 4110, a quantizer 4120, an entropy encoder 4130, an inverse quantizer 4140, a normalizer 4150, an inverse transformer 4160, and a predictor. 4170 and the restoration unit 4180.

The transformer 4110 generates a transform block by performing a transform on the residual block including the residual component. The residual component refers to a component representing the difference between the original block and the prediction block.

The quantization unit 4120 generates a quantization block by quantizing the transform block. The entropy encoder 4130 entropy codes the quantization block to generate entropy coded coefficients, and generates a bitstream including the entropy coded coefficients.

The inverse quantization unit 4140 may generate inverse quantization blocks by inverse quantization of the quantized quantization block. For example, the inverse quantization unit 4140 may generate the sample value of the inverse quantization block by multiplying the sample values of the quantized quantization block by the quantization parameter.

The normalizer 4150 may generate a result value by performing normalization on the inverse quantization block. The normalized and generated result value may be an input signal of the inverse transform unit 4160.

The normalizer 4150 may perform normalization using the output signal generated by performing inverse transformation on the result value by the inverse transformer 4160 and the output signal of the predictor 4170.

The normalization unit 4150 may perform normalization on the inverse quantization block using Equation 6 as follows.

Equation 6

Xdeq may mean an inverse quantized transform coefficient, and Y may mean a normalized result matrix. Ф1 is a function that defines how close Xdeq should be to Y. It is a weight function for the accuracy function.

J (K) may mean a normalization function for K, and P may mean a predicted signal predicted in the time domain. · May mean a multiplication symbol for each element in the matrix. IDCT (Y) may mean a matrix in which an inverse transform (eg, IDCT) is performed on the result value Y. λ may refer to a trade off parameter that balances accuracy and normalization.

That is, according to Equation 6, the flatness of the matrixes (that is, the reconstructed signal matrices) obtained by synthesizing the difference between the result matrix Y and the original matrix Xdeq and the inverse transform of the result matrix Y and the predicted signal matrix The result matrix Y may be determined in consideration of the smoothness. argminY {K} is a function for obtaining a result matrix Y whose value of K is minimized.

On the other hand, the normalization function J (K) may be defined as J 1 (K) by the following equation (7).

Equation 7

Here, J1 (K) may mean a total variation of the matrix K matrix. In detail, J1 (K) may be an isotropic total variation of the K matrix. For example, the smaller the value of J1 (K), the smaller the difference between the signals included in the image signal K matrix, so that the flatness of the image may increase.

According to another embodiment, the normalization function J (K) may be defined as J2 (K) by Equation 8 as follows.

Equation 8

Here, J2 (K) may mean a total variation of the image signal K matrix. In detail, J2 (K) may be an anisotropic total variation of the image signal K matrix. For example, the smaller the value of J2 (K), the smaller the difference between the signals included in the image signal K matrix, so that the flatness of the image may be increased.

As a result, the normalizer 4150 may obtain an improved signal by performing normalization on the result value on the transform domain (eg, the DCT domain).

The inverse transform unit 4160 may generate a residual block by performing an inverse transform on a block including a normalized result value.

The prediction unit 4170 may generate a prediction block of the current block by performing inter or intra prediction on the current block.

The reconstruction unit 4180 may reconstruct the current block by using the prediction block and the residual block.

Referring to FIG. 4C, the video encoding apparatus 4200 may include a transformer 4210, a quantizer 4220, an entropy encoder 4230, an inverse quantizer 4240, a normalized inverse transformer 4250, and a predictor ( 4260 and the restoration unit 4270.

The transform unit 4210, the quantizer 4220, the entropy encoder 4230, the inverse quantizer 4240, and the predictor 4260 of the video encoding apparatus 4200 are transform units 4110 of the video encoding apparatus 4100. ), The same operations as the quantization unit 4120, the entropy encoding unit 4130, the inverse quantization unit 4140, and the prediction unit 4170 are omitted.

The normalized inverse transform unit 4250 may perform normalized inverse transform on the inverse quantization block by using Equation 9 as follows.

Equation 9

Here, Xdeq denotes a matrix including inverse quantized transform coefficients, and Z denotes a matrix including a result of performing normalized inverse transform. Ф1 is a function that defines how close Xdeq should be to y, and means a weight function for the accuracy function. J (K) may mean a normalization function, and P may mean a prediction signal predicted in the time domain. · May mean a multiplication symbol for each element in the matrix. [lambda] can mean a trade-off parameter that adjusts the balance between accuracy and normalization. argminY {K} is a function for obtaining a result matrix Y whose value of K is minimized.

That is, according to Equation 9, the difference between the resultant matrix Z and the input matrix Xdeq generated by performing normalization and the smoothness of the values (that is, the reconstructed signal matrix) obtained by combining the resultant matrix Z and the predictive signal matrix P. ), The result of performing the normalized inverse transform may be determined. That is, the normalized inverse transform unit 4250 may obtain an improved result value in the time domain through the normalized inverse transform.

4D is a graph illustrating a weight function for accuracy used in the process of performing normalization on an inverse quantized signal.

FIG. 4D shows a graph showing the Ф function, which is a form of the F1 function defined in Equations 8 and 9. FIG. In more detail, Ф (x) may be a matrix defining weights for each element of the matrix X. For example, if the quantization error has a specific value (eg, T) as an upper limit, referring to FIG. 4D, Ф (x) indicates that element x in matrix X is a specific value (eg, If smaller than T), Ф (x) may be less than or equal to Th. Ф (x) may be greater than or equal to Th when element x in matrix X is greater than or equal to a particular value (eg, T).

Meanwhile, the present invention is not limited thereto, and Ф (x) may be a function of various forms. For example, the weight may be adaptively weighted using Ф (x) to maintain components for a specific frequency.

An iterative process may be performed to determine the result by normalization. That is, the result value that minimizes the value of the equation among the result values determined in the iterative process is determined. The iterative process should theoretically carry out an infinite iterative process unless there are special conditions. Therefore, conditions for stopping repetitive processes such as the above-mentioned normalization, normalized inverse quantization and normalized inverse transformation need to be defined in advance.

The

video decoding apparatus

20 or 40 according to an exemplary embodiment may repeat the number of repetitive processes by a predetermined number of times. In other words, the number of repetitive processes may be constant.

The

video decoding apparatus

20 or 40 according to an exemplary embodiment obtains information on the number of repetitive processes from the bitstream, and the number of repetitive processes is determined from information on the number of repetitive processes obtained from the bitstream. Can be.

The

video decoding apparatus

20 or 40 according to an embodiment may determine that the repetitive process is stopped when the difference between normalization function values obtained while performing an iterative process for normalization is less than or equal to a predetermined threshold value T1. . That is, as the iterative process for normalization is performed, the normalization function values converge. Therefore, if the difference between the normalization function values is less than or equal to the predetermined threshold value T1, the video decoding apparatus determines that the normalization function value converges to the minimum value and stops the iterative process, and the normalization function value of one of the normalization function values is determined. Can be determined by the result.

The

video decoding apparatus

20 or 40 according to an embodiment may repeat the process of normalization when a difference between the result value of the normalization and the original value is greater than or equal to a predetermined threshold value T2 during the iterative process. You can stop. That is, the

video decoding apparatuses

20 and 40 may determine the result value within a range in which the difference between the original value and the result value is not large.

The

video decoding apparatuses

20 and 40 according to an embodiment may determine the threshold T1 or the threshold T2 as a predetermined value.

However, the

video decoding apparatuses

20 and 40 are not limited thereto and may determine the threshold T1 or T2 by various methods. For example, the threshold T1 or T2 may be determined based on various syntax elements and semantic elements. In detail, the

video decoding apparatuses

20 and 40 may include a quantization parameter (QP), a size of a coding unit (CU_Size), a size of a maximum transformation unit (Max_TU_Size), a size of a minimum transformation unit (Min_TU_Size), a prediction mode (PredMode), and color. It may be determined by a function relating to a syntax element or a semantic element of at least one of a channel (Color Channel) and a flag indicating a coded block.

Referring to FIG. 5A, the video encoding apparatus 5000 includes a predictor 5010, a normalizer 5020, a residual generator 5030, a transformer 5040, and a quantizer 5040. The prediction unit 5010 may perform inter prediction using samples in a previously reconstructed picture, or may generate a prediction block by performing intra prediction using samples in a previously reconstructed current picture.

The normalizer 5020 may generate a normalized prediction block by performing normalization on the prediction block. For example, the normalizer 5020 may determine the normalized prediction block by Equation 10 as follows.

Equation 10

Here, x means prediction signal, y means normalized result value, TV (y) means total variation for y, and λ means trade-off parameter for adjusting the balance between accuracy and normalization. do. miny {k} means a function for obtaining a result y whose k is minimized.

The residual generator 5030 may generate a residual block indicating a difference between the original block including the original pixels and the normalized prediction block.

The transformer 5040 may perform a transform on the residual block to generate a transform block including the transform coefficients.

The quantization unit 5050 may generate a quantization block by performing quantization on a transform block including the transform coefficients. The video encoding apparatus 5000 according to an embodiment may improve the quality of the prediction signal by performing normalization on the prediction signal. Therefore, as the quality of the prediction component is improved, the size of the residual component is reduced, and thus, the amount of information to be encoded can be reduced, thereby improving coding efficiency.

The video encoding apparatus 5100 according to an embodiment may perform inter prediction on the current block. The video encoding apparatus 5100 may perform bi-prediction to predict the current block by using two reference pictures. The first inter prediction unit 5110 may generate a first prediction block for the current block by using the first reference picture. The second inter prediction unit 5120 may generate a second prediction block for the current block by using the second reference picture. The first inter prediction unit 5110 and the second inter prediction unit 5120 may generate the first prediction block and the second prediction block by using the bit depth increased from the bit depth of the input signal.

The normalizer (not shown) may include a first normalizer 5130 and a second normalizer 5140.

The first normalizer 5130 may perform normalization on the first prediction block generated by the first inter predictor 5110. The second normalizer 5140 may perform normalization on the second prediction block generated by the second inter predictor 5120. For example, the first normalization unit 5130 and the second normalization unit 5140 may perform normalization on the first prediction block and the second prediction block, respectively, by Equation (11). In this case, since normalization is performed on the first prediction block and the second prediction block having the increased bit depth, normalization is precisely performed with high accuracy for each prediction block, and the quality of the prediction signal can be improved more.

Equation 11

Here, x denotes a prediction signal included in each prediction block, y denotes a normalized result value, and TV (y) represents a total variation on y and λ is a trade-off for adjusting a balance between accuracy and normalization. Means a parameter. miny {k} means a function for obtaining a result y whose k is minimized.

The bit depth reducer 5150 may reduce the bit depth of the sample of the synthesized block generated by adding the sample value of the first prediction block and the sample value of the second prediction block. In this case, the bit depth reducer 5150 may reduce the bit depth of the sample of the synthesized floc to the bit depth of the input signal (for example, the bit depth of the sample value included in the reconstructed block) of the predictor. . The residual generator 5160 may generate a residual block for the current block by using original pixel values of the current block and sample values of pixels included in the prediction block. The residual generator 5160 may generate a residual block indicating a difference between the original pixels of the current block and the sample values of the pixels included in the prediction block.

The transform unit 5170 may generate a transform block including transform coefficients by performing transform on the residual block.

The quantization unit 5180 may generate a quantization block by performing quantization on the transform block.

The video encoding apparatus 5100 according to an embodiment may perform normalization on the prediction signal with an integer precision. The video encoding apparatus 5100 may perform an operation of increasing a bit depth of a prediction signal in order to perform normalization with an integer precision. The video encoding apparatus 5100 may normalize a prediction signal having an increased bit depth. In this case, the video encoding apparatus 5100 may normalize the prediction signal having the increased bit depth with an integer precision. After performing normalization, the video encoding apparatus 5100 may reduce the bit depth of the normalized signal to the bit depth before increasing the bit depth. The video encoding apparatus 5100 may increase the precision of normalization by increasing the bit depth of the prediction signal and then accepting normalization. That is, the quality of the prediction signal can be improved by performing normalization with high precision. The video encoding apparatus 5100 may increase the trade-off parameter λ of Equation 11 to reflect the increased bit depth and then perform normalization.

Referring to FIG. 6A, the video decoding apparatus 6000 includes an inverse quantizer 6010, an inverse transformer 6020, a predictor 6030, and a normalizer 6040.

The inverse quantizer 6010 may inverse quantize a quantization block including coefficients obtained from a bitstream to generate a transform block including transform coefficients. The inverse transform unit 6020 may generate a residual block for the current block by performing an inverse transform on the transform block.

The prediction unit 6030 may generate a prediction block of the current block by using a previously reconstructed reference picture or previously reconstructed samples.

The current block may be reconstructed using the residual block and the prediction block. That is, the sample value of the current block may be restored by adding the sample value of the residual block and the sample value of the prediction block.

The normalizer 6040 may perform normalization on the restored current block. For example, the normalization unit 6040 may perform normalization on the current block restored by Equation 12.

Equation 12

Where x is the element contained in the restored current block, y is the normalized result, and TV (y) is the total variance for y and λ is a trade-off that adjusts the balance between accuracy and normalization. Means a parameter. miny {k} means a function for obtaining a result y whose k is minimized.

The video decoding apparatus 6000 may improve the quality of the reconstructed signals by performing normalization on the reconstructed signals.

Referring to FIG. 6B, the normalization unit 6115 may normalize the extended current block 6120 by extending the size of the restored current block 6105. That is, as shown in FIG. 6D, in the process of reconstructing the current block, there may be pixels 6110 reconstructed before the current block 6105, and the normalizer 6215 reconstructs the current block 6105 before the current block 6105. The expanded current block 6120 may be generated by expanding the pixels including the left or upper pixels 6015 adjacent to the boundary of the current block 6105. For example, when the height of the current block is N and the width is M, the height of the expanded block of the current block to be expanded may be (N + h1) and the width may be (M + w1). The direction in which the block is extended may be leftward or upwardly.

The normalization unit 6115 may normalize the extended current block. In more detail, the normalization unit 6115 may perform normalization on the current block extended by Equation 13.

Equation 13

Where x is the element contained in the expanded current block, y is the normalized result, and TV (y) is the total variance for y and λ is a trade-off that controls the balance between accuracy and normalization. Means a parameter. miny {k} means a function for obtaining a result y whose k is minimized.

The normalization unit 6115 may reduce the size of the block generated by being normalized with respect to the expanded current block to the size of the current block 6105. At this time, pixels corresponding to the position of the pixel in the current block 6105 among the pixels in the normalized generated block (eg, the position of the pixel in the current block 6105 among the pixels in the normalized generated block) The block containing the pixels may be determined as the normalized current block. For example, if the height of the expanded block of the current block to be expanded is (N + h1) and the width is (M + w1), the height of the normalized generated block is N + h1 and the width is M + w1, The height of the normalized current block determined therefrom may be N, and the width may be M.

The video decoding apparatus including the normalization unit 6115 according to an embodiment may reduce the blocking phenomenon that may occur when normalization is performed on the current block by performing normalization by extending the size of the restored current block. . That is, when normalization is performed, the flatness between the pixels in the block is increased. In this case, the flatness between the current block and the neighboring block can be increased by performing normalization including the neighboring block, and thus, normalization is performed. Blocked phenomenon can be reduced because the pixels having a pixel value similar to those of the neighboring block.

The video decoding apparatus 20 according to an embodiment decodes an image on a block basis, and thus a blocking phenomenon may occur near a boundary of blocks. To reduce such blocking, normalization may be performed on the filtered block.

In particular, on the assumption that the pixels near the boundary of the block have a higher noise level than the blocks inside the block, normalization may be performed by the following equation (14) for pixels adjacent to the boundary of the block.

Equation 14

Where X is the matrix for the extended current block, Y is the normalized result matrix, J (Y) is the normalization function for Y, and λ is a trade-off that controls the balance between accuracy and normalization. The off parameter means the multiplicative symbol for each element in the matrix. Ф may mean a weight function with respect to the accuracy function. For example, J (Y) may be an isotropic total variation for Y. The video decoding apparatus 20 may determine a boundary pixel and a non-boundary pixel among pixels adjacent to the boundary. In this case, Ф may have a different weight depending on whether the current pixel is a boundary pixel or a non-boundary pixel. For example, a weight lower than a pixel determined as a non-boundary pixel may be applied to a pixel determined as a boundary pixel. That is, by applying a low weight to the boundary pixels, the dependency on the J (Y) function is increased, so that the noise level of the boundary pixels having the high noise level can be effectively reduced because the concentration related to the normalization is minimized.

Referring to FIG. 6C, the video decoding apparatus 20 may apply a low weight to the boundary pixel portion 6230 of a block in the image portion 6210, and apply a high weight to the remaining portion 6220 to filter the current. Normalization can be performed on blocks.

On the other hand, trade-off parameter values that balance the balance between accuracy and normalization play an important role in performing normalization.

The

video decoding apparatuses

20 and 40 according to an embodiment may use different trade-off parameters according to units of blocks to be normalized. In this case, the trade-off parameter value may be explicitly signaled in the bitstream, and the trade-off parameter value may be derived by a specific algorithm.

In addition, the

video decoding apparatuses

20 and 40 may determine the trade-off parameter value based on the unit of the block on which normalization is performed and the quantization parameter value. For example, the

video decoding apparatuses

20 and 40 may differently determine a trade-off parameter value according to whether a unit of normalization block is a transform unit, a prediction unit, or a coding unit.

When the

video decoding apparatuses

20 and 40 are encoded in the skip mode with respect to the current block, the

video decoding apparatuses

20 and 40 may not perform normalization with respect to the current block. In the case of coding with, normalization may be performed on the current block. In this case, the skip mode means a mode encoded without the residual component.

Meanwhile, the

video decoding apparatuses

20 and 40 may determine whether to perform normalization based on various syntax elements in the bitstream parsing step. For example, various syntax elements include a quantization parameter (QP), a size of a coding unit (CU_Size), a size of a maximum transformation unit (Max_TU_Size), a size of a minimum transformation unit (Min_TU_Size), a prediction mode (PredMode), and a color channel (Color). Channel) and a syntax element for a flag indicating a coded block.

Hereinafter, in the

video encoding apparatuses

10 and 30 and the

video decoding apparatuses

20 and 40 according to the embodiment, blocks in which video data is divided are divided into maximum coding units, and a tree is provided for each maximum coding unit. As described above, it may be encoded and decoded based on coding units of a structure. Hereinafter, an embodiment of a video encoding method and a video decoding method based on coding units having a tree structure according to various embodiments will be described with reference to FIGS. 7 to 26.

7 is a block diagram of a video encoding apparatus 100 based on coding units having a tree structure, according to an embodiment.

According to an embodiment, the video encoding apparatus 100 including video prediction based on coding units having a tree structure may include a maximum coding unit splitter 110, a coding unit determiner 120, and an outputter 130. . For convenience of description below, the video encoding apparatus 100 that includes video prediction based on coding units having a tree structure, according to an embodiment, is abbreviated as “video encoding apparatus 100”.

The maximum coding unit dividing unit 110 may partition the current picture based on the maximum coding unit that is a coding unit of the maximum size for the current picture of the image. If the current picture is larger than the maximum coding unit, image data of the current picture may be divided into at least one maximum coding unit. The maximum coding unit according to an embodiment may be a data unit having a size of 32x32, 64x64, 128x128, 256x256, or the like, and may be a square data unit having a square of two horizontal and vertical sizes. The image data may be output to the coding unit determiner 120 for at least one largest coding unit.

The coding unit according to an embodiment may be characterized by a maximum size and depth. The depth indicates the number of times the coding unit is spatially divided from the maximum coding unit, and as the depth increases, the coding unit for each depth may be split from the maximum coding unit to the minimum coding unit. The depth of the largest coding unit is the highest depth, and the minimum coding unit may be defined as the lowest coding unit. As the maximum coding unit decreases as the depth increases, the size of the coding unit for each depth decreases, and thus, the coding unit of the higher depth may include coding units of a plurality of lower depths.

As described above, according to the maximum size of the coding unit, image data of the current picture may be divided into maximum coding units, and each maximum coding unit may include coding units divided by depths. Since the maximum coding unit is divided according to depths, image data of a spatial domain included in the maximum coding unit may be hierarchically classified according to depth.

The maximum depth and the maximum size of the coding unit that limit the total number of times that the height and width of the maximum coding unit can be hierarchically divided may be preset.

The coding unit determiner 120 encodes at least one divided region obtained by dividing the region of the maximum coding unit for each depth, and determines a depth at which the final encoding result is output for each of the at least one divided region. That is, the coding unit determiner 120 encodes the image data in coding units according to depths for each of the maximum coding units of the current picture, and selects the depth at which the smallest coding error occurs to determine the depth. The determined depth and the image data for each maximum coding unit are output to the output unit 130.

Image data within the maximum coding unit is encoded based on coding units according to depths according to at least one depth less than or equal to the maximum depth, and encoding results based on the coding units for each depth are compared. As a result of comparing the encoding error of the coding units according to depths, a depth having the smallest encoding error may be selected. At least one depth may be determined for each maximum coding unit.

As the depth of the maximum coding unit increases, the coding units are divided hierarchically and the number of coding units increases. In addition, even if the coding units of the same depth included in one maximum coding unit, the coding error for each data is measured and it is determined whether to divide into lower depths. Therefore, even in the data included in one largest coding unit, since the encoding error for each depth varies depending on the position, the depth may be differently determined according to the position. Accordingly, one or more depths may be set for one maximum coding unit, and data of the maximum coding unit may be partitioned according to coding units of one or more depths.

Accordingly, the coding unit determiner 120 according to an embodiment may determine coding units having a tree structure included in the current maximum coding unit. The coding units according to the tree structure according to an embodiment include coding units having a depth determined as a depth among all deeper coding units included in the current maximum coding unit. The coding unit of the depth may be determined hierarchically according to the depth in the same region within the maximum coding unit, and may be independently determined for the other regions. Similarly, the depth for the current area may be determined independently of the depth for other areas.

The maximum depth according to an embodiment is an index related to the number of splits from the maximum coding unit to the minimum coding unit. The first maximum depth according to an embodiment may represent the total number of splits from the maximum coding unit to the minimum coding unit. The second maximum depth according to an embodiment may represent the total number of depth levels from the maximum coding unit to the minimum coding unit. For example, when the depth of the largest coding unit is 0, the depth of the coding unit obtained by dividing the maximum coding unit once may be set to 1, and the depth of the coding unit that is divided twice may be set to 2. In this case, if the coding unit divided four times from the maximum coding unit is the minimum coding unit, depth levels of 0, 1, 2, 3, and 4 exist, so that the first maximum depth is set to 4 and the second maximum depth is set to 5. Can be.

Predictive encoding and transformation of the largest coding unit may be performed. Similarly, prediction encoding and transformation are performed based on depth-wise coding units for each maximum coding unit and for each depth below the maximum depth.

Since the number of coding units for each depth increases each time the maximum coding unit is divided for each depth, encoding including prediction encoding and transformation should be performed on all the coding units for each depth generated as the depth deepens. For convenience of explanation, the prediction encoding and the transformation will be described based on the coding unit of the current depth among at least one maximum coding unit.

The video encoding apparatus 100 according to an embodiment may variously select a size or shape of a data unit for encoding image data. The encoding of the image data is performed through prediction encoding, transforming, entropy encoding, and the like. The same data unit may be used in every step, or the data unit may be changed in steps.

For example, the video encoding apparatus 100 may select not only a coding unit for encoding the image data, but also a data unit different from the coding unit in order to perform predictive encoding of the image data in the coding unit.

For predictive encoding of the largest coding unit, prediction encoding may be performed based on a coding unit of a depth, that is, a more strange undivided coding unit, according to an embodiment. The intra-partition prediction unit for prediction is determined from the coding unit. The prediction unit may include a partition in which at least one of a coding unit and a height and a width of the coding unit are divided. The partition is a data unit in which the prediction unit of the coding unit is split, and may be a partition having the same size as the coding unit.

For example, when a coding unit having a size of 2Nx2N (where N is a positive integer) is no longer split, it becomes a prediction unit of size 2Nx2N, and the size of a partition may be 2Nx2N, 2NxN, Nx2N, NxN, or the like. Partition mode according to an embodiment is a geometric type, as well as partitions divided in an asymmetric ratio such as 1: n or n: 1, as well as symmetric partitions in which the height or width of the prediction unit is divided in a symmetrical ratio. It may optionally include partitioned partitions, arbitrary types of partitions, and the like.

The prediction mode of the prediction unit may be at least one of an intra mode, an inter mode, and a skip mode. For example, the intra mode and the inter mode may be performed on partitions having sizes of 2N × 2N, 2N × N, N × 2N, and N × N. In addition, the skip mode may be performed only for partitions having a size of 2N × 2N. The encoding may be performed independently for each prediction unit within the coding unit to select a prediction mode having the smallest encoding error.

Also, the video encoding apparatus 100 according to an embodiment may perform conversion of image data of a coding unit based on not only a coding unit for encoding image data, but also a data unit different from the coding unit. In order to transform the coding unit, the transformation may be performed based on a transformation unit having a size smaller than or equal to the coding unit. For example, the transformation unit may include a data unit for intra mode and a transformation unit for inter mode.

In a similar manner to the coding unit according to the tree structure according to an embodiment, the transformation unit in the coding unit is also recursively divided into smaller transformation units, so that the residual data of the coding unit is determined according to the tree structure according to the transformation depth. Can be partitioned according to the conversion unit.

For a transform unit according to an embodiment, a transform depth indicating a number of divisions between the height and the width of the coding unit divided to the transform unit may be set. For example, if the size of the transform unit of the current coding unit of size 2Nx2N is 2Nx2N, the transform depth is 0, the transform depth 1 if the size of the transform unit is NxN, and the transform depth 2 if the size of the transform unit is N / 2xN / 2. Can be. That is, the transformation unit having a tree structure may also be set for the transformation unit according to the transformation depth.

Depth coded information requires not only depth but also prediction related information and transformation related information. Accordingly, the coding unit determiner 120 may determine not only the depth that generates the minimum coding error, but also a partition mode in which the prediction unit is divided into partitions, a prediction mode for each prediction unit, and a size of a transformation unit for transformation.

A method of determining a coding unit, a prediction unit / partition, and a transformation unit according to a tree structure of a maximum coding unit according to an embodiment will be described in detail with reference to FIGS. 7 to 19.

The coding unit determiner 120 may measure a coding error of coding units according to depths using a Lagrangian Multiplier-based rate-distortion optimization technique.

The output unit 130 outputs the image data of the maximum coding unit and the information about the encoding modes according to depths, in the form of a bit stream, based on at least one depth determined by the coding unit determiner 120.

The encoded image data may be a result of encoding residual data of the image.

The information about the encoding modes according to depths may include depth information, partition mode information of a prediction unit, prediction mode information, size information of a transformation unit, and the like.

Depth information may be defined using depth-specific segmentation information indicating whether to encode in a coding unit of a lower depth without encoding to the current depth. If the current depth of the current coding unit is a depth, since the current coding unit is encoded in a coding unit of the current depth, split information of the current depth may be defined so that it is no longer divided into lower depths. On the contrary, if the current depth of the current coding unit is not the depth, encoding should be attempted using the coding unit of the lower depth, and thus split information of the current depth may be defined to be divided into coding units of the lower depth.

If the current depth is not the depth, encoding is performed on the coding unit divided into the coding units of the lower depth. Since at least one coding unit of a lower depth exists in the coding unit of the current depth, encoding may be repeatedly performed for each coding unit of each lower depth, and recursive coding may be performed for each coding unit of the same depth.

Since coding units having a tree structure are determined in one largest coding unit and information on at least one coding mode should be determined for each coding unit of a depth, information on at least one coding mode may be determined for one maximum coding unit. have. In addition, since the data of the maximum coding unit is divided hierarchically according to the depth, the depth may be different for each location, and thus split information may be set for the data.

Accordingly, the output unit 130 according to an embodiment may allocate corresponding split information to at least one of a coding unit, a prediction unit, and a minimum unit included in the maximum coding unit.

The minimum unit according to an embodiment is a square data unit having a size obtained by dividing a minimum coding unit, which is the lowest depth, into four segments. The minimum unit according to an embodiment may be a square data unit having a maximum size that may be included in all coding units, prediction units, partition units, and transformation units included in the maximum coding unit.

For example, the encoding information output through the output unit 130 may be classified into encoding information according to depth coding units and encoding information according to prediction units. The encoding information for each coding unit according to depth may include prediction mode information and partition size information. The encoding information transmitted for each prediction unit includes information about an estimation direction of the inter mode, information about a reference image index of the inter mode, information about a motion vector, information about a chroma component of an intra mode, and information about an inter mode of an intra mode. And the like.

Information about the maximum size and information about the maximum depth of the coding unit defined for each picture, slice, or GOP may be inserted into a header, a sequence parameter set, or a picture parameter set of the bitstream.

In addition, the information on the maximum size of the transform unit and the minimum size of the transform unit allowed for the current video may also be output through a header, a sequence parameter set, a picture parameter set, or the like of the bitstream. The output unit 130 may encode and output the related SAO parameters described above with reference to FIGS. 1A through 14.

According to an embodiment of the simplest form of the video encoding apparatus 100, a coding unit according to depths is a coding unit having a size in which a height and a width of a coding unit of one layer higher depth are divided by half. That is, if the size of the coding unit of the current depth is 2Nx2N, the size of the coding unit of the lower depth is NxN. In addition, the current coding unit having a size of 2N × 2N may include up to four lower depth coding units having a size of N × N.

Accordingly, the video encoding apparatus 100 determines a coding unit having an optimal shape and size for each maximum coding unit based on the size and maximum depth of the maximum coding unit determined in consideration of the characteristics of the current picture. Coding units may be configured. In addition, since each maximum coding unit may be encoded in various prediction modes and transformation methods, an optimal encoding mode may be determined in consideration of image characteristics of coding units having various image sizes.

Therefore, if an image having a very high resolution or a very large data amount is encoded in an existing macroblock unit, the number of macroblocks per picture is excessively increased. Accordingly, since the compressed information generated for each macroblock increases, the transmission burden of the compressed information increases, and the data compression efficiency tends to decrease. Therefore, the video encoding apparatus according to an embodiment may adjust the coding unit in consideration of the image characteristics while increasing the maximum size of the coding unit in consideration of the size of the image, thereby increasing image compression efficiency.

The video encoding apparatus 100 of FIG. 7 may perform operations of the

video encoding apparatuses

10 and 30 described above with reference to FIGS. 1A and 6.

8 is a block diagram of a video decoding apparatus 200 based on coding units having a tree structure, according to an embodiment.

According to an embodiment, a video decoding apparatus 200 including video prediction based on coding units having a tree structure includes a receiver 210, image data and encoding information extractor 220, and image data decoder 230. do. For convenience of description below, the video decoding apparatus 200 that includes video prediction based on coding units having a tree structure, according to an embodiment, is abbreviated as “video decoding apparatus 200”.

Definition of various terms such as a coding unit, a depth, a prediction unit, a transformation unit, and information about various encoding modes for a decoding operation of the video decoding apparatus 200 according to an embodiment may be described with reference to FIG. 15 and the video encoding apparatus 100. Same as described above with reference.

The receiver 210 receives and parses a bitstream of an encoded video. The image data and encoding information extractor 220 extracts image data encoded for each coding unit according to coding units having a tree structure for each largest coding unit from the parsed bitstream, and outputs the encoded image data to the image data decoder 230. The image data and encoding information extractor 220 may extract information about a maximum size of a coding unit of the current picture from a header, a sequence parameter set, or a picture parameter set for the current picture.

In addition, the image data and encoding information extractor 220 extracts split information and encoding information about coding units having a tree structure for each largest coding unit from the parsed bitstream. The extracted split information and the encoded information are output to the image data decoder 230. That is, the image data of the bit string may be divided into the maximum coding units so that the image data decoder 230 may decode the image data for each maximum coding unit.

Partitioning information and encoding information splitting information and encoding information for each largest coding unit may be set for one or more pieces of split information, and the encoding information for each depth may be divided into partition mode mode information, prediction mode information, and transformation unit of a corresponding coding unit. Information and the like. In addition, split information for each depth may be extracted as the final depth information.

The split information and the encoding information for each of the largest coding units extracted by the image data and the encoding information extracting unit 220 are repetitively for each coding unit for each deeper coding unit, as in the video encoding apparatus 100 according to an embodiment. The splitting information and the encoding information determined to perform the encoding to generate the minimum encoding error. Therefore, the video decoding apparatus 200 may reconstruct an image by decoding data according to an encoding method that generates a minimum encoding error.

Since the split information and the encoded information according to an embodiment may be allocated to a predetermined data unit among the corresponding coding unit, the prediction unit, and the minimum unit, the image data and the encoding information extractor 220 may divide the split information according to the predetermined data unit. And encoding information can be extracted. If the split information and the encoding information of the maximum coding unit are recorded for each of the predetermined data units, the predetermined data units having the same split information and the encoding information may be inferred as data units included in the same maximum coding unit.

The image data decoder 230 reconstructs the current picture by decoding image data of each maximum coding unit based on split information and encoding information for each maximum coding unit. That is, the image data decoder 230 may decode the encoded image data based on the read partition mode, the prediction mode, and the transformation unit for each coding unit among the coding units having the tree structure included in the maximum coding unit. Can be. The decoding process may include a prediction process including intra prediction and motion compensation, and an inverse transform process.

The image data decoder 230 may perform intra prediction or motion compensation according to each partition and prediction mode for each coding unit, based on the partition mode information and the prediction mode information of the prediction unit of the coding unit according to depths.

In addition, the image data decoder 230 may read transform unit information according to a tree structure for each coding unit and perform inverse transform based on the transformation unit for each coding unit for inverse transformation for each largest coding unit. Through inverse transformation, the pixel value of the spatial region of the coding unit may be restored.

The image data decoder 230 may determine the final depth of the current maximum coding unit by using the split information for each depth. If the split information indicates that the split information is no longer divided at the current depth, the current depth is the final depth. Accordingly, the image data decoder 230 may decode the coding unit of the current depth using the partition mode, the prediction mode, and the transformation unit split information of the prediction unit with respect to the image data of the current maximum coding unit.

In other words, by observing the encoding information set for a predetermined data unit among the coding unit, the prediction unit, and the minimum unit, the data units having the encoding information including the same split information are gathered, and the image data decoder 230 It may be regarded as one data unit to be decoded in the same encoding mode. The decoding of the current coding unit may be performed by obtaining information about an encoding mode for each coding unit determined in this way.

Furthermore, the video decoding apparatus 200 of FIG. 8 may perform operations of the

video decoding apparatuses

20 and 40 described above with reference to FIG. 2A.

9 illustrates a concept of coding units, according to various embodiments.

As an example of a coding unit, a size of a coding unit may be expressed by a width x height, and may include 32x32, 16x16, and 8x8 from a coding unit having a size of 64x64. Coding units of size 64x64 may be partitioned into partitions of size 64x64, 64x32, 32x64, and 32x32, coding units of size 32x32 are partitions of size 32x32, 32x16, 16x32, and 16x16, and coding units of size 16x16 are 16x16. Coding units of size 8x8 may be divided into partitions of size 8x8, 8x4, 4x8, and 4x4, into partitions of 16x8, 8x16, and 8x8.

As for the video data 310, the resolution is set to 1920x1080, the maximum size of the coding unit is 64, and the maximum depth is 2. For the video data 320, the resolution is set to 1920x1080, the maximum size of the coding unit is 64, and the maximum depth is 3. As for the video data 330, the resolution is set to 352x288, the maximum size of the coding unit is 16, and the maximum depth is 1. The maximum depth illustrated in FIG. 17 represents the total number of divisions from the maximum coding unit to the minimum coding unit.

When the resolution is high or the amount of data is large, it is preferable that the maximum size of the coding size is relatively large not only to improve the coding efficiency but also to accurately shape the image characteristics. Accordingly, the

video data

310 or 320 having a higher resolution than the video data 330 may be selected to have a maximum size of 64.

Since the maximum depth of the video data 310 is 2, the coding unit 315 of the video data 310 is divided twice from the maximum coding unit having the long axis size of 64, and the depth is deepened by two layers, and the long axis size is 32, 16. Up to coding units may be included. On the other hand, since the maximum depth of the video data 330 is 1, the coding unit 335 of the video data 330 is divided once from coding units having a long axis size of 16, and the depth is deepened by one layer to increase the long axis size to 8. Up to coding units may be included.

Since the maximum depth of the video data 320 is 3, the coding unit 325 of the video data 320 is divided three times from the maximum coding unit having the long axis size of 64, and the depth is three layers deep. , Up to 8 coding units may be included. As the depth increases, the expressive power of the detailed information may be improved.

10 is a block diagram of an image encoder 400 based on coding units, according to various embodiments.

The image encoder 400 according to an embodiment performs operations that are performed to encode image data by the picture encoder 120 of the video encoding apparatus 100. That is, the intra prediction unit 420 performs intra prediction on each coding unit of the intra mode of the current image 405, and the inter prediction unit 415 performs the current image on the prediction unit of the coding unit of the inter mode. Inter-prediction is performed using the reference image acquired at 405 and the reconstructed picture buffer 410. The current image 405 may be divided into maximum coding units and then sequentially encoded. In this case, encoding may be performed on the coding unit in which the largest coding unit is to be divided into a tree structure.

Residual data is generated by subtracting the prediction data for the coding unit of each mode output from the intra prediction unit 420 or the inter prediction unit 415 from the data for the encoding unit of the current image 405, and The dew data is output as transform coefficients quantized for each transform unit through the transform unit 425 and the quantization unit 430. The quantized transform coefficients are reconstructed into residue data in the spatial domain through the inverse quantizer 445 and the inverse transformer 450. Residual data of the reconstructed spatial domain is added to the prediction data of the coding unit of each mode output from the intra predictor 420 or the inter predictor 415, thereby adding the residual data of the spatial domain to the coding unit of the current image 405. The data is restored. The reconstructed spatial region data is generated as a reconstructed image through the deblocking unit 455 and the SAO performing unit 460. The generated reconstructed image is stored in the reconstructed picture buffer 410. The reconstructed images stored in the reconstructed picture buffer 410 may be used as reference images for inter prediction of another image. The transform coefficients quantized by the transformer 425 and the quantizer 430 may be output as the bitstream 440 through the entropy encoder 435.

In order for the image encoder 400 to be applied to the video encoding apparatus 100, an inter predictor 415, an intra predictor 420, and a transformer ( 425, the quantization unit 430, the entropy encoding unit 435, the inverse quantization unit 445, the inverse transform unit 450, the deblocking unit 455, and the SAO performer 460 each have a tree structure for each maximum coding unit. An operation based on each coding unit among the coding units may be performed.

In particular, the intra prediction unit 420 and the inter prediction unit 415 determine the partition mode and the prediction mode of each coding unit among the coding units having a tree structure in consideration of the maximum size and the maximum depth of the current maximum coding unit. The transform unit 425 may determine whether to split the transform unit according to the quad tree in each coding unit among the coding units having the tree structure.

11 is a block diagram of an image decoder 500 based on coding units, according to various embodiments.

The entropy decoding unit 515 parses the encoded image data to be decoded from the bitstream 505 and encoding information necessary for decoding. The encoded image data is a quantized transform coefficient, and the inverse quantizer 520 and the inverse transform unit 525 reconstruct residue data from the quantized transform coefficients.

The intra prediction unit 540 performs intra prediction for each prediction unit with respect to the coding unit of the intra mode. The inter prediction unit 535 performs inter prediction using the reference image obtained from the reconstructed picture buffer 530 for each coding unit of the coding mode of the inter mode among the current pictures.

By adding the prediction data and the residue data of the coding unit of each mode through the intra prediction unit 540 or the inter prediction unit 535, the data of the spatial domain of the coding unit of the current image 405 is reconstructed and restored. The data of the space area may be output as a reconstructed image 560 through the deblocking unit 545 and the sample compensator 550. Also, the reconstructed images stored in the reconstructed picture buffer 530 may be output as reference images.

In order to decode the image data by the picture decoder 230 of the video decoding apparatus 200, step-by-step operations after the entropy decoder 515 of the image decoder 500 may be performed.

In order for the image decoder 500 to be applied to the video decoding apparatus 200 according to an embodiment, the entropy decoder 515, the inverse quantizer 520, and the inverse transformer ( 525, the intra prediction unit 540, the inter prediction unit 535, the deblocking unit 545, and the sample compensator 550 based on each coding unit among coding units having a tree structure for each maximum coding unit. You can do it.

In particular, the intra predictor 540 and the inter predictor 535 determine a partition mode and a prediction mode for each coding unit among coding units having a tree structure, and the inverse transformer 525 has a quad tree structure for each coding unit. It is possible to determine whether to divide the conversion unit according to.

12 is a diagram of deeper coding units according to depths, and partitions, according to an embodiment.

The video encoding apparatus 100 according to an embodiment and the video decoding apparatus 200 according to an embodiment use hierarchical coding units to consider image characteristics. The maximum height, width, and maximum depth of the coding unit may be adaptively determined according to the characteristics of the image, and may be variously set according to a user's request. According to the maximum size of the preset coding unit, the size of the coding unit for each depth may be determined.

The hierarchical structure 600 of a coding unit according to an embodiment illustrates a case in which a maximum height and a width of a coding unit are 64 and a maximum depth is four. In this case, the maximum depth indicates the total number of splits from the maximum coding unit to the minimum coding unit. Since the depth deepens along the vertical axis of the hierarchical structure 600 of the coding unit according to an embodiment, the height and the width of the coding unit for each depth are divided. In addition, a prediction unit and a partition on which the prediction encoding of each depth-based coding unit is shown along the horizontal axis of the hierarchical structure 600 of the coding unit are illustrated.

That is, the coding unit 610 has a depth of 0 as the largest coding unit in the hierarchical structure 600 of the coding unit, and the size, ie, the height and width, of the coding unit is 64x64. A depth deeper along the vertical axis includes a coding unit 620 of depth 1 having a size of 32x32, a coding unit 630 of depth 2a having a size of 16x16, and a coding unit 640 of depth 3 having a size of 8x8. A coding unit 640 of depth 3 having a size of 4 × 4 is a minimum coding unit.

Prediction units and partitions of the coding unit are arranged along the horizontal axis for each depth. That is, if the coding unit 610 of size 64x64 having a depth of zero is a prediction unit, the prediction unit may include a partition 610 of size 64x64, partitions 612 of size 64x32, and size included in the coding unit 610 of size 64x64. 32x64 partitions 614, 32x32 partitions 616.

Similarly, the prediction unit of the coding unit 620 having a size of 32x32 having a depth of 1 includes a partition 620 of size 32x32, partitions 622 of size 32x16 and a partition of size 16x32 included in the coding unit 620 of size 32x32. 624, partitions 626 of size 16x16.

Similarly, the prediction unit of the coding unit 630 of size 16x16 having a depth of 2 includes a partition 630 of size 16x16, partitions 632 of size 16x8, and a partition of size 8x16 included in the coding unit 630 of size 16x16. 634, partitions 636 of size 8x8.

Similarly, the prediction unit of the coding unit 640 of size 8x8 having a depth of 3 includes a partition 640 of size 8x8, partitions 642 of size 8x4 and a partition of size 4x8 included in the coding unit 640 of size 8x8. 644, partitions 646 of size 4x4.

The coding unit determiner 120 of the video encoding apparatus 100 according to an embodiment may determine a coding depth of each depth included in the maximum coding unit 610 in order to determine a final depth of the maximum coding unit 610. Encoding must be performed every time.

The number of deeper coding units according to depths for including data having the same range and size increases as the depth increases. For example, four coding units of depth 2 are required for data included in one coding unit of depth 1. Therefore, in order to compare the encoding results of the same data for each depth, each of the coding units having one depth 1 and four coding units having four depths 2 should be encoded.

For each depth coding, encoding may be performed for each prediction unit of a coding unit according to depths along a horizontal axis of the hierarchical structure 600 of the coding unit, and a representative coding error, which is the smallest coding error at a corresponding depth, may be selected. . In addition, a depth deeper along the vertical axis of the hierarchical structure 600 of the coding unit, the encoding may be performed for each depth, and the minimum coding error may be searched by comparing the representative coding error for each depth. The depth and partition in which the minimum coding error occurs among the maximum coding units 610 may be selected as the final depth and partition mode mode of the maximum coding unit 610.

13 illustrates a relationship between a coding unit and transformation units, according to an embodiment.

The video encoding apparatus 100 according to an embodiment or the video decoding apparatus 200 according to an embodiment encodes or decodes an image in coding units having a size smaller than or equal to the maximum coding unit for each maximum coding unit. The size of a transformation unit for transformation in the encoding process may be selected based on a data unit that is not larger than each coding unit.

For example, in the video encoding apparatus 100 or the video decoding apparatus 200 according to the embodiment, when the current coding unit 710 is 64x64 size, the 32x32 size conversion unit 720 is The conversion can be performed.

In addition, the data of the 64x64 coding unit 710 is transformed into 32x32, 16x16, 8x8, and 4x4 transform units of 64x64 size or less, and then encoded, and the transform unit having the least error with the original is selected. Can be.

14 is a diagram of deeper encoding information according to depths, according to an embodiment.

The output unit 130 of the video encoding apparatus 100 according to an embodiment is information about an encoding mode, and information about a partition mode 800 and information 810 about a prediction mode for each coding unit of each final depth. The information 820 about the size of the transformation unit may be encoded and transmitted.

The information 800 about the partition mode is a data unit for predictive encoding of the current coding unit, and represents information about a type of a partition in which the prediction unit of the current coding unit is divided. For example, the current coding unit CU_0 of size 2Nx2N may be any one of a partition 802 of size 2Nx2N, a partition 804 of size 2NxN, a partition 806 of size Nx2N, and a partition 808 of size NxN. It can be divided and used. In this case, the information 800 about the partition mode of the current coding unit represents one of a partition 802 of size 2Nx2N, a partition 804 of size 2NxN, a partition 806 of size Nx2N, and a partition 808 of size NxN. It is set to.

Information 810 relating to the prediction mode indicates the prediction mode of each partition. For example, through the information 810 about the prediction mode, whether the partition indicated by the information 800 about the partition mode is performed in one of the intra mode 812, the inter mode 814, and the skip mode 816 is performed. Whether or not can be set.

In addition, the information about the transform unit size 820 indicates whether to transform the current coding unit based on the transform unit. For example, the transform unit may be one of a first intra transform unit size 822, a second intra transform unit size 824, a first inter transform unit size 826, and a second intra transform unit size 828. have.

The image data and encoding information extractor 210 of the video decoding apparatus 200 according to an embodiment may include information about a partition mode 800, information 810 about a prediction mode, and transformation for each depth-based coding unit. Information 820 about the unit size may be extracted and used for decoding.

15 is a diagram of deeper coding units according to depths, according to an exemplary embodiment.

Segmentation information may be used to indicate a change in depth. The split information indicates whether a coding unit of a current depth is split into coding units of a lower depth.

The prediction unit 910 for predictive encoding of the coding unit 900 having depth 0 and 2N_0x2N_0 size includes a partition mode 912 of 2N_0x2N_0 size, a partition mode 914 of 2N_0xN_0 size, a partition mode 916 of N_0x2N_0 size, and N_0xN_0 May include a partition mode 918 of size. Although only

partitions

912, 914, 916, and 918 in which the prediction unit is divided by a symmetrical ratio are illustrated, as described above, the partition mode is not limited thereto, and asymmetric partitions, arbitrary partitions, geometric partitions, and the like. It may include.

For each partition mode, prediction coding must be performed repeatedly for one 2N_0x2N_0 partition, two 2N_0xN_0 partitions, two N_0x2N_0 partitions, and four N_0xN_0 partitions. For partitions having a size 2N_0x2N_0, a size N_0x2N_0, a size 2N_0xN_0, and a size N_0xN_0, prediction encoding may be performed in an intra mode and an inter mode. The skip mode may be performed only for prediction encoding on partitions having a size of 2N_0x2N_0.

If the encoding error due to one of the

partition modes

912, 914, and 916 of sizes 2N_0x2N_0, 2N_0xN_0, and N_0x2N_0 is the smallest, it is no longer necessary to divide it into lower depths.

If the encoding error of the partition mode 918 of size N_0xN_0 is the smallest, the depth 0 is changed to 1 and split (920), and the encoding is repeatedly performed on the depth 2 and the coding units 930 of the partition mode of size N_0xN_0. We can search for the minimum coding error.

The prediction unit 940 for prediction encoding of the coding unit 930 having a depth of 1 and a size of 2N_1x2N_1 (= N_0xN_0) includes a partition mode 942 having a size of 2N_1x2N_1, a partition mode 944 having a size of 2N_1xN_1, and a partition mode having a size of N_1x2N_1. 946, a partition mode 948 of size N_1xN_1.

In addition, if the encoding error due to the partition mode 948 having the size N_1xN_1 is the smallest, the depth 1 is changed to the depth 2 and split (950), and repeatedly for the depth 2 and the coding units 960 of the size N_2xN_2. The encoding may be performed to search for a minimum encoding error.

When the maximum depth is d, depth-based coding units may be set until depth d-1, and split information may be set up to depth d-2. That is, when encoding is performed from the depth d-2 to the depth d-1 to the depth d-1, the prediction encoding of the coding unit 980 of the depth d-1 and the size 2N_ (d-1) x2N_ (d-1) The prediction unit for 990 is a partition mode 992 of size 2N_ (d-1) x2N_ (d-1), a partition mode 994 of size 2N_ (d-1) xN_ (d-1), and size A partition mode 996 of N_ (d-1) x2N_ (d-1) and a partition mode 998 of size N_ (d-1) xN_ (d-1) may be included.

Among the partition modes, one partition 2N_ (d-1) x2N_ (d-1), two partitions 2N_ (d-1) xN_ (d-1), two sizes N_ (d-1) x2N_ By encoding through prediction encoding repeatedly for each partition of (d-1) and four partitions of size N_ (d-1) xN_ (d-1), a partition mode in which a minimum encoding error occurs may be searched. .

Even if the encoding error of the partition mode 998 of size N_ (d-1) xN_ (d-1) is the smallest, the maximum depth is d, so the coding unit CU_ (d-1) of the depth d-1 is no longer The depth of the current maximum coding unit 900 may be determined as the depth d-1, and the partition mode may be determined as N_ (d-1) xN_ (d-1) without going through a division process into lower depths. In addition, since the maximum depth is d, split information is not set for the coding unit 952 having the depth d-1.

The data unit 999 may be referred to as a 'minimum unit' for the current maximum coding unit. According to an embodiment, the minimum unit may be a square data unit having a size obtained by dividing the minimum coding unit, which is the lowest depth, into four divisions. Through this iterative encoding process, the video encoding apparatus 100 compares depth-to-depth encoding errors of the coding units 900, selects a depth at which the smallest encoding error occurs, and determines a depth. The partition mode and the prediction mode may be set to the encoding mode of the depth.

In this way, depths with the smallest error can be determined by comparing the minimum coding errors for all depths of

depths

0, 1, ..., d-1, and d. The depth, the partition mode of the prediction unit, and the prediction mode may be encoded and transmitted as information about an encoding mode. In addition, since the coding unit must be split from the depth 0 to the depth, only the split information of the depth is set to '0', and the split information for each depth except the depth should be set to '1'.

The image data and encoding information extractor 220 of the video decoding apparatus 200 according to an embodiment may extract information about a depth and a prediction unit of the coding unit 900 and use it to decode the coding unit 912. have. The video decoding apparatus 200 according to an embodiment may identify a depth having split information of '0' as a depth using split information for each depth, and may use the decoding information by using information about an encoding mode for a corresponding depth. .

16, 17, and 18 illustrate a relationship between a coding unit, a prediction unit, and a transformation unit, according to an embodiment.

The coding units 1010 are deeper coding units determined by the video encoding apparatus 100 according to an embodiment with respect to the maximum coding unit. The prediction unit 1060 is partitions of prediction units of each deeper coding unit among the coding units 1010, and the transform unit 1070 is transform units of each deeper coding unit.

If the depth-based coding units 1010 have a depth of 0, the

coding units

1012 and 1054 have a depth of 1, and the

coding units

1014, 1016, 1018, 1028, 1050, and 1052 have depths. 2,

coding units

1020, 1022, 1024, 1026, 1030, 1032, and 1048 have a depth of three, and

coding units

1040, 1042, 1044, and 1046 have a depth of four.

Some of the

partitions

1014, 1016, 1022, 1032, 1048, 1050, 1052, and 1054 of the prediction units 1060 are obtained by splitting coding units. That is,

partitions

1014, 1022, 1050, and 1054 are 2NxN partition modes,

partitions

1016, 1048, and 1052 are Nx2N partition modes, and partitions 1032 are NxN partition modes. Prediction units and partitions of the coding units 1010 according to depths are smaller than or equal to each coding unit.

The image data of the part 1052 of the transformation units 1070 is transformed or inversely transformed into a data unit having a smaller size than the coding unit. In addition, the

transformation units

1014, 1016, 1022, 1032, 1048, 1050, 1052, and 1054 are data units having different sizes or shapes when compared to corresponding prediction units and partitions among the prediction units 1060. That is, the video encoding apparatus 100 according to an embodiment and the video decoding apparatus 200 according to an embodiment may be intra prediction / motion estimation / motion compensation operations and transform / inverse transform operations for the same coding unit. Each can be performed on a separate data unit.

Accordingly, encoding is performed recursively for each coding unit having a hierarchical structure for each largest coding unit, thereby determining an optimal coding unit, and thus, coding units having a recursive tree structure may be configured. The encoding information may include split information about the coding unit, partition mode information, prediction mode information, and transformation unit size information. Table 1 below shows an example that can be set in the video encoding apparatus 100 and the video decoding apparatus 200 according to an embodiment.

Table 1

The output unit 130 of the video encoding apparatus 100 according to an embodiment outputs encoding information about coding units having a tree structure, and the encoding information extraction unit of the video decoding apparatus 200 according to an embodiment ( 220 may extract encoding information about coding units having a tree structure from the received bitstream.

The split information indicates whether the current coding unit is split into coding units of a lower depth. If the split information of the current depth d is 0, the partition depth information, the prediction mode, and the transform unit size information are defined for the final depth because the depth in which the current coding unit is no longer divided into the lower coding units is the final depth. Can be. If it is to be further split by the split information, encoding should be performed independently for each coding unit of the divided four lower depths.

The prediction mode may be represented by one of an intra mode, an inter mode, and a skip mode. Intra mode and inter mode can be defined in all partition modes, and skip mode can only be defined in partition mode 2Nx2N.

The partition mode information indicates symmetric partition modes 2Nx2N, 2NxN, Nx2N, and NxN, in which the height or width of the prediction unit is divided by symmetrical ratios, and asymmetric partition modes 2NxnU, 2NxnD, nLx2N, nRx2N, divided by asymmetrical ratios. Can be. The asymmetric partition modes 2NxnU and 2NxnD are divided into heights of 1: 3 and 3: 1, respectively, and the asymmetric partition modes nLx2N and nRx2N are divided into 1: 3 and 3: 1 widths, respectively.

The conversion unit size may be set to two kinds of sizes in the intra mode and two kinds of sizes in the inter mode. That is, if the transformation unit split information is 0, the size of the transformation unit is set to the size 2Nx2N of the current coding unit. If the transform unit split information is 1, a transform unit having a size obtained by dividing the current coding unit may be set. In addition, if the partition mode for the current coding unit having a size of 2Nx2N is a symmetric partition mode, the size of the transform unit may be set to NxN, and N / 2xN / 2 if it is an asymmetric partition mode.

Encoding information of coding units having a tree structure according to an embodiment may be allocated to at least one of a coding unit, a prediction unit, and a minimum unit unit of a depth. The coding unit of the depth may include at least one prediction unit and at least one minimum unit having the same encoding information.

Therefore, if the encoding information held by each adjacent data unit is checked, it may be determined whether the data is included in the coding unit having the same depth. In addition, since the coding unit of the corresponding depth may be identified using the encoding information held by the data unit, the distribution of depths within the maximum coding unit may be inferred.

Therefore, in this case, when the current coding unit is predicted with reference to the neighboring data unit, the encoding information of the data unit in the depth-specific coding unit adjacent to the current coding unit may be directly referenced and used.

In another embodiment, when the prediction coding is performed by referring to the neighboring coding unit, the data adjacent to the current coding unit in the coding unit according to depths is encoded by using the encoding information of the adjacent coding units according to depths. The neighboring coding unit may be referred to by searching.

FIG. 19 illustrates a relationship between a coding unit, a prediction unit, and a transformation unit, according to encoding mode information of Table 1. FIG.

The maximum coding unit 1300 includes

coding units

1302, 1304, 1306, 1312, 1314, 1316, and 1318 of depths. Since one coding unit 1318 is a coding unit of depth, split information may be set to zero. The partition mode information of the coding unit 1318 having a size of 2Nx2N includes partition modes 2Nx2N 1322, 2NxN 1324, Nx2N 1326, NxN 1328, 2NxnU 1332, 2NxnD 1334, and nLx2N 1336. And nRx2N 1338.

The transform unit split information (TU size flag) is a type of transform index, and a size of a transform unit corresponding to the transform index may be changed according to a prediction unit type or a partition mode of the coding unit.

For example, if the partition mode information is set to one of symmetric partition modes 2Nx2N 1322, 2NxN 1324, Nx2N 1326, and NxN 1328, if the conversion unit partition information is 0, a conversion unit of size 2Nx2N ( 1342 is set, and if the transform unit split information is 1, a transform unit 1344 of size NxN may be set.

When partition mode information is set to one of asymmetric partition modes 2NxnU (1332), 2NxnD (1334), nLx2N (1336), and nRx2N (1338), if the conversion unit partition information (TU size flag) is 0, a conversion unit of size 2Nx2N ( 1352 is set, and if the transform unit split information is 1, a transform unit 1354 of size N / 2 × N / 2 may be set.

Although the conversion unit splitting information (TU size flag) described above with reference to FIG. 12 is a flag having a value of 0 or 1, the conversion unit splitting information according to an embodiment is not limited to a 1-bit flag and is set to 0 according to a setting. , 1, 2, 3., etc., and may be divided hierarchically. The transformation unit partition information may be used as an embodiment of the transformation index.

In this case, when the transformation unit split information according to an embodiment is used together with the maximum size of the transformation unit and the minimum size of the transformation unit, the size of the transformation unit actually used may be expressed. The video encoding apparatus 100 according to an embodiment may encode maximum transform unit size information, minimum transform unit size information, and maximum transform unit split information. The encoded maximum transform unit size information, minimum transform unit size information, and maximum transform unit split information may be inserted into the SPS. The video decoding apparatus 200 according to an embodiment may use the maximum transform unit size information, the minimum transform unit size information, and the maximum transform unit split information to use for video decoding.

For example, (a) if the current coding unit is 64x64 in size and the maximum transform unit size is 32x32, (a-1) when the transform unit split information is 0, the size of the transform unit is 32x32, (a-2) When the split information is 1, the size of the transform unit may be set to 16 × 16, and (a-3) when the split unit information is 2, the size of the transform unit may be set to 8 × 8.

As another example, (b) if the current coding unit is size 32x32 and the minimum transform unit size is 32x32, (b-1) when the transform unit split information is 0, the size of the transform unit may be set to 32x32. Since the size cannot be smaller than 32x32, no further conversion unit split information can be set.

As another example, (c) if the current coding unit is 64x64 and the maximum transform unit split information is 1, the transform unit split information may be 0 or 1, and no other transform unit split information may be set.

Therefore, when the maximum transform unit split information is defined as 'MaxTransformSizeIndex', the minimum transform unit size is 'MinTransformSize', and the transform unit split information is 0, the minimum transform unit possible in the current coding unit is defined as 'RootTuSize'. The size 'CurrMinTuSize' can be defined as in relation (1) below.

CurrMinTuSize

= max (MinTransformSize, RootTuSize / (2 ^ MaxTransformSizeIndex)) ... (1)

Compared to the minimum transform unit size 'CurrMinTuSize' possible in the current coding unit, 'RootTuSize', which is a transform unit size when the transform unit split information is 0, may indicate a maximum transform unit size that can be adopted in the system. That is, according to relation (1), 'RootTuSize / (2 ^ MaxTransformSizeIndex)' is a transformation obtained by dividing 'RootTuSize', which is the size of the transformation unit when the transformation unit division information is 0, by the number of times corresponding to the maximum transformation unit division information. Since the unit size is 'MinTransformSize' is the minimum transform unit size, a smaller value among them may be the minimum transform unit size 'CurrMinTuSize' possible in the current coding unit.

According to an embodiment, the maximum transform unit size RootTuSize may vary depending on a prediction mode.

For example, if the current prediction mode is the inter mode, RootTuSize may be determined according to the following relation (2). In relation (2), 'MaxTransformSize' represents the maximum transform unit size and 'PUSize' represents the current prediction unit size.

RootTuSize = min (MaxTransformSize, PUSize) ......... (2)

That is, when the current prediction mode is the inter mode, 'RootTuSize', which is a transform unit size when the transform unit split information is 0, may be set to a smaller value among the maximum transform unit size and the current prediction unit size.

If the prediction mode of the current partition unit is a mode when the prediction mode is an intra mode, 'RootTuSize' may be determined according to Equation (3) below. 'PartitionSize' represents the size of the current partition unit.

RootTuSize = min (MaxTransformSize, PartitionSize) ........... (3)

That is, if the current prediction mode is the intra mode, the conversion unit size 'RootTuSize' when the conversion unit split information is 0 may be set to a smaller value among the maximum conversion unit size and the current partition unit size.

However, it should be noted that the current maximum conversion unit size 'RootTuSize' according to an embodiment that changes according to the prediction mode of the partition unit is only an embodiment, and a factor determining the current maximum conversion unit size is not limited thereto.

According to the video encoding method based on the coding units of the tree structure described above with reference to FIGS. 7 to 19, the image data of the spatial domain is encoded for each coding unit of the tree structure, and the video decoding method based on the coding units of the tree structure. As a result, decoding is performed for each largest coding unit, and image data of a spatial region may be reconstructed to reconstruct a picture and a video, which is a picture sequence. The reconstructed video can be played back by a playback device, stored in a storage medium, or transmitted over a network.

In addition, an offset parameter may be signaled for each picture or every slice or every maximum coding unit, every coding unit according to a tree structure, every prediction unit of a coding unit, or every transformation unit of a coding unit. For example, by adjusting the reconstructed pixel values of the maximum coding unit by using the offset value reconstructed based on the offset parameter received for each maximum coding unit, the maximum coding unit in which the error with the original block is minimized may be restored.

For convenience of description, the video encoding method described above with reference to FIGS. 1A to 18 is collectively referred to as a 'video encoding method'. In addition, the video decoding method described above with reference to FIGS. 1A to 18 is referred to as a 'video decoding method'.

In addition, a video encoding apparatus including the video encoding apparatus 10, the video encoding apparatus 100, or the image encoding unit 400 described above with reference to FIGS. 1A to 18 is collectively referred to as a “video encoding apparatus”. In addition, a video decoding apparatus including the video decoding apparatus 20, the video decoding apparatus 200, or the image decoding unit 500 described above with reference to FIGS. 2A to 19 is referred to as a “video decoding apparatus”.

A computer-readable storage medium in which a program is stored according to an embodiment of the present invention will be described in detail below.

20 illustrates a physical structure of a disk 26000 in which a program is stored, according to an exemplary embodiment. The disk 26000 described above as a storage medium may be a hard drive, a CD-ROM disk, a Blu-ray disk, or a DVD disk. The disk 26000 is composed of a plurality of concentric tracks tr, and the tracks are divided into a predetermined number of sectors Se in the circumferential direction. A program for implementing the above-described quantization parameter determination method, video encoding method, and video decoding method may be allocated and stored in a specific region of the disc 26000 which stores the program according to the above-described embodiment.

A computer system achieved using a storage medium storing a program for implementing the above-described video encoding method and video decoding method will be described below with reference to FIG.

21 shows a disc drive 26800 for recording and reading a program using the disc 26000. The computer system 26700 may store a program for implementing at least one of a video encoding method and a video decoding method on the disc 26000 using the disc drive 26800. In order to execute a program stored on the disk 26000 on the computer system 26700, the program may be read from the disk 26000 by the disk drive 26800, and the program may be transferred to the computer system 26700.

In addition to the disk 26000 illustrated in FIGS. 20 and 21, a program for implementing at least one of a video encoding method and a video decoding method may be stored in a memory card, a ROM cassette, and a solid state drive (SSD).

A system to which the video encoding method and the video decoding method according to the above-described embodiment are applied will be described below.

FIG. 22 illustrates the overall structure of a content supply system 11000 for providing a content distribution service. The service area of the communication system is divided into cells of a predetermined size, and

wireless base stations

11700, 11800, 11900, and 12000 that serve as base stations are installed in each cell.

The content supply system 11000 includes a plurality of independent devices. For example, independent devices such as a computer 12100, a personal digital assistant (PDA) 12200, a camera 12300, and a mobile phone 12500 may be an Internet service provider 11200, a communication network 11400, and a wireless base station. 11700, 11800, 11900, and 12000 to connect to the Internet 11100.

However, the content supply system 11000 is not limited to the structure shown in FIG. 16, and devices may be selectively connected. The independent devices may be directly connected to the communication network 11400 without passing through the

wireless base stations

11700, 11800, 11900, and 12000.

The video camera 12300 is an imaging device capable of capturing video images like a digital video camera. The mobile phone 12500 is such as Personal Digital Communications (PDC), code division multiple access (CDMA), wideband code division multiple access (W-CDMA), Global System for Mobile Communications (GSM), and Personal Handyphone System (PHS). At least one communication scheme among various protocols may be adopted.

The video camera 12300 may be connected to the streaming server 11300 through the wireless base station 11900 and the communication network 11400. The streaming server 11300 may stream and transmit the content transmitted by the user using the video camera 12300 through real time broadcasting. Content received from the video camera 12300 may be encoded by the video camera 12300 or the streaming server 11300. Video data captured by the video camera 12300 may be transmitted to the streaming server 11300 via the computer 12100.

Video data captured by the camera 12600 may also be transmitted to the streaming server 11300 via the computer 12100. The camera 12600 is an imaging device capable of capturing both still and video images, like a digital camera. Video data received from the camera 12600 may be encoded by the camera 12600 or the computer 12100. Software for video encoding and decoding may be stored in a computer readable recording medium such as a CD-ROM disk, a floppy disk, a hard disk drive, an SSD, or a memory card that the computer 12100 may access.

In addition, when video is captured by a camera mounted on the mobile phone 12500, video data may be received from the mobile phone 12500.

The video data may be encoded by a large scale integrated circuit (LSI) system installed in the video camera 12300, the mobile phone 12500, or the camera 12600.

In the content supply system 11000 according to an embodiment, such as, for example, on-site recording content of a concert, a user is recorded using a video camera 12300, a camera 12600, a mobile phone 12500, or another imaging device. The content is encoded and sent to the streaming server 11300. The streaming server 11300 may stream and transmit content data to other clients who have requested the content data.

The clients are devices capable of decoding the encoded content data, and may be, for example, a computer 12100, a PDA 12200, a video camera 12300, or a mobile phone 12500. Thus, the content supply system 11000 allows clients to receive and play encoded content data. In addition, the content supply system 11000 enables clients to receive and decode and reproduce encoded content data in real time, thereby enabling personal broadcasting.

The video encoding apparatus and the video decoding apparatus may be applied to encoding and decoding operations of independent devices included in the content supply system 11000.

An embodiment of the mobile phone 12500 of the content supply system 11000 will be described in detail below with reference to FIGS. 23 and 24.

23 is a diagram illustrating an external structure of the mobile phone 12500 to which a video encoding method and a video decoding method are applied, according to an embodiment. The mobile phone 12500 is not limited in functionality and may be a smart phone that can change or expand a substantial portion of its functions through an application program.

The mobile phone 12500 includes a built-in antenna 12510 for exchanging RF signals with the wireless base station 12000, and displays images captured by the camera 1530 or images received and decoded by the antenna 12510. And a display screen 12520 such as an LCD (Liquid Crystal Display) and an OLED (Organic Light Emitting Diodes) screen for displaying. The smartphone 12510 includes an operation panel 12540 including a control button and a touch panel. When the display screen 12520 is a touch screen, the operation panel 12540 further includes a touch sensing panel of the display screen 12520. The smart phone 12510 includes a speaker 12580 or another type of audio output unit for outputting voice and sound, and a microphone 12550 or another type of audio input unit for inputting voice and sound. The smartphone 12510 further includes a camera 1530 such as a CCD camera for capturing video and still images. In addition, the smartphone 12510 may be a storage medium for storing encoded or decoded data, such as video or still images captured by the camera 1530, received by an e-mail, or obtained in another form. 12570); And a slot 12560 for mounting the storage medium 12570 to the mobile phone 12500. The storage medium 12570 may be another type of flash memory such as an electrically erasable and programmable read only memory (EEPROM) embedded in an SD card or a plastic case.

16 illustrates an internal structure of the mobile phone 12500. In order to systematically control each part of the mobile phone 12500 including the display screen 12520 and the operation panel 12540, the power supply circuit 12700, the operation input controller 12640, the image encoder 12720, and the camera interface (12630), LCD control unit (12620), image decoding unit (12690), multiplexer / demultiplexer (12680), recording / reading unit (12670), modulation / demodulation unit (12660) and The sound processor 12650 is connected to the central controller 12710 through the synchronization bus 1730.

When the user operates the power button to set the 'power off' state from the 'power off' state, the power supply circuit 12700 supplies power to each part of the mobile phone 12500 from the battery pack, thereby causing the mobile phone 12500 to operate. Can be set to an operating mode.

The central controller 12710 includes a CPU, a read only memory (ROM), and a random access memory (RAM).

In the process in which the mobile phone 12500 transmits the communication data to the outside, the digital signal is generated in the mobile phone 12500 under the control of the central controller 12710, for example, the digital sound signal is generated in the sound processor 12650. In addition, the image encoder 12720 may generate a digital image signal, and text data of the message may be generated through the operation panel 12540 and the operation input controller 12640. When the digital signal is transmitted to the modulator / demodulator 12660 under the control of the central controller 12710, the modulator / demodulator 12660 modulates a frequency band of the digital signal, and the communication circuit 12610 is a band-modulated digital signal. Digital-to-analog conversion and frequency conversion are performed on the acoustic signal. The transmission signal output from the communication circuit 12610 may be transmitted to the voice communication base station or the radio base station 12000 through the antenna 12510.

For example, when the mobile phone 12500 is in a call mode, the sound signal acquired by the microphone 12550 is converted into a digital sound signal by the sound processor 12650 under the control of the central controller 12710. The generated digital sound signal may be converted into a transmission signal through the modulation / demodulation unit 12660 and the communication circuit 12610 and transmitted through the antenna 12510.

When a text message such as an e-mail is transmitted in the data communication mode, the text data of the message is input using the operation panel 12540, and the text data is transmitted to the central controller 12610 through the operation input controller 12640. Under the control of the central controller 12610, the text data is converted into a transmission signal through the modulator / demodulator 12660 and the communication circuit 12610, and transmitted to the radio base station 12000 through the antenna 12510.

In order to transmit the image data in the data communication mode, the image data photographed by the camera 1530 is provided to the image encoder 12720 through the camera interface 12630. The image data photographed by the camera 1252 may be directly displayed on the display screen 12520 through the camera interface 12630 and the LCD controller 12620.

The structure of the image encoder 12720 may correspond to the structure of the video encoding apparatus described above. The image encoder 12720 encodes the image data provided from the camera 1252 according to the above-described video encoding method, converts the image data into compression-encoded image data, and multiplexes / demultiplexes 12680 the encoded image data. Can be printed as The sound signal obtained by the microphone 12550 of the mobile phone 12500 is also converted into digital sound data through the sound processor 12650 during recording of the camera 1250, and the digital sound data is converted into the multiplex / demultiplexer 12680. Can be delivered.

The multiplexer / demultiplexer 12680 multiplexes the encoded image data provided from the image encoder 12720 together with the acoustic data provided from the sound processor 12650. The multiplexed data may be converted into a transmission signal through the modulation / demodulation unit 12660 and the communication circuit 12610 and transmitted through the antenna 12510.

In the process of receiving the communication data from the outside of the mobile phone 12500, the signal received through the antenna (12510) converts the digital signal through a frequency recovery (Analog-Digital conversion) process . The modulator / demodulator 12660 demodulates the frequency band of the digital signal. The band demodulated digital signal is transmitted to the video decoder 12690, the sound processor 12650, or the LCD controller 12620 according to the type.

When the mobile phone 12500 is in the call mode, the mobile phone 12500 amplifies a signal received through the antenna 12510 and generates a digital sound signal through frequency conversion and analog-to-digital conversion processing. The received digital sound signal is converted into an analog sound signal through the modulator / demodulator 12660 and the sound processor 12650 under the control of the central controller 12710, and the analog sound signal is output through the speaker 12580. .

In the data communication mode, when data of a video file accessed from a website of the Internet is received, a signal received from the radio base station 12000 via the antenna 12510 is converted into multiplexed data as a result of the processing of the modulator / demodulator 12660. The output and multiplexed data is transmitted to the multiplexer / demultiplexer 12680.

In order to decode the multiplexed data received through the antenna 12510, the multiplexer / demultiplexer 12680 demultiplexes the multiplexed data to separate the encoded video data stream and the encoded audio data stream. By the synchronization bus 1730, the encoded video data stream is provided to the video decoder 12690, and the encoded audio data stream is provided to the sound processor 12650.

The structure of the image decoder 12690 may correspond to the structure of the video decoding apparatus described above. The image decoder 12690 decodes the encoded video data to generate reconstructed video data by using the above-described video decoding method, and restores the reconstructed video data to the display screen 1252 via the LCD controller 1262. Video data can be provided.

Accordingly, video data of a video file accessed from a website of the Internet can be displayed on the display screen 1252. At the same time, the sound processor 1265 may convert the audio data into an analog sound signal and provide the analog sound signal to the speaker 1258. Accordingly, audio data contained in a video file accessed from a website of the Internet can also be reproduced in the speaker 1258.

The mobile phone 1250 or another type of communication terminal may be a transmitting / receiving terminal including both a video encoding apparatus and a video decoding apparatus, a transmitting terminal including only the video encoding apparatus described above, or a receiving terminal including only a video decoding apparatus.

The communication system is not limited to the structure described above with reference to FIG. For example, FIG. 25 illustrates a digital broadcasting system employing a communication system, according to an exemplary embodiment. The digital broadcasting system according to the embodiment of FIG. 25 may receive a digital broadcast transmitted through a satellite or terrestrial network using a video encoding apparatus and a video decoding apparatus.

Specifically, the broadcast station 12890 transmits the video data stream to the communication satellite or the broadcast satellite 12900 through radio waves. The broadcast satellite 12900 transmits a broadcast signal, and the broadcast signal is received by the antenna 12860 in the home to the satellite broadcast receiver. In each household, the encoded video stream may be decoded and played back by the TV receiver 12610, set-top box 12870, or other device.

As the video decoding apparatus is implemented in the playback device 12230, the playback device 12230 may read and decode the encoded video stream recorded on the storage medium 12020 such as a disk and a memory card. The reconstructed video signal may thus be reproduced in the monitor 12840, for example.

The video decoding apparatus may also be mounted in the set top box 12870 connected to the antenna 12860 for satellite / terrestrial broadcasting or the cable antenna 12850 for cable TV reception. Output data of the set-top box 12870 may also be reproduced by the TV monitor 12880.

As another example, a video decoding apparatus may be mounted on the TV receiver 12810 itself instead of the set top box 12870.

An automobile 12920 with an appropriate antenna 12910 may receive signals from satellite 12800 or radio base station 11700. The decoded video may be played on the display screen of the car navigation system 12930 mounted on the car 12920.

The video signal may be encoded by the video encoding apparatus and recorded and stored in a storage medium. Specifically, the video signal may be stored in the DVD disk 12960 by the DVD recorder, or the video signal may be stored in the hard disk by the hard disk recorder 12950. As another example, the video signal may be stored in the SD card 12970. If the hard disk recorder 12950 includes a video decoding apparatus according to an embodiment, the video signal recorded on the DVD disk 12960, the SD card 12970, or another type of storage medium may be reproduced on the monitor 12880. have.

The vehicle navigation system 12930 may not include the camera 1530, the camera interface 12630, and the image encoder 12720 of FIG. 25. For example, the computer 12100 and the TV receiver 12610 may not include the camera 1250, the camera interface 12630, and the image encoder 12720 of FIG. 25.

FIG. 26 illustrates a network structure of a cloud computing system using a video encoding apparatus and a video decoding apparatus, according to an embodiment.

The cloud computing system may include a cloud computing server 14100, a user DB 14100, a computing resource 14200, and a user terminal.

The cloud computing system provides an on demand outsourcing service of computing resources through an information communication network such as the Internet at the request of a user terminal. In a cloud computing environment, service providers integrate the computing resources of data centers located in different physical locations into virtualization technology to provide users with the services they need. The service user does not install and use computing resources such as application, storage, operating system, and security in each user's own terminal, but services in virtual space created through virtualization technology. You can choose as many times as you want.

A user terminal of a specific service user accesses the cloud computing server 14100 through an information communication network including the Internet and a mobile communication network. The user terminals may be provided with a cloud computing service, particularly a video playback service, from the cloud computing server 14100. The user terminal may be any electronic device capable of accessing the Internet, such as a desktop PC 14300, a smart TV 14400, a smartphone 14500, a notebook 14600, a portable multimedia player (PMP) 14700, a tablet PC 14800, and the like. It can be a device.

The cloud computing server 14100 may integrate and provide a plurality of computing resources 14200 distributed in a cloud network to a user terminal. The plurality of computing resources 14200 include various data services and may include data uploaded from a user terminal. In this way, the cloud computing server 14100 integrates a video database distributed in various places into a virtualization technology to provide a service required by a user terminal.

The user DB 14100 stores user information subscribed to a cloud computing service. Here, the user information may include login information and personal credit information such as an address and a name. In addition, the user information may include an index of the video. Here, the index may include a list of videos that have been played, a list of videos being played, and a stop time of the videos being played.

Information about a video stored in the user DB 14100 may be shared among user devices. Thus, for example, when a playback request is provided from the notebook 14600 and a predetermined video service is provided to the notebook 14600, the playback history of the predetermined video service is stored in the user DB 14100. When the playback request for the same video service is received from the smartphone 14500, the cloud computing server 14100 searches for and plays a predetermined video service with reference to the user DB 14100. When the smartphone 14500 receives the video data stream through the cloud computing server 14100, the operation of decoding the video data stream and playing the video may be performed by the operation of the mobile phone 12500 described above with reference to FIG. 23. similar.

The cloud computing server 14100 may refer to a playback history of a predetermined video service stored in the user DB 14100. For example, the cloud computing server 14100 receives a playback request for a video stored in the user DB 14100 from a user terminal. If the video was being played before, the cloud computing server 14100 may have a streaming method different depending on whether the video is played from the beginning or from the previous stop point according to the user terminal selection. For example, when the user terminal requests to play from the beginning, the cloud computing server 14100 streams the video to the user terminal from the first frame. On the other hand, if the terminal requests to continue playing from the previous stop point, the cloud computing server 14100 streams the video to the user terminal from the frame at the stop point.

In this case, the user terminal may include the video decoding apparatus described above with reference to FIGS. 1A through 26. As another example, the user terminal may include the video encoding apparatus described above with reference to FIGS. 1A through 26. In addition, the user terminal may include both the video encoding apparatus and the video decoding apparatus described above with reference to FIGS. 1A through 26.

Various embodiments of using the video encoding method, the video decoding method, the video encoding apparatus, and the video decoding apparatus described above with reference to FIGS. 1A through 26 have been described above with reference to FIGS. 13 through 19. However, various embodiments in which the video encoding method and the video decoding method described above with reference to FIGS. 1A through 19 are stored in a storage medium, or in which the video encoding apparatus and the video decoding apparatus are implemented in a device, are illustrated in FIGS. 20 to 26. It is not limited to.

In the present specification, the description "A may include one of a1, a2, and a3" has a broad meaning that an exemplary element that may be included in an element of A is a1, a2, or a3.

The above description does not necessarily mean that the elements capable of constituting element A are limited to a1, a2 or a3. Therefore, it should be noted that the elements capable of constituting A are not exclusively interpreted, meaning that they exclude other elements which are not illustrated other than a1, a2, and a3.

In addition, the above description means that A may include a1, include a2, or include a3. The above description does not mean that elements constituting A are necessarily determined within a predetermined set. It should be noted, for example, that the above description is not necessarily to be construed as limited that a1, a2, or a3 selected from the set comprising a1, a2 and a3 constitutes component A.

In addition, in the present specification, "at least one of a1, a2 or (and) a3" is a technology, a1; a2; a3; a1 and a2; a1 and a3; a2 and a3; One of a1, a2, and a3.

Thus, unless at least one of a1, at least one of a2 or at least one of a3 and / or a3 is expressly stated, “at least one of a1, a2 or (and) a3” means that the description of at least one of a1 1, at least one of a2 or (and) at least one of a3 ".

Meanwhile, the above-described embodiments can be written as a program that can be executed in a computer, and can be implemented in a general-purpose digital computer which operates the program using a computer-readable recording medium. The computer-readable recording medium may include a storage medium such as a magnetic storage medium (eg, a ROM, a floppy disk, a hard disk, etc.) and an optical reading medium (eg, a CD-ROM, a DVD, etc.).

So far I looked at the preferred embodiments. Those skilled in the art will appreciate that the embodiments may be embodied in a modified form without departing from the essential characteristics thereof. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the various embodiments is set forth in the claims rather than the foregoing description, and all differences within the scope will be construed as being included in the various embodiments.

Claims

Obtaining coefficients from the bitstream;

Generating an inverse quantization block by performing inverse quantization on the quantization block including the obtained coefficients;

Generating a residual block by performing inverse transform on the inverse quantization block;

Reconstructing a current block using the residual block and the prediction block; And

Generating a filtered current block by performing filtering on the restored current block;

And normalizing the at least one block of the inverse quantization block, the prediction block, the reconstructed current block, and the filtered current block.
The method of claim 1,

The normalization is

And determining the result values at which the difference between the original values and the result values and the difference between the result values are minimized.
The method of claim 2,

Normalized dequantization block

A block including result values generated by performing normalization on the inverse quantization block;

The normalized restore block is

A block generated by synthesizing the prediction block with a normalized residual block generated as a result of performing an inverse transform on the normalized inverse quantization block,

If the inverse quantization block is normalized,

A pixel value of the normalized inverse quantization block that minimizes a difference between pixel values included in the normalized dequantization block and pixel values of the inverse quantization block and a pixel value difference between pixels included in the normalization reconstruction blocks Video decoding method characterized in that for determining.
The method of claim 3, wherein

If the inverse quantization block is normalized,

In the normalized inverse quantization block to minimize the difference between the pixel value included in the normalized dequantization block and the pixel value of the inverse quantization block multiplied by the weight W and the pixels in the normalized decompression block The pixel values are determined,

The weight W is a value smaller than a predetermined threshold when a difference between pixel values included in the normalized dequantization block and pixel values of the dequantization block is smaller than T (T is a predetermined value), and the normalization inverse And if the difference between the pixel values included in the quantization block and the pixel values of the dequantization block is greater than or equal to the T, the video decoding method is greater than or equal to the predetermined threshold.
The method of claim 2,

Normalized prediction block

A block including result values generated by performing normalization on the prediction block,

If the prediction block is normalized,

Characterized in that the pixel values of the normalization prediction block are minimized to minimize the difference between the pixel values included in the prediction block and the pixel values of the normalization prediction block and the pixels included in the normalization prediction block. Video decoding method.
The method of claim 1,

The prediction block is generated using pixel values of the first prediction block predicted from the first reference picture and pixel values of the second prediction block predicted from the second reference picture,

If the prediction block is normalized,

And the first prediction block and the second prediction block are normalized.
The method of claim 2,

Normalized restore block

A block including result values generated by performing normalization on the restored current block,

If the restored current block is normalized,

Pixel values included in the normalized reconstruction block for minimizing a difference between pixel values included in the reconstructed current block and pixel values of the normalized reconstructed block and pixels included in the normalized reconstructed block are determined. Video decoding method.
The method of claim 7, wherein

An extended current block including a previously decoded neighboring block and the restored current block is generated,

The normalized extended restore block

A block including result values generated by performing normalization on the extended current block,

If the restored current block is normalized,

A pixel value of a normalized extension recovery block which minimizes a difference between pixel values included in the extended current block and pixel values of the normalized extension recovery block and a pixel value difference between pixels included in the normalized extension recovery block. Are determined, and the pixel values corresponding to the positions of the pixels included in the current block among the pixel values included in the normalized extended reconstruction block are determined as the pixel values included in the normalized reconstructed block. Way.
The method of claim 2,

The normalized filtering block

A block including result values generated by performing normalization on the filtered current block,

If the filtered current block is normalized,

The normalized filtering to minimize the difference in pixel values between the pixel values included in the filtered current block and the pixel values of the normalized filtering block by multiplying a weight W and the pixels included in the normalized filtering block. The pixel values of the block are determined,

And the weight W is a value less than or equal to a predetermined value for pixels adjacent to a boundary of the filtered current block.
The method of claim 1,

The normalization is

Performing an iterative process to determine the difference between the original values and the result values and the difference between the result values;

The number of iteration of the iterative process is determined according to a predetermined syntax.
The method of claim 2,

The normalization is

Determining the result values in consideration of a trade-off parameter λ relating to the difference between the original values and the result values and the difference between the result values;

The λ is determined according to the type of the at least one block to be normalized.
Encoding a coefficient included in a current block;

Generating an inverse quantization block by performing inverse quantization on the quantization block including the encoded coefficients;

Generating a residual block by performing inverse transform on the inverse quantization block;

Reconstructing the current block using the residual block and the prediction block; And

Generating a filtered current block by performing filtering on the restored current block;

And normalizing the at least one block of the inverse quantization block, the prediction block, the reconstructed current block, and the filtered current block.
An inverse quantization unit configured to obtain a coefficient from a bitstream and perform inverse quantization on the quantization block including the obtained coefficient to generate an inverse quantization block;

An inverse transform unit generating a residual block by performing an inverse transform on the inverse quantization block;

A reconstruction unit for reconstructing a current block by using the residual block and the prediction block;

A filtering unit configured to perform filtering on the restored current block to generate a filtered current block; And

A normalization unit performing normalization on at least one data unit,

The normalization unit performs normalization on at least one of the inverse quantization block, the prediction block, the reconstructed current block, and the filtered current block.
Obtaining coefficients from the bitstream;

Generating a normalized dequantization block by performing normalized de-quantization on the quantization block including the obtained coefficients;

Generating a residual block by performing an inverse transform on the normalized inverse quantization block; And

Reconstructing a current block using the residual block and the prediction block,

The normalized quantization block is a block generated by quantizing a normalized inverse quantization block generated by performing inverse quantization on the quantization block,

Generating the normalized dequantization block,

Generating the normalized inverse quantization block that minimizes a difference between pixel values of the normalized quantization block and pixel values of the quantization block and a pixel value difference between pixels included in the normalized inverse quantization block. Video decoding method comprising a.
A computer-readable recording medium having recorded thereon a program for implementing the method of claim 1.