# US 10,455,252 B2 · Video encoding method and device and decoding method and device

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- Number: US 10,455,252 B2
- Document ID: US10455252B2
- Status: Granted
- Kind: B2
- Application number: 16/025,391
- Filed: 2018-07-02
- Published: 2018-10-25
- Granted: 2019-10-22
- Earliest claimed: 2010-09-28
- Assignees: Samsung Electronics Co., Ltd.
- Applicants: Samsung Electronics Co., Ltd.
- Inventors: Yoon-Mi Hong; Woo-Jin Han; Min-Su Cheon; Jianle Chen
- Web page: https://patentgrep.com/patent/US10455252B2

## CPC

- H04N 19/60: using transform coding
- G06F 17/147: {Discrete orthonormal transforms, e.g. discrete cosine transform, discrete sine transform, and variations therefrom, e.g. modified discrete cosine transform, integer transforms approximating the discrete cosine transform (G06F17/145 takes precedence)}
- H04N 19/126: Details of normalisation or weighting functions, e.g. normalisation matrices or variable uniform quantisers
- H04N 19/176: the region being a block, e.g. a macroblock
- H04N 19/625: using discrete cosine transform [DCT]
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION
- G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N)

## Abstract

A video encoding method, a video encoding apparatus, a video decoding method, and a video decoding apparatus are provided. The video encoding method includes producing a fast transform matrix based on a transform matrix which is used for frequency transformation on a block which has a predetermined size; producing a transformed block by transforming the block having the predetermined size by using the fast transform matrix; and performing scaling with respect to the transformed block in order to correct a difference between the transform matrix used for the frequency transformation and the fast transform matrix.

## Claims

### Claim 1

A video decoding apparatus comprising a processor configured to:
receive a quantized transform block which has a predetermined size,
determine a scaling constant for scaling of transform coefficients included in the quantized transform block based on a quantization parameter,
scale the transform coefficients by using the scaling constant, and
inverse-transform the transform block that includes the scaled transform coefficients,
wherein, where i denotes a remainder after the quantization parameter is divided by 6, the scaling constant for i=0 is 40, the scaling constant for i=1 is 45, the scaling constant for i=2 is 51, the scaling constant for i=3 is 57, the scaling constant for i=4 is 64, and the scaling constant for i=5 is 72, and
the transform block is inverse-transformed by using discrete cosine inverse-transform.

### Claim 2

A video encoding apparatus comprising a processor configured to:
obtain a transform block by transforming a residual block indicating differences between a current block and a predicted block of the current block,
determine a scaling constant for quantization of transform coefficients included in the transform block based on a quantization parameter,
quantize the transform coefficients in the transform block based on the scaling constant,
entropy-code the quantized transform block, and
output a bitstream including quantized transform block information indicating the quantized transform block,
wherein, where i denotes a remainder after the quantization parameter is divided by 6, the scaling constant for i=0 is 40, the scaling constant for i=1 is 45, the scaling constant for i=2 is 51, the scaling constant for i=3 is 57, the scaling constant for i=4 is 64, and the scaling constant for i=5 is 72.

### Claim 3

A video encoding method comprising:
obtaining a transform block by transforming a residual block indicating differences between a current block and a predicted block of the current block;
determining a scaling constant for quantization of transform coefficients included in the transform block based on a quantization parameter;
quantizing the transform coefficients in the transform block based on the scaling constant;
entropy-coding the quantized transform block; and
output a bitstream including quantized transform block information indicating the quantized transform block,
wherein, where i denotes a remainder after the quantization parameter is divided by 6, the scaling constant for i=0 is 40, the scaling constant for i=1 is 45, the scaling constant for i=2 is 51, the scaling constant for i=3 is 57, the scaling constant for i=4 is 64, and the scaling constant for i=5 is 72, and
the transform block is transformed by using discrete cosine transform.

### Claim 4

A video encoding apparatus comprising a processor configured to:
obtain a transform block by transforming a residual block indicating differences between a current block and a predicted block of the current block,
determine a scaling constant for quantization of transform coefficients included in the transform block based on a quantization parameter,
quantize the transform coefficients in the transform block based on the scaling constant,
entropy-code the quantized transform block, and
output a bitstream including quantized transform block information indicating the quantized transform block,
wherein, where i denotes a remainder after the quantization parameter is divided by 6, the scaling constant for i=0 is 40, the scaling constant for i=1 is 45, the scaling constant for i=2 is 51, the scaling constant for i=3 is 57, the scaling constant for i=4 is 64, and the scaling constant for i=5 is 72, and
the transform block is transformed by using discrete cosine transform.

### Claim 5

A video encoding method comprising:
obtaining a transform block by transforming a residual block indicating differences between a current block and a predicted block of the current block;
determining a scaling constant for quantization of transform coefficients included in the transform block based on a quantization parameter;
quantizing the transform coefficients in the transform block based on the scaling constant;
entropy-coding the quantized transform block; and
output a bitstream including quantized transform block information indicating the quantized transform block,
wherein, where i denotes a remainder after the quantization parameter is divided by 6, the scaling constant for i=0 is 40, the scaling constant for i=1 is 45, the scaling constant for i=2 is 51, the scaling constant for i=3 is 57, the scaling constant for i=4 is 64, and the scaling constant for i=5 is 72, and
a transform matrix includes elements that are integers.

### Claim 6

A non-transitory computer-readable recording medium comprising a bitstream, the bitstream comprising:
quantized transform block information indicating a quantized transform block of a current block;
quantization parameter information indicating a quantization parameter; and
prediction mode information indicating a prediction mode of the current block,
wherein,
the quantized transform block is derived by entropy-decoding the quantized transform block information,
transform coefficients in the quantized transform block are scaled by using a scaling constant that is determined based on the quantization parameter,
a transform block that includes the scaled transform coefficients is inverse-transformed to obtain a residual block indicating differences between the current block and a predicted block of the current block,
the predicted block of the current block is determined based on the prediction mode of the current block,
wherein, where i denotes a remainder after the quantization parameter is divided by 6, the scaling constant for i=0 is 40, the scaling constant for i=1 is 45, the scaling constant for i=2 is 51, the scaling constant for i=3 is 57, the scaling constant for i=4 is 64, and the scaling constant for i=5 is 72, and
the transform block is transformed by using discrete cosine transform.

### Claim 7

A non-transitory computer-readable recording medium comprising a bitstream, the bitstream comprising:
quantized transform block information indicating a quantized transform block of a current block;
quantization parameter information indicating a quantization parameter; and
prediction mode information indicating a prediction mode of the current block,
wherein,
the quantized transform block is derived by entropy-decoding the quantized transform block information,
transform coefficients in the quantized transform block are scaled by using a scaling constant that is determined based on the quantization parameter,
a transform block that includes the scaled transform coefficients is inverse-transformed to obtain a residual block indicating differences between the current block and a predicted block of the current block,
the predicted block of the current block is determined based on the prediction mode of the current block,
wherein, where i denotes a remainder after the quantization parameter is divided by 6, the scaling constant for i=0 is 40, the scaling constant for i=1 is 45, the scaling constant for i=2 is 51, the scaling constant for i=3 is 57, the scaling constant for i=4 is 64, and the scaling constant for i=5 is 72, and
the transform matrix includes elements that are integers.

### Claim 8

A non-transitory computer-readable recording medium comprising a bitstream, the bitstream comprising:
quantized transform block information indicating a quantized transform block of a current block;
quantization parameter information indicating a quantization parameter; and
prediction mode information indicating a prediction mode of the current block,
wherein,
the quantized transform block is derived by entropy-decoding the quantized transform block information,
transform coefficients in the quantized transform block are scaled by using a scaling constant that is determined based on the quantization parameter,
a transform block that includes the scaled transform coefficients is inverse-transformed to obtain a residual block indicating differences between the current block and a predicted block of the current block,
the predicted block of the current block is determined based on the prediction mode of the current block,
wherein, where i denotes a remainder after the quantization parameter is divided by 6, the scaling constant for i=0 is 40, the scaling constant for i=1 is 45, the scaling constant for i=2 is 51, the scaling constant for i=3 is 57, the scaling constant for i=4 is 64, and the scaling constant for i=5 is 72,
the transform block is transformed by using discrete cosine transform and includes elements that are integers.

### Claim 9

A non-transitory computer-readable recording medium comprising a bitstream, the bitstream comprising:
quantized transform block information indicating a quantized transform block of a current block;
quantization parameter information indicating a quantization parameter; and
prediction mode information indicating a prediction mode of the current block,
wherein,
the quantized transform block is derived by entropy-decoding the quantized transform block information,
transform coefficients in the quantized transform block are scaled by using a scaling constant that is determined based on the quantization parameter,
a transform block that includes the scaled transform coefficients is inverse-transformed to obtain a residual block indicating differences between the current block and a predicted block of the current block,
the predicted block of the current block is determined based on the prediction mode of the current block,
wherein, where i denotes a remainder after the quantization parameter is divided by 6, the scaling constant for i=0 is 40, the scaling constant for i=1 is 45, the scaling constant for i=2 is 51, the scaling constant for i=3 is 57, the scaling constant for i=4 is 64, and the scaling constant for i=5 is 72,
the transform block is transformed by using discrete cosine transform and includes elements that are integers,
the prediction information indicates an intra mode or an inter mode.