Intra prediction using perspective / vanishing point

Abstract

Systems, methods, and instrumentalities are disclosed for performing intra prediction with perspective. For example, a perspective mode can be used. The perspective mode can be used if an angular intra prediction mode is used. The perspective mode can include prediction using a perspective point. A perspective indication can be used to indicate whether a perspective prediction mode is used. The perspective mode can be signaled and / or derived.

Description

[0001] Cross-references to related applications This application claims the benefit of European Patent Application No. 23306662.0, filed on 2 October 2023, the contents of which are incorporated herein by reference in their entirety. Background Technology

[0002] Video coding systems can be used to compress digital video signals, for example, to reduce the storage and / or transmission bandwidth required for such signals. Video coding systems can include, for example, block-based, wavelet-based, and / or object-based systems. Summary of the Invention

[0003] Systems, methods, and means for performing intra-frame prediction using perspective are disclosed. For example, a perspective mode can be used. If an angular intra-frame prediction mode is used, a perspective mode can also be used. A perspective mode may include prediction using perspective points. A perspective indicator can be used to indicate whether a perspective prediction mode is used. A perspective mode can be signaled and / or derived.

[0004] A device (e.g., a video encoder or video decoder) can perform intra-frame prediction using perspective modes. For example, the device can determine that an angular intra-frame prediction mode is used for a coding block. The device can (e.g., based on the determination that an angular intra-frame prediction mode is used for a coding block) determine whether to use a perspective mode for the coding block. The device can obtain an indication of the perspective mode (e.g., a PerspectiveFlag). The device can (e.g., based on the determination that a perspective mode is used for a coding block) determine a perspective point associated with the coding block. This perspective point can be used for encoding and / or decoding functions associated with the coding block. The coding block can be encoded and / or decoded based on the determined perspective point. The device (e.g., an encoder) can transmit the encoded coding block and the indication (e.g., a PerspectiveFlag) indicating the use of a perspective mode for the encoded coding block in the video data.

[0005] In the example, rate-distortion (RD) cost determination can be performed, for example, to determine the perspective mode to use. For example, a full RD cost determination can be performed against a list of candidate intra-prediction modes. The mode associated with the lowest RD cost among the candidate intra-prediction modes (e.g., a perspective mode) can be selected. For example, RD cost determination can include two rounds. For example, the first round can include determining an initial list of candidate intra-prediction modes based on partial RD criteria (e.g., from the list of candidate intra-prediction modes). The second round can include a full RD cost determination associated with the initial list of candidate intra-prediction modes.

[0006] In the example, multiple perspective modes can be used. Multiple perspective points can be determined (e.g., one perspective point for each perspective mode).

[0007] A fixed perspective point can be used and / or determined. The fixed perspective point can be determined based on one or more of the following: a most probable mode (MPM) list; a decoder-side intra-mode derivation (DIMD) mode; a template-based intra-mode derivation and fusion (TIMD) mode; etc.

[0008] The systems, methods, and means described herein may relate to a decoder. In some examples, the systems, methods, and means described herein may relate to an encoder. In some examples, the systems, methods, and means described herein may relate to signals (e.g., from an encoder and / or received by a decoder). A computer-readable medium may include instructions for causing one or more processors to perform the methods described herein. A computer program product may include instructions that, when executed by one or more processors, cause the one or more processors to perform the methods described herein. Attached Figure Description

[0009] Figure 1A This is a system diagram illustrating an example communication system in which one or more of the disclosed embodiments may be implemented.

[0010] Figure 1B The illustration shows a method according to one embodiment. Figure 1A The diagram shows a system diagram of an example wireless transmit / receive unit (WTRU) used in a communication system.

[0011] Figure 1C The illustration shows a method according to one embodiment. Figure 1A The diagram illustrates a system diagram of an example radio access network (RAN) and an example core network (CN) used in the communication system.

[0012] Figure 1D The illustration shows a method according to one embodiment. Figure 1A The illustrated system diagram shows yet another example RAN and yet another example CN used in the communication system.

[0013] Figure 2 The illustration shows a sample video encoder.

[0014] Figure 3 The illustration shows an example video decoder.

[0015] Figure 4 The illustration shows an example of a system that can implement various aspects and examples.

[0016] Figure 5 The illustration shows an example of angle prediction for a target block in intra-frame prediction.

[0017] Figure 6 The illustration shows an example of perspective prediction for a target block in intra-frame prediction.

[0018] Figure 7 The illustration shows an example of defining a perspective point.

[0019] Figure 8 The illustration shows an example of the perspective points of a square target block.

[0020] Figure 9 The illustration shows an example of the perspective points of a rectangular target block.

[0021] Figure 10 The illustration shows an example of a mirrored perspective point.

[0022] Figure 11 The illustration shows an example prediction with perspective points.

[0023] Figure 12 The illustration shows example perspective points at different distances from the target block but associated with the same prediction pattern.

[0024] Figure 13 The illustration shows an example dead zone for a perspective point.

[0025] Figure 14 The location is shown in the diagram. An example of deriving the angle parameters of the target pixel at a given location.

[0026] Figure 15 The illustration shows an example of intra-frame prediction using perspective.

[0027] Figure 16 The illustration shows an example of intra-frame prediction using perspective. Detailed Implementation

[0029] A more detailed understanding can be obtained from the description given below with reference to the accompanying drawings and examples.

[0030] Figure 1AThis diagram illustrates an example communication system 100 in which one or more of the disclosed embodiments may be implemented. The communication system 100 may be a multi-access system that provides content such as voice, data, video, messaging, and broadcasting to multiple wireless users. The communication system 100 enables multiple wireless users to access such content by sharing system resources, including wireless bandwidth. For example, the communication system 100 may employ one or more channel access methods, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal FDMA (OFDMA), Single Carrier FDMA (SC-FDMA), Zero-Tail Unique Word DFT-Spread Spectrum OFDM (ZT UW DTS-s OFDM), Unique Word OFDM (UW-OFDM), Resource Block Filtered OFDM, Filter Bank Multicarrier (FBMC), and so on.

[0031] like Figure 1A As shown, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, RAN 104 / 113, CN 106 / 115, Public Switched Telephone Network (PSTN) 108, Internet 110, and other networks 112. However, it should be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, and 102d may be any type of device configured to operate and / or communicate in a wireless environment. For example, WTRUs 102a, 102b, 102c, and 102d (any of which may be referred to as a “station” and / or “STA”) may be configured to transmit and / or receive wireless signals and may include user equipment (UE), mobile stations, fixed or mobile subscriber units, subscription-based units, pagers, cellular phones, personal digital assistants (PDAs), smartphones, laptops, netbooks, personal computers, wireless sensors, hotspots or Mi-Fi devices, Internet of Things (IoT) devices, watches or other wearable devices, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in industrial and / or automated processing chain environments), consumer electronics devices, devices operating on commercial and / or industrial wireless networks, and so on. Any of WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0032] The communication system 100 may also include base station 114a and / or base station 114b. Each of base stations 114a and 114b may be any type of device configured to wirelessly interface with at least one of WTRUs 102a, 102b, 102c, and 102d to facilitate access to one or more communication networks, such as CN 106 / 115, the Internet 110, and / or other networks 112. For example, base stations 114a and 114b may be base transceiver stations (BTS), Node-B, eNode B, home Node B, home eNodeB, gNB, NR Node B, site controllers, access points (APs), wireless routers, etc. Although base stations 114a and 114b are each depicted as a single element, it should be understood that base stations 114a and 114b may include any number of interconnected base station and / or network elements.

[0033] Base station 114a may be part of RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as base station controllers (BSCs), radio network controllers (RNCs), relay nodes, etc. Base station 114a and / or base station 114b may be configured to transmit and / or receive radio signals on one or more carrier frequencies, which may be referred to as cells (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage of a specific geographic area, which may be relatively fixed or may change over time. The cell may be further divided into cell sectors. For example, the cell associated with base station 114a may be divided into three sectors. Therefore, in one embodiment, base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In one embodiment, base station 114a may employ multiple-input multiple-output (MIMO) technology and may use multiple transceivers for each sector of the cell. For example, beamforming can be used to transmit and / or receive signals in a desired spatial direction.

[0034] Base stations 114a and 114b can communicate with one or more of WTRUs 102a, 102b, 102c, and 102d via air interface 116. Air interface 116 can be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). Any suitable radio access technology (RAT) can be used to establish air interface 116.

[0035] More specifically, as described above, the communication system 100 can be a multi-access system and can employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, base stations 114a and WTRUs 102a, 102b, and 102c in RAN 104 / 113 can implement radio technologies such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which can establish air interfaces 115 / 116 / 117 using Wideband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed ​​Packet Access (HSPA) and / or evolved HSPA (HSPA+). HSPA may include High-Speed ​​Downlink (DL) Packet Access (HSDPA) and / or High-Speed ​​UL Packet Access (HSUPA).

[0036] In one embodiment, base station 114a and WTRUs 102a, 102b, 102c may implement radio technologies such as evolved UMTS terrestrial radio access (E-UTRA), which may use Long Term Evolution (LTE) and / or Advanced LTE (LTE-A) and / or Advanced LTE Pro (LTE-A Pro) to establish air interface 116.

[0037] In one embodiment, base station 114a and WTRUs 102a, 102b, 102c can implement radio technologies such as NR radio access, which can use New Radio (NR) to establish air interface 116.

[0038] In one embodiment, base station 114a and WTRUs 102a, 102b, and 102c can implement multiple radio access technologies. For example, base station 114a and WTRUs 102a, 102b, and 102c can jointly implement LTE radio access and NR radio access, for example, using the dual connectivity (DC) principle. Therefore, the air interface used by WTRUs 102a, 102b, and 102c can be characterized by multiple types of radio access technologies and / or transmissions sent to / from multiple types of base stations (e.g., eNBs and gNBs).

[0039] In other embodiments, base station 114a and WTRUs 102a, 102b, 102c can implement radio technologies such as IEEE 802.11 (i.e., Wi-Fi), IEEE 802.16 (i.e., WiMAX), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Provisional Standard 2000 (IS-2000), Provisional Standard 95 (IS-95), Provisional Standard 856 (IS-856), Global System for Mobile Communications (GSM), Enhanced Data Rate GSM Evolution (EDGE), GSM EDGE (GERAN), etc.

[0040] For example, Figure 1A Base station 114b can be a wireless router, home Node B, home eNodeB, or access point, and can utilize any suitable RAT to facilitate wireless connectivity in a localized area, such as commercial locations, homes, vehicles, campuses, industrial facilities, air corridors (e.g., for drone use), roads, etc. In one embodiment, base station 114b and WTRUs 102c, 102d can implement radio technologies such as IEEE 802.11 to establish a wireless local area network (WLAN). In one embodiment, base station 114b and WTRUs 102c, 102d can implement radio technologies such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, base station 114b and WTRUs 102c, 102d can utilize cellular-based RATs (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish picocells or femtocells. Figure 1A As shown, base station 114b can be directly connected to the Internet 110. Therefore, base station 114b may not need to access the Internet 110 via CN 106 / 115.

[0041] RAN 104 / 113 can communicate with CN 106 / 115, which can be any type of network configured to provide voice, data, application, and / or Voice over Internet Protocol (VoIP) services to one or more of WTRUs 102a, 102b, 102c, and 102d. Data can have different Quality of Service (QoS) requirements, such as different throughput requirements, latency requirements, fault tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. CN 106 / 115 can provide call control, billing services, location-based services, prepaid calling, internet connectivity, video distribution, and / or perform advanced security functions such as user authentication. Although in Figure 1AAlthough not shown, it should be understood that RAN104 / 113 and / or CN 106 / 115 can communicate directly or indirectly with other RANs that use the same RAT as or a different RAT than RAN 104 / 113. For example, in addition to being connected to RAN 104 / 113, which may utilize NR radio technology, CN 106 / 115 can also communicate with another RAN (not shown) that uses GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0042] CN 106 / 115 can also serve as a gateway for WTRU 102a, 102b, 102c, 102d to access PSTN 108, the Internet 110, and / or other networks 112. PSTN 108 may include a circuit-switched telephone network providing Common Old-Style Telephone Service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices using common communication protocols such as Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and / or Internet Protocol (IP) from the TCP / IP Internet Protocol suite. Network 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, network 112 may include another CN connected to one or more RANs, which may use the same RAT as RAN 104 / 113 or a different RAT.

[0043] Some or all of the WTRUs 102a, 102b, 102c, and 102d in the communication system 100 may include multi-mode capabilities (e.g., WTRUs 102a, 102b, 102c, and 102d may include multiple transceivers for communicating with different wireless networks via different wireless links). For example... Figure 1A The WTRU 102c shown can be configured to communicate with base station 114a, which may employ cellular-based radio technology, and to communicate with base station 114b, which may employ IEEE 802 radio technology.

[0044] Figure 1B This is a system diagram illustrating example WTRU 102. (Example:) Figure 1BAs shown, among other things, WTRU 102 may include, in particular, a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power supply 134, a global positioning system (GPS) chipset 136, and / or other peripheral devices 138, etc. It should be understood that WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with the embodiments.

[0045] Processor 118 may be a general-purpose processor, a special-purpose processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, etc. Processor 118 may perform signal encoding, data processing, power control, input / output processing, and / or any other functions that enable WTRU 102 to operate in a wireless environment. Processor 118 may be coupled to transceiver 120, which may be coupled to transmitting / receiving element 122. Although Figure 1B The processor 118 and transceiver 120 are depicted as separate components, but it should be understood that the processor 118 and transceiver 120 may be integrated together in an electronic package or chip.

[0046] Transmitting / receiving element 122 can be configured to transmit signals to or receive signals from a base station (e.g., base station 114a) over air interface 116. For example, in one embodiment, transmitting / receiving element 122 can be an antenna configured to transmit and / or receive RF signals. In one embodiment, transmitting / receiving element 122 can be, for example, a transmitter / detector configured to transmit and / or receive IR, UV, or visible light signals. In yet another embodiment, transmitting / receiving element 122 can be configured to transmit and / or receive both RF and optical signals. It should be understood that transmitting / receiving element 122 can be configured to transmit and / or receive any combination of wireless signals.

[0047] Although the transmitting / receiving element 122 is in Figure 1B While depicted as a single element, WTRU 102 may include any number of transmit / receive elements 122. More specifically, WTRU 102 may employ MIMO technology. Thus, in one embodiment, WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals on air interface 116.

[0048] Transceiver 120 can be configured to modulate signals transmitted by transmitting / receiving element 122 and demodulate signals received by transmitting / receiving element 122. As described above, WTRU 102 can have multi-mode capability. Thus, for example, transceiver 120 can include multiple transceivers to enable WTRU 102 to communicate via multiple RATs such as NR and IEEE 802.11.

[0049] The processor 118 of WTRU 102 can be coupled to a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) unit or an organic light-emitting diode (OLED) display unit) and can receive user input data therefrom. The processor 118 can also output user data to the speaker / microphone 124, keypad 126, and / or display / touchpad 128. Furthermore, the processor 118 can access and store information from any type of suitable memory, such as non-removable memory 130 and / or removable memory 132. Non-removable memory 130 may include random access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. Removable memory 132 may include a user identification module (SIM) card, memory stick, secure digital storage (SD) card, etc. In other embodiments, the processor 118 can access and store information from memory that is not physically located on WTRU 102, such as a server or home computer (not shown).

[0050] The processor 118 can receive power from the power supply 134 and can be configured to distribute and / or control power to other components in the WTRU 102. The power supply 134 can be any suitable device that powers the WTRU 102. For example, the power supply 134 may include one or more dry cell battery packs (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0051] The processor 118 may also be coupled to a GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) about the current location of the WTRU 102. In addition to, or instead of, information from the GPS chipset 136, the WTRU 102 may receive location information on the air interface 116 from base stations (e.g., base stations 114a, 114b) and / or determine its location based on the timing of signals received from two or more nearby base stations. It should be understood that the WTRU 102 may acquire location information using any suitable location determination method while remaining consistent with the embodiments.

[0052] The processor 118 may be further coupled to other peripheral devices 138, which may include one or more software and / or hardware modules providing additional features, functions, and / or wired or wireless connectivity. For example, peripheral devices 138 may include accelerometers, electronic compasses, satellite transceivers, digital cameras (for photos and / or videos), Universal Serial Bus (USB) ports, vibration devices, television transceivers, hands-free headsets, Bluetooth® modules, FM radio units, digital music players, media players, video game player modules, internet browsers, virtual reality and / or augmented reality (VR / AR) devices, activity trackers, and so on. Peripheral devices 138 may include one or more sensors, such as gyroscopes, accelerometers, Hall effect sensors, magnetometers, orientation sensors, proximity sensors, temperature sensors, time sensors; geolocation sensors, altimeters, light sensors, touch sensors, magnetometers, barometers, attitude sensors, biosensors, and / or humidity sensors.

[0053] WTRU 102 may include a full-duplex radio for which the transmission and reception of some or all signals (e.g., signals associated with specific subframes for both UL (e.g., for transmission) and downlink (e.g., for reception)) may be concurrent and / or simultaneous. The full-duplex radio may include an interference management unit to reduce and / or substantially eliminate self-interference via hardware (e.g., chokes) or via signal processing by a processor (e.g., a separate processor (not shown) or via processor 118). In one embodiment, WTRU 102 may include a half-duplex radio for which the transmission and reception of some or all signals (e.g., signals associated with specific subframes for UL (e.g., for transmission) or downlink (e.g., for reception)) may be concurrent and / or simultaneous.

[0054] Figure 1C This diagram illustrates a system diagram of RAN 104 and CN 106 according to an embodiment. As described above, RAN 104 can communicate with WTRUs 102a, 102b, and 102c via air interface 116 using E-UTRA radio technology. RAN 104 can also communicate with CN 106.

[0055] RAN 104 may include eNode-Bs 160a, 160b, and 160c; however, it should be understood that RAN 104 may include any number of eNode-Bs while remaining consistent with the embodiments. eNode-Bs 160a, 160b, and 160c may each include one or more transceivers for communicating with WTRUs 102a, 102b, and 102c on air interface 116. In one embodiment, eNode-Bs 160a, 160b, and 160c may implement MIMO technology. Therefore, for example, eNode-B 160a may use multiple antennas to transmit and / or receive radio signals from WTRU 102a.

[0056] Each of the eNode-B 160a, 160b, and 160c can be associated with a specific cell (not shown) and can be configured to handle radio resource management decisions, handover decisions, user scheduling in UL and / or DL, etc. Figure 1C As shown, eNode-B 160a, 160b, and 160c can communicate with each other on the X2 interface.

[0057] Figure 1C The CN 106 shown may include a Mobility Management Entity (MME) 162, a Serving Gateway (SGW) 164, and a Packet Data Network (PDN) Gateway (or PGW) 166. While each of the foregoing elements is described as part of CN 106, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0058] The MME 162 can connect to each of the eNode-Bs 162a, 162b, and 162c in RAN 104 via the S1 interface and can act as a control node. For example, the MME 162 can be responsible for authenticating users of WTRUs 102a, 102b, and 102c, bearer activation / deactivation, selecting a specific serving gateway during the initial attachment of WTRUs 102a, 102b, and 102c, and so on. The MME 162 can provide control plane functions for handover between RAN 104 and other RANs (not shown) employing other radio technologies such as GSM and / or WCDMA.

[0059] The SGW 164 can connect to each of the eNode Bs 160a, 160b, and 160c in RAN 104 via the S1 interface. The SGW 164 can typically route and forward user data packets to / from WTRUs 102a, 102b, and 102c. The SGW 164 can perform other functions such as anchoring the user plane during inter-eNode B handover, triggering paging when DL data is available for WTRUs 102a, 102b, and 102c, managing and storing the context of WTRUs 102a, 102b, and 102c, etc.

[0060] SGW 164 can connect to PGW 166, which can provide WTRU 102a, 102b, 102c with access to packet-switched networks such as Internet 110, so as to facilitate communication between WTRU 102a, 102b, 102c and IP-enabled devices.

[0061] CN 106 can facilitate communication with other networks. For example, CN 106 can provide WTRU 102a, 102b, and 102c with access to a circuit-switched network such as PSTN 108, facilitating communication between WTRU 102a, 102b, and 102c and traditional landline communication equipment. For example, CN 106 may include, or be able to communicate with, an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between CN 106 and PSTN 108. Furthermore, CN 106 can provide WTRU 102a, 102b, and 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0062] Despite WTRU in Figure 1A-1D While described as a wireless terminal, it is conceivable that, in some representative embodiments, such a terminal may use (e.g., temporarily or permanently) a wired communication interface with a communication network.

[0063] In a representative embodiment, another network 112 may be a WLAN.

[0064] A WLAN in Infrastructure Basic Services Set (BSS) mode can have an access point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP can access or interface with a distributed system (DS) or another type of wired / wireless network that carries traffic to and / or out of the BSS. Traffic originating outside the BSS destined for a STA can reach and be delivered to the STA via the AP. Traffic originating from a STA destined for an external BSS can be sent to the AP for delivery to the appropriate destination. For example, traffic between STAs within the BSS can be sent via the AP, where the source STA can send traffic to the AP, and the AP can deliver traffic to the destination STA. Traffic between STAs within the BSS can be considered and / or referred to as peer-to-peer traffic. Peer-to-peer traffic can be sent between source and destination STAs (e.g., directly between them) using Direct Link Establishment (DLS). In some representative embodiments, the DLS can use 802.11e DLS or 802.11z Tunneled DLS (TDLS). A WLAN using the Standalone BSS (IBSS) mode may not have an access point (AP), and STAs within the IBSS or using the IBSS (e.g., all STAs) can communicate directly with each other. The IBSS communication mode is sometimes referred to as the "ad-hoc" communication mode in this document.

[0065] When using 802.11ac infrastructure operating mode or a similar operating mode, the AP can transmit beacons on a fixed channel, such as the primary channel. The primary channel can be of a fixed width (e.g., a 20 MHz bandwidth) or dynamically set via signaling. The primary channel can be the operating channel of the BSS and can be used by the STA to establish a connection with the AP. In some representative embodiments, such as in an 802.11 system, Carrier Sense Multiple Access (CSMA / CA) with collision avoidance can be implemented. For CSMA / CA, each STA, including the AP, can sense the primary channel. If a particular STA senses / detects and / or determines that the primary channel is busy, that particular STA can back off. A single STA (e.g., only one station) can transmit at any given time within a given BSS.

[0066] High-throughput (HT) STAs can communicate using a 40 MHz wide channel, for example, by combining a primary 20 MHz channel with adjacent or non-adjacent 20 MHz channels.

[0067] Very High Throughput (VHT) STAs can support channels with widths of 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz. 40 MHz and / or 80 MHz channels can be formed by combining consecutive 20 MHz channels. A 160 MHz channel can be formed by combining eight consecutive 20 MHz channels, or by combining two non-consecutive 80 MHz channels, which can be referred to as an 80+80 configuration. For the 80+80 configuration, after channel coding, the data passes through a segment resolver, which splits the data into two streams. Each stream can be processed separately using Inverse Fast Fourier Transform (IFFT) and time-domain processing. The streams can be mapped onto two 80 MHz channels, and the data can be transmitted by the transmitting STA. At the receiver of the receiving STA, the above operations for the 80+80 configuration can be reversed, and the combined data can be sent to the Media Access Control (MAC).

[0068] 802.11af and 802.11ah support operating modes below 1 GHz. The channel operating bandwidth and carrier in 802.11af and 802.11ah are reduced compared to those used in 802.11n and 802.11ac. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV whitespace (TVWS) spectrum, while 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah can support metering-type control / machine-type communications, such as MTC devices in macro coverage areas. MTC devices may have certain capabilities, such as limited capabilities, including support for (e.g., only) certain and / or limited bandwidths. MTC devices may include batteries with a battery life exceeding a threshold (e.g., to maintain a very long battery life).

[0069] WLAN systems that can support multiple channels and channel bandwidths (such as 802.11n, 802.11ac, 802.11af, and 802.11ah) include a channel that can be designated as the primary channel. The bandwidth of the primary channel can be equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel can be set and / or limited by the STA among all STAs operating in the BSS that supports the minimum bandwidth operating mode. In the example of 802.11ah, for a STA that supports (e.g., only supports) the 1 MHz mode (e.g., an MTC type device), the primary channel can be 1 MHz wide, even if the AP and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier Sense and / or Network Allocation Vector (NAV) settings may depend on the status of the primary channel. If the primary channel is busy, for example, because an STA (which only supports the 1 MHz operating mode) is transmitting to the AP, the entire available band can be considered busy, even if most of the band remains idle and can be available.

[0070] In the United States, the available frequency band for 802.11ah is from 902 MHz to 928 MHz. In South Korea, the available frequency band is from 917.5 MHz to 923.5 MHz. In Japan, the available frequency band is from 916.5 MHz to 927.5 MHz. The total available bandwidth for 802.11ah is 6 MHz to 26 MHz, depending on the country code.

[0071] Figure 1D This diagram illustrates a system diagram of RAN 113 and CN 115 according to one embodiment. As described above, RAN 113 can communicate with WTRUs 102a, 102b, and 102c via air interface 116 using NR radio technology. RAN 113 can also communicate with CN 115.

[0072] RAN 113 may include gNBs 180a, 180b, and 180c; however, it should be understood that RAN 113 may include any number of gNBs while remaining consistent with the embodiments. gNBs 180a, 180b, and 180c may each include one or more transceivers for communicating with WTRUs 102a, 102b, and 102c on air interface 116. In one embodiment, gNBs 180a, 180b, and 180c may implement MIMO technology. For example, gNBs 180a and 180b may utilize beamforming to transmit signals to and / or receive signals from gNBs 180a, 180b, and 180c. Therefore, for example, gNB 180a may use multiple antennas to transmit radio signals to and / or receive radio signals from WTRU 102a. In one embodiment, gNBs 180a, 180b, and 180c can implement carrier aggregation technology. For example, gNB 180a can transmit multiple component carriers (not shown) to WTRU 102a. A subset of these component carriers can be on unlicensed spectrum, while the remaining component carriers can be on licensed spectrum. In one embodiment, gNBs 180a, 180b, and 180c can implement Coordinated Multipoint (CoMP) technology. For example, WTRU 102a can receive coordinated transmissions from gNBs 180a and 180b (and / or gNB 180c).

[0073] WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c using transmissions associated with scalable digitization. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing can differ for different transmissions, different cells, and / or different portions of the radio transmission spectrum. WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c using subframes or transmission time intervals (TTIs) of various or scalable lengths (e.g., containing a variable number of OFDM symbols and / or a continuously variable absolute time).

[0074] gNBs 180a, 180b, and 180c can be configured to communicate with WTRUs 102a, 102b, and 102c in standalone and / or non-standalone configurations. In standalone configuration, WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c without accessing other RANs (e.g., eNode-Bs 160a, 160b, and 160c). In standalone configuration, WTRUs 102a, 102b, and 102c can utilize one or more of gNBs 180a, 180b, and 180c as mobility anchors. In standalone configuration, WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c using signals in unlicensed frequency bands. In a non-standalone configuration, WTRUs 102a, 102b, and 102c can communicate / connect with gNBs 180a, 180b, and 180c, while also communicating / connecting with another RAN such as eNode-Bs 160a, 160b, and 160c. For example, WTRUs 102a, 102b, and 102c can implement DC principles to communicate substantially simultaneously with one or more gNBs 180a, 180b, and 180c, as well as one or more eNode-Bs 160a, 160b, and 160c. In a non-standalone configuration, eNode-Bs 160a, 160b, and 160c can act as mobility anchors for WTRUs 102a, 102b, and 102c, and gNBs 180a, 180b, and 180c can provide additional coverage and / or throughput for serving WTRUs 102a, 102b, and 102c.

[0075] Each of gNBs 180a, 180b, and 180c can be associated with a specific cell (not shown) and can be configured to handle radio resource management decisions, handover decisions, user scheduling in UL and / or DL, network slicing support, dual connectivity, interoperability between NR and E-UTRA, routing user plane data to User Plane Functions (UPF) 184a and 184b, routing control plane information to Access and Mobility Management Functions (AMF) 182a and 182b, etc. Figure 1D As shown, gNB 180a, 180b, and 180c can communicate with each other on the Xn interface.

[0076] Figure 1DThe CN 115 shown may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. Although each of the foregoing elements is depicted as part of the CN 115, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0077] AMF 182a and 182b can connect to one or more of gNBs 180a, 180b, and 180c in RAN 113 via the N2 interface and can act as control nodes. For example, AMF 182a and 182b can be responsible for authenticating users of WTRU 102a, 102b, and 102c, supporting network slicing (e.g., handling different PDU sessions with different requirements), selecting specific SMF183a and 183b, managing registration areas, terminating NAS signaling, mobility management, and so on. AMF 182a and 182b can use network slicing to customize CN support for WTRU 102a, 102b, and 102c based on the service types used by WTRU 102a, 102b, and 102c. For example, different network slices can be established for different use cases, such as services relying on Ultra Reliable Low Latency Time (URLLC) access, services relying on Enhanced Massive Mobile Broadband (eMBB) access, services for Machine Type Communication (MTC) access, and / or so on. AMF 162 can provide control plane functions for handover between RAN 113 and other RANs (not shown) employing other radio technologies such as LTE, LTE-A, LTE-A Pro and / or non-3GPP access technologies such as WiFi.

[0078] SMFs 183a and 183b can connect to AMFs 182a and 182b in CN 115 via the N11 interface. SMFs 183a and 183b can also connect to UPFs 184a and 184b in CN 115 via the N4 interface. SMFs 183a and 183b can select and control UPFs 184a and 184b, and configure the routing of services through UPFs 184a and 184b. SMFs 183a and 183b can perform other functions, such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notifications, etc. PDU session types can be IP-based, non-IP-based, Ethernet-based, etc.

[0079] UPF 184a and 184b can be connected to one or more gNBs 180a, 180b, and 180c in RAN 113 via the N3 interface. This N3 interface provides WTRU 102a, 102b, and 102c with access to packet-switched networks (such as Internet 110) to facilitate communication between WTRU 102a, 102b, 102c and IP-enabled devices. UPF 184 and 184b can perform other functions such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, and so on.

[0080] CN 115 can facilitate communication with other networks. For example, CN 115 may include, or be able to communicate with, an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between CN 115 and PSTN 108. Furthermore, CN 115 can provide WTRUs 102a, 102b, and 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, WTRUs 102a, 102b, and 102c may be connected to the local data network (DN) 185a and 185b via the N3 interface to UPFs 184a and 184b and the N6 interface between UPFs 184a and 184b and DNs 185a and 185b.

[0081] Given Figure 1A-1D as well as Figure 1A-1D The corresponding descriptions herein indicate that one or more, or all, of the functions described herein with respect to one or more of the following can be performed by one or more emulation devices (not shown): WTRU 102a-d, Base Station 114a-b, eNode-B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF 182a-b, UPF 184a-b, SMF 183a-b, DN 185a-b, and / or one or more other devices described herein. An emulation device can be one or more devices configured to emulate one or more, or all, of the functions described herein. For example, an emulation device can be used to test other devices and / or simulate network and / or WTRU functions.

[0082] Simulation devices can be designed to perform tests on one or more other devices in laboratory and / or carrier network environments. For example, one or more simulation devices can perform one or more or all functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to test other devices within the communication network. One or more simulation devices can perform one or more or all functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. Simulation devices can be directly coupled to another device for testing purposes and / or can perform tests using over-the-air wireless communication.

[0083] One or more simulation devices may perform one or more functions, including all functions, rather than being implemented / deployed as part of a wired and / or wireless communication network. For example, simulation devices may be used to test test scenarios in laboratory and / or non-deployment (e.g., testing) wired and / or wireless communication networks to implement the testing of one or more components. One or more simulation devices may be test devices. Simulation devices may transmit and / or receive data using direct RF coupling and / or wireless communication via RF circuitry (e.g., which may include one or more antennas).

[0084] This application describes various aspects, including tools, features, examples, models, methods, etc. Many of these aspects are described in detail, and often in a manner that may seem restrictive, at least to illustrate individual characteristics. However, this is for clarity and not to limit the application or scope of those aspects. In fact, all the different aspects can be combined and interchanged to provide further aspects. Furthermore, this aspect can also be combined and interchanged with aspects described in earlier applications.

[0085] The aspects described and contemplated in this application can be implemented in many different forms. Figure 5-16 Some examples can be provided, but other examples are envisioned. Figure 5-16 The discussion does not limit the breadth of implementation. At least one of these aspects generally relates to video encoding and decoding, and at least one other aspect generally relates to the transmission of generated or encoded bitstreams. These and other aspects can be implemented as methods, apparatus, computer-readable storage media having instructions stored thereon for encoding or decoding video data according to any of the methods, and / or computer-readable storage media having a bitstream generated according to any of the methods stored thereon.

[0086] In this application, the terms “reconstructed” and “decoded” are used interchangeably, the terms “pixel” and “sample” are used interchangeably, and the terms “image”, “picture” and “frame” are used interchangeably.

[0087] This document describes various methods, and each method includes one or more steps or actions for implementing the method. Unless the correct operation of the method requires a specific order of steps or actions, the order and / or use of specific steps and / or actions can be modified or combined. Furthermore, terms such as "first," "second," etc., can be used in various examples to modify elements, components, steps, operations, etc., such as, for example, "first decoding" and "second decoding." Unless specifically required, the use of such terms does not imply an ordering of the modified operations. Therefore, in this example, the first decoding does not need to be performed before the second decoding and can occur, for example, before, during, or in a time period overlapping with the second decoding.

[0088] The various methods and other aspects described in this application can be used to modify, for example... Figure 2 and Figure 3 The illustrated video encoder 200 and decoder 300 modules are, for example, decoding modules. Furthermore, the subject matter disclosed herein can be applied to, for example, any type, format, or version of video encoding, whether described in standards or recommendations, whether pre-existing or future-developed, and any extensions to such standards and recommendations. Unless otherwise stated or technically excluded, the aspects described in this application may be used individually or in combination.

[0089] Various numerical values, such as (1 / 32), (1 / 64), etc., are used in the examples described in this application. These and other specific values ​​are for the purpose of describing examples, and the aspects described are not limited to these specific values.

[0090] Figure 2 This is a diagram illustrating an example video encoder. Variations of the example encoder 200 are envisioned, but for clarity, encoder 200 is described below without describing all anticipated variations.

[0091] Before being encoded, the video sequence may undergo pre-coding (201), for example, applying color transformations to the input color image (e.g., a conversion from RGB 4:4:4 to YCbCr 4:2:0), or performing remapping of the input image components to obtain a signal distribution more resilient to compression (e.g., histogram equalization using one of the color components). Metadata may be associated with pre-processing and attached to the bitstream.

[0092] In encoder 200, as described below, the image is encoded by encoder elements. The image to be encoded is partitioned (202) and processed in units, for example, coding units (CUs). Each unit is encoded using, for example, an intra-frame mode or an inter-frame mode. When a unit is encoded in intra-frame mode, it performs intra-frame prediction (260). In inter-frame mode, motion estimation (275) and compensation (270) are performed. The encoder determines (205) which of the intra-frame or inter-frame modes is used to encode the unit and indicates the intra-frame / inter-frame decision by, for example, a prediction mode flag. For example, the prediction residual is calculated by subtracting (210) the prediction block from the original image block.

[0093] The predicted residual is then transformed (225) and quantized (230). The quantized transform coefficients, along with the motion vector and other syntax elements, are entropy encoded (245) to output a bitstream. The encoder can skip the transform and apply quantization directly to the untransformed residual signal. The encoder can bypass both the transform and quantization, i.e., directly encode the residual without applying either the transform or quantization process.

[0094] The encoder decodes the encoded blocks to provide a reference for further prediction. The quantized transform coefficients are dequantized (240) and inversely transformed (250) to decode the prediction residuals. The image blocks are reconstructed by combining (255) the decoded prediction residuals and the prediction blocks. An in-loop filter (265) is applied to the reconstructed image to perform, for example, deblocking / SAO (sample adaptive offset) filtering to reduce coding artifacts. The filtered image is stored at the reference image buffer (280).

[0095] Figure 3 This is a diagram illustrating an example video decoder. In the example decoder 300, as described below, the bitstream is decoded by decoder elements. The video decoder 300 typically performs operations similar to... Figure 2 The decoding rounds are the inverse of the encoding rounds described in the diagram. Encoder 200 typically also performs video decoding as part of the encoding of the video data.

[0096] Specifically, the input to the decoder includes a video bitstream, which can be generated by the video encoder 200. The bitstream is first entropy decoded (330) to obtain transform coefficients, motion vectors, and other encoded information. Picture partitioning information indicates how the picture is partitioned. Therefore, the decoder can partition (335) the picture based on the decoded picture partitioning information. The transform coefficients are dequantized (340) and inverse transformed (350) to decode the prediction residuals. By combining (355) the decoded prediction residuals and prediction blocks, the image blocks are reconstructed. The prediction blocks can be obtained (370) from intra-frame prediction (360) or motion-compensated prediction (i.e., inter-frame prediction) (375). An in-loop filter (365) is applied to the reconstructed image. The filtered image is stored at the reference picture buffer (380).

[0097] The decoded image can undergo further post-decoding processing (385), such as inverse color transformation (e.g., a conversion from YCbCr4:2:0 to RGB4:4:4) or inverse remapping of the remapping process performed in pre-encoding processing (201). Post-decoding processing can utilize metadata derived in pre-encoding processing and signaled in the bitstream. In one example, the decoded image (e.g., after applying an in-loop filter (365) and / or after post-decoding processing (385), if post-decoding processing is used) can be sent to a display device for presentation to a user.

[0098] Figure 4 This is a diagram illustrating examples of systems in which the various aspects and examples described herein may be implemented. System 400 may be embodied as a device including the various components described below and configured to perform one or more of the aspects described in this document. Examples of such devices include, but are not limited to, various electronic devices such as personal computers, laptop computers, smartphones, tablet computers, digital multimedia set-top boxes, digital television receivers, personal video recording systems, connected home appliances, and servers. Elements of system 400 may be embodied individually or in combination in a single integrated circuit (IC), multiple ICs, and / or discrete components. For example, in at least one example, the processing and encoder / decoder elements of system 400 are distributed across multiple ICs and / or discrete components. In various examples, system 400 is communicatively coupled to one or more other systems or other electronic devices via, for example, a communication bus or through dedicated input and / or output ports. In various examples, system 400 is configured to implement one or more of the aspects described in this document.

[0099] System 400 includes at least one processor 410 configured to execute instructions loaded thereon to implement various aspects, such as those described in this document. Processor 410 may include embedded memory, input / output interfaces, and various other circuitry as known in the art. System 400 includes at least one memory 420 (e.g., a volatile memory device and / or a non-volatile memory device). System 400 includes a storage device 440 which may include non-volatile memory and / or volatile memory, including but not limited to electrically erasable programmable read-only memory (EEPROM), read-only memory (ROM), programmable read-only memory (PROM), random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), flash memory, disk drives, and / or optical disk drives. As a non-limiting example, storage device 440 may include internal storage devices, attached storage devices (including removable and non-removable storage devices), and / or network-accessible storage devices.

[0100] System 400 includes an encoder / decoder module 430 configured to, for example, process data to provide encoded or decoded video, and the encoder / decoder module 430 may include its own processor and memory. The encoder / decoder module 430 represents one or more modules that can be included in a device to perform encoding and / or decoding functions. As is known, a device may include one or both of an encoding module and a decoding module. Furthermore, as is known to those skilled in the art, the encoder / decoder module 430 may be implemented as a separate element of system 400, or it may be incorporated within processor 410 as a combination of hardware and software.

[0101] Program code to be loaded onto processor 410 or encoder / decoder 430 to execute the various aspects described in this document may be stored in storage device 440 and subsequently loaded onto memory 420 for execution by processor 410. Depending on various examples, one or more of processor 410, memory 420, storage device 440, and encoder / decoder module 430 may store one or more various items during the execution of the processes described in this document. Such stored items may include, but are not limited to, input video, decoded video or portions of decoded video, bitstreams, matrices, variables, and intermediate or final results from the processing of equations, formulas, operations, and operational logic.

[0102] In some examples, the memory within processor 410 and / or encoder / decoder module 430 is used to store instructions and provide working memory for processing required during encoding or decoding. However, in other examples, external memory (e.g., the processing device may be processor 410 or encoder / decoder module 430) is used for one or more of these functions. External memory may be memory 420 and / or storage device 440, such as dynamically volatile memory and / or non-volatile flash memory. In several examples, external non-volatile flash memory is used to store, for example, the operating system of a television. In at least one example, fast external dynamically volatile memory, such as RAM, is used as working memory for video encoding and decoding operations.

[0103] Inputs to the components of system 400 may be provided by various input devices, as indicated in block 445. Such input devices include, but are not limited to: (i) an RF section that receives radio frequency (RF) signals transmitted over the air, for example by a broadcasting device; (ii) a component (COMP) input terminal (or a set of COMP input terminals); (iii) a universal serial bus (USB) input terminal; and / or (iv) a high-definition multimedia interface (HDMI) input terminal. Figure 4 Other examples not shown include composite videos.

[0104] In various examples, as is known in the art, the input device of block 445 has associated respective input processing elements. For example, the RF section may be associated with elements suitable for: (i) selecting a desired frequency (also known as selecting a signal, or limiting the signal band to a band), (ii) down-converting the selected signal, (iii) band-limiting it again to a narrower band to select, for example, a signal band that may be referred to as a channel in some examples, (iv) demodulating the down-converted and band-limited signal, (v) performing error correction, and / or (vi) demultiplexing to select a desired data packet stream. The RF section of various examples includes one or more elements to perform these functions, such as frequency selectors, signal selectors, band limiters, channel selectors, filters, downconverters, demodulators, error correctors, and demultiplexers. The RF section may include a tuner that performs various of these functions, including, for example, down-converting a received signal to a lower frequency (e.g., intermediate frequency or near-baseband frequency) or baseband. In one set-top box example, the RF section and its associated input processing elements receive RF signals transmitted via a wired (e.g., cable) medium and perform frequency selection by filtering, down-converting, and re-filtering to the desired frequency band. Various examples rearrange the order of the above (and other) components, remove some of these components, and / or add other components that perform similar or different functions. Adding components may include inserting components between existing components, such as, for example, inserting an amplifier and an analog-to-digital converter. In various examples, the RF section includes an antenna.

[0105] USB and / or HDMI terminals may include their respective interface processors for connecting system 400 to other electronic devices across USB and / or HDMI connections. It should be understood that various aspects of input processing (e.g., Reed Solomon error correction) can be implemented as needed, for example, within a separate input processing IC or within processor 410. Similarly, various aspects of USB or HDMI interface processing can be implemented as needed, either within a separate interface IC or within processor 410. Demodulated, error-corrected, and demultiplexed streams are provided to various processing elements, including, for example, processor 410 and encoder / decoder 430, to operate in conjunction with memory and storage elements to process the data streams as needed for presentation on the output device.

[0106] Various components of system 400 can be housed within an integrated housing. Within the integrated housing, various components can be interconnected and transmit data between them using suitable connection arrangements 425 (e.g., internal buses as known in the art, including inter-IC (I2C) buses, wiring, and printed circuit boards).

[0107] System 400 includes a communication interface 450 that enables communication with other devices via a communication channel 460. The communication interface 450 may include, but is not limited to, a transceiver configured to transmit and receive data via the communication channel 460. The communication interface 450 may include, but is not limited to, a modem or network interface card (NIC), and the communication channel 460 may be implemented, for example, in a wired and / or wireless medium.

[0108] In various examples, data is streamed to or otherwise provided to system 400 using a wireless network such as a Wi-Fi network (e.g., IEEE 802.11 (IEEE refers to the Institute of Electrical and Electronics Engineers)). In these examples, the Wi-Fi signal is received via a communication channel 460 and a communication interface 450 suitable for Wi-Fi communication. The communication channel 460 in these examples is typically connected to an access point or router that provides access to external networks, including the Internet, to allow streaming applications and other over-the-top communications. Other examples use a set-top box that delivers data via an HDMI connection to input block 445 to provide streaming data to system 400. Still other examples use an RF connection to input block 445 to provide streaming data to system 400. As indicated above, various examples provide data in a non-streaming manner. Furthermore, various examples use wireless networks instead of Wi-Fi, such as cellular networks or Bluetooth® networks.

[0109] System 400 can provide output signals to various output devices, including display 475, speaker 485, and other peripheral devices 495. Display 475, in various examples, includes one or more of, for example, a touchscreen display, an organic light-emitting diode (OLED) display, a curved display, and / or a foldable display. Display 475 can be used in televisions, tablets, laptops, mobile phones, or other devices. Display 475 can also be integrated with other components (e.g., as in a smartphone) or separate (e.g., as in an external monitor for a laptop). In various examples, other peripheral devices 495 include one or more of a standalone digital video disc (or digital multifunction disc) (both terms refer to DVDs), a disc player, a stereo system, and / or a lighting system. Various examples use one or more peripheral devices 495 that provide functionality based on the output of system 400. For example, a disc player performs the function of playing the output of system 400.

[0110] In various examples, signaling such as AV.Link, Consumer Electronics Control (CEC), or other communication protocols that enable device-to-device control with or without user intervention is used to communicate control signals between system 400 and display 475, speaker 485, or other peripheral devices 495. Output devices can be communicatively coupled to system 400 via dedicated connections through their respective interfaces 470, 480, and 490. Alternatively, output devices can be connected to system 400 via communication interface 450 using communication channel 460. Display 475 and speaker 485 can be integrated into a single unit with other components of system 400 in electronic devices such as, for example, a television set. In various examples, display interface 470 includes display drivers, such as, for example, a timing controller (TCon) chip.

[0111] For example, if the RF section of input 445 is part of a standalone set-top box, then display 475 and speaker 485 can alternatively be separate from one or more other components. In various examples where display 475 and speaker 485 are external components, the output signal can be provided via dedicated output connections, including, for example, an HDMI port, a USB port, or a COMP output.

[0112] The example can be implemented by computer software implemented by processor 410, or by hardware, or by a combination of hardware and software. As a non-limiting example, the example can be implemented by one or more integrated circuits. As a non-limiting example, memory 420 can be of any type suitable for the technical environment and can be implemented using any suitable data storage technology, such as optical storage devices, magnetic storage devices, semiconductor-based memory devices, fixed memory, and removable memory. As a non-limiting example, processor 410 can be of any type suitable for the technical environment and can encompass one or more of microprocessors, general-purpose computers, special-purpose computers, and processors based on multi-core architectures.

[0113] Various implementations involve decoding. As used herein, "decoding" can include, for example, all or part of a process performed on a received encoded sequence to produce a final output suitable for display. In various examples, such a process includes one or more processes typically performed by a decoder, such as entropy decoding, inverse quantization, inverse transform, and differential decoding. In various examples, such a process also or alternatively includes processes performed by a decoder of the various implementations described herein, such as determining an angular intra-frame prediction mode used for the encoded block, determining a perspective mode used for the encoded block, determining a perspective point associated with the encoded block, decoding the encoded block based on the determined perspective point, etc.

[0114] As further examples, in one example, "decoding" refers only to entropy decoding; in another example, "decoding" refers only to differential decoding; and in yet another example, "decoding" refers to a combination of entropy decoding and differential decoding. It will be clear, and is considered well understood by one of ordinary skill in the art, whether the phrase "decoding process" is intended to refer specifically to a subset of operations or to a broader decoding process, based on the specific context of the description.

[0115] Various implementations involve encoding. In a manner similar to the discussion above regarding “decoding,” “encoding,” as used herein, can include, for example, all or part of a process performed on an input video sequence to produce an encoded bitstream. In various examples, such a process includes one or more processes typically performed by an encoder, such as partitioning, differential coding, transform, quantization, and entropy coding. In various examples, such a process also or alternatively includes processes performed by an encoder of the various implementations described herein, such as determining an angular intra-frame prediction mode to be used for a coding block, determining a perspective mode to be used for a coding block, determining a perspective point associated with the coding block, encoding the coding block based on the determined perspective point, transmitting the encoded coding block in video data, and an indication indicating the use of the perspective mode for the encoded coding block, etc.

[0116] As further examples, in one example, "encoding" refers only to entropy encoding; in another, "encoding" refers only to differential encoding; and in yet another, "encoding" refers to a combination of differential and entropy encoding. It will be clear, and is considered well understood by those skilled in the art, whether the phrase "encoding process" is intended to specifically refer to a subset of operations or to refer generally to the broader decoding process, based on the specific context of the description.

[0117] Note that the grammatical elements used in this article (such as the encoding grammar for perspective mode indication, etc.) are descriptive terms. Accordingly, they do not preclude the use of other grammatical element names.

[0118] When a diagram is presented as a flowchart, it should be understood that it also provides a block diagram of the corresponding device. Similarly, when a diagram is presented as a block diagram, it should be understood that it also provides a flowchart of the corresponding method / process.

[0119] The implementations and aspects described herein can be implemented, for example, in a method or process, apparatus, software program, data stream, or signal. Even if discussed only in the context of a single implementation (e.g., discussed only as a method), the implementation of the discussed features can also be implemented in other forms (e.g., apparatus or program). An apparatus can be implemented, for example, in appropriate hardware, software, and firmware. A method can be implemented, for example, in a processor, which generally refers to a processing device, including, for example, a computer, microprocessor, integrated circuit, or programmable logic device. A processor also includes communication devices, such as, for example, a computer, a cellular phone, a portable / personal digital assistant (“PDA”), and other devices that facilitate information communication between end users.

[0120] References to “an example” or “an example” or “an implementation” or “an implementation”, and their other variations, mean that the specific feature, structure, characteristic, etc., described in connection with the example is included in at least one example. Therefore, the appearance of the phrase “in an example” or “in the example” or “in an implementation” or “in the implementation”, and any other variations appearing in different places throughout the application, do not necessarily refer to the same example.

[0121] Additionally, this application may refer to "determining" various information pieces. Determining information may include, for example, one or more of estimation information, calculation information, prediction information, or information retrieved from memory. Obtaining may include receiving, retrieving, constructing, generating, and / or determining.

[0122] Furthermore, this application may refer to "accessing" various information fragments. Accessing information may include, for example, receiving information, retrieving information (e.g., from memory), storing information, moving information, copying information, calculating information, determining information, predicting information, or estimating information, or one or more of these.

[0123] Additionally, this application may refer to "receiving" various pieces of information. Like "access," "receiving" is intended to be a broad term. Receiving information may include, for example, accessing information or retrieving information (e.g., from memory) one or more. Furthermore, "receiving" is generally referred to in one way or another during operations such as, for example, storing information, processing information, transmitting information, moving information, copying information, erasing information, calculating information, determining information, predicting information, or estimating information.

[0124] It will be understood that the use of any of the following “ / ”, “and / or”, and “at least one”, for example, in the cases of “A / B”, “A and / or B”, and “at least one of A and B”, is intended to include selecting only the first listed option (A), or only the second listed option (B), or selecting both options (A and B). As another example, in the cases of “A, B, and / or C” and “at least one of A, B, and C”, such wording is intended to include selecting only the first listed option (A), or only the second listed option (B), or only the third listed option (C), or only the first and second listed options (A and B), or only the first and third listed options (A and C), or only the second and third listed options (B and C), or selecting all three options (A, B, and C). As will be apparent to those skilled in the art and related fields, this can be extended to a large number of listed items.

[0125] Furthermore, as used herein, the word "signal" specifically refers, among other things, to instructing the corresponding decoder to something. Encoder signals may include, for example, encoded blocks, indications of perspective modes, indications of perspective points, etc. In this way, in the examples, the same parameters can be used on both the encoder and decoder sides. Thus, for example, the encoder can transmit (explicitly signal) a specific parameter to the decoder so that the decoder can use the same specific parameter. Conversely, if the decoder already has the specific parameter as well as other parameters, signaling can be used without transmission (implicitly signal) to simply allow the decoder to know and select the specific parameter. Bit savings are achieved in various examples by avoiding the transmission of any actual functionality. It will be understood that signaling can be implemented in many ways. For example, in various examples, one or more syntax elements, flags, etc., are used to signal information to the corresponding decoder. Although the verb form of the word "signal" has been mentioned above, the word "signal" can also be used as a noun in this article.

[0126] As will be apparent to those skilled in the art, the implementation can generate various signals, which are formatted to carry information, for example, that can be stored or transmitted. This information may include, for example, instructions for performing a method, or data generated by one of the implementations. For example, the signal may be formatted to carry a bit stream of the example. Such a signal may be formatted as, for example, electromagnetic waves (e.g., using the radio frequency portion of the spectrum) or baseband signals. Formatting may include, for example, encoding the data stream and modulating a carrier wave with the encoded data stream. The information carried by the signal may be, for example, analog or digital information. As is known, the signal can be transmitted via a variety of different wired or wireless links. The signal may be stored on, accessed from, or received from a processor-readable medium.

[0127] This document describes numerous examples. Features of the examples may be provided individually or in any combination across various claim classes and types. Furthermore, examples may include one or more of the features, devices, or aspects described herein, individually or in any combination across various claim classes and types. For example, the features described herein may be implemented in a bitstream or signal including information generated as described herein. According to any of the described embodiments, this information may allow a decoder to decode the bitstream, encoder, bitstream, and / or decoder. For example, the features described herein may be implemented by creating and / or transmitting and / or receiving and / or decoding a bitstream or signal. For example, the features described herein may be implemented as a method, process, apparatus, medium storing instructions, medium storing data, or signal. For example, the features described herein may be implemented by a TV, set-top box, mobile phone, tablet computer, or other electronic device performing decoding. The TV, set-top box, mobile phone, tablet computer, or other electronic device may display (e.g., using a monitor, screen, or other type of display) the resulting image (e.g., an image reconstructed from the residual of a video bitstream). The TV, set-top box, mobile phone, tablet computer, or other electronic device may receive a signal including an encoded image and perform decoding.

[0128] Systems, methods, and means for performing intra-frame prediction using perspective are disclosed. For example, a perspective mode can be used. If an angular intra-frame prediction mode is used, a perspective mode can also be used. A perspective mode may include prediction using perspective points. A perspective indicator can be used to indicate whether a perspective prediction mode is used. A perspective mode can be signaled and / or derived.

[0129] A device (e.g., a video encoder or video decoder) can perform intra-frame prediction using perspective modes. For example, the device can determine that an angular intra-frame prediction mode is used for a coding block. The device can (e.g., based on the determination that an angular intra-frame prediction mode is used for a coding block) determine whether to use a perspective mode for the coding block. The device can obtain an indication of the perspective mode (e.g., a PerspectiveFlag). The device can (e.g., based on the determination that a perspective mode is used for a coding block) determine a perspective point associated with the coding block. This perspective point can be used for encoding and / or decoding functions associated with the coding block. The coding block can be encoded and / or decoded based on the determined perspective point. The device (e.g., an encoder) can transmit the encoded coding block and the indication (e.g., a PerspectiveFlag) indicating the use of a perspective mode for the encoded coding block in the video data.

[0130] In the example, rate-distortion (RD) cost determination can be performed, for example, to determine the perspective mode to use. For example, a full RD cost determination can be performed against a list of candidate intra-prediction modes. The mode associated with the lowest RD cost among the candidate intra-prediction modes (e.g., a perspective mode) can be selected. For example, RD cost determination can include two rounds. For example, the first round can include determining an initial list of candidate intra-prediction modes based on partial RD criteria (e.g., from the list of candidate intra-prediction modes). The second round can include a full RD cost determination associated with the initial list of candidate intra-prediction modes.

[0131] In the example, multiple perspective modes can be used. Multiple perspective points can be determined (e.g., one perspective point for each perspective mode).

[0132] A fixed perspective point can be used and / or determined. The fixed perspective point can be determined based on one or more of the following: a most probable mode (MPM) list; a decoder-side intra-mode derivation (DIMD) mode; a template-based intra-mode derivation and fusion (TIMD) mode; etc.

[0133] The systems, methods, and means described herein may relate to a decoder. In some examples, the systems, methods, and means described herein may relate to an encoder. In some examples, the systems, methods, and means described herein may relate to signals (e.g., from an encoder and / or received by a decoder). A computer-readable medium may include instructions for causing one or more processors to perform the methods described herein. A computer program product may include instructions that, when executed by one or more processors, cause the one or more processors to perform the methods described herein.

[0134] In intra-frame prediction, any target block can have a prediction mode (e.g., one of the specified prediction modes). Angular prediction modes can be associated with different prediction directions. For a prediction mode (e.g., any of those prediction modes), pixels in the target block can be predicted along the same prediction direction. Many natural scenes (e.g., architectural videos, driving on roads, river cruises, etc.) may not be efficiently modeled by such constant prediction models, for example, because of the use of perspective. In these cases, video codecs using constant prediction models may either perform inefficient prediction or partition the block into many smaller blocks (e.g., in perspective regions), leading to inefficient compression performance, for example. For instance, a perspective mode for intra-frame prediction could be used, where perspective points can be used to perform prediction.

[0135] Intra-frame prediction can be performed using one or more perspective points, which may be referred to as vanishing points. For example, a perspective pattern can be used, where the perspective pattern can refer to a prediction with perspective points. These points can be located at a distance from the target block (e.g., a specific distance) along the prediction direction. Similar to conventional prediction directions, perspective points can be identified by their perspective direction relative to the target block (e.g., a unique perspective direction). For a given perspective point, a target pixel can be predicted (e.g., each) along a direction that joins the target pixel location with the perspective point location. Therefore, target pixels in any row or column of a block can have different prediction directions. After prediction, residual errors can be encoded using subsequent steps such as transform coding, quantization, lossless coding of the quantized coefficients, etc. Rate-distortion performance can be compared to those of existing conventional prediction patterns. The best prediction can be selected. A perspective indicator (e.g., a flag) can be used to indicate, for example, whether the selected perspective prediction pattern is used. The perspective mode itself can be indicated by a signal (e.g., explicitly indicated by a signal) or can be inferred from the normal perspective of the decoded mode, from the set of most probable modes (MPMs), or from the decoder-side intra-mode derivation (DIMD) mode or template-based intra-mode derivation and fusion (TIMD) mode (e.g., implicitly inferred).

[0136] Intra-frame prediction of the target block can be considered. Pixels in the target block can be predicted, for example, based on multiple (e.g., two) arrays of reference samples (e.g., which may include already decoded pixels to the left and above the block). For this purpose, several angles and multiple (e.g., two) non-angle prediction modes can be defined. For angle modes (e.g., such as...) Figure 5As shown in the diagram, all target pixels can be predicted in the same direction, for example, the direction can be the prediction direction associated with the prediction mode. Reference samples located in the prediction direction can be used as predictors for the target pixels, for example, as direct copies or by using interpolation.

[0137] Figure 5 The illustration shows an example of angle prediction for a target block in intra-frame prediction. For example... Figure 5 As shown, target pixels (e.g., all target pixels) can have the same prediction orientation.

[0138] For example, if (for instance) the frame consists of foreground objects that do not have much 3D perspective, this constant prediction orientation model for the target pixel block can be used.

[0139] Some or all of a frame can have perspective, for example, frames containing natural scenes (e.g., because the 3D nature of the world can have perspective). Perspective is common in video sequences with walls, ceilings, etc. (e.g., in architectural videos, or in video sequences shot indoors, or in video sequences containing scenes of driving on a road, cruising on a river, etc.). In those scenarios with perspective, constant prediction direction prediction models may not be efficient. Figure 6 As shown, (e.g., all) target pixels in a block can have different prediction orientations, for example, depending on the perspective orientation. In these cases, video codecs using constant prediction models may either make insufficient predictions, leading to other prediction types (e.g., such as template-based intra-frame prediction (IntraTMP), intra-block copy (IBC), hybrid prediction such as in decoder-side intra-mode derivation (DIMD), template-based intra-mode derivation and fusion (TIMD), spatial geometric partitioning mode (SGPM), etc.), or partition the block into many smaller blocks in the perspective region (e.g., this may lead to inefficient compression performance).

[0140] Figure 6 The illustration shows an example of perspective prediction for a target block in intra-frame prediction. Target pixels in a row or column can have different prediction orientations. For example... Figure 6 As shown, the perspective point can be at the top of the block.

[0141] Perspective mode can be used for intra-frame prediction, where perspective points are used to perform prediction. Perspective mode (PM) and perspective points (PP) can be enabled, used, and / or provided.

[0142] Angle patterns can be specified (e.g., 65 regular angle patterns and 28 wide-angle patterns). Among these patterns, some (e.g., only 65 patterns) may be possible for (e.g., any) target block, depending on its aspect ratio. Angle patterns can also be called direction patterns (e.g., because each pattern can be associated with a prediction direction). Regular angle patterns can be associated with prediction directions spanning an angle range from 45 degrees to -135 degrees, while wide-angle patterns can be associated with directions beyond this range. Square-shaped target blocks (e.g., blocks with height = width) can have regular angle patterns (e.g., any one of the 65 regular angle patterns), while rectangular-shaped target blocks (e.g., blocks with height > width, or blocks with height < width) can have continuous angle patterns (e.g., any one of the 65 continuous angle patterns consisting of some regular angle patterns and some wide-angle patterns). Patterns associated with directions below the diagonal (e.g., along a -45 degree direction from the top left to the bottom right) can be called horizontal patterns, while patterns associated with directions above the diagonal can be called vertical patterns.

[0143] A perspective pattern (PM) can be considered an angular pattern with perspective prediction. Prediction can be made using perspective points (PPs) (e.g., vanishing points), which are located at a specified distance from the target block along a direction associated with the angular pattern (e.g., as shown in the image). Figure 7 (as shown in the image).

[0144] Figure 7 The illustration shows an example of defining a perspective point. For a given prediction mode, the perspective point can be (e.g., it can be located) at the intersection of the prediction direction at the center of the target block and a line parallel to the edge of the target block at an offset distance. For a vertical mode, this line can be horizontal, and for a horizontal mode, the line can be vertical. The offset distance of this line from the target block can be defined as the vertical and horizontal perspective distances. H and W can represent the height and width of the target block. In the example, the vertical and horizontal perspective distances can be equal (e.g., as shown in the image). Figure 7 (as shown in the image).

[0145] The perspective point (PP) can be defined as the intersection of the prediction direction at the center of the target block (e.g., the prediction direction associated with the pattern) and a line parallel to the edge of the block at an offset distance. For a vertical prediction pattern, this line can be horizontal at offset distance dy, while for a horizontal pattern, the line can be vertical at offset distance dx (e.g., as shown in the image). Figure 7 (As shown in the diagram). For example, dx and dy can include the horizontal perspective distance and the vertical perspective distance, respectively. For example, if the predicted pattern index is m, the perspective point associated with the pattern can be represented as P. m .

[0146] The applicable prediction directions can span a range from 45 degrees to -135 degrees (e.g., for square target blocks). For example... Figure 8 As shown, there may exist perspective points that correspond to (e.g., each) a defined (e.g., uniquely defined) prediction pattern. A perspective point (PP) associated with a vertical pattern can be called a vertical PP, and a PP associated with a horizontal pattern can be called a horizontal PP. For example, there may be 33 vertical PPs associated with 33 vertical patterns. For example, there may be 32 horizontal PPs associated with 32 horizontal patterns. For example, if dx and dy are equal (e.g., chosen as equal), then a PP can lie on a square, such as... Figure 8 As shown in the image.

[0147] Figure 8 The illustration shows an example of perspective points for a square target block. There may be 33 vertical perspective points (PPs) and 32 horizontal perspective points corresponding to 33 vertical angle patterns and 32 horizontal angle patterns. In the example, the horizontal and vertical perspective distances can be equal.

[0148] For example, the number of vertical and horizontal modes can depend on the shape of the block (e.g., for a rectangular block) because some wide-angle modes can exist in addition to regular angular modes. For instance, a mode can be defined as vertical or horizontal depending on whether the associated prediction direction is greater than or less than -45 degrees. Even if dx and dy are chosen such that their ratio (dx / dy) equals the block's aspect ratio (e.g., (W / H)), the placement of the PP may not be on a rectangle. The PP can be defined by the prediction direction and offset distance (e.g., uniquely defined) (e.g., as...). Figure 9 (As shown in the image). By finding the intersection with the top horizontal line in this example to change some horizontal PPs into vertical PPs, or by finding the intersection with the left vertical line to change some vertical PPs into horizontal PPs (e.g., for tall rectangular blocks, i.e., when height > width), PPs can be placed (e.g., all of them) on the outer rectangle.

[0149] Figure 9 The illustration shows an example of perspective points for a rectangular target block. Here, perspective distances can be selected such that their ratio equals the block's aspect ratio. There may be 65 perspective points associated with 65 angle modes.

[0150] For (e.g., any) perspective point P m You can define a mirror perspective point. A mirrored perspective point can be located on opposite sides of a block. A mirrored perspective point (PP) can be obtained by extending the prediction direction through the center of the target block and identifying its intersection with a line parallel to the top or left side line (e.g., as shown in the image). Figure 10(As shown in the diagram). The mirror image of vertical PP can be vertical. Similarly, the mirror image of horizontal PP can be horizontal. To distinguish these two pairs, they can be referred to as vertically upward and vertically downward PP, and horizontally to the left and horizontally to the right PP, respectively. The mirror image of P2 can be P... 66 And vice versa.

[0151] Figure 10 The illustration shows an example of a mirrored perspective point. Perspective points pointing vertically upwards and downwards can be mirrored. Perspective points pointing horizontally to the left and right can also be mirrored.

[0152] For example, the top and left reference samples can be used (for example, always) to predict the target block, regardless of the location of the perspective point. Figure 11 An example of perspective prediction is shown if PP and its mirror PP are in a purely vertical direction (e.g., mode 50). The predicted direction of any target pixel (e.g., any) can be from PP toward itself (e.g., if PP is at the top) or from itself toward PP (e.g., if PP is at the bottom). For horizontal prediction modes, the situation may be similarly determined depending on whether PP is on the left or right. Perspective prediction can be based on (e.g., assumed to be based on) a first reference line (e.g., the nearest reference array to the top and left of the target block). Figure 11 The illustration shows an example prediction with perspective points. For example, the prediction can be based on (e.g., always based on) the left and top reference arrays, regardless of the position of the perspective points.

[0153] For example, for any given prediction direction, there can be more than two prediction directions. Figure 12 As shown, PP can be located at different distances from the edge of the target block. Figure 12 As shown, two projective propagators (PPs) can be located at distances d and 2d from the top edge of the block, and their respective mirror images of each PP can be located below the block. PPs can (e.g., generally) be located at distances d1 and d2 from the block. For prediction pattern m, PPs can be represented, for example, in increasing order of their distances from the target block. , wait. Figure 12 The illustration shows example perspective points at different distances from the target block but associated with the same prediction pattern.

[0154] Dead zones of PP can be identified, determined, and / or detected.

[0155] There may be areas where PPs can be avoided (e.g., should not be placed) (e.g., some areas), for example, because the reference samples used for prediction on the top and left sides of the target block may have a finite length. Figure 13As shown, a PP placed in a dead zone region of a PP may cause the reference sample to be insufficient to predict the target block (e.g., the entire target block). These regions can be referred to as dead zones of a PP. These dead zones may appear at mirror perspective points (e.g., only mirror perspective points). Perspective points located in dead zones may be avoided from being considered (e.g., not considered) for prediction.

[0156] Figure 13 The illustration shows an example dead zone of a perspective point. The marked area on the right side of the block (e.g., in...) Figure 13 (In the middle) can be the dead zone of the horizontal perspective point. The marked area at the bottom of the block (e.g., in) Figure 13 (middle) can be the dead zone of the vertical perspective point.

[0157] Having defined perspective points and perspective modes, this paper describes the details of perspective-based prediction. The main difference between normal prediction and perspective-based prediction can include the prediction direction along rows or columns, which can be variable in perspective-based prediction. The angular parameter `predIntraAngle` can be a function of the target pixel position. To distinguish between these two prediction types, the term `perspectiveAngle` can refer to the original `predIntraAngle`, while... Can refer to pixel position The angle parameter at that location.

[0158] Figure 14 The location is shown in the diagram. An example of deriving the angle parameters of the target pixel at that location. For illustrative purposes, Figure 14 The illustration shows a vertical perspective mode. A similar situation might occur for a horizontal perspective mode, for example, if the target block is transposed along with the swapped left and top reference arrays. The width and height of the target block can be represented as W and H, respectively. For example, the perspective height can be d, which can be the vertical distance PP from the top edge of the target block. To avoid division, d can be assumed to be a power of 2. For example, d = k * H can be used, where... , Where Kmax can be a preset integer. For horizontal mode, d = k * W can be used, where , For the sake of derivation, a (1 / 32) pixel resolution of the predicted angle can be used, but the same result can be obtained for a (1 / 64) pixel resolution. For example, It can represent Value, and The `perspectiveAngle` parameter can be the same as the angle parameter associated with the prediction direction.

[0159] Figure 15The illustration shows an example of intra-frame prediction using perspective. The predictor for the target pixel can be a reference sample located in the direction that joins the target pixel with the perspective point.

[0160] For example, Equation 1 can be used to calculate... The angular parameters of the target pixel at that location. As shown in Equation 1, triangle similarity can be used.

[0161] Equation 1 Therefore, equation 2 can be determined.

[0162] Equation 2 Since d can be a power of 2, the division operation in equation 2 can be implemented using bit shifting. Equations 3 and 4 can be used to calculate... The pixels at that location.

[0163] Equation 3 Equation 4 This can be equivalently represented as Equation 5: Equation 5 To avoid division, the above calculation (e.g., equation 5) can be implemented as follows: Equation 6 in, Equation 7 Integer value It can be pre-computed and stored in the array.

[0164] Once it has been calculated The steps used to identify predictor samples (e.g., the remaining steps) can be the same as those used in conventional procedures. For example, This can represent the predictor's distance from The x-offset of the target pixel at that location. For example, and It can represent The integer and decimal parts. (See reference) Figure 15 Equation 8-10 can be determined as: Equation 8 Equation 9 Equation 10 For example, a (1 / 32) pixel resolution can be used for intra-frame prediction angles. In the case of a (1 / 64) pixel resolution for the intra-frame prediction angle, the integer and fractional parts of the offset can be obtained according to equation 11-12: Equation 11 Equation 12 Figure 16 The illustration shows an example of intra-frame prediction using perspective. For example... Figure 16 As shown, the predictor for the target pixel can be interpolated using six nearest reference samples. Alternatively, it can be interpolated using four nearest reference samples, or linearly interpolated using (e.g., only) two nearest reference samples.

[0165] The predictor samples can be interpolated using six nearest reference samples. Figure 16 Six reference samples can be identified based on Table 1. Table 1.

[0166] For example, refMain can be the master reference matrix pointing to the top-left pixel. The interpolation filter can be determined based on the value of deltaFrac(x,y). If f(n) represents the filter coefficients, then the predictor samples are interpolated according to Equation 13.

[0167] Equation 13.

[0168] In the example, deltaFrac can be used (e.g., deltaFrac alone can be used) to determine the filter (e.g., it can remain constant for a given row of pixels). For example, depending on the value of deltaFrac(x,y), the filter can change pixel by pixel, even within the same row. For example, depending on the indicator (e.g., a flag called interpolationFlag), the filter for a given target block can be a smoothing filter or a cubic filter. The same criteria can be maintained here.

[0169] In the example, the four nearest reference samples (e.g., P1, P2, P3, and P4) can be used to interpolate the predictor samples. Alternatively, the predictor can be linearly interpolated using the two nearest samples (e.g., only the two nearest reference samples), P2 and P3.

[0170] This paper provides a design example incorporating perspective prediction. In the case of perspective prediction, one or more of the following can be assumed: no intra-fraction sub-segment (ISP); prediction is performed using a first reference array; DIMD indicators (e.g., flags), SGPM indicators (e.g., flags), TIMD indicators (e.g., flags), intraTmp (e.g., flags), etc. are disabled (e.g., all are disabled); etc. The derivation of the most probable list (MPM) can remain unchanged.

[0171] In the example, a device (e.g., a video encoder) can examine angle prediction patterns in both normal and perspective modes. Associated with each angle pattern, there may be (e.g., only one) perspective point, and therefore, a perspective prediction. The perspective point can be located at a predefined distance from the target block location. For example, a two-round process can be performed (e.g., where an initial fast round pre-selects several patterns based on partial RD criteria) to avoid exhaustive checking of all patterns for full RD performance. Patterns included in the initial list can undergo RD checking (e.g., full RD) in a second round. The pattern that produces the minimum RD cost can be selected by the device (e.g., the encoder) for prediction. The device (e.g., the encoder) can examine patterns in this fast round, for example, in both normal and perspective modes. For example, if a candidate angle pattern gives a lower cost than the perspective mode, an indication (e.g., a flag called perspectiveFlag) can be enabled (e.g., otherwise, it might be disabled). The device (e.g., the encoder) can pre-select multiple candidate patterns to undergo full RD checking in the second round. The device (e.g., an encoder) can examine the perspective indicator (e.g., `perspectiveFlag`) value to determine which prediction mode to use for the angular mode, for example, for full RD cost calculation. RD cost calculation may include CABAC encoding of the perspective indicator (e.g., `perspectiveFlag`). The device (e.g., the encoder) can encode the prediction mode in a normal manner. If the optimal prediction mode is angular, it can encode the perspective indicator (e.g., `perspectiveFlag`) (e.g., also encode it). The device (e.g., a decoder) can decode the prediction mode in a normal manner. If the decoded prediction mode is angular, it can decode the perspective indicator (e.g., `perspectiveFlag`). Depending on whether the perspective indicator (e.g., `perspectiveFlag`) is enabled or disabled, prediction of the target block can be performed with or without perspective.

[0172] In the example, the device (e.g., encoder) can limit perspective prediction to angle patterns included in the Most Probable Pattern (MPM) list (e.g., limited to angle patterns included in the MPM list). For each angle pattern in the MPM list, the device (e.g., encoder) can check performance in fast rounds and can add candidate patterns to an initial list of patterns to be tested for full RD, for example, if the cost is lower than any pattern already included in the list. The full RD check can be performed in the same manner as described herein. If the best pattern is angled and belongs to the MPM list, the device (e.g., encoder) can encode the perspective indication (e.g., perspectiveFlag). Thus, for example, if (e.g., only if) the pattern is angled and belongs to the MPM list, the device (e.g., decoder) can decode the perspectiveFlag.

[0173] In the example, the device (e.g., an encoder) can check the optimal angular pattern in the initial shortlist (e.g., only the optimal angular pattern) using perspective prediction before a full RD check. A pattern with perspective prediction can replace the initial shortlist, for example, if the cost is lower than the cost of patterns in the initial shortlist with normal prediction (e.g., any of the patterns). The full RD check can be performed as described herein. For example, if the optimal pattern is angular, the device (e.g., the encoder) can encode the perspective indicator (e.g., the perspectiveFlag). For example, if the decoded pattern is angular, the device (e.g., the decoder) can decode the perspective indicator (e.g., the perspectiveFlag).

[0174] In the example, multiple perspective points can be used with (e.g., each) angle modes. The device (e.g., encoder) can examine angle prediction modes, such as in a normal mode and multiple perspective modes. The design can be similar to those described herein, except that multiple perspective points are present. In addition to the perspective indicator (e.g., `perspectiveFlag`), there may be another syntax element associated with the perspective mode indicator (e.g., called `perspectiveModeFlag`) to distinguish (e.g., one) perspective mode from another. For example, if the perspective indicator (e.g., `perspectiveFlag`) is enabled, the perspective mode indicator (e.g., `perspectiveModeFlag`) can be encoded. For example, if multiple (e.g., two) perspective points exist (e.g., pairs of points consisting of a perspective point and its mirror image), the perspective mode indicator (e.g., `perspectiveModeFlag`) can be encoded with one bit. If three perspective points exist, `perspectiveModeFlag` can be encoded with two bits (e.g., 0, 10, or 11). For example, if the mode is angular, the device (e.g., a decoder) can decode the perspective indicator (e.g., the perspectiveFlag). For example, if the perspectiveFlag is 1, the perspectiveModeFlag can be decoded. For example, depending on the decoded value, the perspective point can be selected, and prediction can be performed accordingly.

[0175] In the example, the device (e.g., an encoder) can limit perspective prediction to, for example, angle patterns included in the MPM list (e.g., limited to angle patterns only). This may be similar to the process described here, but with multiple perspective points associated with the angle MPM patterns.

[0176] In the example, one or more fixed perspective parameters (PPs) can be used. For example, the device (e.g., encoder) may have (e.g., decide to have) (e.g., only one) vertical perspective and (e.g., one) horizontal perspective. Perspective predictions using these PPs can be viewed as different (e.g., new) prediction modes, for example, on top of existing modes. Encoding of prediction modes can be done in different ways. One way is to use a perspective indicator (e.g., perspectiveFlag) (e.g., as described herein). For example, if the predicted mode being decoded is associated with one of the PPs, the perspective indicator (e.g., perspectiveFlag) can be decoded (e.g., otherwise, no decoding is performed). Perspective modes can be included in a list of modes to be encoded. For example, if the corresponding angular mode (e.g., already) is in the MPM list, the perspective mode can be included in the MPM list. In this case, for example, the existing encoding and decoding of modes can remain similar, except that the number of modes may increase. Perspective indicators (e.g., perspectiveFlag) can be used in conjunction with a list of perspectiveModes. Perspective indicators (e.g., perspectiveFlag) can indicate whether perspective prediction is used. The index of a perspective mode in a list containing (e.g., all) perspective modes can be encoded. In this case, the device (e.g., a decoder) can first decode the perspective indicator (e.g., the perspectiveFlag). If the flag is 1, it can decode the candidate perspective modes; otherwise, it can decode the normal modes in the usual way (e.g., as described herein).

[0177] In the example, the fixed perspective feature (PP) can be determined based on an MPM list pattern, a DIMD pattern, or a TIMD pattern, etc. Among the predefined PPs, the PP closest to the MPM, DIMD, or TIMD pattern, etc., can be selected for perspective prediction. In this case, (e.g., only) the perspective indicator (e.g., perspectiveFlag) can be encoded (e.g., it needs to be encoded) because the location of the PP can be easily identified. For example, if multiple PPs exist along the same direction, the perspective mode indicator (e.g., perspectiveModeFlag) can be used.

[0178] A perspective point can be defined relative to the center of the target block. In the example, a perspective point can be defined relative to another point, for example, at a predefined offset from the center of the target block. The perspective point can be defined using the prediction direction associated with the specified intra-prediction mode. In the example, the perspective point (PP) can be defined at a predefined angular offset from the prediction direction associated with the specified prediction mode.

[0179] A perspective-based intra-frame prediction model can be provided, enabled, and / or used. In sequences with perspective, this prediction model can achieve (e.g., result in) higher compression efficiency (e.g., compared to a normal prediction model that does not use any perspective model).

[0180] Although the features and elements have been described above in specific combinations, those skilled in the art will appreciate that each feature or element can be used alone or in any combination with other features and elements. Furthermore, the methods described herein can be implemented in a computer program, software, or firmware incorporated into a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted via a wired or wireless connection) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media (such as internal hard disks and removable disks), magneto-optical media, and optical media (such as CD-ROM discs and digital multifunction discs (DVDs)). The processor associated with the software can be used to implement a radio frequency transceiver used in a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

1. A video decoding device, comprising: The processor is configured as follows: It is determined that the perspective mode is used for the coded block; Determine perspective points associated with the coded block, wherein the perspective points are associated with a prediction direction and a distance from the coded block; as well as The encoded block is decoded based on the determined perspective points.

2. The video decoding device according to claim 1, wherein, The processor is further configured to: Obtain instructions associated with using perspective mode; The angle prediction pattern is determined and used in the coded block; Based on the angle prediction mode used to determine the coded block, the indication associated with the use of the perspective mode is decoded, wherein the perspective mode is used to determine the coded block based on the decoded indication.

3. The video decoding device according to claim 1 or 2, wherein, The perspective point is a point associated with the intersection of the prediction direction at the center of the coded block and with a line parallel to the edge of the coded block at an offset distance.

4. The video decoding device according to any one of claims 1 to 3, wherein, The processor is further configured to: Obtain an indication of a list of most probable modes (MPMs), wherein candidate intra-frame prediction modes are determined based at least on the list of MPMs.

5. The video decoding device according to any one of claims 1 to 4, wherein, The perspective mode is a first perspective mode, wherein the perspective point is a first perspective point, and wherein the processor is further configured to: Determine whether the second perspective mode is used in the coded block; and Based on the second perspective mode being used to determine the encoded block, a second perspective point associated with the encoded block is determined, wherein the encoded block is decoded based on the first perspective point and the second perspective point.

6. The video decoding device according to claim 5, wherein, The processor is further configured to: Obtain a perspective mode indication, wherein the perspective mode indication indicates the first perspective mode and the second perspective mode.

7. The video decoding device according to any one of claims 1 to 6, wherein, The perspective point is a fixed perspective point.

8. The video decoding device according to any one of claims 1 to 7, wherein, The perspective point is determined based on at least one of the most probable mode (MPM) list, decoder-side intra-mode derivation mode, or template-based intra-mode derivation (TIMD) mode.

9. The video decoding device according to any one of claims 1 to 8, wherein, The processor is further configured to: An angle intra-prediction mode is used for the coding block, wherein the determination of whether to use a perspective mode for the coding block is based on the angle intra-prediction mode being used for the determination of the coding block.

10. The video decoding device according to any one of claims 1 to 9, wherein, The processor is further configured to: Determine the angle parameters associated with the perspective point, wherein the angle parameters are determined based on the height associated with the coded block, the width associated with the coded block, and the perspective height associated with the perspective point.

11. The video decoding device according to claim 10, wherein, The height associated with the perspective point is the vertical distance between the perspective point and the top edge of the coded block.

12. A video encoding device, comprising: The processor is configured as follows: It is determined that the perspective mode is used for the coded block; Determine perspective points associated with the coded block, wherein the perspective points are associated with a prediction direction and a distance from the coded block; as well as The coded block is encoded based on the determined perspective points.

13. The video encoding device according to claim 12, wherein, The perspective point is a point associated with the intersection of the prediction direction at the center of the coded block and with a line parallel to the edge of the coded block at an offset distance.

14. The video encoding device according to claim 12 or 13, wherein, The perspective mode used to determine the coded block includes determining the rate-distortion (RD) cost associated with the candidate intra-prediction mode, and determining the perspective mode associated with the lowest RD cost among the candidate intra-prediction modes.

15. The video encoding apparatus according to any one of claims 12 to 14, wherein, To determine that the perspective mode is used in the coded block, the processor is further configured to: A preliminary list of candidate intra-prediction modes is determined from a set of candidate intra-prediction modes based on the partial rate distortion (RD) criterion. as well as The lowest RD cost among the initial list of candidate intra-prediction modes is determined to be associated with the perspective mode.

16. The video encoding device according to claim 15, wherein, The determination of the lowest RD cost associated with the perspective mode and the initial list of candidate intra-prediction modes is associated with a full RD check.

17. The video encoding device according to claim 15 or 16, wherein, The processor is further configured to: Obtain an indication of a list of most probable modes (MPMs), wherein the candidate intra-prediction mode is determined based at least on the list of MPMs.

18. The video encoding apparatus according to any one of claims 12 to 17, wherein, The perspective mode is a first perspective mode, wherein the perspective point is a first perspective point, and wherein the processor is further configured to: Determine whether the second perspective mode is used in the coded block; Based on the second perspective mode being used to determine the encoded block, a second perspective point associated with the encoded block is determined, wherein the encoded block is encoded based on the first perspective point and the second perspective point; and The encoded blocks and the indications of the first perspective mode and the second perspective mode are included in the video data.

19. The video encoding apparatus according to any one of claims 12 to 18, wherein, The perspective point is a fixed perspective point.

20. The video encoding apparatus according to any one of claims 12 to 19, wherein, The perspective point is determined based on one of the most probable mode (MPM) list, the decoder-side intra-mode derivation mode, or the template-based intra-mode derivation (TIMD) mode.

21. The video encoding apparatus according to any one of claims 12 to 20, wherein, The processor is further configured to: An angle intra-prediction mode is used for the coding block, wherein the determination of whether to use a perspective mode for the coding block is based on the angle intra-prediction mode being used for the determination of the coding block.

22. The video encoding apparatus according to any one of claims 12 to 21, wherein, The processor is further configured to: The encoded blocks and the indications for using the perspective mode on the encoded blocks are included in the video data.

23. The video encoding apparatus according to any one of claims 12 to 22, wherein, The processor is further configured to: Determine the angle parameters associated with the perspective point, wherein the angle parameters are determined based on the height associated with the coded block, the width associated with the coded block, and the perspective height associated with the perspective point.

24. The video encoding device according to claim 23, wherein, The height associated with the perspective point is the vertical distance between the perspective point and the top edge of the coded block.

25. A method for video decoding, comprising: It is determined that the perspective mode is used for the coded block; Determine perspective points associated with the coded block, wherein the perspective points are associated with a prediction direction and a distance from the coded block; as well as The encoded block is decoded based on the determined perspective points.

26. The method of claim 25, further comprising: Obtain instructions associated with using perspective mode; The angle prediction pattern is determined and used in the coded block; Based on the angle prediction mode used to determine the coded block, the indication associated with the use of the perspective mode is decoded, wherein the perspective mode is used to determine the coded block based on the decoded indication.

27. The method according to claim 25 or 26, wherein, The perspective point is a point associated with the intersection of the prediction direction at the center of the coded block and with a line parallel to the edge of the coded block at an offset distance.

28. The method according to any one of claims 25 to 27, wherein, The processor is further configured to: Obtain an indication of a list of most probable modes (MPMs), wherein candidate intra-frame prediction modes are determined based at least on the list of MPMs.

29. The method according to any one of claims 25 to 28, wherein, The perspective mode is a first perspective mode, wherein the perspective point is a first perspective point, and wherein the method further includes: Determine whether the second perspective mode is used in the coded block; and Based on the second perspective mode being used to determine the encoded block, a second perspective point associated with the encoded block is determined, wherein the encoded block is decoded based on the first perspective point and the second perspective point.

30. The method according to claim 29, wherein, The method further includes: Obtain a perspective mode indication, wherein the perspective mode indication indicates the first perspective mode and the second perspective mode.

31. The method according to any one of claims 25 to 30, wherein, The perspective point is a fixed perspective point.

32. The method according to any one of claims 25 to 31, wherein, The perspective point is determined based on at least one of the most probable mode (MPM) list, decoder-side intra-mode derivation mode, or template-based intra-mode derivation (TIMD) mode.

33. The method according to any one of claims 25 to 32, wherein, The method further includes: An angle intra-prediction mode is used for the coding block, wherein the determination of whether to use a perspective mode for the coding block is based on the angle intra-prediction mode being used for the determination of the coding block.

34. The method according to any one of claims 25 to 33, wherein, The method further includes: Determine the angle parameters associated with the perspective point, wherein the angle parameters are determined based on the height associated with the coded block, the width associated with the coded block, and the perspective height associated with the perspective point.

35. The method according to claim 34, wherein, The height associated with the perspective point is the vertical distance between the perspective point and the top edge of the coded block.

36. A method for video encoding, the method comprising: It is determined that the perspective mode is used for the coded block; Determine perspective points associated with the coded block, wherein the perspective points are associated with a prediction direction and a distance from the coded block; as well as The coded block is encoded based on the determined perspective points.

37. The method according to claim 36, wherein, The perspective point is a point associated with the intersection of the prediction direction at the center of the coded block and with a line parallel to the edge of the coded block at an offset distance.

38. The method according to claim 36 or 37, wherein, The perspective mode used to determine the coded block includes determining the rate-distortion (RD) cost associated with the candidate intra-prediction mode, and determining the perspective mode associated with the lowest RD cost among the candidate intra-prediction modes.

39. The method according to any one of claims 36 to 38, wherein, To determine that the perspective mode is used in the coded block, the method further includes: A preliminary list of candidate intra-prediction modes is determined from a set of candidate intra-prediction modes based on the partial rate distortion (RD) criterion; and The lowest RD cost among the initial list of candidate intra-prediction modes is determined to be associated with the perspective mode.

40. The method according to claim 39, wherein, The determination of the lowest RD cost associated with the perspective mode and the initial list of candidate intra-prediction modes is associated with a full RD check.

41. The method according to claim 39 or 40, wherein, The method further includes: Obtain an indication of a list of most probable modes (MPMs), wherein the candidate intra-prediction mode is determined based at least on the list of MPMs.

42. The method according to any one of claims 36 to 41, wherein, The perspective mode is a first perspective mode, wherein the perspective point is a first perspective point, and wherein the method further includes: Determine whether the second perspective mode is used in the coded block; Based on the second perspective mode being used to determine the encoded block, a second perspective point associated with the encoded block is determined, wherein the encoded block is encoded based on the first perspective point and the second perspective point; and The encoded blocks and the indications of the first perspective mode and the second perspective mode are included in the video data.

43. The method according to any one of claims 36 to 42, wherein, The perspective point is a fixed perspective point.

44. The method according to any one of claims 36 to 43, wherein, The perspective point is determined based on one of the most probable mode (MPM) list, the decoder-side intra-mode derivation mode, or the template-based intra-mode derivation (TIMD) mode.

45. The method according to any one of claims 36 to 44, wherein, The method further includes: An angle intra-prediction mode is used for the coding block, wherein the determination of whether to use a perspective mode for the coding block is based on the angle intra-prediction mode being used for the determination of the coding block.

46. ​​The method according to any one of claims 36 to 45, wherein, The method further includes: The encoded blocks and the indications for using the perspective mode on the encoded blocks are included in the video data.

47. The method according to any one of claims 36 to 46, wherein, The method further includes: Determine the angle parameters associated with the perspective point, wherein the angle parameters are determined based on the height associated with the coded block, the width associated with the coded block, and the perspective height associated with the perspective point.

48. The method according to claim 47, wherein, The height associated with the perspective point is the vertical distance between the perspective point and the top edge of the coded block.

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