Method and apparatus for processiing image service
A method, performed by a digital device, for processing an image service according to the present document comprises the steps of: receiving image information; decoding a first image on the basis of the image information; processing the decoded first image to be displayed on a first area of a display screen; and processing a second image to be displayed on a second area of the display screen.
1. A decoding apparatus for an image decoding, the decoding apparatus comprising:
a memory; and
at least one processor connected to the memory, the at least one processor configured to:
obtain image information including Most Probable Mode (MPM) flag information from a bitstream;
derive a first intra prediction mode based on a first neighboring block which is located in a left side of a current block;
derive a second intra prediction mode based on a second neighboring block which is located in an upper side of the current block;
configure an MPM list for the current block based on the first intra prediction mode and the second intra prediction mode;
derive an intra prediction mode of the current block based on the MPM flag information and the MPM list;
generate prediction samples for the current block based on the intra prediction mode; and
generate a reconstructed picture for the current block based on the prediction samples,
wherein the MPM list comprises MPM candidates derived based on whether at least one of the first intra prediction mode or the second intra prediction mode is non-directional intra prediction mode,
wherein the MPM candidates which are derived based on a case that the first intra prediction mode and the second intra prediction mode are both the non-directional intra prediction mode, comprise:
a DC intra prediction mode, a vertical directional intra prediction mode, a horizontal directional intra prediction mode, an intra prediction mode of which mode number is equal to a mode number of the vertical directional intra prediction mode minus 4, and an intra prediction mode of which mode number is equal to the mode number of the vertical directional intra prediction mode plus 4, and
wherein the MPM candidates which are derived based on a case that one of the first intra prediction mode and the second intra prediction mode is the non-directional intra prediction mode and the other is directional intra prediction mode, comprise:
one of the first intra prediction mode and the second intra prediction mode, an intra prediction mode of which mode number is equal to a maximum mode number of the first intra prediction mode and the second intra prediction mode minus 1, an intra prediction mode of which mode number is equal to the maximum mode number plus 1, an intra prediction mode of which mode number is equal to the maximum mode number minus 2.
2. An encoding apparatus for an image encoding, the encoding apparatus comprising:
a memory; and
at least one processor connected to the memory, the at least one processor configured to:
derive a first intra prediction mode based on a first neighboring block which is located in a left side of a current block;
derive a second intra prediction mode based on a second neighboring block which is located in an upper side of the current block;
configure a Most Probable Mode (MPM) list for the current block based on the first intra prediction mode and the second intra prediction mode;
determine an intra prediction mode of the current block;
generate prediction samples for the current block based on the intra prediction mode;
generate MPM flag information based on the MPM list and the intra prediction mode; and
encode image information including the MPM flag information,
wherein the MPM list comprises MPM candidates derived based on whether at least one of the first intra prediction mode or the second intra prediction mode is non-directional intra prediction mode,
wherein the MPM candidates which are derived based on a case that the first intra prediction mode and the second intra prediction mode are both the non-directional intra prediction mode, comprise:
a DC intra prediction mode, a vertical directional intra prediction mode, a horizontal directional intra prediction mode, an intra prediction mode of which mode number is equal to a mode number of the vertical directional intra prediction mode minus 4, and an intra prediction mode of which mode number is equal to the mode number of the vertical directional intra prediction mode plus 4, and
wherein the MPM candidates which are derived based on a case that one of the first intra prediction mode and the second intra prediction mode is the non-directional intra prediction mode and the other is directional intra prediction mode, comprise:
one of the first intra prediction mode and the second intra prediction mode, an intra prediction mode of which mode number is equal to a maximum mode number of the first intra prediction mode and the second intra prediction mode minus 1, an intra prediction mode of which mode number is equal to the maximum mode number plus 1, an intra prediction mode of which mode number is equal to the maximum mode number minus 2.
3. An apparatus for transmitting data for an image, the apparatus comprising:
at least one processor configured to obtain a bitstream, wherein the bitstream is generated based on deriving a first intra prediction mode based on a first neighboring block which is located in a left side of a current block, deriving a second intra prediction mode based on a second neighboring block which is located in an upper side of the current block, configuring an most probable mode (MPM) list for the current block based on the first intra prediction mode and the second intra prediction mode, determining an intra prediction mode of the current block, generating prediction samples for the current block based on the intra prediction mode, generating MPM flag information based on the MPM list and the intra prediction mode, and generating the bitstream by encoding image information including MPM flag information; and
a transmitter configured to transmit the data comprising the bitstream,
wherein the MPM list comprises MPM candidates derived based on whether at least one of the first intra prediction mode or the second intra prediction mode is non-directional intra prediction mode,
wherein the MPM candidates which are derived based on a case that the first intra prediction mode and the second intra prediction mode are both the non-directional intra prediction mode, comprise:
a DC intra prediction mode, a vertical directional intra prediction mode, a horizontal directional intra prediction mode, an intra prediction mode of which mode number is equal to a mode number of the vertical directional intra prediction mode minus 4, and an intra prediction mode of which mode number is equal to the mode number of the vertical directional intra prediction mode plus 4, and
wherein the MPM candidates which are derived based on a case that one of the first intra prediction mode and the second intra prediction mode is the non-directional intra prediction mode and the other is directional intra prediction mode, comprise:
one of the first intra prediction mode and the second intra prediction mode, an intra prediction mode of which mode number is equal to a maximum mode number of the first intra prediction mode and the second intra prediction mode minus 1, an intra prediction mode of which mode number is equal to the maximum mode number plus 1, an intra prediction mode of which mode number is equal to the maximum mode number minus 2.