JP2012023514A - Encoding device and decoding device adaptively determining scan order of orthogonal transform coefficient - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a video encoding device, a video decoding device, and a program thereof which adaptively determine a rearrangement order.SOLUTION: An encoding device comprises: a signal prediction unit 21 for generating a prediction signal predicted from a block signal obtained by locally decoding a block signal to be encoded; an orthogonal transformation unit 12 for applying two-dimensional orthogonal transformation to a prediction difference signal consisting of a difference between the block signal to be encoded and the prediction signal to generate a two-dimensional signal based on orthogonal transformation coefficients of a two-dimensional array; and a coefficient rearrangement unit 14 for generating adjacent pixel difference signals with respect to a pixel group constituting the prediction signal and pixel groups constituting decoded block signals adjacent to the prediction signal, calculating an energy distribution by applying one-dimensional orthogonal transformation to the respective adjacent pixel difference signals, determining the rearrangement order of rows and/or columns of the two-dimensional array based on energy values, and rearranging the signal components of the orthogonal transformation coefficients of the two-dimensional array to a one-dimensional signal.

Description

  The present invention relates to a method of encoding a multidimensional signal using orthogonal transform, and adaptively determines a scanning order (scanning order) when transmitting a signal subjected to orthogonal transform, and performs efficient coding. The present invention relates to an encoding device and a decoding device for realizing the above.

  As typical systems for encoding multidimensional signals, MPEG-2 and MPEG-4 AVC / H. H.264. In these encoding methods, an input signal is converted into an expression by frequency component energy by orthogonal transform (for example, DCT). For example, in the case of a two-dimensional DCT, a signal component having a low frequency is arranged on the upper left and a signal component having a high frequency is arranged on the lower right when represented in a two-dimensional array. In general, in a signal in which DCT is used, energy is biased toward a low-frequency component. For example, in the case of a video signal, it is known that the sensitivity to a low-frequency signal is high as a human visual characteristic. The signal of the frequency component is regarded as important.

  Because of this property, zigzag scanning that rearranges coefficients from low frequency components to zigzag when rearranging to a one-dimensional signal for signal transmission is used.

  Further, according to such rearrangement to a one-dimensional signal, it is expected that the signal sequence will be arranged in descending order, and by transmitting some coefficients from the top and cutting off the subsequent coefficients, Most of the information can be transmitted, and the amount of data to be transmitted can be reduced.

  As a technique for improving the coding performance by changing the scanning order as described above, the distribution of the orthogonal transform coefficients has a specific bias according to the characteristics included in the signal, and a plurality of predetermined values obtained by signal analysis are used. A technique for improving the coding efficiency by selecting an appropriate scanning order is known (see, for example, Patent Document 1).

  In addition, a technique is known that selectively switches the scanning order depending on a prediction method (selected depending on the property of the image) predetermined in the encoding method to improve the encoding efficiency (for example, Patent Document 2).

Japanese Patent No. 4128604 JP 2009-27541 A

  MPEG-2 and MPEG-4 AVC / H. In an encoding method such as H.264, various signal prediction techniques (for example, motion compensation prediction and intra prediction) are employed to express a signal with less number. The signal that is actually orthogonally transformed using the signal prediction technique is not a signal source itself but a difference signal between the predicted signal and the actual signal. The orthogonal transformation result of the prediction difference signal does not necessarily concentrate on the frequency component having low energy, and often the coding efficiency is not suitable.

  Further, in the techniques of Patent Documents 1 and 2 that disclose a technique for improving the encoding performance by changing the scanning order, it is necessary to prepare and selectively switch a plurality of patterns in the order designed in advance when determining the scanning order. The gain depends on the number of patterns in the order designed in advance, and in order to prevent this, a large number of patterns must be prepared in advance. A multi-bit control flag indicating whether it has been used must be transmitted.

An object of the present invention is to efficiently determine a scanning order (scanning order) when transmitting an orthogonally transformed signal without using a plurality of patterns prepared in advance, in view of the above-described problem, and efficiently. It is an object to provide an encoding device and a decoding device for realizing proper encoding.
Another object of the present invention is to provide an encoding device and a decoding device that can perform pattern switching with a small amount of switching information even when a plurality of patterns of scanning orders prepared in advance are prepared. To provide an apparatus.

  Video signals and audio signals are signals having high correlation between signals that are temporally or spatially adjacent. For such signals, signal prediction techniques such as motion compensation prediction and intra prediction are used in video coding schemes such as MPEG. For example, in motion compensation prediction, a signal similar to a coding region included in a different frame is detected and used for prediction. While the high correlation between the frame signals at different times is used, the correlation between adjacent regions in the same frame is not used.

  Therefore, according to the present invention, in rearranging the signals, the energy of the coefficients is rearranged more appropriately in descending order.

  More specifically, the encoding device according to the present invention is a coding device that predicts a signal to be encoded from a decoded signal, and calculates a difference signal (prediction difference signal) between the signal to be encoded and the prediction signal. Performs two-dimensional orthogonal transform processing, adaptively rearranges the two-dimensional signal into a one-dimensional signal based on the difference signal between adjacent signals of the prediction signal and the decoded signal around the processing region, and encodes the one-dimensional signal Configured to do. The scanning means for rearranging the two-dimensional signal into the one-dimensional signal performs a one-dimensional orthogonal transform on a difference signal between adjacent signals of the prediction signal and a decoded signal around the processing region, and orthogonalizes based on the energy distribution of the orthogonal transform coefficient. The rearrangement order of the converted signals is determined.

  On the other hand, the decoding apparatus according to the present invention predicts a signal to be decoded from a decoded signal and adaptively uses a one-dimensional signal based on a difference signal between adjacent signals of the prediction signal and a decoded signal in the processing region range. Are rearranged into a two-dimensional signal, and the prediction difference signal decoded by inverse orthogonal transform and the prediction signal are added to decode the image. Also on the decoding device side, the scanning means for rearranging the two-dimensional signal into the one-dimensional signal performs one-dimensional orthogonal transformation on the difference signal between adjacent signals of the prediction signal and the decoded signal around the processing region, and calculates the orthogonal transformation coefficient. The rearrangement order of signals orthogonally transformed based on the energy distribution is determined.

  That is, the encoding apparatus of the present invention is an encoding apparatus that encodes a moving image, and generates a prediction signal predicted from a locally decoded block signal for a block signal to be encoded in the moving image. Means, and orthogonal transform means for performing two-dimensional orthogonal transformation on a prediction difference signal composed of a difference between the block signal to be encoded and the prediction signal, and generating a two-dimensional signal based on an orthogonal transformation coefficient of a two-dimensional array; A pixel group that constitutes the prediction signal, and a pixel group that constitutes a decoded block signal that is adjacent to any one or more of up, down, left, and right of the prediction signal. A difference in a processing target area having a predetermined number of pixels from the position where the pixels constituting the decoding block signal are adjacent to each other, and the already decoded block adjacent to any one or more of the upper, lower, left, and right. A neighboring pixel difference signal is generated for each of the neighboring signals, and a one-dimensional orthogonal transformation is performed on each neighboring pixel difference signal to calculate an energy distribution. Based on the calculated energy value, the two-dimensional array column and / or Energy rank predicting means for determining a row rearrangement order and generating a control signal representing the rearrangement order, and based on the control signal, a signal component of the two-dimensional signal based on the orthogonal transform coefficient of the two-dimensional array Scanning means for rearranging into a one-dimensional signal, and encoding means for encoding the one-dimensional signal. This encoding process corresponds to adaptively determining the scan order of orthogonal transform coefficients. The decoded block signal that is adjacent to any one or more of the predicted signal in the upper, lower, left, and right directions is, for example, an already decoded block that is adjacent to the predicted signal on the upper, lower, left, and right sides. Since the order of the block signals to be decoded first is determined according to the encoding method, it is preferable to select adjacent block signals according to the order according to the encoding method.

  Further, in the encoding device of the present invention, the energy rank prediction unit generates an adjacent pixel difference signal for a decoded block signal adjacent to any one or more of the upper, lower, left and right, and each adjacent pixel difference signal. The one-dimensional orthogonal transformation is applied to the energy distribution to calculate the energy distribution, the calculated energy values are weighted according to frequency components, and the columns and / or rows of the two-dimensional array are arranged in descending order from the largest. The rearrangement order is determined, and a control signal representing the rearrangement order is generated.

  Further, in the encoding device of the present invention, the energy rank prediction means generates adjacent pixel difference signals for the decoded block signals adjacent to the left side and the upper side, respectively, and performs one-dimensional processing on each adjacent pixel difference signal. The energy distribution is calculated by performing orthogonal transformation, and the rearrangement order of the columns and / or rows of the two-dimensional array is determined so that the calculated energy value is in descending order, and the rearrangement order is expressed. It has a means for generating a control signal.

  In the encoding device according to the present invention, the processing target region includes a plurality of pixels including pixels that constitute the prediction signal adjacent to each other and pixels that constitute the decoded block signal. .

  In the encoding device of the present invention, the pattern for rearranging the signal components of the two-dimensional signal into a one-dimensional signal is composed of a plurality of patterns prepared in advance, and the scanning unit is controlled by the energy rank prediction unit. It has a means for switching the plurality of patterns by a signal.

  In the encoding device according to the present invention, the scanning unit may perform a row operation based on the control signal determined by calculating an energy distribution for the row out of the two-dimensional signal based on the orthogonal transform coefficient of the two-dimensional array. First scanning means for performing rearrangement, among the two-dimensional signals based on the orthogonal transform coefficients of the two-dimensional array, the first scanning unit performs rearrangement for the columns based on the control signal determined by calculating the energy distribution for the columns. Among the two-dimensional signals based on the orthogonal transform coefficients of the two-dimensional array and the two-dimensional array, the rows and / or columns are rearranged based on the control signals determined by calculating the energy distribution for the rows and / or columns. A third scanning unit that performs scanning, and a fourth scanning unit that scans in the predetermined rearrangement order among the two-dimensional signals based on the orthogonal transformation coefficients of the two-dimensional array. Instead, it has switching means for rearranging the signal components of the two-dimensional signal based on the orthogonal transform coefficients of the two-dimensional array into a one-dimensional signal, and the coding efficiency of the coding means is compared for the switching of the rearrangement. Control the switching means and compare the coding efficiency when using the rearrangement of the row and / or column and when not using the rearrangement, and select the one with the highest coding efficiency The apparatus further comprises output judging means for performing the above.

  Further, the decoding device of the present invention is a decoding device for decoding a signal encoded for a moving image, and a decoding means for inputting the bit stream encoded for the moving image and decoding the one-dimensional signal. A signal prediction unit that generates a prediction signal from a block signal that has already been decoded, a pixel group that constitutes the prediction signal, and a decoded block signal that is adjacent to the prediction signal in any one of the upper, lower, left, and right directions With respect to the constituent pixel group, any one of the upper, lower, left, and right sides is subtracted within a processing target area having a predetermined number of pixels from a position where the pixel constituting the prediction signal and the pixel constituting the decoded block signal are adjacent to each other. Generate an adjacent pixel difference signal for a decoded block signal adjacent to one or more, and perform one-dimensional orthogonal transformation on each adjacent pixel difference signal to calculate the energy distribution Energy order predicting means for determining a rearrangement order of the columns and / or rows of the two-dimensional array used in the inverse orthogonal transform process based on the calculated energy value, and generating a control signal representing the rearrangement order; Based on the control signal, scanning means for rearranging the signal component of the one-dimensional signal into a two-dimensional signal based on the orthogonal transform coefficient of the two-dimensional array, and an inverse orthogonal transform that performs inverse orthogonal transformation on the two-dimensional signal Means, and addition means for adding the signal obtained by performing the inverse orthogonal transform and the prediction signal to restore a block signal in the moving image. This decoding process corresponds to adaptively determining the scan order of orthogonal transform coefficients.

  Further, the program of the present invention generates a prediction signal predicted from a locally decoded block signal for a block signal to be encoded in a moving image in a computer configured as an encoding device for encoding a moving image; Performing a two-dimensional orthogonal transformation on a prediction differential signal composed of a difference between the block signal to be encoded and the prediction signal to generate a two-dimensional signal based on an orthogonal transformation coefficient of a two-dimensional array; And the pixel group constituting the decoded block signal adjacent to any one or more of the prediction signal in the vertical and horizontal directions with respect to the prediction signal, and the pixel signal constituting the prediction signal and the decoded block signal Adjacent to one or more of the top, bottom, left, and right by making a difference within a processing target region having a predetermined number of pixels from the position where the pixels constituting the An adjacent pixel difference signal for the decoded block signal is generated, and one-dimensional orthogonal transformation is performed on each adjacent pixel difference signal to calculate an energy distribution. Based on the calculated energy value, the two-dimensional array sequence and And / or determining a row rearrangement order and generating a control signal representing the rearrangement order; and based on the control signal, the signal component of the two-dimensional signal based on the orthogonal transformation coefficient of the two-dimensional array is 1 It is a program for executing a step of rearranging to a one-dimensional signal and a step of encoding the one-dimensional signal.

  The program of the present invention includes a step of inputting a bit stream encoded for a moving image to a computer configured as a decoding device for decoding a signal encoded for the moving image, and decoding the one-dimensional signal; Generating a prediction signal from a block signal that has already been decoded, a group of pixels that form the prediction signal, and a block signal that has already been decoded and is adjacent to at least one of the top, bottom, left, and right of the prediction signal With respect to a pixel group, any one of the top, bottom, left, and right is obtained by making a difference within a processing target area having a predetermined number of pixels from a position where a pixel constituting the prediction signal and a pixel constituting the decoded block signal are adjacent to each other. The adjacent pixel difference signal for the already decoded block signal adjacent to the above is generated, and one-dimensional orthogonal transformation is performed on each adjacent pixel difference signal to obtain the error. Calculating a ruby distribution, determining a rearrangement order of columns and / or rows of a two-dimensional array used in inverse orthogonal transform processing based on the calculated energy value, and generating a control signal representing the rearrangement order; Rearranging the signal component of the one-dimensional signal based on the control signal into a two-dimensional signal based on the orthogonal transformation coefficient of the two-dimensional array; and performing inverse orthogonal transformation on the two-dimensional signal; A program for adding a signal obtained by performing the inverse orthogonal transform and the prediction signal to restore a block signal in the moving image.

  According to the present invention, it is possible to perform efficient transmission by rearranging signals to be encoded into a small number of coefficient sequences, thereby improving encoding efficiency.

It is a block diagram of the encoding apparatus of one Example by this invention. (A), (b), (c) is a figure which shows the example of scanning. It is a figure explaining exchange of a coefficient sequence. It is a figure which shows the relationship between the signal of the estimated image estimated by motion compensation prediction, and an adjacent decoded signal. (A), (b), (c) is a figure which shows the adjacent pixel difference signal in the encoding apparatus of one Example by this invention. It is a figure which shows the example of replacement | exchange of the coefficient in the encoding apparatus of one Example by this invention. In the encoding apparatus according to an embodiment of the present invention, a lower end pixel of an upper decoded signal that is adjacent in the vertical direction, a right end pixel of an adjacent left decoded signal in the horizontal direction, and a prediction generated by intra prediction or motion compensation prediction It is a figure which illustrates the relationship of a signal. It is a figure which shows the example of conversion into the one-dimensional signal sequence in the encoding apparatus of one Example by this invention. It is a figure which shows the decoding apparatus of one Example by this invention. It is a block diagram of the coefficient rearrangement part of the modification by this invention. It is a block diagram of the coefficient rearrangement part of the modification by this invention.

  First, an encoding apparatus according to an embodiment of the present invention will be described.

[Encoding device]
FIG. 1 is a block diagram of an encoding apparatus according to an embodiment of the present invention. In general, in encoding a moving image, an image is encoded by motion compensation prediction, orthogonal transformation, quantization, and entropy encoding. In the case of an encoding method using motion compensation prediction or intra prediction, a decoding device (local decoder) is included in the encoding device in order to use a decoded image for prediction. In this embodiment, the input signal is subjected to orthogonal transformation of the difference between the prediction signal and the input signal by an encoding method that involves signal prediction, and after quantization processing, the orthogonal transformation coefficients are rearranged to perform entropy coding. An example of performing

  The encoding apparatus 1 of the present embodiment includes a preprocessing unit 10, a subtraction unit 11, an orthogonal transformation unit 12, a quantization unit 13, and a coefficient rearrangement unit 14 that rearranges a two-dimensional signal into a one-dimensional signal. Entropy encoding unit 15, coefficient inverse rearrangement unit 16 that rearranges a one-dimensional signal into a two-dimensional signal, inverse quantization unit 17, inverse orthogonal transform unit 18, addition unit 19, memory 20, and signal prediction Unit 21 and energy rank prediction unit 22.

  The preprocessing unit 10 is a functional unit that performs preprocessing necessary for encoding processing such as frame rearrangement and format conversion. As a more specific example, the preprocessing unit 10 inputs a frame image and holds it in a buffer (not shown). The buffer is divided into macro blocks of 16 × 16 pixels, for example, and the macro blocks are divided into 8 × 8 pixels and sent to the subtracting unit 11 in a predetermined order. Note that the block size and its division can be determined and adopted as appropriate. In the following, an example in which processing is performed in units of pixel blocks of small areas divided into 8 × 8 pixels will be described. Note that the encoding target macroblock is also sent to the signal prediction unit 21.

  In addition, the signal prediction unit 21 receives a signal used as a reference signal as the signal prediction unit, selects a method that gives an optimal prediction from prediction methods determined in advance by an encoding method, and outputs a prediction signal As a more specific example, it is a functional unit that generates a prediction image that predicts a macroblock to be encoded by summarizing both intra prediction and motion compensated prediction, and in the case of motion compensated prediction, a preprocessing unit 10, motion vector detection is performed using the reference image acquired from the memory 20 for the encoding target block supplied from 10, motion compensation is performed using the obtained motion vector, and a prediction image obtained as a result is obtained. The result is output to the subtraction unit 11 and the addition unit 19. The information on the motion vector is sent to the entropy encoding unit 15. In the case of intra prediction, the signal prediction unit 21 performs extrapolation using a reference image acquired from the memory 20, and outputs a prediction image obtained as a result to the subtraction unit 11 and the energy rank prediction unit 22. As a signal prediction method, motion compensation prediction and AVC / H. Although there is intra prediction used in H.264, it is not limited to the prediction method.

  Hereinafter, since the same processing is performed for both intra prediction and motion compensation prediction, the case of motion compensation prediction will be described.

  The subtraction unit 11 generates a differential signal between the encoding target block from the preprocessing unit 10 and the predicted image from the signal prediction unit 21 and sends the difference signal to the orthogonal transformation unit 12.

  The orthogonal transform unit 12 performs orthogonal transform on the difference signal of 8 × 8 blocks supplied from the subtraction unit 11 and sends the result to the quantization unit 13.

  The quantization unit 13 uses the quantization matrix for performing quantization with an array corresponding to the orthogonal transform coefficient of the 8 × 8 block difference signal supplied from the orthogonal transform unit 12, and uses the quantization matrix for the 8 × 8 block difference signal. The orthogonal transform coefficients are quantized, and the obtained quantized blocks are sent to the coefficient rearranging unit 14.

  The coefficient rearranging unit 14 adaptively reads out the quantized block according to the control signal from the energy rank predicting unit 22 with respect to the rearrangement order of the orthogonal transformation matrix quantized by the quantizing unit 13, that is, is orthogonal. The two-dimensional signal of the quantization block corresponding to the transformation matrix is rearranged into a one-dimensional signal for performing entropy coding, and is sent to the entropy coding unit 15.

  The entropy coding unit 15 performs entropy coding processing (selectable adaptive variable length coding processing or arithmetic coding processing) on the quantized block of the one-dimensional signal supplied from the quantization unit 13 and converts the bitstream into a bitstream. While generating, the information of the motion vector supplied from the signal estimation part 21 also performs an entropy encoding process, and outputs it.

  The coefficient inverse rearrangement unit 16 converts the one-dimensional signal for adaptively reading out the quantization blocks in the rearrangement order designated by the control signal from the energy rank prediction unit 22, that is, entropy encoding, to the orthogonal transformation matrix. The two-dimensional signals of the quantization blocks corresponding to are rearranged and sent to the inverse quantization unit 17. That is, the coefficient reverse rearrangement unit 16 converts the one-dimensional signal rearranged by the coefficient rearrangement unit 14 into a two-dimensional signal so as to be in the order of columns and / or rows of the original two-dimensional array of orthogonal transform coefficients. Rearrange.

  The inverse quantization unit 17 performs an inverse quantization process on the quantization block supplied from the coefficient inverse rearrangement unit 16 and outputs the result to the inverse orthogonal transform unit 18.

  The inverse orthogonal transform unit 18 performs inverse orthogonal transform on the orthogonal transform coefficient supplied from the inverse quantization unit 17 and outputs the result to the addition unit 19.

  The adding unit 19 adds the signal obtained by the inverse orthogonal transform obtained from the inverse orthogonal transform unit 18 and the prediction image obtained through the signal prediction unit 21 to generate a decoded image and stores the decoded image in the memory 20. The image stored in the memory 20 is used as a reference image in motion compensation prediction (however, in the case of intra prediction, a reference image in a frame).

  In this embodiment of the video encoding system, in many cases, video signal encoding is an example in which two-dimensional image information is encoded by orthogonal transform. In the irreversible encoding process, the code amount can be reduced by quantizing the orthogonal transform coefficient. In an encoding method including signal prediction, a decoding device (local decoder) is provided in the encoding device, and a decoded adjacent signal and a reference signal used for signal prediction are supplied by decoding processing. In this embodiment, AVC / H. Although a loop filter (deblocking filter) used in H.264 and the like is not shown, a loop filter may be provided.

  Of the predicted image from the signal predicting unit 21 and the reference image stored in the memory 20, the energy rank predicting unit 22 is a group of decoded pixels adjacent to the predicted image (hereinafter referred to as “adjacent decoded signal”). ) To calculate the difference between the pixel group of the adjacent decoded signal and the pixel group of the predicted image adjacent to this pixel group in the horizontal direction and the vertical direction, and obtain the difference in the horizontal direction and the vertical direction, respectively. The obtained difference signal is subjected to a one-dimensional orthogonal transform (for example, DCT) in the horizontal direction and the vertical direction, respectively, to calculate an energy distribution (for example, an absolute value of amplitude) for each row of the two-dimensional array of orthogonal transform coefficients. The absolute value of the signal sequence for each row of the two-dimensional array of orthogonal transform coefficients is sorted in descending order, and the absolute value of the signal sequence for each column of the two-dimensional array of orthogonal transform coefficients is sorted in descending order, so that A control signal representing the rearrangement order of the columns and / or rows of the two-dimensional array of orthogonal transform coefficients ranked in order from the highest to the lowest is generated, and is sent to the coefficient rearrangement unit 14 and the coefficient reverse rearrangement unit 16. Send it out.

  Therefore, the coefficient rearrangement unit 14 uses this control signal to change the two-dimensional signal in the column and / or row rearrangement order of the two-dimensional array of orthogonal transform coefficients ranked in order from the highest energy to the lowest. Can be rearranged into a one-dimensional signal, and the coefficient reverse rearrangement unit 16 uses the control signal to convert the one-dimensional signal rearranged by the coefficient rearrangement unit 14 into the two-dimensional original transformation coefficient. A two-dimensional signal can be rearranged into a one-dimensional signal so as to be in the order of columns and / or rows of the array.

  Note that when rearranging from a two-dimensional signal to a one-dimensional signal, a zigzag scan in which coefficients are rearranged from a low frequency component to a zigzag, or a vertical priority scan or a horizontal priority scan changed according to signal characteristics is used (see FIG. 2 (a), (b), (c)).

  For example, in the example shown in FIG. 3, 100, 50, 42, 32, 45, 30, 20, 14, 36, 9, 20, 15, 20, 12, 0, 8 in the conventional zigzag scanning with low-frequency priority. , 0, 0, 13, 5, 0, 0, 0, 0, 0, 0, 0, 6, (hereinafter 37 coefficients are not transmitted), according to this embodiment, Coefficient sequences to be transmitted by switching the eyes and the sixth row are 100, 50, 42, 32, 45, 30, 20, 14, 36, 9, 20, 15, 20, 12, 8, 0, 6, 0, 13, 5 (hereinafter, 44 coefficients are not transmitted), which can be shortened, and the coding efficiency is improved.

  The operations of the energy rank prediction unit 22, the coefficient rearranging unit 14, and the coefficient reverse rearranging unit 16 will be described in more detail.

  FIG. 4 shows a relationship between a predicted image signal predicted by motion compensation prediction and an adjacent decoded signal. In motion compensation prediction, a signal similar to a coding region included in a different frame is detected and used for prediction. While the high correlation between the frame signals at different times is used, the correlation between adjacent regions in the same frame is not used.

  In general, since an image signal has a high correlation in the spatial direction, a predicted image signal decoded by adding a prediction difference signal also has a high correlation with an adjacent region. From another viewpoint, the prediction difference signal is a component that increases the correlation between the prediction signal of the coding region and the adjacent region with respect to the prediction image signal of the motion compensation prediction that is predicted without using the correlation in the spatial direction. I can say that.

  Assuming that the correlation between adjacent pixels is extremely high, the prediction difference signal in the adjacent region neighboring pixels of the encoding target region is the difference between the adjacent region neighboring pixels of the prediction signal of the encoding target region and the encoding target neighboring pixels of the adjacent region. Can be approximated by difference. For this reason, for example, referring to FIG. 5A, the adjacent pixel difference signal R in the left adjacent area with respect to the encoding target area (predicted signal area) and the upper adjacent area with respect to the encoding coping area. The adjacent pixel difference signal Q is used as an approximate value near the adjacent region of the prediction difference signal. By performing frequency analysis on these neighboring signals, it is possible to approximate the frequency analysis of the prediction difference signal, and use this to optimize scanning (see FIG. 6).

  For example, the example of FIG. 5A shows an example of calculating a difference between adjacent pixels. As shown in FIG. 5B, the encoding target area (predicted signal area) is shown. Generate an adjacent pixel difference signal R between an average value including a simple average or a square average of a plurality of pixels in each row and a pixel in the left adjacent region, or in each column of an encoding target region (predicted signal region) It can be configured to generate an adjacent pixel difference signal Q between an average value including a simple average or a square average of a plurality of pixels and a pixel in the upper adjacent region. Alternatively, an adjacent pixel difference signal R having an average value including a simple average or a square average of a plurality of pixels in each row of the left adjacent region is generated for the encoding target region (prediction signal region), or It may be configured to generate an adjacent pixel difference signal Q based on an average value including a simple average or a square average of a plurality of pixels in each column of the left adjacent region for the conversion target region (prediction signal region). it can.

  Further, as shown in FIG. 5C, as an example of using a pixel group in a neighboring region between adjacent blocks, a simple average or a square average of a plurality of pixels in each row of an encoding target region (predicted signal region) is used. The adjacent pixel difference signal R between the average value including the average value including the simple average or the square average of a plurality of pixels in each row of the left adjacent region, or each of the encoding target regions (predicted signal regions) An adjacent pixel difference signal Q is generated between an average value including a simple average or a square average of a plurality of pixels in a column and an average value including a simple average or a square average of a plurality of pixels in each column of the upper adjacent region. It can be constituted as follows. Alternatively, it is configured such that a column process and / or a row of pixel columns in the encoding target area are subjected to filtering, and a filtering process is performed on the left side area and / or the upper side area to generate the respective difference signals Q and R. be able to. In this case, since the low-pass process is performed on the column of adjacent pixels to be processed and / or the one-dimensional pixel column in the row, there is an effect of suppressing the sensitivity to the high frequency component.

  That is, a specific processing procedure in the energy rank prediction unit 22 will be described. The adjacent difference signal between the decoded signal in the vertical direction and the prediction signal is Q, and the adjacent difference signal between the decoded signal in the horizontal direction and the prediction signal is R. , Q and R are subjected to a one-dimensional orthogonal transformation to obtain a frequency component of a signal that enhances signal correlation.

  The energy (for example, the absolute value of the coefficient) of the frequency components of the one-dimensional orthogonal transform coefficients Q ′ and R ′ in the horizontal direction or the vertical direction is compared, and the frequency component index is switched so that the energy is in descending order.

  For example, when Q ′ [0] = 12, Q ′ [1] = − 30, Q ′ [2] = 4, Q ′ [3] = − 7, the index is changed to 1, 0, 3, 2.

  For example, when R ′ [0] = 8, R ′ [1] = − 2, R ′ [2] = − 4, and R ′ [3] = 0, the indexes are switched to 0, 2, 1, and 3.

  Using the replaced index, the two-dimensional orthogonal transform coefficient is replaced, and zigzag scanning is performed (see FIG. 6).

  The prediction of the same readout order can also be performed on the decoding device side, and coefficient information transmitted in one dimension is arranged in a two-dimensional array by reversely applying a zigzag scan, and the energy order of the estimated difference signal is in order. The information can be correctly restored by replacing the columns and / or rows and rearranging the coefficients in the correct order.

  Although motion compensated prediction has been described as an example, prediction of signal energy order according to the present invention can be similarly performed in intra prediction. In the case of intra prediction, the adjacent pixel difference signal may be 0 in some modes. In this case, the row and the column are not replaced.

  A processing example of the energy rank prediction unit 22 will be further described. An example of the most widely adopted video encoding method using MPEG will be described. In the MPEG video encoding method, a screen is divided into blocks and sequentially encoded. Therefore, the upper and left blocks have already been encoded, and the decoding process is immediately performed by the encoding device as a signal that can be used by the decoder, and is used for encoding the next block. Such a signal is defined as an adjacent decoded signal.

  For example, MPEG-4 AVC / H. In the case of H.264, there are intra prediction and motion compensation prediction. Intra prediction is a method of predicting a signal using a signal of an already decoded adjacent block in the screen, and the signal of the already decoded adjacent block is temporally identical to a reference signal that is an input signal to the signal prediction unit 21. It is a frame. On the other hand, in the case of motion compensation prediction, video signals of temporally different frames are input to the signal prediction unit 21 as reference signals.

  In FIG. 7, the lower end pixel A [x] of the adjacent upper decoded signal in the vertical direction and the right end pixel B [y] of the adjacent left decoded signal in the horizontal direction are generated by intra prediction or motion compensation prediction. The relationship of the prediction signal P [y] [x] is shown.

The difference signals between the adjacent decoded pixels A and B and the upper end and left end signals of the prediction pixel P are subjected to one-dimensional orthogonal transformation, and the indices of the respective orders are switched in order of energy. Here, when Q [x] is the difference between the lower pixel of the upper decoded signal and the upper pixel of the predicted image,
Q [x] = A [x] −P [0] [x],
x = 0, 1, 2,..., N−1
Here, when DCT is used for orthogonal transform coding of the block, one-dimensional DCT is performed on Q [x]. When orthogonal transform, other than DCT, such as DST, for example, is adopted, the transform is performed by a one-dimensional DST as the orthogonal transform.

  In the present embodiment, a case where DCT is used will be described as an example. The coefficient Q ′ [m] of the one-dimensional DCT of the signal Q is as follows.

  Here, m = 0, 1, 2,..., N−1.

Sort () is stored in I _hor [m] as a function that sorts Q ′ in descending order with respect to the absolute value of the signal string and returns an index string.

I _hor = Sort (Q ')
m = 0, 1, 2,..., N−1

For example, if N = 4 and Q ′ is the following coefficient sequence:
Q '= 12, -30, 4, -7
I _hor [m] is
I _hor = 1,0,3,2
It becomes.

Similarly, if R [y] is the difference between the rightmost pixel of the left decoded signal and the leftmost pixel of the predicted image,
R [y] = B [y] -P [y] [0]

  Here, y = 0, 1, 2,..., N−1.

  The coefficient R ′ [n] of the one-dimensional DCT of the signal sequence R is as follows.

  Here, n = 0, 1, 2,..., N−1.

An index string in which the coefficient R ′ is sorted is stored in I _vert [n].
I _vert = Sort (R ′)
n = 0, 1, 2,..., N−1

For example, when N = 4 and the coefficient R ′ is the following coefficient sequence,
R ′ = 8, −2, −4, 0
I _vert [n] is
I _vert = 0, 2, 1, 3
It becomes.

The video signal is known to have a very high correlation between adjacent signals, and the orthogonal transform coefficient distribution of the difference signal between the predicted image and the decoded adjacent signal indicates the correlation between adjacent pixels of the prediction error signal. It can be expected to be a component that enhances. It can be expected that the obtained energy distribution of the orthogonal transformation coefficient of the horizontal component and the vertical component also reflects the energy distribution of the prediction difference signal. Therefore, the obtained index string I _hor , I _vert is used as the energy rank of the horizontal component and the vertical component of the prediction difference signal.

Here, the orthogonal transformation coefficient of the difference signal between the actual signal and the prediction signal P is E [n] [m]. E [n] [m] performs quantization according to the necessity of the encoding method. The orthogonal transformation coefficient E ′ [n] [m] with the exchanged index is realized as follows using I _hor [m], I _vert [n].
E ′ [n] [m] = E [I _vert [[n]] [I _hor [m]]
n, m = 0, 1, 2,..., N−1

For example, if N = 4 and I _hor = 1, 0, 3, 2, Ivert = 0, 2, 1, 3, E ′ [n] “m” is represented by E [n] [m] as shown in FIG. Configured.

  The orthogonal transform coefficient E ′ [n] [m] with the replaced index is converted into a one-dimensional signal by a zigzag scan.

  For example, as shown in FIG. 8, as an example of conversion to a one-dimensional signal sequence, E [0] [1], E [0] [0], E [2] [1], E [1] [1] , E [2] [0], E [0] [3], E [0] [2], E [2] [3], E [1] [0], E [3] [1], E [3] [0], E [1] [3], E [2] [2], E [1] [2], E [3] [3], E [3] [2].

  As described above, when the encoding apparatus 1 according to the present embodiment predicts the signal to be encoded from the decoded signal, the difference signal (prediction difference signal) between the signal to be encoded and the prediction signal is two-dimensionally orthogonalized. Transform the difference signal between adjacent signals of the prediction signal and the decoded signal around the processing region, and determine the rearrangement order of the orthogonally transformed signal based on the energy distribution of the orthogonal transformation coefficient Thus, since the two-dimensional signal is adaptively rearranged into a one-dimensional signal and the one-dimensional signal is entropy-encoded, the signal to be encoded can be rearranged into a small number of coefficient sequences, and efficient transmission can be performed. Thus, encoding efficiency can be improved.

  The energy rank prediction unit 22 generates an adjacent pixel difference signal for each of the decoded block signals adjacent to one or more of the upper, lower, left, and right, and performs one-dimensional orthogonal transformation on each adjacent pixel difference signal. Calculating the energy distribution, weighting the calculated energy value by frequency component, and determining the rearrangement order of the columns and / or rows of the two-dimensional array in descending order from the largest, A control signal representing the rearrangement order can be generated. For this weighting, it is preferable to perform weighting such that the lower frequency component is scanned first. For example, when the coefficient Q ′ [m] (m = 0, 1, 2,..., N−1) of the one-dimensional DCT of the signal Q is taken as an example, from m = 0 toward m = N−1. After multiplying the absolute value of the amplitude by a weighting factor that decreases in order, the energy distribution is calculated.

  Next, a decoding apparatus according to an embodiment of the present invention will be described.

[Decoding device]
FIG. 9 shows a block diagram of a decoding apparatus according to an embodiment of the present invention. The decoding device 5 of the present embodiment includes an entropy decoding unit 51, a coefficient inverse rearrangement unit 52, an inverse quantization unit 53, an inverse orthogonal transform unit 54, an addition unit 55, a post-processing unit 56, and a memory 57. And a signal prediction unit 58 and an energy rank prediction unit 59. The decoding device 5 of the present embodiment is a device that decodes the signal encoded by the encoding device shown in FIG.

  The entropy decoding unit 51 receives the encoded bit stream, performs entropy decoding processing (adaptive variable length decoding processing or arithmetic coding decoding processing specified on the encoding device side), and reverse coefficient rearrangement The data is sent to the replacement unit 52.

  The coefficient inverse rearrangement unit 52 reads out the quantization blocks in the rearrangement order designated by the control signal from the energy rank prediction unit 59 and sends the quantization blocks to the inverse quantization unit 53. The motion vector information is sent to the signal prediction unit 58. That is, the coefficient reverse rearrangement unit 52 rearranges the one-dimensional signal rearranged on the encoding side into the two-dimensional signal so that the order of the columns and / or rows of the original two-dimensional array of orthogonal transform coefficients is obtained. .

  The inverse quantization unit 53 performs inverse quantization processing on the quantization signal of the quantization block supplied from the entropy decoding unit 51 to obtain an orthogonal transform coefficient of the difference signal of 8 × 8 blocks, and performs inverse orthogonal transform The data is sent to the unit 54.

  The inverse orthogonal transform 54 performs inverse orthogonal transform on the orthogonal transform coefficient of the difference signal of the 8 × 8 block supplied from the inverse quantization unit 53 and adds the obtained difference signal of the 8 × 8 block to the addition unit 55. To send.

  The signal prediction unit 58 generates a prediction image using the reference image obtained from the memory 57 and the motion vector obtained from the entropy decoding unit 51, and outputs the prediction image to the addition unit 55.

  The adder 55 adds the difference signal obtained from the inverse orthogonal transform unit 54 and the prediction image supplied from the signal prediction unit 58 to restore the image signal of the 8 × 8 pixel block, and the restored image signal The data is sent to the post-processing unit 56 and stored in the memory 57.

  The energy rank prediction unit 59 includes a prediction image from the signal prediction unit 58 and a decoded pixel group adjacent to the prediction image among the reference images stored in the memory 57 (that is, “adjacent decoded signal”). Is used to calculate the difference between the pixel group of the adjacent decoded signal and the pixel group of the predicted image adjacent to this pixel group in the horizontal direction and the vertical direction, and to obtain the difference obtained by performing the difference in the horizontal direction and the vertical direction, respectively. The signal is subjected to a one-dimensional orthogonal transformation (for example, DCT) in the horizontal direction and the vertical direction, respectively, and an energy distribution (absolute value of amplitude) for each row of the two-dimensional array of orthogonal transformation coefficients is calculated. Sorting in descending order for the absolute value of the signal sequence for each row of the two-dimensional array of, and sorting in descending order for the absolute value of the signal sequence for each column of the two-dimensional array of orthogonal transform coefficients And generates et low although sequentially ranked and control signals representative of the sort order of the columns and / or rows of the two-dimensional array of orthogonal transform coefficients, and sends the coefficients inverse reordering unit 52.

Thus, in the decoding process, the received encoded signal is decoded by the entropy decoding unit, and the decoding process is controlled according to the control signal from the energy rank prediction unit 59. The decoded one-dimensional orthogonal transform coefficient is converted into a two-dimensional signal by reversely performing a zigzag scan, and E ′ [n] [m] is obtained. E [n] [m] is decoded by reordering with an index sequence obtained from I _hor [m] and I _vert [n] obtained from the adjacent decoded upper and lower adjacent signals and the prediction signal. The obtained E [n] [m] is inversely quantized and then inversely transformed by the inverse orthogonal transform unit 54 and added to the prediction signal to reproduce the decoded signal.

  The decoding device 5 according to the present embodiment sequentially encodes a signal from the upper and left regions by using existing general block-based encoding (for example, MPEG-1, 2, 4, AVC / H.264). Since the case has been described as an example, the already-encoded block is set as the upper and lower blocks of the encoded block. However, adjacent signals are similarly applied even in the case of the encoding method in which the encoding order is processed first on the right or the lower side. Can be used to determine the order of scanning.

  As an application example of the above-described embodiment, when a plurality of patterns of scanning orders prepared in advance are prepared, the pattern can be switched by a control signal of the energy rank prediction unit 22. For example, as shown in FIG. 10, when the coefficient rearrangement unit 14 switches the scanning order based on a plurality of patterns, a significant coefficient string in the horizontal direction or the vertical direction is compared, and this coefficient string is longer. Are preferentially scanned. In the example of FIG. 10, when the control signal of the energy rank prediction unit 22 indicates that the significant coefficient sequence in the vertical direction is longer than the significant coefficient sequence in the horizontal direction, the vertical priority coefficient rearranging unit 14e If it is selected to use a pattern and indicates that the significant coefficient sequence in the horizontal direction is longer than the significant coefficient sequence in the vertical direction, it is selected to use the pattern of the horizontal priority coefficient rearranging unit 14f. The coefficient rearrangement unit 14 can be provided with switching means for selecting to use the zigzag scan coefficient rearrangement unit 14g. Note that by defining the scanning order pattern on the encoding side and the decoding side in advance, the decoding process is performed by the decoding apparatus 5 without separately transmitting a special control flag related to this switching by the encoding apparatus 1. It can be carried out. For example, by configuring the coefficient reverse rearrangement unit 52 of the decoding device 5 as illustrated in FIG. 10, switching can be performed according to the control signal generated by the energy rank prediction unit 59.

  As an application example of the embodiment described above, as shown in FIG. 11, the coefficient rearranging unit 14 determines the control signal determined by calculating the energy distribution for the row among the signals based on the orthogonal transform coefficients of the two-dimensional array. A coefficient reordering unit 14a that reorders the rows based on the data, a coefficient reordering unit 14b that reorders the columns based on the control signal determined by calculating the energy distribution for the columns, and / or A coefficient rearrangement unit 14c that rearranges the rows and / or columns based on the control signal determined by calculating the energy distribution for the columns, and a predetermined rearrangement order (for example, a default that is not based on the energy distribution). The coefficient rearrangement unit 14d that scans in order) can be arranged in parallel, and entropy marks are used for each rearrangement. It is possible to configure the output determining means for comparing the coded results of the reduction unit 15, selects a good most coding efficiency as provided to the entropy coding unit 15. In this case, a control flag (2 bits are sufficient) indicating which of the above four types has been selected is sent to the decoding side. The decoding device 5 can correctly decode by acquiring the control flag in the coefficient reverse rearrangement unit 52 and performing the coefficient rearrangement according to the control flag.

  Furthermore, as one aspect of the present invention, the encoding device 1 and the decoding device 5 can be configured as a computer. A program for causing a computer to realize each component of the encoding device 1 and the decoding device 5 described above is stored in a storage unit provided inside or outside the computer. Such a storage unit can be realized by an external storage device such as an external hard disk or an internal storage device such as ROM or RAM. The control unit provided in the computer can be realized by controlling a central processing unit (CPU) or the like. In other words, the CPU can appropriately read from the storage unit a program in which the processing content for realizing the function of each component is described, and realize the function of each component on the computer. Here, the function of each component may be realized by a part of hardware.

  In addition, the program describing the processing contents can be distributed by selling, transferring, or lending a portable recording medium such as a DVD or CD-ROM, and such a program can be distributed on a server on a network, for example. Can be distributed by transferring the program from the server to another computer via the network.

  In addition, a computer that executes such a program can temporarily store, for example, a program recorded on a portable recording medium or a program transferred from a server in its own storage unit. As another embodiment of the program, the computer may directly read the program from a portable recording medium and execute processing according to the program, and each time the program is transferred from the server to the computer. In addition, the processing according to the received program may be executed sequentially.

  While the embodiments of the present invention have been described in detail with specific examples, it will be apparent to those skilled in the art that various modifications and changes can be made without departing from the scope of the claims of the present invention.

  According to the present invention, an image is represented by orthogonal transformation, and the orthogonal transformation coefficient is quantized and variable-length encoded as necessary, so that the quality is reduced with a small signal representation, or the quality is reduced to a minimum. This is useful for video encoding technology for transmitting signals, and can be used in the field of video encoding.

DESCRIPTION OF SYMBOLS 1 Encoding apparatus 5 Decoding apparatus 10 Preprocessing part 11 Subtraction part 12 Orthogonal transformation part 13 Quantization part 14, 14a, 14b, 14c, 14d, 14e, 14f, 14g Coefficient rearrangement part 15 Entropy encoding part 16 Coefficient reverse arrangement Replacement unit 17 Inverse quantization unit 18 Inverse orthogonal transformation unit 19 Addition unit 20 Memory 21 Signal prediction unit 22 Energy rank prediction unit 51 Entropy decoding unit 52 Coefficient inverse rearrangement unit 53 Inverse quantization unit 54 Inverse orthogonal transformation unit 55 Addition unit 56 Post-processing unit 57 Memory 58 Signal prediction unit 59 Energy rank prediction unit

Claims (9)

An encoding device for encoding a moving image,
Signal prediction means for generating a prediction signal predicted from a locally decoded block signal for a block signal to be encoded in a moving image;
Orthogonal transformation means for performing a two-dimensional orthogonal transformation on a prediction difference signal composed of a difference between the block signal to be encoded and the prediction signal, and generating a two-dimensional signal based on an orthogonal transformation coefficient of a two-dimensional array;
A pixel group constituting the prediction signal, and a pixel group constituting a decoded block signal adjacent to any one or more of the prediction signal in the vertical and horizontal directions, and the decoded signal and the decoded pixel The pixel constituting the block signal is differentiated within a processing target area having a predetermined number of pixels from the position adjacent to the pixel, and an adjacent pixel difference signal with respect to the already-decoded block signal adjacent to any one of the upper, lower, left and right is obtained. Generate and calculate a one-dimensional orthogonal transformation for each adjacent pixel difference signal to calculate an energy distribution, and determine a column and / or row rearrangement order of the two-dimensional array based on the calculated energy value. Energy rank predicting means for generating a control signal representing the rearrangement order;
Scanning means for rearranging signal components of the two-dimensional signal based on the orthogonal transformation coefficient of the two-dimensional array into a one-dimensional signal based on the control signal;
Encoding means for encoding the one-dimensional signal;
An encoding device comprising:   The energy rank prediction unit generates an adjacent pixel difference signal for a decoded block signal adjacent to any one or more of the upper, lower, left, and right, and performs one-dimensional orthogonal transformation on each adjacent pixel difference signal. The energy distribution is calculated, the calculated energy values are weighted according to frequency components, and the rearrangement order of the columns and / or rows of the two-dimensional array is determined in descending order from the largest, The encoding apparatus according to claim 1, further comprising means for generating a control signal representing a rearrangement order.   The energy rank prediction unit generates adjacent pixel difference signals for the decoded block signals adjacent to the left side and the upper side, respectively, and performs one-dimensional orthogonal transformation on each adjacent pixel difference signal to calculate an energy distribution. And a means for determining a rearrangement order of the columns and / or rows of the two-dimensional array so that the calculated energy value is in descending order and generating a control signal representing the rearrangement order. The encoding apparatus according to claim 1, wherein the encoding apparatus is characterized.   The said process target area | region consists of the several pixel number containing the pixel which comprises the said prediction signal adjacent to each other, and the pixel which comprises the said decoded block signal, The one of Claims 1-3 characterized by the above-mentioned. The encoding device according to item. The pattern for rearranging the signal components of the two-dimensional signal into a one-dimensional signal is composed of a plurality of patterns prepared in advance.
5. The encoding apparatus according to claim 1, wherein the scanning unit includes a unit that switches the plurality of patterns in accordance with a control signal from the energy rank prediction unit. The scanning means includes
A first scanning means for rearranging the rows based on the control signal determined by calculating an energy distribution for the rows among the two-dimensional signals based on the orthogonal transformation coefficients of the two-dimensional array;
Second scanning means for rearranging the columns based on the control signal determined by calculating the energy distribution for the columns among the two-dimensional signals based on the orthogonal transformation coefficients of the two-dimensional array;
A second one of rearranging the rows and / or columns based on the control signal determined by calculating the energy distribution for the rows and / or columns of the two-dimensional signals based on the orthogonal transform coefficients of the two-dimensional array; Scanning means, and
Of the two-dimensional signals based on the orthogonal transformation coefficients of the two-dimensional array, the fourth scanning means for scanning in the predetermined rearrangement order is switched, and the signal of the two-dimensional signal based on the orthogonal transformation coefficients of the two-dimensional array Switching means for rearranging the components into a one-dimensional signal;
When the switching means is controlled so as to compare the encoding efficiency of the encoding means for the switching of the rearrangement, and the rearrangement of the row and / or the column is used, and the rearrangement is not used 5. The encoding apparatus according to claim 1, further comprising: an output determination unit that compares the encoding efficiencies in and selects the one with the highest encoding efficiency. 6. A decoding device for decoding a signal encoded for a moving image,
Decoding means for inputting a bitstream encoded for a moving image and decoding the one-dimensional signal;
Signal prediction means for generating a prediction signal from the already decoded block signal;
The pixel constituting the prediction signal and the pixel group constituting the decoded block signal adjacent to any one or more of up, down, left and right with respect to the prediction signal and the pixel constituting the prediction signal and the already decoded The pixel constituting the block signal is differentiated within a processing target area having a predetermined number of pixels from the position adjacent to the pixel, and an adjacent pixel difference signal with respect to the already-decoded block signal adjacent to any one of the upper, lower, left and right is obtained. Generate an energy distribution by performing one-dimensional orthogonal transformation on each adjacent pixel difference signal, and arrange columns and / or rows of a two-dimensional array used in inverse orthogonal transformation processing based on the calculated energy value Energy rank predicting means for determining a rearrangement order and generating a control signal representing the rearrangement order;
Scanning means for rearranging the signal component of the one-dimensional signal into a two-dimensional signal based on the orthogonal transformation coefficient of the two-dimensional array based on the control signal;
Inverse orthogonal transform means for performing inverse orthogonal transform on the two-dimensional signal;
Adding means for adding a signal obtained by performing the inverse orthogonal transform and the prediction signal to restore a block signal in the moving image;
A decoding apparatus comprising: In a computer configured as an encoding device for encoding a moving image,
Generating a predicted signal predicted from a locally decoded block signal for a block signal to be encoded in a moving image;
Performing two-dimensional orthogonal transformation on a prediction difference signal composed of a difference between the block signal to be encoded and the prediction signal, and generating a two-dimensional signal based on an orthogonal transformation coefficient of a two-dimensional array;
A pixel group constituting the prediction signal, and a pixel group constituting a decoded block signal adjacent to any one or more of the prediction signal in the vertical and horizontal directions, and the decoded signal and the decoded pixel The pixel constituting the block signal is differentiated within a processing target area having a predetermined number of pixels from the position adjacent to the pixel, and an adjacent pixel difference signal with respect to the already-decoded block signal adjacent to any one of the upper, lower, left and right is obtained. Generate and calculate a one-dimensional orthogonal transformation for each adjacent pixel difference signal to calculate an energy distribution, and determine a column and / or row rearrangement order of the two-dimensional array based on the calculated energy value. Generating a control signal representing the rearrangement order;
Rearranging a signal component of a two-dimensional signal based on the orthogonal transformation coefficient of the two-dimensional array into a one-dimensional signal based on the control signal;
Encoding the one-dimensional signal;
A program for running A computer configured as a decoding device for decoding a signal encoded for a moving image;
Inputting a bitstream encoded for a moving image and decoding the one-dimensional signal;
Generating a prediction signal from an already decoded block signal;
The pixel constituting the prediction signal and the pixel group constituting the decoded block signal adjacent to any one or more of up, down, left and right with respect to the prediction signal and the pixel constituting the prediction signal and the already decoded The pixel constituting the block signal is differentiated within a processing target area having a predetermined number of pixels from the position adjacent to the pixel, and an adjacent pixel difference signal with respect to the already-decoded block signal adjacent to any one of the upper, lower, left and right is obtained. Generate an energy distribution by performing one-dimensional orthogonal transformation on each adjacent pixel difference signal, and arrange columns and / or rows of a two-dimensional array used in inverse orthogonal transformation processing based on the calculated energy value Determining a rearrangement order and generating a control signal representing the rearrangement order;
Rearranging the signal component of the one-dimensional signal into a two-dimensional signal based on the orthogonal transform coefficient of the two-dimensional array based on the control signal;
Applying an inverse orthogonal transform to the two-dimensional signal;
Adding the signal obtained by performing the inverse orthogonal transform and the prediction signal to restore a block signal in the moving image;
A program for running

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