Abstract: A conversion method for converting luminance of a video, including a luminance value in a first luminance range, to be displayed on a display apparatus includes: acquiring a first luminance signal indicating a code value obtained by quantization of the luminance value of the video; and converting the code value indicated by the acquired first luminance signal into a second luminance value determined based on a luminance range of the display apparatus, the second luminance value being compatible with a second luminance range with a maximum value smaller than a maximum value of the first luminance range and larger than 100 nit. This provides the conversion method capable of achieving further improvement.

Abstract: A display system includes a conversion apparatus converting video luminance including a luminance value in a first luminance range and a display apparatus connected thereto and displaying the video. The conversion apparatus includes a first acquisition unit, a first luminance converter, a second luminance converter, a quantization converter, and an output unit outputting a third luminance signal to the display apparatus.

Abstract: An image coding method includes: deriving a candidate for a motion vector of a current block from a co-located motion vector; adding the candidate to a list; selecting the motion vector of the current block from the list; and coding the current block, wherein the deriving includes: deriving the candidate by a first derivation scheme in the case of determining that each of a current reference picture and a co-located reference picture is a long-term reference picture; and deriving the candidate by a second derivation scheme in the case of determining that each of the current reference picture and the co-located reference picture is a short-term reference picture.

Abstract: An image coding method includes: writing, into a sequence parameter set, buffer description defining information for defining a plurality of buffer descriptions; writing, into the sequence parameter set, reference list description defining information for defining a plurality of reference list descriptions corresponding to the buffer descriptions; and writing, into a first header of each processing unit which is included in a coded bitstream, buffer description selecting information for specifying a selected buffer description.

Abstract: A moving picture coding includes: coding a first flag indicating whether or not temporal motion vector prediction is used; when the first flag indicates that the temporal motion vector prediction is used: coding a first parameter for calculating the temporal predictive motion vector; wherein when the first flag indicates that the temporal motion vector prediction is not used, the first parameter is not coded.

Abstract: An image decoding method includes: dividing a current block into sub-blocks; deriving, for each sub-block, one or more prediction information candidates; obtaining an index; and decoding the current block using the prediction information candidate selected by the index.

Abstract: An image encoding method includes: determining respective decoding times of a plurality of pictures included in a motion picture such that decoding times of a plurality of lower layer picture which do not belong to a highest layer of a plurality of layers are spaced at regular intervals, and decoding timing for each of the plurality of lower layer pictures is identical between a case where the plurality of encoded pictures included in the motion picture are decoded and a case where only the plurality of lower layer pictures are decoded, encoding each of the plurality of pictures included in the motion picture in accordance with the encoding order according to the determined respective decoding times, and generating an encoded stream including the plurality of encoded pictures and the determined respective decoding times for the plurality of pictures.

Abstract: An image coding method includes: performing context arithmetic coding to consecutively code (i) first information indicating whether or not to perform sample adaptive offset (SAO) processing for a first region of an image and (ii) second information indicating whether or not to use, in the SAO processing for the first region, information on SAO processing for a region other than the first region, the context arithmetic coding being arithmetic coding using a variable probability, the SAO processing being offset processing on a pixel value; and performing bypass arithmetic coding to code other information which is information on the SAO processing for the first region and different from the first information or the second information, after the first information and the second information are coded, the bypass arithmetic coding being arithmetic coding using a fixed probability.

Abstract: An image coding method includes: deriving a candidate for a motion vector of a current block from a co-located motion vector; adding the candidate to a list; selecting the motion vector of the current block from the list; and coding the current block, wherein the deriving includes: deriving the candidate by a first derivation scheme in the case of determining that each of a current reference picture and a co-located reference picture is a long-term reference picture; and deriving the candidate by a second derivation scheme in the case of determining that each of the current reference picture and the co-located reference picture is a short-term reference picture.

Abstract: A method of performing motion vector prediction for a current block in a picture is provided which includes: deriving a candidate for a motion vector predictor to code a current motion vector of the current block, from a first motion vector of a first block that is spatially adjacent or temporally adjacent to the current block; adding the derived candidate to a list of candidates; and deriving at least one motion vector predictor based on a selected candidate from the list of candidates, wherein the deriving of the candidate includes determining whether to derive the candidate from the first motion vector, based on a type of a current reference picture and a type of a first reference picture, the current reference picture being referred to from the current block using the current motion vector, the first reference picture being referred to from the first block using the first motion vector.

Abstract: An image coding method includes: selecting a first picture from plural pictures; setting a first temporal motion vector prediction flag which is associated with the first picture and is a temporal motion vector prediction flag indicating whether or not temporal motion vector prediction is to be used, to indicate that the temporal motion vector prediction is not to be used, and coding the first temporal motion vector prediction flag; coding the first picture without using the temporal motion vector prediction; and coding a second picture which follows the first picture in coding order, with referring to a motion vector of a picture preceding the first picture in coding order being prohibited.

Abstract: A data output apparatus includes: a video decoder that decodes a video stream to generate a first video signal; an external metadata acquisition unit that acquires one or more pieces of metadata corresponding to one or more first conversion modes; an HDR metadata interpreter that interprets one of the one or more pieces of metadata to acquire characteristic data and conversion auxiliary data; a DR converter that supports one or more second conversion modes and performs conversion processing of a luminance range of the first video signal based on the conversion auxiliary data to generate a second video signal; and an HDMI output unit that outputs the second video signal to a display apparatus.

Abstract: An image coding method includes: deriving a candidate for a motion vector predictor from a co-located motion vector; adding the candidate to a list; selecting the motion vector predictor from the list; and coding a current block and coding a current motion vector, wherein the deriving includes: deriving the candidate by a first derivation scheme in the case of determining that each of a current reference picture and a co-located reference picture is a long-term reference picture; and deriving the candidate by a second derivation scheme in the case of determining that each of the current reference picture and the co-located reference picture is a short-term reference picture.

Abstract: An image coding method includes: performing context arithmetic coding to consecutively code (i) first information indicating whether or not to perform sample adaptive offset (SAO) processing for a first region of an image and (ii) second information indicating whether or not to use, in the SAO processing for the first region, information on SAO processing for a region other than the first region, the context arithmetic coding being arithmetic coding using a variable probability, the SAO processing being offset processing on a pixel value; and performing bypass arithmetic coding to code other information which is information on the SAO processing for the first region and different from the first information or the second information, after the first information and the second information are coded, the bypass arithmetic coding being arithmetic coding using a fixed probability.

Abstract: An image coding method of hierarchically coding a plurality of pictures to generate a bitstream, includes: coding each of the plurality of pictures, which belongs to any one of a plurality of hierarchical layers, with reference to a picture belonging to a hierarchical layer which is same as or lower than a hierarchical layer to which the picture belongs, and without reference to a picture belonging to a hierarchical layer which is higher than the hierarchical layer to which the picture belongs; and generating the bitstream by coding the coded pictures and time information indicating decoding times of the coded pictures. The time information indicates that the decoding times are set at equal intervals for low-layer pictures which are the plurality of pictures other than highest-layer pictures belonging to a highest layer among the plurality of hierarchical layers.

Abstract: An image encoding method including: a constraint information generating step of generating tile constraint information indicating whether or not there is a constraint in filtering on boundaries between adjacent tiles among a plurality of tiles obtained by dividing a picture, and storing the tile constraint information into a sequence parameter set; and a filter information generating step of generating, for each of the boundaries, one of a plurality of filter information items respectively indicating whether or not filtering is executed on the boundaries, and storing the plurality of filter information items into a plurality of picture parameter sets, wherein, in the filter information generating step, the plurality of filter information items which indicate identical content are generated when the tile constraint information indicates that there is the constraint in the filtering.

Abstract: An image coding method includes: deriving a candidate for a motion vector predictor from a co-located motion vector; adding the candidate to a list; selecting the motion vector predictor from the list; and coding a current block and coding a current motion vector, wherein the deriving includes: deriving the candidate by a first derivation scheme in the case of determining that each of a current reference picture and a co-located reference picture is a long-term reference picture; and deriving the candidate by a second derivation scheme in the case of determining that each of the current reference picture and the co-located reference picture is a short-term reference picture.

Abstract: An image coding method includes: writing, into a sequence parameter set, buffer description defining information for defining a plurality of buffer descriptions; selecting one of the buffer descriptions for each processing unit that is a picture or a slice, and writing buffer description selecting information for specifying the selected buffer description, into a first header of the processing unit which is included in the coded bitstream; and coding the processing unit using the selected buffer description, and the buffer description defining information includes long-term information for identifying, among a plurality of reference pictures indicated in the buffer descriptions, a reference picture to be assigned as a long-term reference picture.

Abstract: Obtaining one or more motion vector predictor candidates includes: (a1) generating a motion vector predictor candidate, based on motion vectors of first adjacent blocks adjacent to a block to be processed in a first direction; and (a2) generating a motion vector predictor candidate, based on motion vectors of second adjacent blocks adjacent to the block to be processed in a second direction, and step (a2) includes: determining whether the first adjacent blocks include an inter-predicted block; and searching for a motion vector on which scaling processing can be performed from among the motion vectors of the second adjacent blocks when it is determined that the first adjacent blocks do not include an inter-predicted block, and executing, when the motion vector on which scaling processing can be performed is obtained in the search, scaling processing on the motion vector obtained in the search.

Abstract: An apparatus is provided for decoding last position information indicating a horizontal position and a vertical position of a last non-zero coefficient in a predetermined order within a current block to be decoded, the current block being included in a picture and including a plurality of coefficients. The apparatus includes one or more processors, a communication unit, and storage coupled to the one or more processors and the communication unit. The communication unit is configured to transmit a request for a bitstream to an external system, and receive the bitstream from the external system. The one or more processors are configured to obtain the bitstream, perform first arithmetic decoding, perform second arithmetic decoding, derive a horizontal component of the last position information, and derive a vertical component of the last position. A system for decoding and a displaying method are also provided.