WO2013014693A1 - 動画像復号化方法及び画像符号化方法 - Google Patents
動画像復号化方法及び画像符号化方法 Download PDFInfo
- Publication number
- WO2013014693A1 WO2013014693A1 PCT/JP2011/004129 JP2011004129W WO2013014693A1 WO 2013014693 A1 WO2013014693 A1 WO 2013014693A1 JP 2011004129 W JP2011004129 W JP 2011004129W WO 2013014693 A1 WO2013014693 A1 WO 2013014693A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- prediction
- image
- coding unit
- unit
- encoding
- Prior art date
Links
- 238000000034 method Methods 0.000 title claims abstract description 75
- 230000008569 process Effects 0.000 description 54
- 238000010586 diagram Methods 0.000 description 15
- 230000006870 function Effects 0.000 description 10
- 230000006835 compression Effects 0.000 description 8
- 238000007906 compression Methods 0.000 description 8
- 238000013139 quantization Methods 0.000 description 7
- 238000000638 solvent extraction Methods 0.000 description 4
- 239000013598 vector Substances 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 230000011218 segmentation Effects 0.000 description 3
- 238000003786 synthesis reaction Methods 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 2
- 230000002457 bidirectional effect Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 230000001131 transforming effect Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
- H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
- H04N19/102—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or selection affected or controlled by the adaptive coding
- H04N19/103—Selection of coding mode or of prediction mode
- H04N19/105—Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
- H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
- H04N19/134—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or criterion affecting or controlling the adaptive coding
- H04N19/167—Position within a video image, e.g. region of interest [ROI]
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
- H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
- H04N19/169—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding
- H04N19/17—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding the unit being an image region, e.g. an object
- H04N19/176—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding the unit being an image region, e.g. an object the region being a block, e.g. a macroblock
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
- H04N19/90—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using coding techniques not provided for in groups H04N19/10-H04N19/85, e.g. fractals
- H04N19/96—Tree coding, e.g. quad-tree coding
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
- H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
- H04N19/102—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or selection affected or controlled by the adaptive coding
- H04N19/119—Adaptive subdivision aspects, e.g. subdivision of a picture into rectangular or non-rectangular coding blocks
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
- H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
- H04N19/134—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or criterion affecting or controlling the adaptive coding
- H04N19/136—Incoming video signal characteristics or properties
- H04N19/137—Motion inside a coding unit, e.g. average field, frame or block difference
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
- H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
- H04N19/134—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or criterion affecting or controlling the adaptive coding
- H04N19/146—Data rate or code amount at the encoder output
- H04N19/149—Data rate or code amount at the encoder output by estimating the code amount by means of a model, e.g. mathematical model or statistical model
Definitions
- the present invention relates to a video signal encoding technique.
- encoding is performed by dividing the entire screen into encoding units called macroblocks of 16 pixels ⁇ 16 pixels.
- the prediction value of the pixel value in the target macroblock is determined for the macroblock to be encoded using surrounding pixels and previous and subsequent pictures, and the prediction error between the encoding target pixel and the prediction value is determined.
- Entropy encoding is performed for the macroblock to be encoded using surrounding pixels and previous and subsequent pictures.
- intra prediction predicted from neighboring pixels and inter prediction predicted from pixels in the previous and subsequent pictures are selected for each macroblock according to the pattern in the macroblock. can do.
- prediction can be performed by dividing into prediction blocks smaller than 16 pixels ⁇ 16 pixels.
- a macro block of 16 pixels ⁇ 16 pixels is divided into 16 4-pixel ⁇ 4-pixel prediction blocks, and each prediction block of FIG.
- the pixels in the prediction block can be predicted by copying the peripheral pixels in the nine types of directions indicated by indexes 0 to 8.
- a prediction block of 16 pixels ⁇ 16 pixels is used to predict by copying neighboring pixels in the four types of directions indicated by indexes 0 to 3 in the figure. Pixels in the block can be predicted.
- a motion vector can be set for each prediction block by dividing the macroblock into smaller prediction blocks. For example, as shown in FIG. 4, when predicting motion from a past picture, 16 pixels ⁇ 16 pixels, 16 pixels ⁇ 8 pixels, 8 pixels ⁇ 16 pixels, 8 pixels ⁇ 8 pixels (in this case, further individual predictions) The block can be divided into prediction blocks of 8 pixels ⁇ 4 pixels, 4 pixels ⁇ 8 pixels, and 4 pixels ⁇ 4 pixels), and different motion vectors can be set for the prediction blocks.
- the size of the macroblock is limited to 16 pixels ⁇ 16 pixels, and it is impossible to predict in larger units or smaller units. .
- selection between intra prediction and inter prediction can be set only in units of macroblocks, selection can be made only in units smaller than 16 pixels ⁇ 16 pixels.
- Patent Document 1 can divide a block of 16 pixels ⁇ 16 pixels into any of 8 pixels ⁇ 8 pixels, 4 pixels ⁇ 4 pixels, and 2 pixels ⁇ 2 pixels according to a quadtree structure.
- the prediction mode can be changed according to these block sizes (Patent Document 1).
- An object of the present invention has been made in view of such a situation, and provides a technique for reducing the amount of information for describing prediction information of a macroblock.
- CU Coding Unit
- the prediction image of a higher-order CU (hereinafter referred to as a parent CU) that is larger than the target CU is encoded. This is achieved by making it possible to select whether to use a part of the code as it is or to perform a prediction process for each encoding target CU.
- the flag information indicating which one is selected is stored in the encoded stream, and the decoding side reads the flag information, thereby performing the prediction process on a certain CU to be encoded. This is achieved by selecting whether to use a part of the predicted image of a higher-order CU (hereinafter referred to as a parent CU) that is larger than that, or to perform prediction processing on the encoding target CU. .
- a prediction image of CU is generated using the prediction result of CU, An image that is a part of the predicted image of CU and corresponds to the region of CU1 is extracted as a predicted image.
- the compression rate is improved by reducing the amount of information describing the prediction process of the CU. Can be made.
- FIG. 1 is a diagram illustrating a schematic configuration of an image encoding device according to Embodiment 1.
- FIG. It is a figure for demonstrating an example of the intra prediction process of a prior art. It is a figure for demonstrating an example of the intra prediction process of a prior art. It is a figure for demonstrating an example of the inter prediction process of a prior art. It is a figure for demonstrating the concept of CU division
- FIG. It is a figure for demonstrating an example of the intra prediction process of a prior art. It is a figure for demonstrating an example of the intra prediction process of a prior art. It is a figure for demonstrating an example of the inter prediction process of a prior art. It
- FIG. 6 is a diagram for explaining an example of CU division according to the first embodiment.
- FIG. 6 is a diagram for explaining an example of syntax in an encoded stream by CU partitioning according to the first embodiment.
- FIG. 10 is a diagram for explaining an example of synthesis of predicted images at the time of CU division according to the first embodiment.
- FIG. 10 is a diagram for explaining another example of the synthesis of the predicted image at the time of CU division according to the first embodiment.
- FIG. 10 is a diagram for explaining processing in intra prediction in the synthesis processing of a predicted image at the time of CU division according to the first embodiment.
- FIG. 3 is a diagram illustrating a schematic configuration of a prediction mode determination unit according to the first embodiment.
- 1 is a diagram illustrating a schematic configuration of an image decoding device according to Embodiment 1.
- FIG. FIG. 3 is a diagram illustrating a schematic configuration of a prediction selection unit according to the first embodiment.
- the present invention uses the prediction image of the parent CU before the division when performing the encoding process with the enlargement or reduction of the encoding unit block (hereinafter referred to as CU, Coding Unit). By omitting the prediction processing of the divided CUs, the amount of prediction information is reduced.
- CU Coding Unit
- FIG. 1 is a diagram illustrating a schematic configuration of an image encoding device according to the first embodiment.
- the image encoding device includes a CU dividing unit 100 that determines a CU size, a difference unit 102 that generates a prediction difference image between a prediction image stored in a prediction image storage unit 107 and an input image 114, and the prediction A transform unit 102 that performs orthogonal transform such as DCT on the difference image, a quantization unit 103 that quantizes the transformed signal, and a variable length coding unit 104 that encodes the quantized signal, and an encoded stream 115 Is output.
- a CU dividing unit 100 that determines a CU size
- a difference unit 102 that generates a prediction difference image between a prediction image stored in a prediction image storage unit 107 and an input image 114
- the prediction A transform unit 102 that performs orthogonal transform such as DCT on the difference image
- a quantization unit 103 that quantizes the transformed signal
- a variable length coding unit 104 that encodes the quantized signal
- the moving picture coding apparatus has two types of prediction processing systems in order to generate the predicted image.
- the first system is based on inter prediction, and in order to obtain a reference image for the next input image, an inverse quantization unit 109 that inversely quantizes the quantized signal output from the quantization unit 103, an inverse quantization signal Inverse transform unit 108 that obtains a prediction difference image by inverse transform, adder 111 that adds the prediction difference image after the inverse transform and the prediction image from prediction image storage unit 107, and a reference obtained by removing block noise from the added image A deblocking processing unit 112 for obtaining an image is included.
- the second system includes a reference image storage unit 113 that stores the obtained reference image, and an inter prediction unit 106 that performs motion prediction between the reference image and the input image 114.
- the second system is based on intra prediction, and has an intra prediction unit 105 that performs intra prediction from the input image 114.
- the processing of the prediction mode determination unit 110 will be described later, but the most predictive using the above two prediction processing systems, that is, the inter prediction image from the inter prediction unit 106 and the intra prediction image from the intra prediction unit 105.
- a prediction process that is estimated to be highly efficient is determined.
- the prediction efficiency index includes, for example, prediction error energy. (Prediction method) may be selected.
- the predicted image obtained by the determined prediction method is stored in the predicted image storage unit 113 and used to generate a predicted difference image from the input image 114.
- Information regarding the prediction mode selected by the prediction mode determination unit 110 (that is, inter prediction or intra prediction, and the size of the prediction unit block in each case) is sent to the variable length encoding unit 104, and the encoded stream 115 Stored in part.
- the prediction process determined by the prediction mode determination unit 110 is characterized.
- the CU division pattern is related to the determination of the prediction process, the processing contents of the CU division unit will be described below. .
- FIG. 5 is a diagram for explaining the concept of the CU.
- CU Coding Unit
- the following properties are assumed for the CU.
- the application of this embodiment is not limited to this assumption.
- (1) CU is square
- the maximum size and minimum size of the CU are described in the encoded stream or defined as a standard
- Quadruple tree structure divides hierarchically into 4 parts from maximum CU to child CUs.
- the maximum size CU is denoted as LCU (Largest Coding Unit), and its size (in the vertical or horizontal direction of the LCU)
- the number of pixels is denoted as LCU size.
- the LCU size is assumed to be a power of 2.
- application of the present embodiment is not limited to being a power of 2.
- one picture is divided in LCU units.
- a group of consecutive LCUs is defined as a slice. This concept corresponds to a prior art macroblock.
- Each LCU is divided into four hierarchically by a quadtree structure.
- FIG. 6 is a diagram illustrating an example of CU partitioning configured by a quadtree structure.
- the LCU is divided into four CU 0 , CU 1 , CU 2 , and CU 3 .
- CU 0 is not divided and is finally determined as CU.
- CU 1 is divided into CU 10 , CU 11 , CU 12 , and CU 13
- CU 2 is divided into CU 20 , CU 21 , CU 22 , and CU 23
- CU 3 is divided into 4 parts each of CU 30 , CU 31 , CU 32 , and CU 33. Has been.
- CU 11 is further CU 110 , CU 111 , CU 112 , CU 113 , CU 12 is CU 120 , CU 121 , CU 122 , CU 123 , CU 30 is CU 300 , CU 301 , CU 302 , CU They are respectively divided into four to 303, and the other CU are determined finally as CU. In this way, the LCU can be divided into four hierarchically, and the division can be performed until the CU size reaches the minimum size.
- CU 10 , CU 11 , CU 12 , and CU 13 obtained by dividing CU 1 are described as children CU of CU 1 .
- CU 1 is described as the parent CU of CU 10 , CU 11 , CU 12 , and CU 13 .
- the CU indicates a coding unit. Strictly speaking, prediction processing and conversion processing are performed for each CU. However, in this specification, when a parent CU is described, it is necessary for this CU. Note that only the prediction process is performed according to the above, and the conversion process is not performed.
- the function coding_unit () indicates the encoding syntax of the CU having the pixel position (x0, y0) and the size of currCUSize.
- PicWidth is the picture width (number of pixels)
- PicHeight is the picture height (number of pixels)
- MinCUSize is the minimum size of the CU.
- Split_flag is a 1-bit flag indicating whether the CU is divided into four (1) or not (0) for the current CU (L700).
- split_flag 1
- the current CU is divided into four.
- the split CU size splitCUSize is 1/2 of the current CU size currCUSize
- y1 y0 + splitCUSize, respectively.
- L702 Four divided CUs (CU 0 to CU 3 ) are stored by recursively calling coding_unit () (L703 to L706). Even in each of the four divided CUs, whether or not to further divide is specified by split_flag. Such a recursive call is performed as long as the CU size is equal to or greater than MinCUSize.
- this CU is determined as an encoding unit, and the main processing of encoding is prediction processing information (function prediction_unit ()) (L707) and orthogonal transformation information of prediction error ( The function transform_unit ()) (L708) is stored.
- the orthogonal transform process is not directly related to the present invention, and is therefore omitted.
- prediction_unit () As information of prediction processing in L707 (prediction_unit ()), for example, the identifier of the intra prediction or inter prediction, information indicating the prediction direction in the case of intra prediction (see FIG. 2 and FIG. 3), inter prediction In some cases, division information and motion vector information (see FIG. 4) inside the CU are stored.
- the present invention is not limited to the prediction processing method and the content of the information.
- the prediction process can be performed with a smaller size.
- the code amount increases.
- the prediction mode determination unit 110 includes the parent CU prediction unit 1400, thereby reducing the amount of prediction information when the number of CU divisions increases.
- processing contents in the prediction mode determination unit 110 will be described.
- FIG. 14 is a configuration diagram of the prediction mode determination unit 110.
- the prediction mode determination unit 110 includes a parent CU prediction unit 1400 and a prediction cost comparison unit 1401.
- the parent CU prediction unit 1400 stores the prediction image of the parent CU of the encoding target CU, and calculates the prediction cost when the prediction process of the current CU is replaced with a part of the prediction image of the parent CU. calculate.
- the prediction cost comparison unit 1401 compares a plurality of intra prediction processes in a plurality of CU sizes, an inter prediction image, and a prediction cost from the parent CU prediction unit 1400, and determines a prediction process that minimizes the prediction cost.
- the predicted image obtained by this prediction process is stored in the predicted image storage unit 107.
- the calculation method of the prediction cost is not limited, but may be defined by, for example, the sum of absolute differences between the input image 114 and the prediction image and the weighted sum of the total bit amount required for the prediction information. According to this definition, the closer the predicted image is to the input image, and the smaller the amount of bits required for the prediction information, the higher the prediction efficiency of the encoding process.
- parent CU prediction unit 1400 a prediction image in the parent CU of the encoding target CU is generated and stored in advance, and the prediction process of the encoding target CU is performed on the prediction image of the parent CU. Calculate the estimated cost when the part is replaced. A scene in which such replacement of a parent CU with a predicted image is effective will be described with reference to FIG.
- the encoding target LCU (X) of a certain encoding target picture and the area Y of the immediately preceding picture have almost the same background, and there is an object that moves only within the background.
- the prediction processing of the LCU (X) when the prediction processing is divided into the prediction processing for the entire background and the object portion with internal motion, it is estimated that highly accurate prediction is performed. Therefore, the LCU (X) may be divided into a background CU and a motion object CU, and individual prediction processing may be specified for each CU.
- the number of segmented CUs may increase depending on the position of the moving object in the LCU, and as a result, prediction information may increase. Such a case will be described with reference to FIG.
- FIG. 9 (A) when there is a moving object near the center of the LCU, consider dividing it so that the background and the object part are included in different CUs.
- FIG. 5B since CU (1) to CU (4) contain many objects and backgrounds, CU (1) to CU (4) are divided. This causes CU (1 to CU) from CU (1), CU (E to H) from CU (2), CU (I to L) from CU (3), and CU (3) CU (M ⁇ P) is created from each.
- CU (D), CU (G), CU (J), and CU (M) still contain both an object and a background, and thus further divide them.
- CU (D1-D4) from CU (D), CU (G1-G4) from CU (G), CU (J1-J4) from CU (J), and CU (M) CU (M1 to M4) are created (Fig. (D)).
- CU (D4), CU (G3), CU (J2), and CU (M1) contain many objects only, and other CUs contain many backgrounds only.
- the prediction processing information is not necessarily stored for all individual CUs, but a prediction image obtained in advance by the prediction processing of the parent CU is used as a prediction result. It is possible to select one of the prediction processes performed by individual CUs.
- the parent CU prediction unit 1400 calculates a prediction cost when replacement of the former, that is, the prediction image of the parent CU is selected, and passes the prediction cost result to the prediction cost comparison unit 1401.
- the prediction cost comparison unit 1401 compares the latter normal prediction processing, that is, the prediction cost of normal inter prediction or intra prediction, with the prediction cost from the former parent CU prediction unit 1400, and makes a prediction with a low prediction cost. Select a process.
- parent_pred_flag 0
- parent_prediction_unit Whether to replace a part of the predicted image obtained by the prediction process specified in (1) or to perform another prediction process (0) is specified (L1002).
- an image at a position corresponding to the position of the encoding target CU is set as a prediction image of the encoding target CU.
- the parent CU prediction unit 1400 determines the prediction process based on the LCU size as shown in FIG.
- the method of determining the prediction process is not limited in the present invention. For example, in order to describe the difference between the prediction image obtained as a result of performing a plurality of intra predictions and inter predictions, and the input image 114, and the prediction process The cost value defined by the weighted sum of the bit amounts of the prediction information may be calculated, and the prediction process that minimizes the cost value may be determined.
- the prediction image obtained by this prediction processing is stored in the parent CU prediction unit 1400 as a prediction image of the parent CU.
- parent_pred_unit_flag 1 is set, and the determined prediction processing information is stored in parent_prediction_unit ().
- the prediction image of the parent CU (LCU) is used as a prediction result in all CUs obtained by dividing the LCU.
- this determination process is not limited, as an example, the prediction cost when the prediction image of the parent CU is used as the prediction result, and the case where intra prediction is performed individually or when inter prediction is performed
- the prediction cost values obtained by a plurality of prediction processes may be compared by the prediction cost comparison unit 1401 and a prediction process having a small prediction cost value may be selected.
- parent_pred_flag 1 is set for the CU of (1), and the parent CU prediction unit 1400 uses the prediction image of the parent CU (LCU) to predict the predicted image of the location corresponding to the position of each CU individually. CU prediction image.
- the amount of information for prediction processing for the CU in (1) can be reduced, so an improvement in compression rate can be expected.
- the parent CU is not necessarily limited to one.
- parent_pred_unit_flag 1
- the prediction process is stored in parent_prediction_unit ()
- the prediction image of the parent CU is applied to the CU of (1) (see FIG. 12).
- the amount of information for the prediction process is increased by an amount corresponding to parent_prediction_unit () of CU (D) as compared to the case of FIG.
- the prediction process with higher accuracy can be selected separately from the LCU for the location of CU (D)
- the prediction accuracy is improved, and the prediction difference information is reduced, so that the compression rate can be expected to be improved.
- each CU it is possible to specify whether the prediction process is performed individually or the prediction image of the parent CU is used as it is, and the prediction process of the child CU and the prediction process of the parent CU are specified.
- the combination of methods is not limited, and any combination of inter prediction and intra prediction can be applied.
- inter prediction various prediction methods, such as forward prediction using only a temporally previous picture as a reference picture and bidirectional prediction using temporally forward and backward pictures, can be applied.
- the prediction mode determination unit 110 in the image encoding device selects whether to use a prediction image of a parent CU or another prediction process for a prediction process of a certain CU.
- the prediction process information is stored in the encoded stream only when another prediction process is performed. Thereby, the compression rate can be improved by reducing the predicted information amount of the CU.
- FIG. 15 is a diagram illustrating a schematic configuration of an image decoding device according to the embodiment. In FIG.
- an image decoding apparatus receives an encoded stream 1500, a variable length decoding unit 1501 that decodes the encoded stream 1500, and a CU that divides the CU based on CU size information obtained by the variable length decoding unit 1501
- a division unit 1502 an inverse quantization unit 1503 that inversely quantizes the transform-quantized prediction error image in the CU, an inverse transform unit 1504 that inversely transforms the obtained transformed prediction error image,
- An adder 1505 that adds the prediction image stored in the prediction image storage unit 1508 and the prediction error image output from the inverse conversion unit 1504, and a deblocking processing unit 1506 that performs a deblocking process on the addition result image.
- an output image 1512 is output.
- the moving picture decoding apparatus has two types of prediction processing systems in order to generate the predicted image.
- the first system is based on intra prediction, and includes an intra prediction unit 1507 that performs intra prediction using decoded CU image signals (before deblocking processing) that are sequentially stored in CU units.
- the second system is based on inter prediction, and uses a reference image storage unit 1510 for storing an output image, a reference image stored in the reference image storage unit 1510, and a motion vector decoded by the variable length decoding unit 1501.
- An inter prediction unit 1511 is provided that performs motion compensation and obtains an inter prediction image.
- the prediction selection unit 1509 generates a prediction image according to the prediction processing information of the CU decoded by the variable length decoding unit 1501, and stores the prediction image in the prediction image storage unit 1508.
- FIG. 16 is a diagram illustrating an internal configuration of the prediction selection unit 1509.
- the prediction switching unit 1601 switches prediction processing based on the prediction processing information of each CU decoded by the variable length decoding unit 1501, generates a prediction image, and stores the prediction image in the prediction image storage unit 1508.
- prediction processing information of the CU include information on parent_pred_unit_flag, parent_prediction_unit (), parent_pred_flag, and prediction_unit () in FIG.
- the meaning of the syntax of the encoded stream in FIG. 10 and the processing contents of the parent CU prediction unit 1600 corresponding to these syntaxes are the same as those of the parent CU prediction unit 1400 in the encoding device, and thus description thereof is omitted.
- the prediction selection unit 1509 in the image decoding apparatus can use the prediction image of the parent CU as the prediction result of the encoding target CU according to the prediction processing information of the CU of the encoded stream. As a result, the prediction processing information of the encoding target CU in the encoded stream can be reduced, so that the compression rate can be improved.
- the image encoding apparatus performs the same parent CU prediction process in the image decoding apparatus without sending the prediction process information of the encoding target CU.
- a prediction image of the encoding target CU can be generated, and the information amount of the prediction process can be reduced.
- the present invention can also be realized by a program code of software that realizes the functions of the embodiments.
- a storage medium recording the program code is provided to the system or apparatus, and the computer (or CPU or MPU) of the system or apparatus reads the program code stored in the storage medium.
- the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the program code itself and the storage medium storing it constitute the present invention.
- a storage medium for supplying such a program code for example, a flexible disk, CD-ROM, DVD-ROM, hard disk, optical disk, magneto-optical disk, CD-R, magnetic tape, nonvolatile memory card, ROM Etc. are used.
- an OS operating system
- the computer CPU or the like performs part or all of the actual processing based on the instruction of the program code.
- the program code is stored in a storage means such as a hard disk or memory of a system or apparatus, or a storage medium such as a CD-RW or CD-R
- the computer (or CPU or MPU) of the system or apparatus may read and execute the program code stored in the storage means or the storage medium when used.
Abstract
Description
図1は、実施例1による画像符号化装置の概略構成を示す図である。
以下、図面を参照して、CU分割部100の処理内容について詳細に説明する。
(1)CUは正方形である
(2)CUの最大サイズと最小サイズとが符号化ストリーム中に記載されているか、もしくは規格として定義されている
(3)4分木構造によって最大CUから子CU分割に階層的に4分割される
図5において、最大サイズのCUをLCU(Largest Coding Unit)と記し、そのサイズ(LCUの縦もしくは横方向の画素数)をLCU sizeと記す。なお本実施例ではLCU sizeは2のべき乗を想定するが、2のべき乗であることに本実施例の適用が限定されるものではない。
次に実施例1による予測モード決定部110の処理内容について説明する。
(1)処理全体の概要
図14は、予測モード決定部110の構成図である。
(2)親CU予測部の詳細
親CU予測部1400では、符号化対象CUの親CUにおける予測画像を予め生成、格納しておき、符号化対象CUの予測処理を、この親CUの予測画像の一部で置き替えた場合の予測コストを算出する。このような親CUの予測画像による置き換えが有効となるようなシーンについて、図8を用いて説明する。
(3)CUのシンタックスの一例
図10を用いて、実施例1による符号化ストリームのCUのシンタックスの一例を説明する。
(1)親CUの予測画像を予測結果として用いるCU:
CU(A),CU(B),CU(C),CU(D1),CU(D2),CU(D3),CU(E),CU(F),CU(G1),CU(G2),CU(G4),CU(H),CU(I),CU(J1),CU(J3),CU(J4),CU(M2),CU(M3),CU(M4),CU(N),CU(O),CU(P)
(2)別の予測処理を行うCU:
CU(D4),CU(G3),CU(J2),CU(M1)
と決定されたとする。
<画像復号化装置の構成>
図15は、実施例による画像復号化装置の概略構成を示す図である。図15において、画像復号化装置は、符号化ストリーム1500を入力とし、これを復号する可変長復号化部1501と、可変長復号化部1501で得られるCUサイズ情報を基にCUを分割するCU分割部1502と、前記CU内の、変換量子化された予測誤差画像を逆量子化する逆量子化部1503と、得られた、変換された予測誤差画像を逆変換する逆変換部1504と、予測画像格納部1508に格納される予測画像と、逆変換部1504から出力される予測誤差画像とを加算する加算器1505と、加算結果の画像に対してデブロック処理を行うデブロック処理部1506を有し、出力画像1512を出力する。
<予測選択部(復号化側)の処理内容>
以下、図面を参照して画像復号化側の予測選択部1509の処理内容について説明する。
110…予測モード決定部
105…イントラ予測部
106…インター予測部
102…変換部
103…量子化部
104…可変長符号化部
1400…親CU予測部
1401…予測コスト比較部
1501…可変長復号化部
1502…CU分割部
1503…逆量子化部
1504…逆変換部
1507…イントラ予測部
1511…インター予測部
1509…予測選択部
1600…親CU予測部
1601…予測切替部
Claims (6)
- 入力された符号化ストリームを可変長復号化し、符号化単位で逆量子化、逆変換して予測差分画像とし、前記予測差分画像と前記予測画像と加算して動画像を出力する動画像復号化装置において、
前記復号化する符号化ストリームに、第1符号化単位と前記第1符号化単位よりもサイズが大きくかつ前記第1符号化単位を包含する上位の第2符号化単位との双方の符号化単位で符号化されている符号化ストリームであった場合、
前記第1符号化単位で生成された予測画像と第2符号化単位で生成された予測画像とを生成し、
前記第1符号化単位の予測画像として、前記第2符号化単位で生成された予測画像の一部を用いることを特徴とする動画像復号化方法。 - 請求項1において、
前記第2符号化単位の予測画像として、前記第1符号化単位で生成された予測画像の一部を用いるか、前記第2符号化単位毎の予測画像を生成するかのいずれかを選択することを特徴とする動画像復号化方法。 - 請求項1において、
前記符号化ストリームから、前記第2符号化単位の予測画像を生成するか否かを示すフラグ情報を取り出し、
前記フラグ情報が前記第2符号化単位の予測画像を生成することを示す場合に前記第2符号化単位の予測画像を生成し、前記第2符号化単位で生成された予測画像の一部を前記第1符号化単位の予測画像とすることを特徴とする動画像復号化方法。 - 入力画像を符号化単位に分割し、符号化単位内部の予測画像を生成し、予測画像との差分をとり、予測差分画像を変換、量子化、可変長符号化して符号化ストリームを出力する動画像符号化方法であって、
前記第1符号化単位の予測画像と前記第1の符号化単位よりもサイズが大きくかつ前記第1符号化単位を包含する上位の第2符号化単位の予測画像とを生成し、
前記第1符号化単位の予測画像として、前記第2符号化単位で生成された予測画像の一部を用いることを特徴とする動画像符号化方法。 - 請求項1において、
前記第2符号化単位の一部を前記第1符号化単位とするか、前記第1符号化単位毎に別途予測画像を生成するかのいずれかを選択することを特徴とする動画像符号化方法。 - 請求項5において、
前記第2符号化単位の予測画像を生成するか否かを示すフラグ情報を符号化ストリームに格納し、
前記フラグ情報が、前記第2符号化単位の予測画像を生成することを示す場合には、前記第2符号化単位の予測画像を生成するための情報を符号化ストリームに格納することを特徴とする動画像符号化方法。
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US14/233,888 US20140169465A1 (en) | 2011-07-22 | 2011-07-22 | Video decoding method and image encoding method |
CN201611010982.8A CN107071406B (zh) | 2011-07-22 | 2011-07-22 | 运动图像解码方法和编码方法 |
PCT/JP2011/004129 WO2013014693A1 (ja) | 2011-07-22 | 2011-07-22 | 動画像復号化方法及び画像符号化方法 |
CN201180072475.6A CN103703780B (zh) | 2011-07-22 | 2011-07-22 | 运动图像解码方法及图像编码方法 |
JP2013525428A JP5677576B2 (ja) | 2011-07-22 | 2011-07-22 | 動画像復号化方法及び動画像符号化方法 |
EP11869857.0A EP2736254B1 (en) | 2011-07-22 | 2011-07-22 | Video decoding method and image encoding method |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/JP2011/004129 WO2013014693A1 (ja) | 2011-07-22 | 2011-07-22 | 動画像復号化方法及び画像符号化方法 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2013014693A1 true WO2013014693A1 (ja) | 2013-01-31 |
Family
ID=47600592
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2011/004129 WO2013014693A1 (ja) | 2011-07-22 | 2011-07-22 | 動画像復号化方法及び画像符号化方法 |
Country Status (5)
Country | Link |
---|---|
US (1) | US20140169465A1 (ja) |
EP (1) | EP2736254B1 (ja) |
JP (1) | JP5677576B2 (ja) |
CN (2) | CN103703780B (ja) |
WO (1) | WO2013014693A1 (ja) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104410858A (zh) * | 2014-11-18 | 2015-03-11 | 深圳市云宙多媒体技术有限公司 | 一种帧内预测块划分方法和系统 |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5957513B2 (ja) * | 2014-12-16 | 2016-07-27 | 株式会社日立製作所 | 動画像復号化方法 |
CN107852499B (zh) * | 2015-04-13 | 2021-05-07 | 联发科技股份有限公司 | 用于视频数据的视频编解码方法 |
US11265544B2 (en) * | 2018-09-18 | 2022-03-01 | Sony Corporation | Apparatus and method for image compression based on optimal sequential encoding scheme |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH10150664A (ja) * | 1996-11-19 | 1998-06-02 | Mitsubishi Electric Corp | 映像信号符号化装置および復号化装置 |
JPH11164305A (ja) * | 1997-04-24 | 1999-06-18 | Mitsubishi Electric Corp | 動画像符号化方法、動画像符号化装置および動画像復号装置 |
JP2003111082A (ja) * | 2001-09-28 | 2003-04-11 | Toshiba Corp | 動きベクトル検出方法及び装置 |
JP2006129326A (ja) * | 2004-11-01 | 2006-05-18 | Shibasoku:Kk | 動きベクトル検出装置 |
JP2007503784A (ja) | 2003-05-20 | 2007-02-22 | アーエムテー アドバンスド マルチメディア テクノロジー アクティエボラーグ | ハイブリッドビデオ圧縮法 |
JP2010010950A (ja) * | 2008-06-25 | 2010-01-14 | Toshiba Corp | 画像符号化/復号化方法及び装置 |
Family Cites Families (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5748247A (en) * | 1996-04-08 | 1998-05-05 | Tektronix, Inc. | Refinement of block motion vectors to achieve a dense motion field |
JP4213646B2 (ja) * | 2003-12-26 | 2009-01-21 | 株式会社エヌ・ティ・ティ・ドコモ | 画像符号化装置、画像符号化方法、画像符号化プログラム、画像復号装置、画像復号方法、及び画像復号プログラム。 |
JP4438949B2 (ja) * | 2004-12-21 | 2010-03-24 | カシオ計算機株式会社 | 動き補償予測符号化装置、動き補償予測符号化方法及びプログラム |
CN102231835B (zh) * | 2005-07-22 | 2013-04-17 | 三菱电机株式会社 | 图像解码装置及方法 |
JP4734168B2 (ja) * | 2006-05-09 | 2011-07-27 | 株式会社東芝 | 画像復号化装置及び画像復号化方法 |
GB2443667A (en) * | 2006-11-10 | 2008-05-14 | Tandberg Television Asa | Obtaining a motion vector for a partition of a macroblock in block-based motion estimation |
JP2009094828A (ja) * | 2007-10-10 | 2009-04-30 | Hitachi Ltd | 画像符号化装置及び画像符号化方法、画像復号化装置及び画像復号化方法 |
JP2009111691A (ja) * | 2007-10-30 | 2009-05-21 | Hitachi Ltd | 画像符号化装置及び符号化方法、画像復号化装置及び復号化方法 |
KR101517768B1 (ko) * | 2008-07-02 | 2015-05-06 | 삼성전자주식회사 | 영상의 부호화 방법 및 장치, 그 복호화 방법 및 장치 |
US8503527B2 (en) * | 2008-10-03 | 2013-08-06 | Qualcomm Incorporated | Video coding with large macroblocks |
BRPI0922722A2 (pt) * | 2008-12-09 | 2016-01-05 | Sony Corp | dispositivo e método de processamento de imagem |
KR101457894B1 (ko) * | 2009-10-28 | 2014-11-05 | 삼성전자주식회사 | 영상 부호화 방법 및 장치, 복호화 방법 및 장치 |
US9100649B2 (en) * | 2010-02-10 | 2015-08-04 | Lg Electronics Inc. | Method and apparatus for processing a video signal |
RS62794B1 (sr) * | 2010-04-13 | 2022-02-28 | Ge Video Compression Llc | Nasleđivanje u podeli sa više stabala na nizu uzoraka |
US9215470B2 (en) * | 2010-07-09 | 2015-12-15 | Qualcomm Incorporated | Signaling selected directional transform for video coding |
US10440373B2 (en) * | 2011-07-12 | 2019-10-08 | Texas Instruments Incorporated | Method and apparatus for coding unit partitioning |
-
2011
- 2011-07-22 CN CN201180072475.6A patent/CN103703780B/zh active Active
- 2011-07-22 EP EP11869857.0A patent/EP2736254B1/en active Active
- 2011-07-22 WO PCT/JP2011/004129 patent/WO2013014693A1/ja active Application Filing
- 2011-07-22 CN CN201611010982.8A patent/CN107071406B/zh active Active
- 2011-07-22 US US14/233,888 patent/US20140169465A1/en not_active Abandoned
- 2011-07-22 JP JP2013525428A patent/JP5677576B2/ja active Active
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH10150664A (ja) * | 1996-11-19 | 1998-06-02 | Mitsubishi Electric Corp | 映像信号符号化装置および復号化装置 |
JPH11164305A (ja) * | 1997-04-24 | 1999-06-18 | Mitsubishi Electric Corp | 動画像符号化方法、動画像符号化装置および動画像復号装置 |
JP2003111082A (ja) * | 2001-09-28 | 2003-04-11 | Toshiba Corp | 動きベクトル検出方法及び装置 |
JP2007503784A (ja) | 2003-05-20 | 2007-02-22 | アーエムテー アドバンスド マルチメディア テクノロジー アクティエボラーグ | ハイブリッドビデオ圧縮法 |
JP2006129326A (ja) * | 2004-11-01 | 2006-05-18 | Shibasoku:Kk | 動きベクトル検出装置 |
JP2010010950A (ja) * | 2008-06-25 | 2010-01-14 | Toshiba Corp | 画像符号化/復号化方法及び装置 |
Non-Patent Citations (2)
Title |
---|
DOCUMENT: JCTVC-B205, OUTPUT DOCUMENT(DRAFT007), ITU-T, 2010.10.09: "Test Model under Consideration", TEST MODEL UNDER CONSIDERATION, JOINT COLLABORATIVE TEAM ON VIDEO CODING (JCT-VC) OF ITU-T SG16 WP3 AND ISO/IEC JTC1/SC29/WG11 2ND MEETING, 9 October 2010 (2010-10-09), GENEVA, CH, XP008169133 * |
See also references of EP2736254A4 |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104410858A (zh) * | 2014-11-18 | 2015-03-11 | 深圳市云宙多媒体技术有限公司 | 一种帧内预测块划分方法和系统 |
Also Published As
Publication number | Publication date |
---|---|
JP5677576B2 (ja) | 2015-02-25 |
JPWO2013014693A1 (ja) | 2015-02-23 |
CN107071406A (zh) | 2017-08-18 |
US20140169465A1 (en) | 2014-06-19 |
EP2736254B1 (en) | 2018-07-04 |
CN103703780A (zh) | 2014-04-02 |
EP2736254A4 (en) | 2015-04-15 |
EP2736254A1 (en) | 2014-05-28 |
CN103703780B (zh) | 2016-12-07 |
CN107071406B (zh) | 2020-06-30 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US9654795B2 (en) | Method and apparatus for encoding and decoding image through intra prediction | |
US7711196B2 (en) | Apparatus and method for generating coded block pattern for alpha channel image and alpha channel image encoding/decoding apparatus and method using the same | |
EP1571850A2 (en) | Apparatus and method for encoding and decoding image containing grayscale alpha channel image | |
JP7395518B2 (ja) | マージモードに基づくインター予測方法及び装置 | |
KR20100019537A (ko) | 화상 예측 부호화 장치, 화상 예측 복호 장치, 화상 예측 부호화 방법, 화상 예측 복호 방법, 화상 예측 부호화 프로그램, 및 화상 예측 복호 프로그램 | |
KR20110047697A (ko) | 픽처 경계의 부호화 단위를 부호화, 복호화 하는 방법 및 장치 | |
US10652570B2 (en) | Moving image encoding device, moving image encoding method, and recording medium for recording moving image encoding program | |
WO2012101781A1 (ja) | 画像復号化装置 | |
JP2022506423A (ja) | ビデオ信号符号化/復号方法及びその機器 | |
JP2017034531A (ja) | 動画像符号化装置及び動画像符号化方法 | |
KR20200015783A (ko) | 인트라 예측 모드 기반 영상 처리 방법 및 이를 위한 장치 | |
CN111183641A (zh) | 视频编码设备、视频解码设备、视频编码方法、视频解码方法和程序 | |
JP5677576B2 (ja) | 動画像復号化方法及び動画像符号化方法 | |
JP2017034532A (ja) | 動画像符号化装置、動画像符号化方法及び動画像符号化用コンピュータプログラム | |
JP6426648B2 (ja) | 動画像予測復号方法及び動画像予測復号装置 | |
JP2023105190A (ja) | 映像符号化又は映像復号装置、映像符号化又は映像復号方法、プログラム、及び記録媒体 | |
JPWO2016116984A1 (ja) | 動画像符号化装置、動画像符号化方法および動画像符号化プログラム | |
EP3565252A1 (en) | Encoding device, decoding device and program | |
JP5592246B2 (ja) | コンテクスト適応エントロピー符号化方法,コンテクスト適応エントロピー復号方法,コンテクスト適応エントロピー符号化装置,コンテクスト適応エントロピー復号装置およびそれらのプログラム | |
JP7104101B2 (ja) | 符号化装置、復号装置及びプログラム | |
JP5957513B2 (ja) | 動画像復号化方法 | |
JP2018037936A (ja) | 画像符号化装置および画像復号装置 | |
JP2017073598A (ja) | 動画像符号化装置、動画像符号化方法及び動画像符号化用コンピュータプログラム | |
JP6646125B2 (ja) | 動画像予測復号方法及び動画像予測復号装置 | |
JP6101067B2 (ja) | 画像処理装置及び画像処理プログラム |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 11869857 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2013525428 Country of ref document: JP Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2011869857 Country of ref document: EP |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 14233888 Country of ref document: US |