阅读说明：本技术 对编码视频信号解码的方法和对视频信号编码的方法 (Method for decoding a coded video signal and method for coding a video signal ) 是由 李培根 金柱英 于 2016-01-13 设计创作，主要内容包括：公开了对编码视频信号解码的方法和对视频信号编码的方法。对编码视频信号解码的方法包括：当当前块以调色板模式编码时,获得关于至少一个调色板条目的信息以及关于用于标识所述调色板条目的至少一个调色板索引的信息；基于调色板条目的数目来获得逸出存在标记,其中,当所述调色板条目的数目大于0时,获得所述逸出存在标记,并且所述逸出存在标记指示所述当前块是否包括以逸出模式编码的至少一个样本；当所述逸出存在标记等于1时,获得调色板逸出值；根据预定的扫描顺序以所述当前块的样本为单位得到调色板索引；以及通过使用所述调色板逸出值和所述调色板索引来重构所述当前块。(A method of decoding an encoded video signal and a method of encoding a video signal are disclosed. The method of decoding an encoded video signal comprises: obtaining information on at least one palette entry and information on at least one palette index for identifying the palette entry when the current block is encoded in a palette mode; obtaining an escape presence flag based on a number of palette entries, wherein the escape presence flag is obtained when the number of palette entries is greater than 0 and indicates whether the current block includes at least one sample encoded in an escape mode; obtaining a palette escape value when the escape presence flag is equal to 1; obtaining a palette index in a unit of samples of the current block according to a predetermined scanning order; and reconstructing the current block by using the palette escape value and the palette index.)

1. A method of decoding an encoded video signal, the method comprising:

obtaining information on at least one palette entry and information on at least one palette index for identifying the palette entry when the current block is encoded in a palette mode;

obtaining an escape presence flag based on a number of palette entries, wherein the escape presence flag is obtained when the number of palette entries is greater than 0 and indicates whether the current block includes at least one sample encoded in an escape mode;

obtaining a palette escape value when the escape presence flag is equal to 1;

obtaining a palette index in a unit of samples of the current block according to a predetermined scanning order; and

reconstructing the current block by using the palette escape value and the palette index.

2. The method of claim 1, wherein, in the step of obtaining palette escape values, if a value of a resulting palette index for samples of the current block is equal to a maximum value of palette indices, obtaining palette escape values for samples of the current block.

3. The method of claim 1, wherein the escape mode is a method of reconstructing sample values based on obtained palette escape values.

4. The method of claim 1, wherein the palette index is derived by using at least one of an index mode or a copy mode, and

wherein the index mode is a method of deriving a palette index based on the information on at least one palette index, and the copy mode is a method of deriving a palette index of a sample of the current block using palette indices of neighboring samples.

5. A method of encoding a video signal, the method comprising:

encoding information regarding at least one palette entry and information regarding at least one palette index for identifying the palette entry when the current block is encoded in a palette mode;

encoding an escape presence flag based on a number of palette entries, wherein the escape presence flag is encoded when the number of palette entries is greater than 0 and indicates whether the current block includes at least one sample encoded in an escape mode;

encoding a palette escape value when the escape presence flag is encoded as 1;

determining a palette index in units of samples of the current block according to a predetermined scan order; and

reconstructing the current block by using the palette escape value and the palette index.

6. The method of claim 5, wherein, in the step of encoding palette escape values, palette escape values for samples of the current block are encoded if a value of the determined palette index for samples of the current block is equal to a maximum value of palette indices.

7. The method of claim 5, wherein the escape mode is a method of reconstructing sample values based on the palette escape values.

8. The method of claim 5, wherein the palette index is determined by using at least one of an index mode or a copy mode, and

wherein the index mode is a method of determining a palette index based on the information on at least one palette index, and the copy mode is a method of determining a palette index of a sample of the current block using palette indices of neighboring samples.

Technical Field

The present invention relates to a method and apparatus for processing a video signal.

Background

Recently, demands for high-resolution, high-quality images such as high-definition (HD) images and ultra high-definition (UHD) images have increased in various application fields. As video data has higher resolution and higher quality, the video data is larger in amount than conventional video data. Therefore, if video data is transmitted through an existing medium such as a wired/wireless broadband circuit or stored in an existing storage medium, transmission cost and storage cost increase. To avoid these problems encountered with higher resolution, higher quality video data, efficient video compression techniques may be used.

Various video compression techniques exist, including: inter-picture prediction in which pixel values included in a current picture are predicted from pictures before or after the current picture; intra-picture prediction that predicts pixel values included in a current picture using pixel information in the current picture; and entropy coding that assigns short codes to more frequent values and long codes to less frequent values. Using such video compression techniques, video data may be efficiently compressed and transmitted or stored.

As the demand for high-resolution video increases, the demand for three-dimensional (3D) video content as a new video service is also increasing. Video compression techniques for efficiently providing HD and UHD three-dimensional video content are under discussion.

Disclosure of Invention

Technical problem

An object of the present invention is to provide a method and apparatus for predicting or reconstructing a video signal based on a palette mode when encoding/decoding the video signal.

An object of the present invention is to provide a method and apparatus for constructing a palette map of a block to be encoded/decoded when encoding/decoding a video signal.

An object of the present invention is to provide a method and apparatus for obtaining palette indices of a block to be encoded/decoded when encoding/decoding a video signal.

Technical scheme

The method for decoding an encoded video signal according to the present invention includes: obtaining information on at least one palette entry and information on at least one palette index for identifying the palette entry when the current block is encoded in a palette mode; obtaining an escape presence flag based on a number of palette entries, wherein the escape presence flag is obtained when the number of palette entries is greater than 0 and indicates whether the current block includes at least one sample encoded in an escape mode; obtaining a palette escape value when the escape presence flag is equal to 1; obtaining a palette index (palette index) in units of samples of the current block according to a predetermined scan order; and reconstructing the current block by using the palette escape value and the palette index.

In the video signal decoding method according to the present invention, the escape presence flag is signaled only when the number of palette entries belonging to the palette map is greater than a predefined threshold.

In the video signal decoding method according to the present invention, the palette INDEX is obtained using at least one of an INDEX MODE (INDEX MODE) and a COPY MODE (COPY MODE).

In the video signal decoding method according to the present invention, an INDEX MODE (INDEX MODE) is a method of obtaining palette indices based on coded palette INDEX information, and a COPY MODE (COPY MODE) is a method of obtaining palette indices of a current sample using palette indices of neighboring samples.

In the method of decoding a video signal according to the present invention, if the value of the resulting palette index related to the current sample is equal to the number of palette entries constituting the palette map for the current block, the current sample is reconstructed based on an escape MODE (ESACPE MODE).

An apparatus for decoding a video signal according to the present invention includes: an entropy decoding unit for obtaining an escape presence flag of a current block encoded in a palette mode from a bitstream; and a prediction unit for constructing a palette map associated with the current block, for deriving a palette index in units of samples of the current block according to a predetermined scan order, and for reconstructing the current block by using at least one of an escape presence flag, the palette map, or the palette index.

In the video signal decoding apparatus according to the present invention, the escape presence flag is selectively obtained based on the number of palette entries belonging to the palette map.

In the video signal decoding apparatus according to the present invention, the escape presence flag is signaled only when the number of palette entries belonging to the palette map is greater than a predefined threshold.

In the video signal decoding apparatus according to the present invention, the palette INDEX is determined using at least one of an INDEX MODE (INDEX MODE) and a COPY MODE (COPY MODE).

In the video signal decoding apparatus according to the present invention, the INDEX MODE (INDEX MODE) is a method of obtaining palette indices based on coded palette INDEX information, and the COPY MODE (COPY MODE) is a method of obtaining palette indices of a current sample using palette indices of neighboring samples.

In the prediction unit according to the present invention, if the value of the resulting palette index related to the current sample is equal to the number of palette entries constituting the palette map for the current block, the current sample is reconstructed based on an ESCAPE MODE (escade MODE).

The method for encoding a video signal according to the present invention includes: encoding information regarding at least one palette entry and information regarding at least one palette index for identifying the palette entry when the current block is encoded in a palette mode; encoding an escape presence flag based on a number of palette entries belonging to a palette map, wherein the escape presence flag is encoded when the number of palette entries is greater than 0 and indicates whether the current block includes at least one sample encoded in an escape mode; encoding a palette escape value when the escape presence flag is encoded as 1; determining a palette index in units of samples of a current block according to a predetermined scan order; and reconstructing the current block by using the palette escape value and the palette index.

In the video signal encoding method according to the present invention, the escape presence flag is encoded only when the number of palette entries belonging to the palette map is greater than a predefined threshold.

In a video signal encoding method according to the present invention, a palette INDEX is determined using at least one of an INDEX MODE (INDEX MODE) and a COPY MODE (COPY MODE).

In the method of encoding a video signal according to the present invention, an INDEX MODE (INDEX MODE) is a method of obtaining palette indices based on encoded palette INDEX information, and a COPY MODE (COPY MODE) is a method of obtaining palette indices of a current sample using palette indices of neighboring samples.

In the video signal encoding method according to the present invention, in the step of reconstructing the current sample, if a value of a palette index related to the current sample is equal to the number of palette entries constituting the palette map of the current block, the current sample is reconstructed based on an ESCAPE MODE (escade MODE).

An apparatus for encoding a video signal according to the present invention includes: an entropy encoding unit for encoding an escape present flag of a current block encoded in a palette mode; and a prediction unit for constructing a palette map related to the current block, for determining a palette index in units of samples of the current block according to a predetermined scan order, and for reconstructing the current block by using at least one of an escape presence flag, the palette map, or the palette index.

In a video signal encoding apparatus according to the present invention, escape presence flags are selectively encoded based on the number of palette entries belonging to a palette map.

In the video signal encoding apparatus according to the present invention, the escape presence flag is encoded only when the number of palette entries belonging to the palette map is greater than a predefined threshold.

In the prediction unit according to the present invention, if the value of the resulting palette index related to the current sample is equal to the number of palette entries constituting the palette map for the current block, the current sample is reconstructed based on an ESCAPE MODE (escade MODE).

Advantageous effects

According to the present invention, it is possible to improve the efficiency of prediction or reconstruction of a block to be encoded/decoded based on a palette mode.

According to the present invention, it is possible to improve palette entry encoding/decoding efficiency by obtaining a palette map of a block to be encoded/decoded from the palette map of a previous block.

According to the present invention, a palette index of a block to be encoded/decoded can be efficiently obtained based on an index mode or a copy mode.

According to the present invention, compression efficiency can be improved by encoding palette indices using binary vectors based on run encoding (run encoding).

According to the present invention, sample values of a block to be encoded/decoded may be reconstructed based on an escape mode, so that samples outside a palette entry range may be efficiently encoded/decoded.

Drawings

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

Fig. 2 is a block diagram illustrating a video decoding apparatus according to an embodiment of the present invention.

Fig. 3 illustrates a method of reconstructing a current block based on a palette mode according to an embodiment of the present invention.

Fig. 4 illustrates a method of restrictively signaling a reuse flag (previous _ palette _ entry _ flag) according to an embodiment of the present invention.

Fig. 5 shows a method of signaling reuse marks in the form of binary vectors based on run-length coding according to an embodiment of the present invention.

Fig. 6 illustrates a method for restrictively obtaining a reuse flag based on a last entry flag (last _ previous _ entry _ flag) according to an embodiment of the present invention.

Fig. 7 illustrates a method for constructing a palette map associated with a current block according to an embodiment of the present invention.

Fig. 8 illustrates a method of obtaining a palette index of a current block based on palette index information and a palette index run according to an embodiment of the present invention.

Fig. 9 illustrates a method for obtaining a palette index based on COPY MODE (COPY MODE) according to an embodiment of the present invention.

Fig. 10 illustrates a scanning sequence in the palette mode according to an embodiment of the present invention.

Fig. 11 illustrates a method for obtaining a palette index based on escape presence markers according to an embodiment of the present invention.

Best mode for carrying out the invention

The method for decoding a video signal according to the present invention includes: constructing a palette map for a current block encoded in palette mode; obtaining escape presence flags based on the number of palette entries belonging to the palette map; obtaining a palette index (palette index) in units of samples of the current block according to a predetermined scan order; and reconstructing the current block by using at least one of the escape presence flag, the palette map, and the palette index.

In the video signal decoding method according to the present invention, the escape presence flag is signaled only when the number of palette entries belonging to the palette map is greater than a predefined threshold.

In the video signal decoding method according to the present invention, the palette INDEX is obtained using at least one of an INDEX MODE (INDEX MODE) and a COPY MODE (COPY MODE).

In the video signal decoding method according to the present invention, an INDEX MODE (INDEX MODE) is a method of obtaining palette indices based on coded palette INDEX information, and a COPY MODE (COPY MODE) is a method of obtaining palette indices of a current sample using palette indices of neighboring samples.

In the method of decoding a video signal according to the present invention, if the value of the resulting palette index related to the current sample is equal to the number of palette entries constituting the palette map for the current block, the current sample is reconstructed based on an escape MODE (ESACPE MODE).

An apparatus for decoding a video signal according to the present invention includes: an entropy decoding unit for obtaining an escape presence flag of a current block encoded in a palette mode from a bitstream; and a prediction unit for constructing a palette map associated with the current block, for deriving a palette index in units of samples of the current block according to a predetermined scan order, and for reconstructing the current block by using at least one of an escape presence flag, the palette map, or the palette index.

In the video signal decoding apparatus according to the present invention, the escape presence flag is selectively obtained based on the number of palette entries belonging to the palette map.

In the video signal decoding apparatus according to the present invention, the escape presence flag is signaled only when the number of palette entries belonging to the palette map is greater than a predefined threshold.

In the video signal decoding apparatus according to the present invention, the palette INDEX is determined using at least one of an INDEX MODE (INDEX MODE) and a COPY MODE (COPY MODE).

In the video signal decoding apparatus according to the present invention, the INDEX MODE (INDEX MODE) is a method of obtaining palette indices based on coded palette INDEX information, and the COPY MODE (COPY MODE) is a method of obtaining palette indices of a current sample using palette indices of neighboring samples.

In the prediction unit according to the present invention, if the value of the resulting palette index related to the current sample is equal to the number of palette entries constituting the palette map for the current block, the current sample is reconstructed based on an ESCAPE MODE (escade MODE).

The method for encoding a video signal according to the present invention includes: constructing a palette map for a current block encoded in palette mode; encoding an escape presence flag based on a number of palette entries belonging to the palette map; determining a palette index in units of samples of a current block according to a predetermined scan order; and reconstructing the current block by using at least one of the escape presence flag, the palette map, or the palette index.

In the video signal encoding method according to the present invention, the escape presence flag is encoded only when the number of palette entries belonging to the palette map is greater than a predefined threshold.

In a video signal encoding method according to the present invention, a palette INDEX is determined using at least one of an INDEX MODE (INDEX MODE) and a COPY MODE (COPY MODE).

In the method of encoding a video signal according to the present invention, an INDEX MODE (INDEX MODE) is a method of obtaining palette indices based on encoded palette INDEX information, and a COPY MODE (COPY MODE) is a method of obtaining palette indices of a current sample using palette indices of neighboring samples.

In the video signal encoding method according to the present invention, in the step of reconstructing the current sample, if a value of a palette index related to the current sample is equal to the number of palette entries constituting the palette map of the current block, the current sample is reconstructed based on an ESCAPE MODE (escade MODE).

An apparatus for encoding a video signal according to the present invention includes: an entropy encoding unit for encoding an escape present flag of a current block encoded in a palette mode; and a prediction unit for constructing a palette map related to the current block, for determining a palette index in units of samples of the current block according to a predetermined scan order, and for reconstructing the current block by using at least one of an escape presence flag, the palette map, or the palette index.

In a video signal encoding apparatus according to the present invention, escape presence flags are selectively encoded based on the number of palette entries belonging to a palette map.

In the video signal encoding apparatus according to the present invention, the escape presence flag is encoded only when the number of palette entries belonging to the palette map is greater than a predefined threshold.

In the prediction unit according to the present invention, if the value of the resulting palette index related to the current sample is equal to the number of palette entries constituting the palette map for the current block, the current sample is reconstructed based on an ESCAPE MODE (escade MODE).