Granted Patent B2

US 12,192,526 · App. 18/380,044 · Granted Jan 7, 2025

Inventor: Moonmo Koo (Seoul, KR)

Assignee: GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP., LTD.

H04N19/625H04N19/122H04N19/176H04N19/61

Abstract

Claims (36)

1. A decoding apparatus for image decoding, the decoding apparatus comprising:

a memory; and

at least one processor connected to the memory, the at least one processor configured to:

determine a prediction mode as an inter prediction mode to be used for a block;

determine one transform configuration group of a plurality of transform configuration groups to be used for the block of the inter prediction mode, wherein each of the plurality of transform configuration groups includes a plurality of transform combinations;

obtain a transform index, wherein the transform index (i) indicates one of a plurality of transform combinations of the determined one transform configuration group of the plurality of transform configuration groups, (ii) is a single transform index corresponding to a first index value for a horizontal transform and a second index value for a vertical transform, and (iii) is comprised of values of 0, 1, 2, 3, 4, and wherein the first index value and the second index value are determined based on the transform index and the one transform configuration group;

derive a transform combination corresponding to the transform index, wherein the transform combination is configured with a horizontal transform and a vertical transform and includes one of (DST (Discrete Sine Transform)-7, DST-7), (DST-7, DCT (Discrete Cosine Transform)-8), (DCT-8, DST-7) and (DCT-8, DCT-8);

perform an inverse transform on a transform unit based on the transform combination; and

reconstruct the video signal based on the transform unit.

2. The apparatus of claim 1 , wherein the transform combination is selected based on at least one of the prediction mode, a size or a shape of the transform unit.

3. The apparatus of claim 1 , the at least one processor further configured to:

check whether a number of non-zero transform coefficient is greater than a threshold,

wherein the transform index is obtained based on the number of non-zero transform coefficient is greater than the threshold.

4. The apparatus of claim 1 , wherein performing the inverse transform comprises applying an inverse transform of the DST-7 or an inverse transform of the DCT-8 to each row after applying the inverse transform of the DST-7 or the inverse transform of the DCT-8 to each column.

5. The apparatus of claim 1 , wherein the transform index is defined in at least one level of a sequence, a picture, a slice, a block, a coding unit, the transform unit or a prediction unit.

6. An encoding apparatus for image encoding, the encoding apparatus comprising:

a memory; and

at least one processor connected to the memory, the at least one processor configured to:

determine a prediction mode as an inter prediction mode to be used for a block;

derive a transform combination being applied to a transform unit, wherein the transform combination is configured with a horizontal transform and a vertical transform and includes one of (DST-7, DST-7), (DST-7, DCT-8), (DCT-8, DST-7) and (DCT-8, DCT-8);

perform a transform on the transform unit based on the transform combination;

determine one transform configuration group of a plurality of transform configuration groups to be used for the block of the inter prediction mode, wherein each of the plurality of transform configuration groups includes a plurality of transform combinations;

generate a transform index corresponding to the transform combination,

wherein the transform index (i) indicates one of a plurality of transform combinations of the determined one transform configuration group of the plurality of transform configuration groups, (ii) is a single transform index corresponding to a first index value for a horizontal transform and a second index value for a vertical transform, and (iii) is comprised of values of 1, 2, 3, 4, and

wherein the first index value and the second index value are determined based on the transform index and the one transform configuration group.

7. An apparatus for transmitting data for an image, the apparatus comprising:

at least one processor configured to obtain a bitstream generated by an image encoding method; and

a transmitter configured to transmit the bitstream,

wherein the image encoding method comprises:

determining a prediction mode as an inter prediction mode to be used for a block;

deriving a transform combination being applied to a transform unit, wherein the transform combination is configured with a horizontal transform and a vertical transform and includes one of (DST-7, DST-7), (DST-7, DCT-8), (DCT-8, DST-7) and (DCT-8, DCT-8);

performing a transform on the transform unit based on the transform combination;

determining one transform configuration group of a plurality of transform configuration groups to be used for the block of the inter prediction mode, wherein each of the plurality of transform configuration groups includes a plurality of transform combinations;

generating a transform index corresponding to the transform combination,

wherein the transform index (i) indicates one of a plurality of transform combinations of the one transform configuration group of the plurality of transform configuration groups, (ii) is a single transform index corresponding to a first index value for a horizontal transform and a second index value for a vertical transform, and (iii) is comprised of values of 0, 1, 2, 3, 4, and

wherein the first index value and the second index value are determined based on the transform index and the one transform configuration group.

Assignments (2)

Continuity (5)

References Cited (24)