Granted Patent B2

US 12,413,773 · App. 18/385,469 · Granted Sep 9, 2025

Inventors: Virginie Drugeon (Darmstadt, DE); Kiyofumi Abe (Osaka, JP); Takahiro Nishi (Nara, JP); Tadamasa Toma (Osaka, JP)

Assignee: PANASONIC INTELLECTUAL PROPERTY CORPORATION OF AMERICA

H04N19/587H04N19/105H04N19/109H04N19/132H04N19/136H04N19/172H04N19/184H04N19/463H04N19/503

Abstract

Claims (65)

1. An encoder comprising:

circuitry; and

memory coupled to the circuitry,

wherein

in operation, the circuitry:

controls whether to change a resolution of a picture from a resolution of a previous picture preceding the picture in one of display order and encoding order, according to a constraint that allows the changing only when the picture is a random access picture among one or more random access pictures;

when a resolution of a reference picture to be used in encoding of an inter-predicted picture is different from a resolution of the inter-predicted picture, resamples a reference image in the reference picture according to a difference between the resolution of the reference picture and the resolution of the inter-predicted picture, and encodes an image in the inter-predicted picture using the reference image resampled;

encodes at least one first trailing picture belonging to a first group of pictures;

subsequently encodes a random access picture belonging to a second group of pictures following the first group of pictures in the display order, the random access picture being included in the one or more random access pictures;

subsequently encodes at least one leading picture belonging to the first group of pictures; and

subsequently encodes at least one second trailing picture belonging to the second group of pictures, and

the constraint:

allows a resolution of the random access picture to be different from a resolution of the at least one first trailing picture;

does not allow a resolution of the at least one leading picture to be different from the resolution of the random access picture; and

does not allow a resolution of the at least one second trailing picture to be different from the resolution of the at least one leading picture.

2. A decoder comprising:

circuitry; and

memory coupled to the circuitry,

wherein

in operation, the circuitry:

controls whether to change a resolution of a picture from a resolution of a previous picture preceding the picture in one of display order and decoding order, according to a constraint that allows the changing only when the picture is a random access picture among one or more random access pictures;

when a resolution of a reference picture to be used in decoding of an inter-predicted picture is different from a resolution of the inter-predicted picture, resamples a reference image in the reference picture according to a difference between the resolution of the reference picture and the resolution of the inter-predicted picture, and decodes an image in the inter-predicted picture using the reference image resampled;

decodes at least one first trailing picture belonging to a first group of pictures;

subsequently decodes a random access picture belonging to a second group of pictures following the first group of pictures in the display order, the random access picture being included in the one or more random access pictures;

subsequently decodes at least one leading picture belonging to the first group of pictures; and

subsequently decodes at least one second trailing picture belonging to the second group of pictures, and

the constraint:

allows a resolution of the random access picture to be different from a resolution of the at least one first trailing picture;

does not allow a resolution of the at least one leading picture to be different from the resolution of the random access picture; and

does not allow a resolution of the at least one second trailing picture to be different from the resolution of the at least one leading picture.

3. An encoding method comprising:

controlling whether to change a resolution of a picture from a resolution of a previous picture preceding the picture in one of display order and encoding order, according to a constraint that allows the changing only when the picture is a random access picture among one or more random access pictures;

when a resolution of a reference picture to be used in encoding of an inter-predicted picture is different from a resolution of the inter-predicted picture, resampling a reference image in the reference picture according to a difference between the resolution of the reference picture and the resolution of the inter-predicted picture, and encoding an image in the inter-predicted picture using the reference image resampled;

encoding at least one first trailing picture belonging to a first group of pictures;

subsequently encoding a random access picture belonging to a second group of pictures following the first group of pictures in the display order, the random access picture being included in the one or more random access pictures;

subsequently encoding at least one leading picture belonging to the first group of pictures;

subsequently encoding at least one second trailing picture belonging to the second group of pictures,

wherein the constraint:

allows a resolution of the random access picture to be different from a resolution of the at least one first trailing picture;

does not allow a resolution of the at least one leading picture to be different from the resolution of the random access picture; and

does not allow a resolution of the at least one second trailing picture to be different from the resolution of the at least one leading picture.

4. A decoding method comprising:

controlling whether to change a resolution of a picture from a resolution of a previous picture preceding the picture in one of display order and decoding order, according to a constraint that allows the changing only when the picture is a random access picture among one or more random access pictures;

when a resolution of a reference picture to be used in decoding of an inter-predicted picture is different from a resolution of the inter-predicted picture, resampling a reference image in the reference picture according to a difference between the resolution of the reference picture and the resolution of the inter-predicted picture, and decoding an image in the inter-predicted picture using the reference image resampled;

decoding at least one first trailing picture belonging to a first group of pictures;

subsequently decoding a random access picture belonging to a second group of pictures following the first group of pictures in the display order, the random access picture being included in the one or more random access pictures;

subsequently decoding at least one leading picture belonging to the first group of pictures; and

subsequently decoding at least one second trailing picture belonging to the second group of pictures,

wherein the constraint:

allows a resolution of the random access picture to be different from a resolution of the at least one first trailing picture;

does not allow a resolution of the at least one leading picture to be different from the resolution of the random access picture; and

does not allow a resolution of the at least one second trailing picture to be different from the resolution of the at least one leading picture.

5. A non-transitory computer readable medium storing a bitstream,

the bitstream including: a plurality of pictures; and a plurality of parameters to perform a decoding process for decoding the plurality of pictures from the bitstream, wherein

in the decoding process, in operation according to the plurality of parameters,

whether to change a resolution of a picture from a resolution of a previous picture preceding the picture in one of display order and decoding order is controlled according to a constraint that allows the changing only when the picture is a random access picture among one or more random access pictures; and

when a resolution of a reference picture to be used in decoding of an inter-predicted picture is different from a resolution of the inter-predicted picture, a reference image in the reference picture is resampled according to a difference between the resolution of the reference picture and the resolution of the inter-predicted picture, and an image in the inter-predicted picture is decoded using the reference image resampled;

at least one first trailing picture belonging to a first group of pictures is decoded;

a random access picture belonging to a second group of pictures following the first group of pictures in the display order is subsequently decoded, the random access picture being included in the one or more random access pictures;

at least one leading picture belonging to the first group of pictures is subsequently decoded; and

at least one second trailing picture belonging to the second group of pictures is subsequently decoded,

wherein the constraint:

allows a resolution of the random access picture to be different from a resolution of the at least one first trailing picture;

does not allow a resolution of the at least one leading picture to be different from the resolution of the random access picture; and

does not allow a resolution of the at least one second trailing picture to be different from the resolution of the at least one leading picture.

Assignments (1)

Priority Claims (1)

Continuity (2)

References Cited (11)

Cited By (1)

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