KR101479123B1 - Inter Prediction Method and Apparatus Using Adjacent Pixels and Video Coding Method and Apparatus Using Same - Google Patents

Abstract

The present invention relates to an inter prediction method and apparatus using adjacent pixels, and an image coding method and apparatus using the same.

According to the present invention, there is provided an inter prediction method for predictive coding, comprising: estimating motion of a current block to determine a current motion vector; generating a reference block indicated by a current motion vector; The motion compensation coefficient is calculated using the motion compensation coefficient, the change reference block is generated by reflecting the motion compensation coefficient in the reference block, and the change reference block is determined as the prediction block of the current block.

According to the present invention, the compression efficiency can be improved by reducing the difference between the actual block and the predicted block by more accurately predicting the block to be encoded.

Image, encoding, decoding, compression, inter prediction, motion compensation, coefficient

Description

[0001] The present invention relates to an inter prediction method and apparatus using adjacent pixels, and an image encoding / decoding method and apparatus using the same. [0002]

The present invention relates to an inter prediction method and apparatus using adjacent pixels, and an image coding method and apparatus using the same. More particularly, the present invention relates to a method and apparatus for enhancing prediction accuracy by minimizing a difference between a current block and a prediction block in inter-prediction coding an image, and thereby improving compression efficiency.

The Moving Picture Experts Group (MPEG) and the Video Coding Experts Group (VCEG) have developed superior video compression techniques that are superior to the existing MPEG-4 Part 2 and H.263 standards. This new standard was called H.264 / AVC (Advanced Video Coding) and jointly announced as MPEG-4 Part 10 AVC and ITU-T Recommendation H.264.

In H.264 / AVC (hereinafter abbreviated as 'H.264') standard, Intra Prediction and / or Inter Prediction are performed in units of macroblocks having various sub- To generate a residual signal, transforms and quantizes the generated residual signal, and encodes the residual signal. Herein, inter prediction is a method of compressing an image by eliminating temporal redundancy between frames of an image. The inter prediction is a method of compressing a block to be encoded (hereinafter referred to as a " current block ") using one or more reference frames Motion estimation is performed on a block basis, a prediction block of a current block is generated based on the motion estimation result, and motion compensation is performed.

In conventional inter-prediction coding, when motion of a current block is estimated to generate a prediction block, a block most similar to the current block is searched for in a predetermined search range of a reference frame using a predetermined evaluation function. When a block similar to the current block is found, a prediction block is generated using the block, and only the residual signal, which is the difference between the pixel signals of the current block and the prediction block, is encoded and transmitted.

However, if motion compensation is performed like the conventional inter prediction coding described above, it is difficult to efficiently encode when local illumination change or view change occurs in each frame. That is, when the pixel value increases due to the illumination change or the viewpoint change at the current block position, the motion compensation using the prediction block generated by the conventional method increases the size of the residual signal, have.

In order to solve the above-described problems, the present invention has a main purpose of improving the compression efficiency by reducing the difference between a block to be coded and a prediction block when performing inter-prediction coding of an image.

According to an aspect of the present invention, there is provided an inter prediction method for predictive coding comprising: estimating motion of a current block to determine a current motion vector; Generating a reference block indicated by a current motion vector; Calculating a motion compensation coefficient using a current block adjacent pixel and a reference block adjacent pixel; Generating a change reference block by reflecting a motion compensation coefficient in a reference block; And determining a change reference block as a prediction block of the current block.

According to another aspect of the present invention, there is provided an inter-prediction apparatus for predictive coding comprising: a motion estimator for estimating a motion of a current block to determine a current motion vector; A motion compensation coefficient calculator for calculating a motion compensation coefficient using a reference block adjacent pixel and a current block adjacent pixel of a reference block indicated by a current motion vector; And a motion compensator for generating a current block by applying the motion compensation coefficient to the reference block to determine the change reference block as a prediction block.

According to still another aspect of the present invention, there is provided a method of coding an image, the method comprising the steps of: generating a motion compensation coefficient by using a motion compensation coefficient that is calculated using a current block adjacent pixel and a reference block adjacent pixel, Generating a block as a prediction block of the current block; Generating a residual block by subtracting a current block from a prediction block; And encoding the residual block to generate encoded data.

According to still another aspect of the present invention, there is provided an apparatus for coding an image, the apparatus comprising: a change reference unit that reflects a motion compensation coefficient calculated using a current block adjacent pixel and a reference block adjacent pixel in a reference block indicated by a current motion vector; A predictor for generating a block as a prediction block of the current block; A subtractor for subtracting a current block from a prediction block to generate a residual block; And an encoder for coding the residual block to generate encoded data.

According to another aspect of the present invention, there is provided an inter prediction method for predictive decoding, comprising: generating a reference block indicated by a current motion vector reconstructed by decoding encoded data; Calculating a motion compensation coefficient using a current block adjacent pixel and a reference block adjacent pixel; Generating a change reference block by reflecting a motion compensation coefficient in a reference block; And determining a change reference block as a prediction block of the current block.

According to still another aspect of the present invention, there is provided an inter-prediction apparatus for predictive decoding, comprising: a reference block generating unit for generating a reference block indicated by a current motion vector reconstructed by decoding encoded data, A motion compensation coefficient calculator for calculating a motion compensation coefficient using the motion compensation coefficient; And a motion compensator for generating a change reference block by reflecting the motion compensation coefficient in the reference block and determining the change reference block as a prediction block of the current block.

According to another aspect of the present invention, there is provided a method of decoding an image, the decoding method comprising: decoding encoded data to restore a current motion vector and a residual block; Generating a change reference block reflecting a motion compensation coefficient calculated using a current block adjacent pixel and a reference block adjacent pixel as a prediction block of a current block in a reference block indicated by a current motion vector to be restored; And restoring a current block by adding a residual block and a prediction block to be reconstructed.

According to another aspect of the present invention, there is provided an apparatus for decoding an image, the apparatus comprising: a decoder that decodes coded data to restore a current motion vector and a residual block; A predictor for generating a change reference block reflecting a motion compensation coefficient calculated using a current block adjacent pixel and a reference block adjacent pixel in a reference block indicated by a current motion vector to be restored as a prediction block of the current block; And an adder for adding a residual block to be reconstructed and a prediction block to reconstruct a current block.

As described above, according to the present invention, the compression efficiency can be improved by reducing the difference between the actual block and the predicted block by more accurately predicting the block to be encoded.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference numerals whenever possible, even if they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected or connected to the other component, Quot; may be "connected," "coupled," or "connected. &Quot;

A Video Encoding Apparatus, a Video Decoding Apparatus, or an Inter Prediction Apparatus, which will be described below, may be a personal computer (PC), a TV, a notebook computer, a personal digital assistant A personal digital assistant (PMP), a portable multimedia player (PMP), a PlayStation Portable (PSP), a mobile communication terminal, a server computer, A communication device such as a communication modem for performing communication with a communication network, a memory for storing various programs and data for encoding or decoding an image by performing inter prediction or using the same, a microprocessor for executing, And the like.

The video encoded by the video encoding apparatus can be transmitted in real time or in non-real time via a wired or wireless communication network such as the Internet, a local area wireless communication network, a wireless LAN network, a WiBro network, a mobile communication network, ), And the like, is transmitted to the image decoding apparatus, decoded by the image decoding apparatus, and restored and reproduced as an image.

The video encoding apparatus and the video decoding apparatus may be provided with a function for performing intra prediction as well as inter prediction using motion estimation and motion compensation. However, since there is no direct relationship with the embodiment of the present invention, The description will be omitted.

Usually, a moving picture is composed of a series of pictures, and each picture is divided into blocks. Each block is classified into an Intra block and an Inter block according to a coding method. The intra-block refers to a block that is coded using Intra Prediction Coding (P-Coding) scheme. The intra-prediction coding is performed by using pixels of previously decoded and decoded blocks in a current picture, A prediction block is generated by predicting the pixels of the current block and a difference value between the current block and the pixel of the current block is encoded. Inter-block refers to a block that is coded using Inter Prediction Coding. Inter-prediction coding refers to one or more past pictures or a future picture to generate a prediction block by predicting a current block in the current picture, And the difference value is encoded. Here, a picture referred to in encoding or decoding a current picture is referred to as a reference picture.

On the other hand, in a conventional inter-prediction encoding, a prediction block having the same size as the current block is generated, and residual blocks are generated by subtracting pixel values at the same position from each other in the current block and the prediction block. For example, when a current block of 16x16 size is subtracted from a prediction block of the same size to generate a residual block, the residual block can be expressed by Equation (1).

residual _ij = original _ij - reference _ij

In Equation (1), original denotes a current block, reference denotes a prediction block generated by performing motion compensation, and residual denotes a residual block generated by subtracting a prediction block from a current block. And i and j represent pixel positions of each block.

Since H.264 uses inter prediction coding, compression efficiency can be improved when compared with other prediction type coding schemes not using inter prediction coding. However, in the conventional inter-prediction coding such as H.264, residual blocks are generated using only the pixels of the current block and the prediction block. Therefore, when a change of the viewpoint or illumination occurs in the reference picture for generating the prediction block and in the current picture Efficient predictive coding can not be performed. For example, if the brightness is locally darkened or bright in the region including the current block, if motion compensation is performed to generate inter-prediction and residual blocks as in the conventional method, motion compensation can not be performed The value of the residual block becomes relatively large, and efficient predictive encoding becomes difficult.

In an embodiment of the present invention, unlike the existing inter prediction coding method in which motion compensation is performed using only a current block and a prediction block, motion compensation is performed in which characteristics of a block are reflected using a current block adjacent pixel and a prediction block adjacent pixel Thereby performing inter prediction coding. In this case, the characteristic of the block may be a local illumination change or a viewpoint change. In order to consider the block characteristic, the motion of the current block is compensated more accurately by using the current block adjacent pixel and the reference block adjacent pixel, So that the compression efficiency can be improved.

Each picture of the input video to be coded can be input in units of macroblocks. In one embodiment of the present invention, a macroblock is of the MxM type, M and N may have a size of 2 ⁿ , and M and N may be the same. Therefore, a macroblock according to an embodiment of the present invention may be the same as or larger than a macroblock of H.264.

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

The apparatus 100 for encoding an image according to an embodiment of the present invention includes a predictor 110, a subtractor 130, a transformer and a quantizer 130, a coder An encoder 140, an inverse quantizer and an inverse transformer 150, an adder 160, and a reference picture memory 170.

The predictor 110 generates a predictive block by inter-prediction of a block to be coded (e.g., a macroblock or a sub-block, hereinafter abbreviated as a 'current block'). That is, the predictor 110 generates a motion vector by estimating the motion of the current block according to the inter prediction mode in the previous picture that has been already encoded and decoded again, and generates a motion vector using the motion vector The prediction block is generated by compensating the motion of the current block.

The predictor 110 generates a predictive block by compensating for the motion of the current block by using the current block adjacent pixels (hereinafter referred to as " current block adjacent pixels ") and the neighboring pixels The predictor 110 generates a predictive block using a motion vector of a current block determined by estimating motion of a current block, (Motion Compensation Coefficient) calculated using a current block adjacent pixel and a reference block adjacent pixel in a reference block indicated by a current motion vector (hereinafter referred to as a current motion vector) Reference Block), and generate a change reference block as a prediction block of the current block.

For this, the predictor 110 may determine a more efficient block among the reference block and the change reference block as a prediction block of the current block. That is, in order to determine the use of the motion compensation coefficient, the predictor 110 uses a method such as rate-distortion optimization or analyzes a characteristic of an adjacent pixel to determine a block to be used as a prediction block of the current block, You can decide. The predictor 110 will be described in detail with reference to FIG. 2 in the following process.

The subtractor 120 subtracts the prediction block from the current block to generate a residual block. That is, the subtractor 130 subtracts the pixel value of the current block and the pixel value of the prediction block generated by the predictor 110 to generate a residual block having a residual signal.

The transformer and quantizer 130 converts the residual block generated by the subtractor 120 into a frequency domain and quantizes the residual block. That is, the transformer and the quantizer 130 transforms the residual signal of the residual block generated by the subtractor 130 into the frequency domain to generate a transformed residual block having a transform coefficient and transforms the transformed residual block Quantized coefficients to generate quantized residual blocks. In this case, as a conversion method used, a technique of converting an image signal of a spatial domain into a frequency domain such as Hadamard Transform and Discrete Cosine Transform Based Integer Transform is used, Various quantization techniques such as Dead Zone Uniform Threshold Quantization (DZUTQ) or a Quantization Weighted Matrix may be used as the quantization method.

The encoder 140 encodes the quantized transform coefficients of the residual block transformed and quantized by the transformer and the quantizer 130 to generate encoded data. As such an encoding technique, entropy encoding technology may be used, but various other encoding techniques may be used without being limited thereto.

In addition, the encoder 140 may include not only the bit stream in which the quantized transform coefficients are encoded, but also various information necessary for decoding the encoded bit stream in the encoded data. That is, the encoded data includes a first field including a coded block type (CBP: Coded Block Pattern), a Delta Quantization Parameter, and a quantized transform coefficient bit string and information necessary for prediction , An intra prediction mode in the case of intra prediction, or a motion vector in the case of inter prediction).

At this time, the encoder 140 may include the motion compensation coefficient use information indicating that the motion compensation coefficient is used in the encoded data. However, the motion compensation coefficient use information is not necessarily included in the encoded data. The motion compensation coefficient use information may be included in or included in the encoded data depending on whether a change reference block reflecting the motion compensation coefficient is determined as a predicted block of the current block . This will be described in detail with reference to FIG. 2 in the following process.

Meanwhile, the functions of the transducer and the quantizer 130 may be integrated into the encoder 140. FIG. That is, when the encoder is implemented by one encoder, the encoder encodes the residual block to generate encoded data.

The inverse quantizer and inverse transformer 150 inverse quantize and inverse transform the residual block transformed and quantized by the transformer and the quantizer 130 to recover the residual block. In other words, the inverse quantizer and inverse transformer 150 dequantize the quantized residual block transmitted from the transformer and the quantizer 130, reconstruct the residual block having the transform coefficients, And restores the residual block having the residual signal.

The adder 160 adds the prediction block generated by the predictor 110 and the residual blocks reconstructed by the inverse quantizer and the inverse transformer 150 to reconstruct the current block.

The reference picture memory 170 accumulates the current block restored by the adder 160 on a picture-by-picture basis and stores the reference picture as a reference picture. The reference picture to be stored is used when the predictor 110 predicts the next block or the next picture.

Although not shown in FIG. 1, the image encoding apparatus 100 according to an embodiment of the present invention includes an intra predictor for Intra prediction, deblocking filtering for deblocking the restored current block, Filters, and the like. The transformer and quantizer 130 and the dequantizer and inverse transformer 150 may further perform conversion and quantization (or inverse transform and dequantization) operations on a specific picture (e.g., intra picture) It is possible. Here, deblocking filtering refers to a task of reducing block distortion caused by coding an image block by block. The deblocking filter may be applied to a block boundary or a macro block boundary, a deblocking filter may be applied to a macro block boundary, Can be selectively used.

2 is a block diagram schematically illustrating an inter prediction apparatus for predictive coding according to an embodiment of the present invention.

The inter prediction apparatus for predictive encoding according to an embodiment of the present invention can be implemented by the predictor 110 in the image encoding apparatus 100 according to an embodiment of the present invention described above with reference to FIG. It is referred to as a predictor 110 for convenience.

The predictor 110 may include a motion estimator 210, a motion compensation coefficient calculator 220, and a motion compensator 230.

The motion estimator 210 estimates the motion of the current block to determine a current motion vector. That is, the motion estimator 210 estimates the motion of the current block by finding the position of the reference block with the smallest difference from the current block in a picture that has been previously encoded, decoded, and reconstructed. At this time, interpolation between pixels and pixels may be performed to expand a picture. The filter used for interpolation may be a fixed 6-tap filter, an adaptive interpolation filter optimized for a picture or a block, (Adaptive Interpolation Filter). A vector indicating a reference block having a minimum difference from the current block is obtained as a motion vector of the current block, that is, a current motion vector.

The motion compensation coefficient calculator 220 calculates a motion compensation coefficient using a reference block adjacent pixel and a current block adjacent pixel of a reference block indicated by a current motion vector. That is, the motion compensation coefficient calculator 220 calculates a motion compensation coefficient for more accurately compensating for the motion of the current block using the current block neighboring pixels and the reference block neighboring pixels.

3 is an exemplary diagram illustrating adjacent pixels for calculating a motion compensation coefficient according to an embodiment of the present invention.

Referring to FIG. 3, the motion compensation coefficient may be calculated as a difference between an average of the current block neighboring pixels 350 and an average of the reference block adjacent pixels 330. The current motion vector 310 can be obtained by searching the reference block 320 where the difference between the current block 340 and the current block 340 is minimized and estimating the motion of the current block 340. 3, the current block neighboring pixel 350 may be adjacent to the current block 340, and the reference block neighboring pixel 330 may be adjacent to the reference block 320. Referring to FIG.

4 is an exemplary diagram for explaining an adjacent pixel for each inter prediction mode according to an embodiment of the present invention.

In FIG. 4, the size of a macroblock is 16x16, for example. However, a macroblock having a different size may be applied similarly to FIG.

As shown in FIG. 4, when the inter prediction mode is the inter 16x16 mode, 16 neighboring pixels adjacent to the upper and left sides of the reference block and the current block can be used as the reference block adjacent pixel and the current block adjacent pixel, respectively. When the inter prediction mode is the inter 16x8 mode, the 16 adjacent pixels on the upper side of the current block and the 8 adjacent pixels on the left side of each sub-block are adjacent to the current block As shown in FIG. When the inter prediction mode is the inter 8x16 mode, 16 sub-blocks adjacent to the left of the current block and 8 adjacent sub-blocks adjacent to the upper side of the sub-block are adjacent to the current block, As shown in FIG.

When the inter prediction mode is the inter 8x8 mode, the 8 neighboring pixels adjacent to the left side of the current block and the 8 neighboring pixels adjacent to the upper side of the current block are adjacent pixels of the reference block and adjacent pixels of the current block, Can be used. When the inter prediction mode is the inter 8x4 mode, both the upper and lower left pixels can be referred to in the two sub-blocks. When the inter prediction mode is the inter 4x8 mode, the left sub-block can refer to four pixels on the upper side, eight pixels on the left side, and eight pixels on the upper side and the left pixel on the right side. When the inter prediction mode is the inter 4x4 mode, it is possible to refer to all four of the four sub-blocks, and four of the left pixels.

Here, neighboring pixels used for motion compensation coefficient generation are not necessarily used as described above. For example, adjacent pixels used in accordance with the size of the conversion such as 4x4 or 8x8 can be changed to four or eight adjacent pixels adjacent to the upper side and adjacent pixels adjacent to the left side, A motion compensation coefficient may be generated by referring to two pixels other than the upper pixel 4x2 (8x2) and the left pixel 2x4 (2x8).

The motion compensation coefficient calculated using the current block neighboring pixel and the reference block neighboring pixel can be calculated as the difference between the average of the current block neighboring pixels and the average of the neighboring reference block, The current block neighboring pixel and the reference block neighboring pixel are pixels that have already been coded, decoded, and reconstructed before coding the current block.

mc _coeff = m _r - m _c

In Equation (2), m _r represents an average of reference block adjacent pixels, m _c represents an average of current block adjacent pixels, and mc _coeff represents a motion compensation coefficient.

Referring again to FIG. 2, the motion compensator 230 generates a current block by referring to a motion compensation coefficient in a reference block, and determines a change reference block as a prediction block. That is, the motion compensator 230 determines one of a reference block indicated by the current motion vector obtained by the motion estimator 210 and a change reference block generated by reflecting the motion compensation coefficient in the reference block, as a prediction block of the current block .

As an example, the motion compensator 230 may determine the change reference block as a prediction block of the current block based on the encoding cost for the reference block and the encoding cost for the change reference block. For this, the motion compensator 230 calculates the encoding cost for the reference block and the encoding cost for the change reference block, and if the encoding cost for the reference block is larger than the encoding cost for the change reference block, Block. If the encoding cost for the reference block is smaller than or equal to the encoding cost for the change reference block, the reference block can be determined as a prediction block of the current block.

Here, the encoding cost for the reference block refers to the encoding cost required for predicting the current block by using the reference block as a predictive block of the current block. The encoding cost for the change reference block is the prediction cost of the current block And the encoding cost required to predictively encode the current block using the block. As a coding cost, a rate-distortion cost can be used. However, the present invention is not limited to this, and any cost can be used as long as it is a cost required to inter-predictively encode a current block using a reference block or a change reference block as a prediction block.

As another example, the motion compensator 230 may determine the change reference block as a prediction block of the current block based on the value of the motion compensation coefficient. For this, the motion compensator 230 may determine the change reference block as a prediction block of the current block if the motion compensation coefficient is not '0'. If the motion compensation coefficient is '0' Can be determined as a prediction block. When the motion compensation coefficient is '0', a case where a change reference block reflecting the motion compensation coefficient is used as a prediction block of the current block and a reference block that does not reflect the motion compensation coefficient are used as a prediction block of the current block This is because it is not necessary to use the motion compensation coefficient since the result of encoding is the same. When the motion compensation coefficient is within a preset range, the motion compensator 230 may determine the change reference block as a prediction block of the current block. If the motion compensation coefficient is out of the predetermined range, As shown in FIG. Here, the predetermined range may be a range smaller than the upper threshold value and larger than the lower threshold value. The upper threshold value and the lower threshold value may be set to one or more of the variance, standard deviation, and correlation coefficient of the current block adjacent pixel and the reference block adjacent pixel . ≪ / RTI > That is, the motion compensator 230 can determine the change reference block as a prediction block of the current block only when the motion compensation coefficient is within a predetermined range, as shown in Equation (3).

Thd _a < mc _coeff < Thd _b

In Equation (3), mc _coeff denotes a motion compensation coefficient, Thd _a denotes _a lower limit threshold value, and Thd _b denotes an upper limit threshold value.

As described above, when the change reference block is determined as the prediction block of the current block on the basis of the value of the motion compensation coefficient, whether or not the value of the motion compensation coefficient is '0' and the value of the motion compensation coefficient are within a preset range And the change reference block may be determined as the prediction block of the current block by combining the two conditions. However, the change reference block may be determined as the prediction block of the current block by combining the two conditions. That is, the change reference block is determined as a prediction block of the current block only when the value of the motion compensation coefficient is not '0' and is within a predetermined range. If the value of the motion compensation coefficient is '0' 0 'but is outside the predetermined range, the reference block can be determined as a prediction block of the current block.

As another example, the motion compensator 230 may calculate at least one of the variance, the standard deviation, and the correlation coefficient of the current block adjacent pixel and the reference block adjacent pixel, and only when the calculated value satisfies the specific condition, Or if it is not satisfied, the reference block may be determined as the prediction block of the current block.

The motion compensator 230 may generate a change reference block by subtracting the motion compensation coefficient from each pixel of the reference block. That is, each pixel of the change reference block has a difference value obtained by subtracting the motion compensation coefficient from the pixel value of each pixel of the reference block. At this time, since the difference value obtained by subtracting the motion compensation coefficient from the pixel value of each pixel may deviate from the range of values in which the pixel is expressed, the motion compensator 230 subtracts the motion compensation coefficient from each pixel of the reference block, It is possible to generate a change reference block by limiting it to a range of values to be represented.

For example, when each pixel of the current block, the reference block, the change reference block, etc. has a value represented by 8 bits, the value that the pixel can have is one of 0 to 255. [ If one of the pixels of the reference block has a value of '1' and the motion compensation coefficient is calculated as '3', the corresponding pixel in the change reference block has a value of '-2' . &Lt; / RTI &gt; Therefore, in this case, the pixel value of the corresponding pixel of the change reference block is changed so as to have a value of '0' having the minimum value among the values of 0 to 255.

If the change reference block thus generated is determined as a prediction block of the current block to calculate the residual block, the residual block can be calculated as shown in Equation (4).

residual _ij = original _ij - clip ( reference _ij - mc _coeff )

In Equation (4), original _ij denotes each pixel of the current block, referencek _ij denotes each pixel of the reference block, and residual _ij denotes each pixel of the residual block. In this case, clip ( reference _ij - mc _coeff ) represents each pixel of the change reference block. The clip () function changes the value of reference _ij - mc _coeff , which is the pixel of the change reference block, The minimum value and the maximum value are limited to have a value within a range from 0 to 255 when the pixel value is represented by 8 bits.

The motion compensator 230 may further refine the current motion vector by further estimating the motion of the current block by applying a motion compensation coefficient. That is, the motion compensator 230 further performs motion estimation by applying a motion compensation coefficient to an arbitrary range (for example, ± α pixels) around the pixel indicated by the current motion vector determined by the motion estimator 210 The coding efficiency can be further improved by performing more accurate prediction of blocks (or macroblocks) in a region where a local illumination change or view change occurs.

For example, if the current motion vector is (2, 4) and α, which determines an arbitrary range, is set to 1, then (1, 3), (1, 4) Motion compensation using motion compensation coefficients is performed for the positions of (2, 3), (2, 4), (2, 5), The optimum motion vector is calculated by comparing the encoding cost (e.g., rate-distortion cost, Sum of Absolute Difference (SAD), Sum of Absolute Transformed Difference (SATD), or Sum of Squared Difference The optimal motion vector can be finally determined as the current motion vector. Here,? Can be suitably set according to the implementation method or condition, and the larger the?, The higher the encoding efficiency can be.

In addition, the motion compensator 230 may determine whether to determine the change reference block as a prediction block of the current block, on a frame-by-frame basis, not on a block-by-block basis. For this, the motion compensator 230 calculates a coding cost for coding the current frame to be coded using the motion compensation coefficient without using the coding cost and the motion compensation coefficient, By encoding the current frame in a scheme, each frame can be adaptively coded. At this time, the motion compensation coefficient use information for identifying whether or not the motion compensation coefficient is applied to each frame is further included in the encoded data.

Hereinafter, an inter prediction method for predictive coding performed by the predictor 110 will be described with reference to FIG.

According to the inter prediction method for predictive coding, the predictor 110 estimates the motion of the current block to determine a current motion vector, generates a reference block indicated by the current motion vector, A motion compensation coefficient is calculated using a pixel, a change reference block is generated by reflecting a motion compensation coefficient in a reference block, and a change reference block is determined as a prediction block of the current block.

Here, the predictor 110 may determine the change reference block as a prediction block of the current block based on the encoding cost for the reference block and the encoding cost for the change reference block. For this, the predictor 110 calculates the encoding cost for the reference block, calculates the encoding cost for the change reference block, and if the encoding cost for the reference block is greater than the encoding cost for the change reference block, As a prediction block of the current block. If the coding cost for the reference block is less than or equal to the coding cost for the change reference block, the reference block can be determined as a prediction block of the current block.

In addition, the predictor 110 may determine a change reference block as a prediction block of the current block based on the value of the motion compensation coefficient. To this end, the predictor 110 determines a change reference block as a predictive block of the current block when the motion compensation coefficient is not '0', determines a reference block as a predictive block of the current block when the motion compensation coefficient is '0' If the motion compensation coefficient is within a predetermined range, the change reference block is determined as a prediction block of the current block. If the motion compensation coefficient is outside the predetermined range, the reference block can be determined as the prediction block of the current block. Here, the predetermined range is a range smaller than the upper threshold value and larger than the lower threshold value, and the upper threshold value and the lower threshold value may be determined using at least one of variance, standard deviation, and correlation coefficient of the current block adjacent pixel and the reference block adjacent pixel Can be determined.

In addition, the predictor 110 can further adjust the current motion vector by further estimating the motion of the current block by applying a motion compensation coefficient.

The motion compensation coefficient may be a difference between the average of the current block neighboring pixels and the average of the neighboring pixels of the reference block. The current block neighboring pixel and the reference block neighboring pixel may be pixels that have been coded and decoded and restored before coding the current block. have.

In addition, the predictor 110 may generate a change reference block by subtracting the motion compensation coefficient from each pixel of the reference block. The predictor 110 subtracts the motion compensation coefficient from each pixel of the reference block, To generate a change reference block.

FIG. 5 is a flowchart illustrating an example of an inter prediction method for predictive coding according to an embodiment of the present invention.

The inter prediction method for predictive coding according to an embodiment of the present invention described above can be implemented as shown in FIG. That is, the predictor 110 can generate a prediction block by determining whether to perform motion compensation of the current block by applying a motion compensation coefficient based on the encoding cost. Referring to FIG. 5, the predictor 110 estimates motion of a current block to determine a current motion vector (S510), generates a reference block indicated by the current motion vector (S520) A motion compensation coefficient is calculated using a block neighboring pixel in step S530, a change reference block reflecting the motion compensation coefficient is generated in step S540, a coding cost for the reference block is calculated in step S550, The encoding cost is calculated (S560). The predictor 110 determines whether the coding cost for the reference block is greater than the coding cost for the change reference block (S870). If the coding cost for the reference block is greater than the coding cost for the change reference block, (S580). If the coding cost for the reference block is smaller than or equal to the coding cost for the change reference block, the reference block can be determined as a prediction block.

6 is a flowchart illustrating another example of an inter prediction method for predictive coding according to an embodiment of the present invention.

The inter prediction method for predictive coding according to an embodiment of the present invention described above can be implemented as shown in FIG. That is, the predictor 110 may generate a prediction block by determining whether to perform motion compensation of the current block by applying a motion compensation coefficient based on the value of the motion compensation coefficient. Referring to FIG. 6, the predictor 110 estimates motion of a current block to determine a current motion vector (S610), generates a reference block indicated by the current motion vector (S620) In operation S630, a motion compensation coefficient reflecting the motion compensation coefficient is generated in operation S640. In operation S650, a motion compensation coefficient is calculated using motion compensation coefficients (S660). If it is determined that the motion compensation coefficient is within a predetermined range, it is determined whether the motion compensation coefficient is within a predetermined range, that is, whether the motion compensation coefficient is greater than the lower limit threshold and smaller than the upper limit threshold (S670). If the determination result in step S650 is '0', or if the determination result in step S660 indicates that the motion compensation coefficient is within a predetermined range And it is determined as the prediction block to the reference block when the (S680).

Although it has been shown and described that both steps S650 and S660 are performed in Fig. 6, only one of steps S650 and S660 may be performed. That is, the predictor 110 does not necessarily determine the change reference block as a prediction block of the current block only when the value of the motion compensation coefficient is not '0' and is within a predetermined range. If the value of the motion compensation coefficient is '0' The change reference block can be determined as a prediction block of the current block irrespective of whether it is within a preset range or not if the value of the motion compensation coefficient is within a predetermined range, As shown in FIG.

In addition, not all of the steps described above through FIGS. 5 and 6 are necessarily performed, and some steps may be optionally omitted or added. Also, the order of each step is not necessarily set as shown, and the order of the steps of the part or starch may be changed or even performed in parallel.

7 is a flowchart illustrating an image encoding method according to an embodiment of the present invention.

The image coding apparatus 100 generates a change reference block reflecting the motion compensation coefficient calculated using the current block adjacent pixel and the reference block adjacent pixel in the reference block indicated by the current motion vector as a prediction block of the current block (S710 ), The residual block is generated by subtracting the current block from the prediction block (S720), and the residual data is encoded to generate the encoded data.

In step S710, the image encoding apparatus 100 may generate a change reference block as a prediction block of the current block based on the encoding cost of the reference block and the encoding cost of the change reference block. In this case, the motion compensation coefficient is used Can be included in the encoded data. For example, when the coding cost of the reference block is greater than the coding cost of the reference block to generate a change reference block as a prediction block of the current block, the image coding apparatus 100 performs motion compensation In the case of including the coefficient use information (for example, flag '1') in the encoded data and generating the reference block as a prediction block of the current block because the encoding cost for the reference block is smaller than or equal to the encoding cost for the change reference block , Motion compensation coefficient usage information (e.g., flag '0') indicating that the motion compensation coefficient is not used is not included in the encoded data.

In step S710, the image coding apparatus 100 may generate a change reference block as a prediction block of the current block based on the value of the motion compensation coefficient. In this case, the motion compensation coefficient use information indicating that the motion compensation coefficient is used It may not be included in the encoded data. In the case of generating the change reference block as a prediction block of the current block on the basis of the value of the motion compensation coefficient, even if the motion compensation coefficient use information is not included in the encoded data, the motion compensation coefficient is applied in the video decoding apparatus, It is possible to judge whether or not to compensate the motion.

FIG. 8 is a block diagram of a video decoding apparatus according to an embodiment of the present invention. Referring to FIG.

An image decoding apparatus 800 according to an embodiment of the present invention includes a decoder 810, an inverse quantizer and an inverse transformer 820, a predictor 830, an adder 840 and a reference picture memory 850 Lt; / RTI &gt;

The decoder 810 decodes the encoded data and restores the quantized residual block having the current motion vector and the quantized transform coefficients. That is, the decoder 810 decodes the encoded data to extract a quantized transform coefficient sequence, and inversely scans the quantized transform coefficient sequence using various inverse scanning methods such as an inverse zigzag scan to recover a residual block having a quantized transform coefficient. At this time, the decoder 810 can extract and decode the residual block encoded in the first field included in the encoded data, extract information necessary for prediction in the second field included in the encoded data, or decode the extracted information The predictor 830 can predict the current block in the same manner as the predictor 110 of the image encoding apparatus 100 by transmitting information extracted or extracted and decoded and necessary for prediction to the predictor 830 have. If the second field of the encoded data includes the motion compensation coefficient use information, the decoder 830 may extract the motion compensation coefficient use information and transmit the extracted information to the predictor 830.

The inverse quantizer and inverse transformer 820 dequantize the quantized residual block, which is decoded by the decoder 810, to generate an inverse quantized residual block, inversely transform the inverse quantized residual block, The branch restores the residual block.

8 shows that the decoder 810 and the inverse quantizer and the inverse transformer 820 are independently implemented, the functions of the decoder 810, the inverse quantizer and the inverse transformer 820 are integrated And may be implemented as a single decoder. In the case where the functions of the decoder 810, the inverse quantizer and the inverse transformer 820 are integrated, the decoder can decode the encoded data to recover the current motion vector and the residual block, The motion compensation coefficient use information can be extracted from the encoded data.

The predictor 830 predicts a change reference block reflecting a motion compensation coefficient calculated using a current block adjacent pixel and a reference block adjacent pixel in a reference block indicated by a current motion vector decoded and reconstructed from encoded data, . That is, the predictor 830 generates a prediction block for the current block using information required for prediction such as the current motion vector, motion compensation coefficient usage information, and the like from the decoder 810. When the predictor 830 receives the motion compensation coefficient use information from the decoder 610, the predictor 830 applies a motion compensation coefficient based on the motion compensation coefficient use information transmitted when the prediction block is generated, And generate a prediction block. The predictor 830 will be described in detail with reference to FIG. 9 in the following process.

The adder 840 adds the residual block restored by the inverse quantizer and the inverse transformer 820 to the prediction block generated by the predictor 830, and restores the current block. The current block reconstructed by the adder 840 is transferred to the reference frame memory 850 and accumulated as a reference picture in units of pictures in the reference frame memory 850. The reference picture is predicted by the predictor 830 in another block Or to predict other frames.

Although not shown in FIG. 8, the video decoding apparatus 800 according to an embodiment of the present invention may further include an intra predictor for intra prediction, a deblocking filter for deblocking and filtering the restored current block, and the like . In addition, the inverse quantizer and inverse transformer 820 may further perform an inverse transform and an inverse quantization operation on a specific picture (for example, an intra picture).

9 is a block diagram schematically illustrating an inter prediction apparatus for predictive decoding according to an embodiment of the present invention.

The inter prediction apparatus for predictive decoding according to an embodiment of the present invention can be implemented as a predictor 830 in the image decoding apparatus 800 according to an embodiment of the present invention described above with reference to FIG. Quot; predictor 830 &quot;.

The predictor 830 may include a motion compensation coefficient calculator 910 and a motion compensator 920.

The motion compensation coefficient calculator 910 decodes the encoded data to generate a reference block indicated by the current motion vector to be reconstructed, and calculates a motion compensation coefficient using the current block adjacent pixel and the reference block adjacent pixel. That is, when the motion compensation coefficient calculator 910 receives the current motion vector recovered from the decoder 810 or from the motion compensator 920 by the decoder 810, And calculates the motion compensation coefficient using the current block adjacent pixel and the reference block adjacent pixel. The motion compensation coefficient calculator 910 calculates the motion compensation coefficient using the current block neighboring pixel and the reference block neighboring pixel by calculating the motion compensation coefficient in the motion compensation coefficient calculator 220 described above with reference to FIGS. The detailed description thereof will be omitted.

The motion compensator 920 generates a change reference block by reflecting the motion compensation coefficient in the reference block, and determines the change reference block as a prediction block of the current block. Here, the motion compensator 920 may determine the change reference block as a prediction block of the current block based on the motion compensation coefficient use information or the motion compensation coefficient.

For example, when the motion compensation coefficient usage information is received from the decoder 810, the motion compensation coefficient calculator 910 calculates a motion compensation coefficient using information on the motion compensation coefficient, And when the motion compensation coefficient use information indicates that the motion compensation coefficient is not used, the reference block may be determined as a prediction block of the current block. That is, when motion compensation coefficient use information is included in the coded data, the image coding apparatus 100 applies the motion compensation coefficient based on the coding cost for the reference block and the coding cost for the change reference block, (For example, flag '1') or whether the motion compensation coefficient use information indicates the use of the motion compensation coefficient (for example, flag '1') or not '0') and determine whether to determine the change reference block as a prediction block of the current block or the reference block as a prediction block of the current block according to the determination.

As another example, when the motion compensation coefficient is not '0', the motion compensation coefficient calculator 910 determines the change reference block as a prediction block of the current block. If the motion compensation coefficient is '0' Alternatively, when the motion compensation coefficient is within a preset range, the change reference block is determined as a prediction block of the current block. If the motion compensation coefficient is outside the predetermined range, the reference block can be determined as the prediction block of the current block. That is, when the motion compensation coefficient use information is not included in the coded data, the motion compensation coefficient is applied based on the value of the motion compensation coefficient in the image coding apparatus 100 to determine whether to compensate the motion of the current block. It is determined whether the value of the motion compensation coefficient satisfies a preset condition (that is, whether the motion compensation coefficient is '0' and / or whether the motion compensation coefficient is within a predetermined range ) And determine whether to determine the change reference block as a prediction block of the current block or the reference block as a prediction block of the current block according to the determination.

Hereinafter, an inter prediction method for predictive decoding performed by the predictor 830 described above with reference to FIG. 8 will be described.

According to the inter prediction method for predictive decoding, the predictor 830 generates a reference block indicated by a current motion vector reconstructed by decoding the encoded data, and calculates a motion compensation coefficient using a current block adjacent pixel and a reference block adjacent pixel Calculates a change reference block by reflecting the motion compensation coefficient in the reference block, and determines the change reference block as a prediction block of the current block.

Here, if the motion compensation coefficient use information extracted from the encoded data indicates that the motion compensation coefficient is used, the predictor 830 determines the change reference block as a prediction block of the current block, and the motion compensation coefficient use information uses the motion compensation coefficient The reference block can be determined as a prediction block of the current block.

If the motion compensation coefficient is not '0', the predictor 830 determines the change reference block as a prediction block of the current block. If the motion compensation coefficient is '0', the predictor 830 determines the reference block as a prediction block of the current block, When the compensation coefficient is within the predetermined range, the change reference block is determined as a prediction block of the current block. If the compensation coefficient is outside the predetermined range, the reference block can be determined as the prediction block of the current block.

FIG. 10 is a flowchart illustrating an example of an inter prediction method for predictive decoding according to an embodiment of the present invention.

The inter prediction method for predictive decoding according to an embodiment of the present invention described above can be implemented as shown in FIG. That is, the predictor 830 may generate a prediction block by determining whether to perform motion compensation of the current block by applying a motion compensation coefficient based on the motion compensation coefficient usage information.

Referring to FIG. 10, the predictor 830 generates a reference block indicated by a current motion vector reconstructed by decoding the encoded data (S1010), and uses motion compensation coefficient information extracted from the encoded data as a motion compensation coefficient (S1020). If the motion compensation coefficient use information indicates that the motion compensation coefficient is used, a motion compensation coefficient is calculated using the current block neighboring pixel and the reference block neighboring pixel (S1030) (S1040). In step S1040, the reference block that does not reflect the motion compensation coefficient is determined as a prediction block of the current block (S1050).

11 is a flowchart for explaining another example of the inter prediction method for predictive decoding according to an embodiment of the present invention.

The inter prediction method for predictive decoding according to an embodiment of the present invention described above can be implemented as shown in FIG. That is, the predictor 830 can generate a prediction block by determining whether to perform motion compensation of the current block by applying a motion compensation coefficient based on the value of the motion compensation coefficient. Referring to FIG. 11, the predictor 830 decodes the encoded data and generates a reference block indicated by the current motion vector to be reconstructed (S1110). Using the current block neighboring pixel and the reference block neighboring pixel, (S1130). If the motion compensation coefficient is not '0', it is determined whether the motion compensation coefficient is within a predetermined range, that is, whether the motion compensation coefficient is less than the lower limit threshold (S1140). If the motion compensation coefficient is within a predetermined range, the motion compensation coefficient determination unit 120 determines the change reference block as a prediction block of the current block (S1150). If the decision result in the step S1130 is less than the motion compensation coefficient Is '0' or the determination result in step S1140 is out of the preset range, the reference block is determined as a prediction block (S1160).

Although it has been shown and described that both steps S1130 and S1140 are performed in Fig. 11, only one of steps S1130 and S1140 may be performed. That is, the predictor 830 does not necessarily determine the change reference block as a prediction block of the current block only when the value of the motion compensation coefficient is not '0' and is within a predetermined range. If the value of the motion compensation coefficient is '0' The change reference block can be determined as a prediction block of the current block irrespective of whether it is within a preset range or not if the value of the motion compensation coefficient is within a predetermined range, As shown in FIG.

In addition, not all of the steps described above through FIGS. 10 and 11 are necessarily performed, and some steps may be optionally omitted or added. Also, the order of each step is not necessarily set as shown, and the order of the steps of the part or starch may be changed or even performed in parallel.

12 is a flowchart illustrating an image decoding method according to an embodiment of the present invention.

The video decoding apparatus 800 decodes the encoded data to recover the current motion vector and the residual block (S1210), and calculates the motion vector using the current block neighboring pixel and the reference block neighboring pixel in the reference block indicated by the current motion vector to be restored (S720), and restores the current block by adding the residual block to be restored to the predicted block (S1230).

For this, the image decoding apparatus 800 may extract motion compensation coefficient use information from the encoded data. In this case, if the motion compensation coefficient use information indicates that the motion compensation coefficient is used, the image decoding apparatus 800 determines the change reference block to be the prediction block of the current block in step S720. If the motion compensation coefficient use information uses the motion compensation coefficient The reference block can be determined as a prediction block of the current block.

Also, the image decoding apparatus 800 can determine whether to apply the motion compensation coefficient itself without extracting the motion compensation coefficient use information from the encoded data. That is, when the motion compensation coefficient use information is not extracted from the coded data, the video decoding apparatus 800 determines the change reference block as a prediction block of the current block if the motion compensation coefficient is not '0' 0 ', the reference block can be determined as a prediction block of the current block. Alternatively, if the motion compensation coefficient is within a predetermined range, the image decoding apparatus 800 determines the change reference block as a prediction block of the current block. If the motion compensation coefficient is out of the predetermined range, the reference block is determined as a prediction block of the current block .

As described above, according to an embodiment of the present invention, a motion compensation coefficient is adaptively calculated according to characteristics of an image and is reflected in a prediction block to more accurately predict a block to be encoded, The compression efficiency can be improved.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. That is, within the scope of the present invention, all of the components may be selectively coupled to one or more of them. In addition, although all of the components may be implemented as one independent hardware, some or all of the components may be selectively combined to perform a part or all of the functions in one or a plurality of hardware. As shown in FIG. The codes and code segments constituting the computer program may be easily deduced by those skilled in the art. Such a computer program can be stored in a computer-readable storage medium, readable and executed by a computer, thereby realizing an embodiment of the present invention. As the storage medium of the computer program, a magnetic recording medium, an optical recording medium, a carrier wave medium, or the like may be included.

Furthermore, the terms "comprises", "comprising", or "having" described above mean that a component can be implanted unless otherwise specifically stated, But should be construed as including other elements. All terms, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Commonly used terms, such as predefined terms, should be interpreted to be consistent with the contextual meanings of the related art, and are not to be construed as ideal or overly formal, unless expressly defined to the contrary.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

As described above, the present invention is applied to an image compression processing field in which an image is encoded, decoded, and transmitted, and a motion compensation coefficient is adaptively calculated according to characteristics of an image, Prediction is performed, thereby reducing the difference between the actual block and the predicted block, thereby improving the compression efficiency.

1 is a block diagram schematically illustrating a configuration of a video encoding apparatus according to an embodiment of the present invention;

2 is a block diagram schematically illustrating an inter prediction apparatus for predictive coding according to an embodiment of the present invention.

FIG. 3 is a diagram illustrating neighboring pixels for calculating a motion compensation coefficient according to an exemplary embodiment of the present invention. FIG.

4 is an exemplary diagram for explaining an adjacent pixel for each inter-prediction mode according to an embodiment of the present invention.

5 is a flowchart for explaining an example of an inter prediction method for predictive coding according to an embodiment of the present invention.

6 is a flowchart for explaining another example of an inter prediction method for predictive coding according to an embodiment of the present invention.

FIG. 7 is a flowchart illustrating a method of encoding an image according to an embodiment of the present invention. FIG.

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

9 is a block diagram schematically illustrating an inter prediction apparatus for predictive decoding according to an embodiment of the present invention.

FIG. 10 is a flowchart for explaining an example of an inter prediction method for predictive decoding according to an embodiment of the present invention. FIG.

11 is a flowchart for explaining another example of an inter prediction method for predictive decoding according to an embodiment of the present invention.

12 is a flowchart illustrating an image decoding method according to an embodiment of the present invention.

Claims (28)

In an inter prediction method for predictive coding, Estimating motion of a current block to determine a current motion vector; Generating a reference block indicated by the current motion vector; Calculating a motion compensation coefficient using a current block adjacent pixel and a reference block adjacent pixel; Generating a change reference block by reflecting the motion compensation coefficient to the reference block; And Determining the change reference block as a prediction block of the current block Lt; / RTI &gt; Wherein the motion compensation coefficient And a difference between an average of the current block adjacent pixels and an average of the reference block adjacent pixels. The method of claim 1, wherein the step of determining, as a prediction block of the current block, Wherein the change reference block is determined as a prediction block of the current block based on a coding cost for the reference block and a coding cost for the change reference block. In an inter prediction method for predictive coding, Estimating motion of a current block to determine a current motion vector; Generating a reference block indicated by the current motion vector; Calculating a motion compensation coefficient using a current block adjacent pixel and a reference block adjacent pixel; Generating a change reference block by reflecting the motion compensation coefficient to the reference block; And Determining the change reference block as a prediction block of the current block Lt; / RTI &gt; Wherein the step of determining, as a prediction block of the current block, Calculating a coding cost for the reference block; Calculating a coding cost for the change reference block; Determining the change reference block as a prediction block of the current block if the encoding cost for the reference block is greater than the encoding cost for the change reference block; And Determining the reference block as a prediction block of the current block if the encoding cost for the reference block is less than or equal to the encoding cost for the change reference block The inter prediction method comprising the steps of: The method of claim 1, wherein the step of determining, as a prediction block of the current block, And determines the change reference block as a prediction block of the current block based on the value of the motion compensation coefficient. In an inter prediction method for predictive coding, Estimating motion of a current block to determine a current motion vector; Generating a reference block indicated by the current motion vector; Calculating a motion compensation coefficient using a current block adjacent pixel and a reference block adjacent pixel; Generating a change reference block by reflecting the motion compensation coefficient to the reference block; And Determining the change reference block as a prediction block of the current block Lt; / RTI &gt; Wherein the step of determining, as a prediction block of the current block, Determining the change reference block as a prediction block of the current block if the motion compensation coefficient is not '0'; And If the motion compensation coefficient is '0', determining the reference block as a prediction block of the current block The inter prediction method comprising the steps of: In an inter prediction method for predictive coding, Estimating motion of a current block to determine a current motion vector; Generating a reference block indicated by the current motion vector; Calculating a motion compensation coefficient using a current block adjacent pixel and a reference block adjacent pixel; Generating a change reference block by reflecting the motion compensation coefficient to the reference block; And Determining the change reference block as a prediction block of the current block Lt; / RTI &gt; Wherein the step of determining, as a prediction block of the current block, Determining the change reference block as a prediction block of the current block if the motion compensation coefficient is within a predetermined range; And Determining the reference block as a prediction block of the current block if the motion compensation coefficient is out of the predetermined range The inter prediction method comprising the steps of: 7. The method according to claim 6, And the upper limit threshold value and the lower limit threshold value are determined using at least one of a variance, a standard deviation, and a correlation coefficient of the current block adjacent pixel and the reference block adjacent pixel And the inter prediction method. The method of claim 1, wherein the step of determining, as a prediction block of the current block, Wherein the current motion vector is further re-adjusted by further estimating motion of the current block by applying the motion compensation coefficient. delete In an inter prediction method for predictive coding, Estimating motion of a current block to determine a current motion vector; Generating a reference block indicated by the current motion vector; Calculating a motion compensation coefficient using a current block adjacent pixel and a reference block adjacent pixel; Generating a change reference block by reflecting the motion compensation coefficient to the reference block; And Determining the change reference block as a prediction block of the current block Lt; / RTI &gt; The current block neighboring pixel and the reference block neighboring pixel, Wherein the current block is a pixel that has been coded, decoded, and reconstructed before the current block is coded. In an inter prediction method for predictive coding, Estimating motion of a current block to determine a current motion vector; Generating a reference block indicated by the current motion vector; Calculating a motion compensation coefficient using a current block adjacent pixel and a reference block adjacent pixel; Generating a change reference block by reflecting the motion compensation coefficient to the reference block; And Determining the change reference block as a prediction block of the current block Lt; / RTI &gt; Wherein the step of generating the change reference block comprises: Wherein the change reference block is generated by subtracting the motion compensation coefficient from each pixel of the reference block. 12. The method of claim 11, wherein generating the change reference block comprises: Wherein the change reference block is generated by limiting a value obtained by subtracting the motion compensation coefficient from each pixel of the reference block to a value within which a pixel is represented. delete delete delete delete delete delete In an inter prediction method for predictive decoding, Generating a reference block indicated by a current motion vector reconstructed by decoding the encoded data; Calculating a motion compensation coefficient using a current block adjacent pixel and a reference block adjacent pixel; Generating a change reference block by reflecting the motion compensation coefficient to the reference block; And Determining the change reference block as a prediction block of the current block The inter prediction method comprising the steps of: 20. The method of claim 19, wherein the step of determining as a prediction block of the current block comprises: Wherein the motion compensation coefficient determination unit determines the change reference block as a prediction block of the current block when the motion compensation coefficient use information extracted from the encoded data indicates that the motion compensation coefficient is used, The prediction block determining unit determines the reference block as a prediction block of the current block. delete delete delete delete delete delete delete delete

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