Decoder-side intra mode derivation histogram fusion weight

Abstract

Systems, methods, and instrumentalities can be provided for fusing histogram of gradients (HoG) from DIMD and non-DIMD blocks. A video encoding device can generate a first set of blocks, which can select a non-decoder side intra mode derivation (non-DIMD) merge mode for prediction. The device can obtain, from the first set of blocks, coding information associated with a current block, including a prediction mode. A first HoG can be derived based on the prediction mode. The device can determine a first weight associated with the first HoG. The first weight associated with the first HoG can be determined based on the coding information. The device can generate a merge histogram of gradients (MHoG) based on at least a second set of HoGs associated with a second set of blocks (e.g., associated with DIMD blocks) and by applying the first weight to the first HoG.

Description

Cross-reference to related applications

[0001] This application claims the benefit of European Patent Application No. 24305558.9, filed on 8 April 2024, 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 systems. Summary of the Invention

[0003] Systems, methods, and tools are configured for decoder-side intra-frame mode derivation (DIMD) histogram fusion weights. In an example, an apparatus (e.g., a video decoding apparatus) can determine a first block set. Blocks in the first block set select a non-decoder-side intra-frame mode derivation (DIMD) fusion mode for prediction. The apparatus can obtain coding information associated with the current block from the first block set. The coding information may include at least the prediction mode. The apparatus can derive a first HoG. The first HoG can be derived based on the prediction mode. The apparatus can determine a first weight associated with the first HoG. The first weight associated with the first HoG can be determined based on the coding information. The apparatus can obtain a merged gradient histogram (MHoG). The MHoG can be obtained at least by applying the first weight to the first HoG.

[0004] The device can determine a second block set. The blocks in the second block set can select a DIMD merging mode for prediction. The device can derive a second HoG. An MHoG can also be obtained based on at least the first HoG or the second HoG. The first and second block sets can be neighboring blocks associated with the current block. The device can predict the current block based on one or more intra-frame prediction modes obtained from the MHoG.

[0005] The encoding information may include a coded block flag (CBF) or a set of coefficients associated with the current block obtained from the prediction error. The device can derive a normalized HoG. A normalized HoG can be obtained based on normalization information. An MHoG can also be obtained based on the normalized HoG. The device can filter the first block set based on the distance between the current block and blocks in the first block set, or based on the difference between the size of the current block and the size of blocks in the first block set. The first HoG can be a synthetic HoG. The first weight can be a synthetic weight. The first HoG can be a synthetic normalized HoG. Attached Figure Description

[0006] Figure 1A This is a system diagram illustrating an example communication system that can implement one or more of the disclosed embodiments.

[0007] Figure 1B This illustrates that, according to an embodiment, it is possible to Figure 1A The diagram shows a system diagram of an example wireless transmit / receive unit (WTRU) used in a communication system.

[0008] Figure 1C This illustrates that, according to an embodiment, it is possible to Figure 1A The diagram shows a sample radio access network (RAN) and a sample core network (CN) used in the communication system.

[0009] Figure 1D This illustrates that, according to an embodiment, it is possible to Figure 1A The system diagram shown is another example RAN and another example CN used in the communication system.

[0010] Figure 2 This is a diagram showing an example video encoder.

[0011] Figure 3 This is a diagram illustrating an example video decoder.

[0012] Figure 4 This is a diagram illustrating examples of systems in which various aspects and examples can be implemented.

[0013] Figure 5 This is a diagram illustrating an example of extracting gradients from the context of the block to be predicted.

[0014] Figure 6 This is a diagram illustrating an example of the range of intra-frame prediction patterns for identifying targets.

[0015] Figure 7 This is a diagram illustrating an example of calculating the angle θ between the reference axis and the direction perpendicular to the gradient.

[0016] Figure 8 This is another example of a diagram showing the angle θ between the reference axis and the direction perpendicular to the gradient.

[0017] Figure 9 This is a diagram illustrating an example of calculating the index of the target intra-frame prediction mode.

[0018] Figure 10 This is another example of a diagram illustrating the calculation of the index of the target intra-frame prediction mode.

[0019] Figure 11 This is a diagram showing an example of a DIMD region that can be used to infer the location dependency of DIMD patterns.

[0020] Figure 12This is a diagram illustrating an example of calculating the MHOG of the current block based on the HOG associated with one or more neighboring blocks.

[0021] Figure 13 This is a diagram illustrating an example of the workflow for normalizing HOGs involved in the merging process before applying the merge.

[0022] Figure 14 This is a diagram illustrating an example of DIMD merging with non-adjacent candidates.

[0023] Figure 15 This is a diagram illustrating an example of the workflow for normalizing HOGs involved in the merging process before applying the merge.

[0024] Figure 16 This is a diagram illustrating an example of fusing DIMD and non-DIMD HoG.

[0025] Figure 17 This is a diagram illustrating an example of the workflow for merging HoGs from DIMD blocks and HoGs from non-DIMD blocks.

[0026] Figure 18 This is a diagram illustrating an example of merging DIMD and non-DIMD blocks for neighboring blocks.

[0027] Figure 19 This is a diagram illustrating an example of deriving weights from a prediction pattern.

[0028] Figure 20 This is a diagram showing non-adjacent blocks.

[0029] Figure 21 This is a graph illustrating an example computation of the MHOG of the current block based on the HoGs of three non-adjacent blocks. Two blocks can be DIMDs, and one block can be a non-DIMD.

[0030] Figure 22 A diagram showing an example of weighting factors derived from encoded information is provided. Detailed Implementation

[0031] A more detailed understanding can be obtained from the following description, which is given by way of example in conjunction with the accompanying drawings.

[0032] Figure 1AThis diagram illustrates an example communication system 100 that may implement one or more of the disclosed embodiments. The communication system 100 may be a multiple access system providing 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 through shared system resources including wireless broadband. 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 Extended OFDM (ZT UW DTS-s OFDM), Unique Word OFDM (UW-OFDM), Resource Block Filtered OFDM, Filter Bank Multicarrier (FBMC), etc.

[0033] 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 will 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 can 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 the context of industrial and / or automated processing chains), consumer electronics devices, devices operating on commercial and / or industrial wireless networks, etc. Any of WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0034] 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, 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 eNode B, gNB, NR Node B, site controller, access point (AP), wireless router, etc. Although base stations 114a and 114b are each depicted as a single element, it will be understood that base stations 114a and 114b may include any number of interconnected base stations and / or network elements.

[0035] 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 for a specific geographic area that may be relatively fixed or may change over time. A cell may also be 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 per sector of the cell. In embodiments, base station 114a may employ multiple-input multiple-output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to transmit and / or receive signals in a desired spatial direction.

[0036] Base stations 114a and 114b can communicate with one or more of WTRUs 102a, 102b, 102c, and 102d via air interface 116, which 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.

[0037] More specifically, as described above, the communication system 100 can be a multiple access system and can employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, base station 114a in RAN 104 / 113 and WTRUs 102a, 102b, 102c can implement wireless technologies, such as using Wideband CDMA (WCDMA) to establish Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA) for air interfaces 115 / 116 / 117. WCDMA can include communication protocols such as High-Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA can include High-Speed ​​Downlink (DL) Packet Access (HSDPA) and / or High-Speed ​​UL Packet Access (HSUPA).

[0038] In the embodiment, base station 114a and WTRUs 102a, 102b, 102c can implement wireless technologies, such as using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro) to establish Evolved UMTS Terrestrial Radio Access (E-UTRA) for air interface 116.

[0039] In the embodiments, base station 114a and WTRUs 102a, 102b, 102c can implement wireless technologies, such as using New Radio (NR) to establish NR wireless access for air interface 116.

[0040] In the embodiments, base station 114a and WTRUs 102a, 102b, and 102c can implement various radio access technologies. For example, base station 114a and WTRUs 102a, 102b, and 102c can, for instance, use the dual connectivity (DC) principle to jointly implement LTE radio access and NR radio access. Therefore, the air interface used by WTRUs 102a, 102b, and 102c can be characterized by various types of radio access technologies and / or by transmissions sent to / from various types of base stations (e.g., eNBs and gNBs).

[0041] In other embodiments, base station 114a and WTRUs 102a, 102b, 102c may implement wireless 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.

[0042] Figure 1A Base station 114b can be, for example, a wireless router, a home Node B, a home eNode-B, or an access point, and can utilize any suitable RAT to facilitate wireless connectivity in localized areas such as commercial locations, homes, vehicles, campuses, industrial facilities, air corridors (e.g., for use by drones), roads, etc. In one embodiment, base station 114b and WTRUs 102c, 102d can implement wireless technologies such as IEEE 802.11 to establish a wireless local area network (WLAN). In another embodiment, base station 114b and WTRUs 102c, 102d can implement wireless 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 Internet 110. Therefore, base station 114b does not need to access Internet 110 via CN 106 / 115.

[0043] 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 WTRU 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, etc., and / or perform advanced security functions such as user authentication. Although Figure 1AAs not shown, but will be understood, RAN 104 / 113 and / or CN 106 / 115 can communicate directly or indirectly with other RANs using 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 be utilizing NR radio technology, CN 106 / 115 can also communicate with another RAN (not shown) using GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0044] 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.

[0045] Some or all of the WTRUs 102a, 102b, 102c, and 102d in 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 can employ cellular wireless technology, and with base station 114b, which can employ IEEE 802 wireless technology.

[0046] Figure 1B This is a system diagram illustrating example WTRU 102. (See diagram below.) Figure 1B As shown, WTRU 102 may include a processor 118, a transceiver 120, a transmitting / receiving 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 will be understood that, while remaining consistent with the embodiments, WTRU 102 may include any sub-combination of the foregoing elements.

[0047] Processor 118 can 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 can 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 can be coupled to transceiver 120, which can be coupled to transmitting / receiving element 122. Although Figure 1B While the processor 118 and transceiver 120 are depicted as separate components, it will be understood that the processor 118 and transceiver 120 can be integrated together in an electronic package or chip.

[0048] Transmitting / receiving element 122 can be configured to transmit signals to or receive signals from a base station (e.g., base station 114a) via 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 another embodiment, transmitting / receiving element 122 can be a transmitter / detector configured to transmit and / or receive, for example, IR, UV, or visible light signals. In yet another embodiment, transmitting / receiving element 122 can be configured to transmit and / or receive both RF signals and optical signals. It will be understood that transmitting / receiving element 122 can be configured to transmit and / or receive any combination of wireless signals.

[0049] 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 via air interface 116.

[0050] 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. Therefore, transceiver 120 can include multiple transceivers for enabling WTRU 102 to communicate via various RATs (e.g., such as NR and IEEE 802.11).

[0051] The processor 118 of WTRU 102 can be coupled to and receive user input data from: 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). The processor 118 can also output user data to the speaker / microphone 124, keypad 126, and / or display / touchpad 128. Additionally, the processor 118 can access information and store data from any suitable type of 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 subscriber identity module (SIM) card, memory stick, secure digital storage (SD) card, etc. In other embodiments, the processor 118 can access information and store data from memory not actually located on WTRU 102, such as on a server or home computer (not shown).

[0052] The processor 118 may receive power from the power supply 134 and may be configured to distribute power to other components in the WTRU 102 and / or control power to those other components. The power supply 134 may be any suitable device for powering the WTRU 102. For example, the power supply 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0053] 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 from base stations (e.g., base stations 114a, 114b) via air interface 116 and / or determine its location based on the timing of signals received from two or more nearby base stations. It will be understood that, while remaining consistent with the embodiments, the WTRU 102 may acquire location information using any suitable location determination method.

[0054] The processor 118 can also be connected to other peripheral devices 138, which may include one or more software and / or hardware modules that provide 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, etc. Peripheral devices 138 may include one or more sensors, which may be one or more of the following: gyroscopes, accelerometers, Hall effect sensors, magnetometers, orientation sensors, proximity sensors, temperature sensors, time sensors; geolocation sensors; altimeters, light sensors, touch sensors, magnetometers, barometers, gesture sensors, biometric sensors, and / or humidity sensors.

[0055] WTRU 102 may include a full-duplex radio, wherein the transmission and reception of some or all of the signals (e.g., associated with a specific subframe of 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., a choke) or signal processing via a processor (e.g., a separate processor (not shown) or via processor 118). In embodiments, WTRU 102 may include a half-duplex radio, wherein the transmission and reception of some or all of the signals (e.g., associated with a specific subframe of both UL (e.g., for transmission) or downlink (e.g., for reception)) may be concurrent and / or simultaneous.

[0056] Figure 1C This is a system diagram illustrating RAN 104 and CN 106 according to an embodiment. As described above, RAN 104 can employ E-UTRA wireless technology to communicate with WTRUs 102a, 102b, and 102c via air interface 116. RAN 104 can also communicate with CN 106.

[0057] RAN 104 may include eNode-Bs 160a, 160b, and 160c, but it will 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 via 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 radio signals to and / or receive radio signals from WTRU 102a.

[0058] 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 the UL and / or DL, etc. Figure 1C As shown, eNode-B 160a, 160b, and 160c can communicate with each other via the X2 interface.

[0059] 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 will be understood that any of these elements may be owned and / or operated by an entity other than a CN operator.

[0060] 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, activating / deactivating bearers, selecting a specific serving gateway during the initial attachment of WTRUs 102a, 102b, and 102c, etc. 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.

[0061] 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 or from WTRUs 102a, 102b, and 102c. The SGW 164 can perform other functions, such as anchoring the user plane during eNode-B handover, triggering paging when DL data is available to WTRUs 102a, 102b, and 102c, and managing and storing the context of WTRUs 102a, 102b, and 102c.

[0062] SGW 164 can be connected to PGW 166, which can provide WTRU 102a, 102b, 102c with access to packet-switched networks (such as Internet 110) to facilitate communication between WTRU 102a, 102b, 102c and IP-enabled devices.

[0063] CN 106 can facilitate communication with other networks. For example, CN 106 can provide WTRUs 102a, 102b, and 102c with access to circuit-switched networks (such as PSTN 108) to facilitate communication between WTRUs 102a, 102b, and 102c and traditional terrestrial line communication equipment. For example, CN 106 may include an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) or be able to communicate with such an IP gateway as an interface between CN 106 and PSTN 108. Additionally, CN 106 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.

[0064] Despite WTRU in Figures 1A to 1D While described as a wireless terminal, it is envisioned that, in some representative embodiments, such a terminal may (e.g., temporarily or permanently) use a wired communication interface with a communication network.

[0065] In a representative embodiment, the other network 112 may be a WLAN.

[0066] 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 have an interface to a Distribution System (DS) or another type of wired / wireless network that loads and / or loads traffic into and / or out of the BSS. Traffic originating outside the BSS destined for a STA can be delivered to the AP via it. Traffic from a STA to a destination outside the BSS can be sent to the AP for delivery to the appropriate destination. Traffic between STAs within the BSS can be sent via the AP, for example, where a source STA can send traffic to the AP, and the AP can deliver the traffic to the destination STA. Traffic between STAs within the BSS can be considered and / or referred to as point-to-point traffic. Point-to-point traffic can be sent between a source STA and a destination STA using a Direct Link Setup (DLS) (e.g., directly between them). 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 may sometimes be referred to as a "self-organizing" communication mode in this document.

[0067] When operating in 802.11ac infrastructure mode or a similar mode, the AP can transmit beacons on a fixed channel, such as the primary channel. The primary channel can be of 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, Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) can be implemented, for example, in an 802.11 system. For CSMA / CA, each STA (e.g., every STA), including the AP, can sense the primary channel. If a particular STA senses / detects that the primary signal is busy and / or determines that the primary signal is busy, that particular STA can back off. In a given BSS, at any given time, only one STA (e.g., only one station) can transmit.

[0068] 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.

[0069] 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. In the 80+80 configuration, after channel coding, data can be passed through a fragment parser, which splits the data into two streams. Inverse Fast Fourier Transform (IFFT) processing and time-domain processing can be performed on each stream separately. The streams can be mapped onto the two 80 MHz channels, and the data can be transmitted by the transmitting STA. At the receiver of the receiving STA, the above operations of the 80+80 configuration can be reversed, and the combined data can be sent to the Media Access Control (MAC).

[0070] 802.11af and 802.11ah support operating modes below 1 GHz. The channel operating bandwidth and carrier are reduced in 802.11af and 802.11ah compared to those used in 802.11n and 802.11ac. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV Blank (TVWS) spectrum, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to representative embodiments, 802.11ah can support instrument-type control / machine-type communication, such as MTC devices in macro coverage areas. MTC devices may have certain capabilities, such as limited capabilities, including support (e.g., only support) 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).

[0071] 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 primary channel can have a bandwidth 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 STAs operating in the BSS that support the minimum bandwidth operating mode. In the 802.11ah example, for STAs that support (e.g., only support) the 1 MHz mode (e.g., MTC type devices), 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 Assignment Vector (NAV) settings can depend on the status of the primary channel. If the primary channel is busy, for example, due to STAs (which only support the 1 MHz operating mode) transmitting to the AP, the entire available band may be considered busy even if most of the band remains idle and potentially available.

[0072] In the United States, the available frequency band for 802.11ah is 902 MHz to 928 MHz. In South Korea, the available frequency band is 917.5 MHz to 923.5 MHz. In Japan, the available frequency band is 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.

[0073] Figure 1D This is a system diagram illustrating RAN 113 and CN 115 according to an embodiment. As described above, RAN 113 can employ NR radio technology to communicate with WTRUs 102a, 102b, and 102c via air interface 116. RAN 113 can also communicate with CN 115.

[0074] RAN 113 may include gNBs 180a, 180b, and 180c, but it will 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 via 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. Thus, for example, gNB 180a may use multiple antennas to transmit radio signals to and / or receive radio signals from WTRU 102a. In embodiments, gNBs 180a, 180b, and 180c may implement carrier aggregation technology. For example, gNB 180a can transmit multiple component carriers to WTRU 102a (not shown). A subset of these component carriers may be located on unlicensed spectrum, while the remaining component carriers may be located on licensed spectrum. In embodiments, gNBs 180a, 180b, and 180c may implement Coordinated Multipoint (CoMP) technology. For example, WTRU 102a can receive coordinated transmissions from gNBs 180a and 180b (and / or gNB 180c).

[0075] WTRUs 102a, 102b, and 102c can communicate with gNBs 180a, 180b, and 180c using transmissions associated with a scalable digital architecture. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing can vary 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 of various lengths or scalable lengths, or transmission time intervals (TTIs) (e.g., containing different numbers of OFDM symbols and / or absolute times of varying durations).

[0076] 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., eNodeBs 160a, 160b, and 160c). In standalone configuration, WTRUs 102a, 102b, and 102c can use one or more of gNBs 180a, 180b, and 180c as mobile 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 and one or more eNode-Bs 160a, 160b, and 160c. In a non-standalone configuration, eNode-Bs 160a, 160b, and 160c can act as mobile anchors for WTRUs 102a, 102b, and 102c, and gNBs 180a, 180b, and 180c can provide additional coverage and / or throughput to serve WTRUs 102a, 102b, and 102c.

[0077] 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, support for network slicing, dual connectivity, interoperability between NR and E-UTRA, routing of user plane data to User Plane Functions (UPF) 184a and 184b, routing of 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 via the Xn interface.

[0078] 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. While each of the foregoing elements is described as part of the CN 115, it will be understood that any of these elements may be owned and / or operated by an entity other than a CN operator.

[0079] AMF 182a and 182b can connect to one or more of the 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 SMFs 183a and 183b, managing registration areas, terminating NAS signaling, mobility management, etc. AMF 182a and 182b can use network slicing to customize CN support for WTRU 102a, 102b, and 102c based on the service types being utilized by WTRU 102a, 102b, and 102c. For example, different network slices can be established for different use cases, such as services dependent on Ultra Reliable Low Latency (URLLC) access, services dependent on Enhanced Massive Mobile Broadband (eMBB) access, services for Machine Type Communication (MTC) access, etc. AMF 162 can provide control plane functions for handover between RAN 113 and other RANs (not shown) that employ other wireless technologies (such as LTE, LTE-A, LTE-A Pro) and / or non-3GPP access technologies (such as WiFi).

[0080] 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 service routing 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, and providing downlink data notifications. PDU session types can be IP-based, non-IP-based, or Ethernet-based.

[0081] UPF 184a and 184b can connect via the N3 interface to one or more of the gNBs 180a, 180b, and 180c in RAN 113. These gNBs can provide WTRU 102a, 102b, and 102c with access to packet-switched networks (such as the Internet 110) to facilitate communication between WTRU 102a, 102b, and 102c and IP-enabled devices. UPF 184 and 184b can perform other functions such as routing and forwarding packets, enforcing user plane policies, supporting multihomed PDU sessions, handling user plane QoS, buffering downlink packets, and providing mobility anchoring.

[0082] 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 serves as an interface between CN 115 and PSTN 108. Additionally, 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 can be connected to DN 185a and 185b via UPF 184a and 184b through the N3 interface to UPF 184a and 184b and the N6 interface between UPF 184a and 184b and local data networks (DNs) 185a and 185b.

[0083] Given Figures 1A to 1D and Figures 1A to 1D The corresponding descriptions can be performed by one or more emulation devices (not shown) that perform one or more of the functions described herein with respect to: WTRU 102a to 102d, base stations 114a to 114b, eNode-B 160a to 160c, MME 162, SGW 164, PGW 166, gNB 180a to 180c, AMF 182a to 182b, UPF 184a to 184b, SMF 183a to 183b, DN 185a to 185b, and / or any other devices described herein. An emulation device can be one or more devices configured to emulate one or more 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.

[0084] Simulation devices can be designed to perform one or more tests on other devices in laboratory and / or carrier network environments. For example, one or more simulation devices may perform one or more functions when 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 may perform one or more functions when temporarily implemented / deployed as part of a wired and / or wireless communication network. Simulation devices may be directly coupled to another device for testing purposes and / or may use over-the-air wireless communication to perform tests.

[0085] One or more simulation devices may perform one or more (including all) functions when implemented / deployed without being part of a wired and / or wireless communication network. For example, simulation devices may be used to test scenarios in laboratory and / or undeployed (e.g., test) wired and / or wireless communication networks to perform tests on one or more components. One or more simulation devices may be test equipment. Simulation devices may transmit and / or receive data using direct RF connection and / or wireless communication via RF circuitry (e.g., which may include one or more antennas).

[0086] This application describes various aspects, including tools, features, examples, models, methods, etc. Many of these aspects are described in a specific manner, and are generally described in a way that may sound restrictive, at least to illustrate the individual features. However, this is for the purpose of clarity of description and does not limit the application or scope of these aspects. In fact, all the different aspects can be combined and interchanged to provide other aspects. Furthermore, these aspects can also be combined and interchanged with those described in previous documents.

[0087] The aspects described and contemplated in this application can be implemented in many different forms. The accompanying drawings provided herein provide some examples, but other examples are contemplated. The discussion of the drawings does not limit the breadth of implementations. At least one aspect generally relates to video encoding and decoding, and at least one other aspect generally relates to transmitting a generated or encoded bitstream. These and other aspects can be implemented as methods, apparatus, computer-readable media (e.g., storage media) including (e.g., having stored thereon) instructions for encoding or decoding video data according to any of the methods, and / or computer-readable storage media storing bitstreams generated according to any of the methods. When referred to herein, bitstream can refer to transmitted data, but can also refer to data stored, generated, and / or accessed but not transmitted (e.g., non-transitory data).

[0088] In this application, the terms “reconstruction” and “decoding” are used interchangeably, the terms “pixel” and “sample” are used interchangeably, and the terms “image”, “picture” and “frame” are used interchangeably.

[0089] This document describes various methods, each of which includes one or more steps or actions for implementing the described 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. Additionally, in various examples, terms such as "first," "second," etc., may be used 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 a sequence of operations. Therefore, in this example, the first decoding does not need to be performed before the second decoding, but can occur, for example, before, during, or in a time period overlapping with the second decoding.

[0090] 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 include, for example, a decoding module. 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, these aspects described in this application may be used alone or in combination.

[0091] Various numerical values ​​are used in the examples described in this application. These and other specific values ​​are for illustrative purposes only, and the aspects described are not limited to these specific values.

[0092] 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 depicting all anticipated variations.

[0093] Before being encoded, the video sequence may undergo pre-coding processing 201, such as applying color transformations to the input color picture (e.g., a conversion from RGB 4:4:4 to YCbCr 4:2:0), or performing remapping of the input picture components to obtain a signal distribution that is more resilient to compression (e.g., using histogram equalization with one of the color components). Metadata may be associated with the pre-processing and appended to the bitstream.

[0094] In encoder 200, the frame is encoded by encoder elements, as described below. The frame to be encoded is divided 202 and processed in units such as coding units (CUs). Each unit is encoded using, for example, an intra-frame or inter-frame mode. When encoding a unit in intra-frame mode, intra-frame prediction 260 is performed. In inter-frame mode, motion estimation 275 and compensation 270 are performed. The encoder 205 determines which mode, intra-frame or inter-frame, to use to encode the unit and indicates the intra-frame / inter-frame decision via, for example, a prediction mode flag. For example, the prediction residual is calculated by subtracting 210 prediction blocks from the original image block.

[0095] The predicted residual is then transformed (225) and quantized (230). The quantized transform coefficients, motion vectors, and other syntax elements are entropy-coded (245) to output a bitstream. The encoder can skip the transform and directly apply quantization to the untransformed residual signal. Alternatively, the encoder can bypass both transform and quantization, i.e., directly encode the residual without applying either the transform or quantization process.

[0096] The encoder decodes the coded block to provide a reference for further prediction. The quantized transform coefficients are dequantized 240 and inverse transformed 250 to decode the prediction residual. The decoded prediction residual and the prediction block are combined 255 to reconstruct the image block. An in-loop filter 265 is applied to the reconstructed image to perform, for example, deblocking / SAO (sample adaptive offset) filtering, thereby reducing coding artifacts. The filtered image is stored in a reference image buffer (280).

[0097] Figure 3 This is a diagram illustrating an example video decoder. In the example decoder 300, the bitstream is decoded by decoder elements, as described below. The video decoder 300 typically performs operations similar to... Figure 2 The encoding process described herein is the opposite of the decoding process. Encoder 200 typically also performs video decoding as part of the encoded video data.

[0098] Specifically, the decoder's input includes a video bitstream, which can be generated by the video encoder 200. First, entropy decoding 330 is performed on the bitstream to obtain transform coefficients, motion vectors, and other encoded information. Frame segmentation information indicates how the frame should be segmented. Therefore, the decoder can segment the frame 335 based on the decoded frame segmentation information. The transform coefficients are dequantized 340 and inverse transformed 350 to decode the prediction residual. The decoded prediction residual and prediction blocks are combined 355 to reconstruct image blocks. Prediction blocks 370 can be obtained 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 in a reference frame buffer 380.

[0099] The decoded image can also undergo post-decoding processing 385, such as inverse color transformation (e.g., conversion from YCbCr 4:2:0 to RGB 4:4:4) or inverse remapping, which performs the inverse 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 the example, the decoded image (e.g., after applying in-loop filter 365 and / or, in the case of post-decoding processing, after post-decoding processing 385) can be sent to a display device for presentation to the user.

[0100] 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 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 elements 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 aspects described in this document.

[0101] 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 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 that 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.

[0102] 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 a module that can be included in a device to perform encoding and / or decoding functions. It is well known that a device may include one or both encoding and decoding modules. Alternatively, 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 known to those skilled in the art.

[0103] 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 of 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 equations, formulas, operations, and operational logic processing.

[0104] 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 could be processor 410 or encoder / decoder module 430) is used for one or more of these functions. External memory could be memory 420 and / or storage device 440, such as 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 volatile memory such as RAM is used as working memory for video encoding and decoding operations.

[0105] Input to the components of system 400 can be provided through various input devices, as indicated in box 445. Such input devices include, but are not limited to, (i) a radio frequency (RF) section that receives, for example, RF signals transmitted over the air by a broadcaster, (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 video.

[0106] In various examples, the input device of block 445 has corresponding input processing elements known in the art. 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) further band-limiting to a narrower band to select (e.g.,) 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 the desired data packet stream. The RF section of various examples includes one or more elements performing these functions, such as frequency selectors, signal selectors, band limiters, channel selectors, filters, downconverters, demodulators, error correctors, and demultiplexers. The RF section may include tuners performing 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 filtering again 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 inserting amplifiers and analog-to-digital converters. In various examples, the RF section includes an antenna.

[0107] USB and / or HDMI terminals may include corresponding interface processors for connecting system 400 to other electronic devices via USB and / or HDMI connections. It should be understood that aspects of input processing (e.g., Reed-Solomon error correction) may be implemented, for example, within a separate input processing IC or within processor 410, as needed. Similarly, aspects of USB or HDMI interface processing may be implemented, as needed, within a separate interface IC or within processor 410. The demodulated, error-corrected, and demultiplexed stream is provided to various processing elements, including, for example, processor 410 and an encoder / decoder 430 operating in conjunction with memory and storage elements, to process the data stream as needed for presentation on an output device.

[0108] Various components of system 400 can be housed within an integrated housing. Within the integrated housing, the various components can be interconnected and transmit data between them using suitable connection devices 425 (e.g., internal buses known in the art, including inter-IC (I2C) buses, wiring, and printed circuit boards).

[0109] 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 send 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, within a wired and / or wireless medium.

[0110] In various examples, data is streamed to or otherwise provided to system 400 using a wireless network, such as a Wi-Fi network, for example, 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 adapted 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 to provide streaming data to system 400, delivering data via an HDMI connection to input block 445. 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. Additionally, various examples use wireless networks other than Wi-Fi, such as cellular networks or Bluetooth® networks.

[0111] System 400 can provide output signals to various output devices, including display 475, speaker 485, and other peripheral devices 495. Various examples of display 475 include one or more of, for example, touchscreen displays, organic light-emitting diode (OLED) displays, curved displays, and / or foldable displays. 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., in a smartphone) or standalone (e.g., an external monitor for a laptop computer). In various examples, other peripheral devices 495 include one or more of standalone digital video discs (or digital multifunction discs) (DVDs, for both terms), disc players, stereo systems, and / or lighting systems. 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.

[0112] In various examples, signaling (such as AV.Link, Consumer Electronics Control (CEC), or other communication protocols that implement device-to-device control with or without user intervention) is used to transmit control signals between system 400 and display 475, speaker 485, or other peripheral devices 495. Output devices may be communicatively coupled to system 400 via dedicated connections through corresponding interfaces 470, 480, and 490. Alternatively, output devices may be connected to system 400 via communication interface 450 using communication channel 460. Display 475 and speaker 485 may be integrated into a single unit along with other components of system 400 in electronic devices such as televisions. In various examples, display interface 470 includes a display driver, such as a timing controller (TCon) chip.

[0113] For example, if the RF input section 445 is part of a separate set-top box, the display 475 and speaker 485 can alternatively be separate from one or more of the other components. In various examples where the display 475 and speaker 485 are external components, the output signal can be provided via a dedicated output connection, including, for example, an HDMI port, a USB port, or a COMP output.

[0114] The example can be implemented by processor 410 or by computer software implemented by hardware or 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 memory devices, magnetic memory 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 microprocessors, general-purpose computers, special-purpose computers, and processors based on multi-core architectures.

[0115] Various implementations involve decoding. As used herein, “decoding” can encompass all or part of a process performed, for example, 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 includes, or alternatively includes, processes performed by an encoder of the various embodiments described herein.

[0116] 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. Based on the specific context of the description, it will be clear whether the phrase "decoding process" is intended to specifically refer to a subset of operations or to refer to a broader decoding process, and it is believed that those skilled in the art will readily understand this.

[0117] Various implementations include encoding. Similar to the discussion above regarding "decoding," the "encoding" used in this application can include, for example, all or part of the processing performed on an input video sequence to produce an encoded bitstream. In various examples, such processes include one or more processes typically performed by an encoder, such as partitioning, differential coding, transform, quantization, and entropy coding. In various examples, such processes also include, or alternatively include, processes performed by a decoder of the various embodiments described in this application.

[0118] As further examples, in one example, "encoding" refers only to entropy encoding; in another example, "encoding" refers only to differential encoding; and in yet another example, "encoding" refers to a combination of entropy encoding and differential encoding. Based on the specific context of the description, it will be clear whether the phrase "encoding process" is intended to specifically refer to a subset of operations or to refer to a broader encoding process, and it is believed that those skilled in the art will readily understand this.

[0119] It should be noted that the grammatical elements used in this article are descriptive terms. Therefore, the use of other grammatical element names is not excluded.

[0120] When a diagram is presented as a flowchart, it should be understood that a block diagram of the corresponding device is also provided. Similarly, when a diagram is presented as a block diagram, it should be understood that a flowchart of the corresponding method / process is also provided.

[0121] The embodiments and aspects described herein may be implemented, for example, in methods or processes, apparatus, software programs, data streams, or signals. Even if discussed only in the context of a single embodiment (e.g., discussed only as a method), embodiments of the discussed features may be implemented in other forms (e.g., apparatus or program). Apparatus may be implemented, for example, with suitable hardware, software, and firmware. Methods may 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. Processors also include communication devices, such as computers, cellular phones, portable / personal digital assistants (“PDAs”), and other devices that facilitate information communication between end users.

[0122] The references to “an example” or “example” or “an implementation” or “implementation”, and their variations, mean that a particular feature, structure, characteristic, etc., described in connection with the example is included in at least one example. Therefore, the phrases “in an example” or “in a sample” or “in an implementation” or “in an implementation”, and any other variations, appearing throughout this application, do not necessarily refer to the same example.

[0123] Additionally, this application may relate to "determining" various types of information. Determining information may include one or more of the following: for example, estimated information, calculated information, predicted information, or information retrieved from memory. Obtaining may include receiving, retrieving, constructing, generating, and / or determining.

[0124] Furthermore, this application may relate to "accessing" various types of information. Accessing information may include one or more of the following: for example, receiving information, retrieving information (e.g., retrieving from memory), storing information, moving information, copying information, calculating information, determining information, predicting information, or estimating information.

[0125] Additionally, this application may relate to "receiving" various types of information. Like "access," the intent to receive is a broad term. Receiving information may include one or more of the following: for example, accessing information or retrieving information (e.g., retrieving from memory). Furthermore, "receiving" is generally referred to in one or more ways during operation, such as storing information, processing information, transmitting information, moving information, copying information, erasing information, calculating information, determining information, predicting information, or estimating information.

[0126] It should be understood that, for example, in the cases of “A / B,” “A and / or B,” and “at least one of A and B,” the use of any of the following “ / ,” “and / or,” and “at least one” is intended to cover selecting only the first listed option (A), or only the second listed option (B), or selecting both options (A and B). As yet another example, in the cases of “A, B, and / or C” and “at least one of A, B, and C,” this 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.

[0127] Furthermore, as used herein, the term "signaling" specifically refers to instructing the corresponding decoder to do something. In this way, in the examples, the same parameters are used on both the encoder and decoder sides. Therefore, for example, the encoder can send a specific parameter to the decoder (explicit signaling) so that the decoder can use the same specific parameter. Conversely, if the decoder already has the specific parameter along with other parameters, signaling can be used without sending it (implicit signaling) to simply allow the decoder to know and select the specific parameter. Bit savings are implemented in various examples by avoiding the transmission of any actual functionality. It should be understood that signaling can be implemented in several ways. For example, in various examples, one or more syntax elements, flags, etc., are used to send information to the corresponding decoder. Although the verb form of the word "signal" was mentioned above, the word "signal" can also be used as a noun in this article.

[0128] It will be apparent to those skilled in the art that implementations can generate various signals that are formatted to carry, for example, information that can be stored or transmitted. The information may include, for example, instructions for performing a method, or data generated by one of the described implementations. For example, a signal may be formatted to carry a bitstream of the described 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 a 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. It is well known that signals can be transmitted via a variety of different wired or wireless links. Signals may be stored on, or accessed or received from, a processor-readable medium.

[0129] 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 that includes information generated as described herein. This information may allow a decoder to decode the bitstream, the encoder, bitstream, and / or decoder being any of the embodiments described. 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 by a method, process, apparatus, medium storing instructions (e.g., a computer-readable medium), 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 a 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.

[0130] [Related public information starts here] Decoder-side intra-frame mode derivation (DIMD) can be used as an intra-frame prediction tool for block-based video coding. DIMD fusion can depend on a region containing the dominant absolute gradient intensity, which can generate one or more DIMD derivation modes.

[0131] DIMD can be performed based on the assumption that decoded pixels surrounding a given block to be predicted can carry information that can be used to infer the texture orientation within that block. This texture orientation can indicate the intra-prediction mode that can generate the highest quality predictions. The techniques disclosed in this paper are applicable to both video encoders and video decoders.

[0132] An index of the intra-prediction mode that can generate the highest quality prediction can be inferred via one or more of the following operations (e.g., in three steps). In the first operation, gradients can be extracted from the context of decoded pixels surrounding a given block to be predicted. In the second operation, the gradients can be used to populate a histogram of oriented gradients (HOG). In the third operation, the index of the intra-prediction mode that can generate the highest quality prediction can be derived from the HOG (e.g., according to a DIMD derivation process), and fusion can be performed.

[0133] Gradients can be extracted from the context, as follows. For a given block to be predicted, an L-shaped context can be considered, consisting of the decoded pixels in row h above the block and the decoded pixels in column w to the left of the block, such as... Figure 5 As shown. In Figure 5 In the example shown, the block to be predicted is displayed in white, the context of the block (e.g., including the h-row decoded pixels above the block and the w-column pixels to the left of the block) is displayed in gray, and the gradient filter is outlined in black. The L-shaped context can be referred to as a template for a given block. At each decoded pixel of interest within this context, local vertical and horizontal gradients can be computed, for example, based on 3×3 vertical and horizontal Sobel filters, respectively. The decoded pixels of interest within this context can refer to decoded pixels where the gradient filter may not extend beyond the context boundaries. Gradient extraction can be summarized by convolving the 3×3 vertical and horizontal Sobel filters with the context (e.g., effective convolution). In the example, h and / or w can be given the value 3.

[0134] The Histogram of Oriented Gradients (HOG) can be filtered. In the HOG, (e.g., each) bin can be associated with an index of a different directional intra-prediction mode. At initialization, one or more (e.g., all) HOG bins can be equal to 0. For calculating local vertical gradients... and local horizontal gradient The (e.g., each) decoded pixel of interest can be obtained from and The direction is derived from the derivation, and the interval associated with the index of the directional intra-prediction mode that is closest to the derived direction can be increased. This index can be called the target intra-prediction mode index.

[0135] For a given decoded pixel of interest, observations can be made based on the following... and The direction is derived. During block prediction via a directional intra-frame prediction mode, the gradient with the largest absolute value can be perpendicular to the mode direction. From and The direction of the derivation can be perpendicular to the component. and The gradient. For example, using multiple (e.g., 65) directional intra-prediction modes, and considering vertical and horizontal gradient filters where the positive vertical gradient direction can be from top to bottom and the positive horizontal gradient direction can be from right to left, from and absolute value and and The mapping from the symbol to the range of the target frame intra-predictive mode index can be as follows: Figure 6 It should be displayed like that.

[0136] if If so, the reference axis can be a horizontal axis. Otherwise, the reference axis can be a vertical axis. If Then the reference axis is perpendicular to the component and The angle θ between the directions of the gradient G can be obtained from Give it, otherwise, by These are given. Figure 7 and Figure 8 As shown.

[0137] For those who can calculate local vertical gradients and local horizontal gradient The currently decoded pixel of interest, and for in Figure 5 The range of intra-prediction mode indices found in the example can be used to find the index of the intra-prediction mode whose angle relative to the reference axis is closest to θ. The interval associated with the index of the found target intra-prediction mode can be increased. .use i The interval associated with the index of the found target intra-frame prediction mode can be true if: For the currently decoded pixel of interest, if If so, the interval in HOG does not need to be increased.

[0138] For those who can calculate local vertical gradients and local horizontal gradient Given a decoded pixel, and for such Figure 5 The range found for the target intra-prediction mode index shown can be determined without directly comparing the angle θ described herein with the angle of each intra-prediction mode relative to the reference axis within that range. The absolute angle of each intra-prediction mode relative to its reference axis can be stored as a scaled integer. Can be used with indexes i Scaling integer form of the directional intra-prediction mode relative to the reference axis angle Comparison, i ∈ [|0,16|]. Here, floor() can represent the floor operation, thus the result of floor(x) for input x can return the largest integer less than or equal to x. Absolute shift from the index of the reference axis to the index of the target intra-frame prediction mode. It can be The target intra-frame prediction mode index can be equal to the index shift of the reference axis. . Figure 9 It shows in Figure 7 The example shown illustrates how the above discretization of θ can be used to perform the calculation of the index of the target intra-frame prediction mode under the conditions indicated. Figure 10 It shows in Figure 8The example shown illustrates how the above discretization of θ can be used to perform the calculation of the index for the target intra-frame prediction mode under the conditions illustrated. Figure 9 and Figure 10 In the example, and It can be less than 0.

[0139] An index for a directional intra-prediction mode that can generate the highest quality predictions (e.g., once HOG padding is complete) can be determined as an index associated with a histogram interval having the largest amplitude value. More than one (e.g., two) intervals with the largest amplitude values ​​can be identified and used to determine, based on DIMD, an index for a directional intra-prediction mode that can generate the highest quality predictions (e.g., two predictions). Prediction modes can be combined with PLANA (e.g., linearly). The number of intervals can be set to 6.

[0140] For a given luminance coded block (CB) to be predicted, the DIMD can be signaled (e.g., via the DIMD flag) and the DIMD is first placed in the decision tree of the signaling associated with the intra-prediction mode selected to predict that luminance CB (e.g., the DIMD flag can be placed before the Template Match Prediction (TMP) flag and the Matrix-Based Intra-Prediction (MIP) flag).

[0141] DIMD patterns can be location-dependent (e.g., region-based). Non-uniform sample-based weights can be used to fuse DIMD predictions. During DIMD derivation, the use of sample-based fusion and specific weights for a given prediction can be inferred. When deriving a DIMD pattern, it can be determined whether the derivation of this pattern is likely influenced (e.g., primarily inferred by) template regions above or to the left of the current block. If the DIMD pattern is primarily derived from samples above the current block, higher weights can be used for samples closer to the upper portion of the block (e.g., when fusing corresponding predictions).

[0142] To determine whether a particular sample in a template (e.g., a DIMD template) is helpful in inferring a specific DIMD pattern, multiple regions can be considered within the template, such as... Figure 11 As shown (for example, ABOVE-LEFT (top left) region 1101, ABOVE (top) region 1102, and LEFT (left) region 1103 are shown). Gradient calculations can be performed individually for samples in each region, resulting in multiple (e.g., three) histograms, such as those for each region. , and For directional pattern m, It can represent the cumulative magnitude of multiple (e.g., all) samples in the ABOVE region along direction m. It should be noted that, relative to regular DIMD, the template region can be extended by one sample in the upper left corner and one sample in the lower right corner.

[0143] The complete gradient histogram of the entire template can be computed as the sum of multiple (e.g., three) individual histograms. The two directional modes with the largest and second largest cumulative magnitudes in the histograms can be selected as the primary DIMD mode and the secondary DIMD mode, respectively. and .

[0144] Histogram and Can be used to determine and / or It can depend on whether it is a specific template area ABOVE or a specific template area LEFT. Position dependency (represented as) It can be defined as follows: if: ,So: (For example, (This can depend on the region ABOVE).

[0145] Otherwise, if: ,So: (For example, (This can depend on the region LEFT).

[0146] otherwise: (For example, (It doesn't have to be location-related).

[0147] Fusion can be performed to combine the primary DIMD prediction and the secondary DIMD prediction ( and ) and planar prediction Fusion. In DIMD modes not determined to be location-dependent (e.g., In cases where uniform fusion can be applied, the uniform weights can be derived based on the relative magnitudes of the patterns in the histogram. , and And the final DIMD prediction can be calculated as follows:

[0148] If at least one of the DIMD patterns is inferred to be location-dependent, then sample-based fusion can be used. Different weights can be used to fuse each location. The prediction at that location. If Then we can calculate the calculations used for prediction. Sample-based weights This allows the average weight used within a block to be approximately equal to the uniform weight. And / or make it possible to determine based on Use higher weights in the portions of the block closer to the ABOVE or LEFT regions. Ranges can be predefined. This range corresponds to and The maximum deviation. Higher values ​​can lead to larger variations in weights within a block. For a block of size... The block, if Then the following expression can be true:

[0149] if Then the following expression can be true:

[0150] if , Then, according to The values ​​are calculated as in one of the two equations shown above, using the weights of the two predictions. Conversely, if and ,but The weights can be calculated as follows:

[0151] Weights for planar prediction The following can be calculated: 64 -

[0152] Location-dependent DIMD predictions (e.g., the final location-dependent DIMD prediction) can be calculated as follows:

[0153] A DIMD merging mode can be used. In this mode, the merged gradient histogram (MHOG) of the current block can be calculated by combining the HOGs of neighboring blocks that may have already selected DIMD or DIMD merging modes for intra-frame prediction. The index used to predict the intra-frame prediction mode for the current block and / or the weights used for potential DIMD fusion can be derived from this MHOG.

[0154] For the current block (e.g., a combination of HOGs for the current block), if a neighboring block (e.g., a single neighboring block) selects DIMD or DIMD merge mode, then the HOG of that neighboring block can be equal to the MHOG of the current block. If at least two neighboring blocks select DIMD or DIMD merge mode, then the HOGs of these neighboring blocks (e.g., two neighboring blocks) (e.g., two HOGs) can be averaged to form the MHOG of the current block.

[0155] For a given block, DIMD merge mode can be enabled if (for example, only if) the current block has at least one neighboring block that selects DIMD or DIMD merge mode. If enabled, the use of DIMD merge mode can be signaled using a CU-level flag (e.g., a CABAC-encoded CU-level flag).

[0156] Figure 12 An example of calculating the MHOG of the current W×H block is shown. Figure 12 As shown, the current W×H block 1000 can include three neighboring blocks 1001, 1002, and 1003. Blocks 1002 and 1003 can choose DIMD for intra-frame prediction, while block 1001 can choose neither DIMD nor DIMD merging mode for intra-frame prediction. The HOG of block 1003 (denoted as...) The HOG (represented as) of block 1002 can be padded during the encoding / decoding of the current frame based on template 1004 of the reference sample of block 1003. The MHOG of block 1000 can be padded during the encoding / decoding of the current frame based on template 1005 of the reference sample of block 1002. and Calculate by averaging.

[0157] DIMD merging can be associated with histogram normalization. For a current block with at least two neighboring blocks that have chosen a DIMD or new DIMD merging mode for intra-frame prediction, HOG merging may or may not consider the dynamics of the HOGs to be merged. For example, in Figure 12 In the middle, since (1005) is greater than (1004), therefore It can include ratio More gradient magnitude increments. and During the merger, in some examples, The contribution to MHOG may exceed The contribution. In this case. The contribution to MHOG makes the principle of HOG merging less relevant. Histogram normalization can be incorporated before merging. Therefore, histogram normalization can be optional. In the example, gradient magnitude can be obtained based on block size.

[0158] Figure 13 This is a diagram illustrating an example of the workflow for normalizing HOGs involved in the HOG merging process before applying the merge. (It can be found in...) Figure 13 The proposed normalization is applied to the HOGs involved in the HOG merging process before combining HOGs to form the MHOG of the current block.

[0159] At 2000, it is possible to trigger an action on the current... The calculation of the MHOG of the block. At point 2001, neighboring blocks for intra-frame prediction, selected using DIMD or a new DIMD merging mode, can be placed into... At point 2002, the set of neighboring blocks can be reduced by filtering according to criteria. This yields a reduced set of neighboring blocks. For example, a criterion for eliminating a given neighboring block could be based on the distance between the current block and that neighboring block. As an example, a criterion for eliminating a given neighboring block could be based on the difference between the size of the current block and the size of that neighboring block. In 2003, it was possible to eliminate the neighboring block from the current block and... Collecting normalized information At 2004, use and , can be Normalize the HOG of neighboring blocks in the data to obtain the result. At 2005, the normalized HOG could be... Merge into the MHOG of the current block.

[0160] DIMD merging can be associated with non-adjacent blocks. As described in this paper, when neighboring blocks are encoded using DIMD patterns, DIMD histograms can be combined to form a (e.g., a new) DIMD merge histogram for the current block. DIMD merge patterns and weights can then be computed based on this merged histogram.

[0161] As described in this paper, (e.g., new) DIMD merging patterns with non-adjacent blocks can be presented. Non-adjacent spatial candidates can be used for DIMD merging candidate list construction to compute intra-frame predictions for the current block.

[0162] Figure 14This is a diagram illustrating an example of DIMD merging with non-adjacent candidates. While DIMD merging uses DIMD information from neighboring blocks (e.g., adjacent blocks) to predict the current block, as described herein, new DIMD merging with non-adjacent spatial blocks can use candidates from non-adjacent spatial blocks (e.g., 6001), as in... Figure 14 As described in the text.

[0163] The distance between a non-adjacent candidate block (e.g., (6003), (6004), (6005)) and the current block (6002) can be based on the width and height of the current coded block (e.g., it can be defined based on the width and height).

[0164] Figure 15 This is a diagram illustrating an example of the workflow for normalizing HOGs involved in the HOG merging process before applying the merge. (It can be found in...) Figure 15 In summary, before merging HOGs, the HOGs of non-adjacent blocks involved in the HOG merging are normalized to form the MHOG of the current block.

[0165] At 8000, it is possible to trigger an action on the current... The MHOG of the block is calculated. At 8001, the set of non-adjacent blocks for intra-frame prediction, selected using DIMD or a new DIMD merging mode, can be placed into... You can list the blockSet and select a portion of it. For example, a criterion for eliminating a given non-adjacent block could be based on the distance between the current block and the non-adjacent blocks. Alternatively, a criterion for eliminating a given non-adjacent block could be based on the difference between the size of the current block and the size of the non-adjacent blocks.

[0166] At position 8002, the set of non-adjacent blocks can be reduced by filtering according to criteria. This yields a reduced set of non-adjacent blocks. At 8003, it is possible to start from the current block and... Distance information is collected in the middle. As an example, distInfo can be the sum of absolute distances (SAD) between non-adjacent blocks and the current block. For instance, distInfo can be the spatial distance between non-adjacent blocks and the current block. At 8004, distInfo is used. and , can be Normalize the HOG of non-adjacent blocks in the data to obtain the result. At position 8005, the normalized HOG can be... Merge into the MHOG of the current block.

[0167] Figure 16This diagram illustrates an example of fusing DIMD and non-DIMD HoG. DIMD merging can be associated with synthetic DIMD from non-DIMD. Based on the calculation of the merged gradient histogram (MHoG), the features described in this paper can be associated with merged intra-frame mode derivation (MIMD). Similar to DIMD, up to five MIMD modes can be derived from the MHoG and fused together. The mode derivation and fusion weights can follow the process of deriving DIMD modes from the HoG and fusing weights. The MHoG can be calculated directly from the analytical template samples or not, and can be calculated based on information extracted from neighboring blocks.

[0168] Specifically, N neighboring blocks can be considered. If a neighboring block is encoded using (e.g., at least one) a directional intra-prediction mode, then that neighboring block can be considered. If neighboring blocks are encoded using DIMD (5003 or 5002) or MIMD, then the HoG or MHoG of the neighboring blocks can be directly considered as... ,in This refers to the amplitude of the directional mode m in HoG, where m can take values ​​from 0 to... The value of , where This is the maximum number of intra-frame prediction modes. When considering... In such cases, a normalization process can be used.

[0169] If, conversely, a non-DIMD (5001) intra-predictive directional pattern m is used to encode neighboring block i, then HoG can be derived for that neighboring block. Among them, for , , and , among which value Depending on the size of the current block. For neighboring blocks encoded using SGPM or TIMD, which may have more than one directional intra-prediction mode available, the derivation... Two directional patterns can be considered at this time.

[0170] MHoG (5000) The HoG can be calculated using (e.g., all) extracted from available neighboring blocks, as follows:

[0171] MHoG can be used to calculate MIMD patterns and weights. Directional patterns and their weights corresponding to the five highest amplitudes in the MHoG can be selected as the directional patterns and weights for MIMD.

[0172] Figure 16 The fusion is shown by averaging the DIMD blocks and non-DIMD blocks of neighboring blocks.

[0173] As described herein, (e.g., a new) DIMD can be merged into a synthetic HoG (5050) generated from the prediction patterns of non-DIMD neighboring blocks. The fusion may not take into account the relative importance of the HoG from the DIMD block compared to a synthetic HoG from a non-DIMD block. The fusion may also not take into account the relative importance of the prediction pattern compared to another prediction pattern used to derive the synthetic HoG.

[0174] In the example of fusing HoGs from non-DIMD to HoGs from DIMD, the MHoG merging may be (e.g., not very) relevant. The merging can be performed, for example, by taking into account the importance of DIMD compared to non-DIMD and the importance of the prediction pattern to non-DIMD.

[0175] Before merging, a weighted function can be used to fuse HoG from DIMD and HoG from non-DIMD. The weighted function can give the importance of DIMD relative to non-DIMD, and can also give the importance of the prediction mode relative to the other prediction mode.

[0176] In the example, the HoG of DIMD blocks and the HoG of non-DIMD blocks can be fused with different weights. The HoG of non-DIMD blocks can be fused with different weights based on their prediction patterns. The HoGs of DIMD and non-DIMD blocks from neighboring blocks, as well as the HoGs of DIDM and non-DIDM blocks from non-neighboring blocks, can be fused with different weights. For non-DIMD blocks, the HoG can be computed and fused with the HoG from DIMD blocks. Encoding information such as residuals can be used to weight the HoGs. Examples of residuals include CBF, error prediction, etc.

[0177] HoG can fuse DIMD blocks and non-DIMD blocks with different weights. Figure 17 This is a diagram illustrating an example of fusing HoGs from DIMD blocks and HoGs from non-DIMD blocks. (See diagram for example.) Figure 17 As shown, at 4000, an action can be triggered on the current... The MHOG of the block is calculated. At position 4001, the block for intra-frame prediction, selected using DIMD or a new DIMD merging mode, can be placed into... At position 4002, the set of blocks can be reduced by filtering according to criteria. This yields a reduced set of neighboring blocks. For example, the criterion for eliminating a given block could be based on the distance between the current block and that block. For example, the criterion for eliminating a given block could be based on the difference between the size of the current block and the size of that block. At 4003, it is possible to eliminate the current block and... Collecting normalized information At 4004, use and , can be Normalize the HOG of neighboring blocks in the data to obtain the result. As discussed in this article, normalization can be optional. In some examples, HOG is not normalized. It can be used to form MHoG (e.g., as Figure 17 (As indicated by the line bypassing 4003). At 4005, HoG can be... Merge to form MHoG.

[0178] At position 4011, the block selected for non-DIMD intra-prediction can be placed... At position 4012, the set of blocks can be reduced by filtering according to criteria. This results in a reduced set of blocks. For example, the criteria for eliminating a given block could be based on the distance between the current block and that block. Alternatively, the criteria for eliminating a given block could be based on the difference between the size of the current block and the size of that block.

[0179] At position 4013, you can start from the current block and... Collecting normalized information At position 4015, it is possible to start from the current block. The encoding information `codingInfo` is collected, such as the prediction mode (predMod), the code block flag (CBF), or coefficients from the prediction error. At position 4016, it can be retrieved from the current block. The prediction mode predMod derivation (e.g., the novel) HoG is called the synthetic HoG syntHoG. At 4014, using... It can The synthesis of non-DIMD blocks in the HOG syntHoG normalization is obtained to obtain .

[0180] At 4017, use The weights of the normalized synthetic HoG can be determined, thus obtaining... The weights of the normalized HoG HoGnorm from non-DIMD blocks are equal to 1 compared to the weights of 1 for the normalized HoG HoGnorm. It can be equal to 0.8.

[0181] At position 4005, the weights of non-DIMD blocks can be used. Normalized HoG from DIMD blocks and normalized synthetic HOG from non-DIMD blocks Merge into the current block's MHOG.

[0182] In the example, at position 4005, the weight determined at position 4017 can be used. Applied to the synthetic HoG block calculated at 4016 .

[0183] Figure 18 This is a diagram illustrating an example of merging DIMD and non-DIMD blocks for neighboring blocks. Figure 18 In this process, HoGs from neighboring DIMD blocks and HoGs from neighboring non-DIMD blocks can be fused. Compared to the normalized HoG from DIMD blocks with a HoGnorm weight of 1, the synthesized normalized HoG from non-DIMD blocks... weight It can be equal to 0.8.

[0184] The features described in this paper can be associated with weighted strategies. Non-DIMD HoGs can be fused with weights (e.g., different weights) based on their prediction patterns. Figure 19 This is a diagram illustrating an example of deriving weights from a prediction pattern. For HoGs fused from non-DIMD blocks, the weights may not be equal. Weights can be derived from a prediction pattern (10016) from a non-DIMD block (10011). Prediction patterns from non-DIMD blocks can cause different weights to be fused for synthetic HoGs from non-DIMD blocks. The weights for non-DIMD blocks can be derived from prediction pattern (100016). Figure 19 An example diagram is presented showing the calculation of weight factors for non-DIMD blocks based on prediction patterns.

[0185] Non-DIMD blocks can be collected in blocksset2 (1011). In the example, non-DIMD blocks can be filtered as described herein to generate blockssetFiltered2 (10012). Encoding information codingInfo (10015) can be collected from the encoding structure of blocksset2. A prediction mode (10016) can be selected to derive weights (10017). These weights can be used in fusion (4005). Figure 17 An example of how to use weights is shown.

[0186] The intra-prediction modes associated with the derivation of HOG can be one or more of the following: for Spatial Geometry Partitioning (SGPM), the indices of two intra-prediction modes used to predict different partitions of the block of interest; for Template Matching Prediction (TMP), the index of the intra-prediction mode is the DIMD mode first derived when DIMD is applied to the prediction block generated by TMP; for Extrapolation-based Intra-Prediction (EIP), the index of the intra-prediction mode is the DIMD mode first derived when DIMD is applied to the prediction block generated by EIP; for TIMD, the indices of two intra-prediction modes are derived via TIMD and used to predict the block of interest; and for Matrix-based Intra-Prediction (MIP), the index of the intra-prediction mode is the DIMD mode first derived when DIMD is applied to the prediction block generated by MIP.

[0187] In the example, weighting can be defined via sorting based on the “proximity” of the associated directional intra-prediction patterns (e.g., whose indices belong to [|2, 66|]) of the intra-prediction patterns used to predict the block of interest.

[0188] For example, if the intra prediction mode used to predict the block of interest is a directional intra prediction mode inherited from a coding technique (e.g., VVC) (e.g., its index belongs to [|2, 66|]), the priority can be relatively high (e.g., importance level 0). In the example, if the intra prediction mode used to predict the block of interest involves the fusion of two intra predictions of future directional intra prediction modes inherited from the coding technique (e.g., index belongs to [|2, 66|]), the priority may become relatively low (e.g., importance level 1). In the example, if the intra prediction mode used to predict the block of interest is not an intra prediction mode inherited from the coding technique (e.g., its index does not belong to [|0, 66|]), and the intra prediction mode used to predict the block of interest is associated with a directional intra prediction mode inherited from the coding technique (e.g., index in [|2, 66|]) and is obtained by applying DIMD to predict the block of interest, the priority may become low (e.g., importance level 2). In the example, if the intra prediction mode used to predict the block of interest is PLANAR or DC, the priority may be lower (e.g., importance level 3). For example, if the intra prediction mode used to predict the block of interest involves the fusion of two intra predictions, where at least one of the two intra prediction modes is PLANAR or DC, the priority may be even lower (e.g., importance level 4).

[0189] As described in this paper, the weighting associated with the intra-prediction mode selected for predicting the block of interest can be as follows: Inherited directional intra-prediction patterns (e.g., indexes belonging to [|2, 66|]); :TIMD, where the two derived intra-prediction modes are directional (e.g., indexed in [|2, 130|], considering that in TIMD, the space from the top right to the bottom left is traversed via 129 directions instead of 65 directions). SGPM, where the two intra-prediction modes predicting different partitions of the block of interest are directional (e.g., the index belongs to [|2, 66|]). :TMP, in the case that the first derived DIMD pattern obtained by applying DIMD to the prediction block generated by TMP is directional (e.g., its index belongs to [|2, 66|]); EIP, in the case that the first derived DIMD pattern obtained by applying DIMD to the prediction block generated by EIP is directional (e.g., its index belongs to [|2, 66|]); MIP, in the case that the first derived DIMD pattern obtained by applying DIMD to the prediction block generated by MIP is directional (e.g., its index belongs to [|2, 66|]); PLANA or DC; : TIMD, where at least one of the two derived TIMD modes is PLANA or DC; :SGPM, where at least one of the two derived TIMD modes is PLANA or DC; : TIMD, where two of the derived TIMD modes are PLANA or DC. :SGPM, where the two derived TIMD modes are PLANA or DC. For example, .For example,

[0190] For example, by assigning the lowest weight to {PLANAR, DC}, an example correlation between the weighting and the intra-prediction mode selected for predicting the block of interest can be as follows: Inherited directional intra-prediction patterns (e.g., indexes belonging to [|2, 66|]); :TIMD, where the two derivation patterns are directional (e.g., the index is in [|2, 130|], considering that in TIMD, the space from the top right to the bottom left is traversed via 129 directions instead of 65).

[0191] SGPM, where the two intra-prediction modes predicting different partitions of the block of interest are directional (e.g., the index belongs to [|2, 66|]). :TMP, in the case that the first derived DIMD pattern obtained by applying DIMD to the prediction block generated by TMP is directional (e.g., its index belongs to [|2, 66|]); EIP, in the case that the first derived DIMD pattern obtained by applying DIMD to the prediction block generated by EIP is directional (e.g., its index belongs to [|2, 66|]); MIP, in the case that the first derived DIMD pattern obtained by applying DIMD to the prediction block generated by MIP is directional (e.g., its index belongs to [|2, 66|]); : TIMD, where at least one of the two derived TIMD modes is PLANA or DC; :SGPM, where at least one of the two derived TIMD modes is PLANA or DC; : TIMD, where two derived TIMD modes are PLANA or DC; and :SGPM, where the two derived TIMD modes are PLANA or DC. PLANA or DC. For example, .For example, .

[0192] For example, a set of intra-prediction modes with equal weights can be subdivided. An example of subdivision could be as follows: Directional intra-prediction patterns inherited from VVC (e.g., whose index belongs to [|2, 66|]). :TIMD, where the two derivation patterns are directional (e.g., the index is in [|2, 130|], considering that in TIMD, the space from the top right to the bottom left is traversed via 129 directions instead of 65 directions). SGPM, where the two intra-frame prediction modes that predict the (e.g., different) partitions of the block of interest are directional (e.g., the index belongs to [|2, 66|]). :TMP, in the case that the first derived DIMD pattern obtained by applying DIMD to the prediction block generated by TMP is directional (e.g., its index belongs to [|2, 66|]). EIP, in the case that the first derived DIMD pattern obtained by applying DIMD to the prediction block generated by EIP is directional (e.g., its index belongs to [|2, 66|]).

[0193] MIP, in the case that the first derived DIMD pattern obtained by applying DIMD to the prediction block generated by MIP is directional (e.g., its index belongs to [|2, 66|]). PLANA or DC. : TIMD, where at least one of the two derived TIMD modes is PLANA or DC. :SGPM, where at least one of the two derived TIMD modes is PLANA or DC. : TIMD, where two of the derived TIMD modes are PLANA or DC. :SGPM, where the two derived TIMD modes are PLANA or DC. .For example,

[0194] HoG from DIMD blocks and non-DIMD blocks can be fused with different weights. Figure 20 This is a graph showing non-adjacent blocks. In the example, the HOG of non-adjacent blocks involved in the MHOG merged into the current block can be normalized by the spatial distance d from the current block. The number of non-adjacent blocks can vary based on the strategy for selecting non-adjacent blocks. Non-adjacent candidates can be searched around the current block. For example, the range for searching non-adjacent candidates (7001) around the current block (7002) can have a size that depends on the shape of the current block (7002). Figure 20 The non-adjacent blocks are listed in the table, and the non-adjacent blocks are (7003), (7004), (7005) and (7009).

[0195] For example, (7003) is block number 30, (7004) is block number 27, (7005) is block number 27, and (7009) is block number 15. For example, the current block (7002) and non-adjacent blocks (e.g., (7003), (7004), (7005), and (7009)) can be CUs (coding units). In the example, Figure 17 (4003) and (4013) It can be the spatial distance d between non-adjacent blocks involved in the merge.

[0196] exist Figure 20In the diagram, (7005), (7003), and (7004) are DIMD blocks, and (7009) is a non-DIMD block. (7006) corresponds to the template of the reconstructed pixels of (7005) (block number 19). (7008) corresponds to the template of the reconstructed pixels of (7003) (block number 30). (7007) corresponds to the template of the reconstructed pixels of (7004) (block number 27). d19 corresponds to the spatial distance between (7005) and (7002). d30 corresponds to the spatial distance between (7003) and (7002). d27 corresponds to the spatial distance between (7004) and (7002). (7009) corresponds to the non-DIMD block (block number 15). d15 corresponds to the spatial distance between (7005) and (7002). d30 corresponds to the spatial distance between (7003) and (7002). d27 corresponds to the spatial distance between (7004) and (7002). d15 corresponds to the spatial distance between (7009) and (7002). Figure 21 This is a graph illustrating an example computation of the MHOG of the current block based on the HoGs of three non-adjacent blocks. Two blocks can be DIMDs, and one block can be a non-DIMD. Figure 21 As shown, Figure 20 Two non-adjacent blocks (current (7002) and (7003), (7005)) can choose DIMD for intra-frame prediction. For example, (7004), some blocks may neither choose DIMD nor the new DIMD merging mode for intra-frame prediction. The criterion for selecting non-adjacent blocks can be the distance between the non-adjacent block and the current block. For example, non-adjacent block (7004) can be considered too far from the current block (d27). Non-adjacent block (7004) can be not selected. (7004) is an example of a block that was not selected.

[0197] During the encoding / decoding of the current frame, at position 3040, based on the template of the reconstructed pixel (3004) of block (3003), the HOG (denoted as) of (3003) may have been filled. At 3030, based on the template of the reconstructed pixel (3005) of block 30 (3002), the HOG (denoted as) of (3002) may have been filled. (3002) and (3003) can be selected as non-adjacent blocks, and respectively correspond to Figure 20 (7003) and (7005) in the middle.

[0198] At 3050, Normalization can be achieved by dividing each (e.g., each) interval by the spatial distance between that block and the current block (3000). For example, here, the spatial distance is d30 and can be equal to... In the example, (x0, y0) and (x 30 y 30 () can be the center of its corresponding block.

[0199] At 3060, Normalization can be achieved by dividing each of its intervals by the spatial distance between that block and the current block (3000). For example, here, the spatial distance is d19 and can be equal to... In the example, (x0, y0) and (x 19 y 19 () can be the center of its corresponding block.

[0200] At position 3070, encoding information (codingInfo) from block 15 can be collected. Weights are then derived from encodingInfo. For example, if the prediction pattern `predMod` is treated as `codingInfo`, and if all prediction patterns are considered equal, and if non-DIMD blocks are considered less important than DIMD blocks, then it applies... The weight can be set to 0.8, that is, The features described in this paper can be associated with (e.g., other) weighting strategies. At 3080, the pattern predMod from block 15 (3005) can be generated. At 3090, Normalization can be achieved by dividing each of its intervals by the spatial distance between that block and the current block (3000). For example, here, the spatial distance is d19 and can be equal to... In the example, (x0, y0) and (x 15 y 15 () can be the center of its corresponding block. At 3100, it can be achieved through fusion. , , To calculate the MHOG of (3000). Can be weighted To integrate.

[0201] In the example, for the HOGs of non-adjacent blocks involved in the MHOG merged into the current block, the HOG can be normalized by the distance to the HOG of the current block. In the example, the spatial distance d can be replaced with the histogram distance, such as the sum of absolute distances (SAD): for example, SAD30 (3050), and can be equal to .

[0202] For non-DIMD blocks, the HoG can be computed and fused with the HoG from the DIMD block. As described in this paper, for computing local vertical gradients... and local horizontal gradient To construct a gradient histogram of the reconstructed pixels of interest, one can start from... and The direction is derived from the HOG, and the interval associated with the index of the directional intra-prediction mode whose direction is closest to the derived direction can be increased. As mentioned earlier, in the HOG, the interval can be associated with the index of (e.g., different) directional intra-prediction modes. Based on the reconstructed pixels, the HOG is referred to as the recalculated HOG.

[0203] For example, the weighting factor can be derived as follows: a recalculated HOG or HOGnorm (normalized HOG) can be calculated. The weighting factor can be 1. Based on the recalculated HOG, we calculate that the directional intra-prediction mode can be computed, and the synthetic HOG can be derived from the directional intra-prediction mode. The synthetic HOG can be a filtered (e.g., and a simpler version) recalculated HOG. The synthetic HOG may be less significant than the recalculated HOG. The weighting factor can be 0.8.

[0204] The encoding information can be used to weight HoG. Figure 22 A graph illustrating an example of weighting factors derived from encoded information is shown. In this example, the weights may not be equal for HoGs fused from non-DIMD blocks. Figure 22 As shown, weights can be derived from codingInfo (9015) and from the non-DIMD block (9011). The codingInfo from the non-DIMD block can result in synthetic HoG fusion (e.g., different) weights from the non-DIMD block. The codingInfo can be used to derive the weights of the non-DIMD block: for example, the code block flag (CBF), the last signif bit, and the transform coefficients from the prediction residual block. Figure 22 A graph is presented showing the weight factor calculation for non-DIMD blocks based on the encoded information.

[0205] Non-DIMD blocks can be collected in blocksset2 (9011). In the example, non-DIMD blocks can be filtered as previously detailed to generate blockssetFiltered2 (9012). Encoding information codingInfo (9015) can be collected from the encoding structure of blocksset2. Parameters from codingInfo (9016) (e.g., CBF, DCT coefficients, last_xy_sig) can be selected to derive weights. Weights can be used for fusion (4005) and... Figure 17 The details are as follows.

[0206] The Code Block Flag (CBF) can be checked. CBF can be used to indicate whether the encoded result of a CU contains non-zero residuals. If CBF equals 0 (OFF), the residual coefficients of the CU may not need to be encoded. The coefficients can (e.g., all of them) be 0, and the region can be considered as having no details that need to be encoded. For non-DIMD blocks, the weight factor may be low (e.g., very low), such as 0.1. If CBF equals 1 (ON), the residual coefficients of the CU can be encoded. In the example, the residual coefficients of CU (9018) can be used to derive the weight factor to fuse the HOG of that non-DIMD block. The weights can be derived from CBF=ON by setting the weight factor to 0.9 or 1 (or 0.1 if CBF=OFF).

[0207] The distribution of residual coefficients can be used to derive weighting factors (9018). Residuals can be encoded using block-based transforms, such as Discrete Cosine Transform (DCT) or Low-Frequency Inseparable Transform (LFNST). The low-frequency components of the transform coefficients can be located and concentrated in the upper left corner of the block, while the high-frequency components can be in the lower right corner. The weighting factors can be derived from the distribution of the DCT coefficients. For example, X can be a vector of the DCT coefficients of the CU. The vector X can be obtained by, for example, listing (e.g., all) the matrix coefficients in raster scan order (e.g., using vectorization (e.g., any vectorization), such as z-scan). The first non-zero DCT coefficient from X can be given its relative position m in X. The weighting factor can be m / length(X).

[0208] In the example, the Last_xy_sig flag (9017) can be used to obtain similar information about the coefficient distribution. The Last_xy_sig flag (9017) can correspond to the position (x, y) of the last valid quantized DCT coefficient. For example, X can be a vector of the DCT coefficients of the CU. The vector X can be obtained, for example, by listing all matrix coefficients in raster scan order (e.g., using vectorization (e.g., any vectorization), such as a z-scan). Last_xy_sig corresponds to position n in X. The weighting factor can be n / length(X).

[0209] HOGs can be smoothed. The features described herein can be associated with the smoothing of HOGs involved in merging prior to merging. In the examples, the HOG from the DIMD block of the current block involved in the merging or fusion that produces the MHOG and / or the synthesized HOG from the non-DIM block of that current block can be filtered by filters prior to merging. Filters that reduce pixel noise in the template of the reconstructed samples reflected in the HOG interval can be used. Filters that reduce artifacts / errors in the synthesized HOG can be used. For example, a Gaussian filter can be used.

[0210]

[0211] It is the average value and can be equal to 0. This is the variance of the Gaussian filter kernel. The filtering process can be expressed as follows.

[0212]

[0213] A Gaussian filter LUT can be used to approximate Gaussian(y). For example, a Laplace filter can be used.

[0214]

[0215] It is the average value and can be equal to 0. This is the scaling parameter. The filtering process can be expressed as follows.

[0216]

[0217] A Laplace filter LUT can be used to approximate laplace(y). The MHOG can be smoothed after fusion. After obtaining the MHOG from the HOG of the current block involved in the fusion and merging process, the MHOG can be filtered. Filters (e.g., any filter) can be used. For example, in the case of using a Gaussian filter, the filtering process can be expressed as follows.

[0218]

[0219] HOG fusion and HOG smoothing can be combined. In the examples, HOG normalization as described in this paper can be directly combined with examples of HOG smoothing as described in this paper.

[0220] Although the features and elements have been described above in specific combinations, those skilled in the art will understand 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 disks (DVDs). The processor associated with the software can be used to implement a radio frequency transceiver for a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

1. A video decoding device, comprising: Processor, the processor being configured to: A first block set is determined, wherein each block in the first block set selects a non-decoder-side intra-frame mode derivation (DIMD) merging mode for prediction; Obtain encoding information associated with the current block from the first block set, wherein the encoding information includes at least a prediction pattern; Derive the first HoG, wherein the first HoG is derived based on the prediction pattern; Determine a first weight associated with the first HoG, wherein the first weight associated with the first HoG is determined based on the encoding information; and A merged gradient histogram (MHoG) is obtained, wherein the MHoG is obtained by at least applying the first weight to the first HoG.

2. The video decoding apparatus according to claim 1, wherein, The processor is also configured to: A second set of blocks is determined, wherein each block in the second set selects a DIMD merging pattern for prediction; and The second HoG is derived, wherein the MHoG is obtained based at least on the first HoG or the second HoG.

3. The video decoding apparatus according to claim 2, wherein, The first block set and the second block set are neighboring blocks associated with the current block, and the processor is further configured to predict the current block based on one or more intra-frame prediction modes obtained according to the MHoG.

4. The video decoding device according to claim 1, wherein, The encoding information includes a coded block flag (CBF) or a set of coefficients associated with the current block obtained from the prediction error.

5. The video decoding apparatus according to claim 1, wherein, The processor is also configured to: The normalized HoG is derived, wherein the normalized HoG is obtained based on normalization information, and wherein the MHoG is also obtained based on the normalized HoG.

6. The video decoding apparatus according to claim 1, wherein, The processor is further configured to filter the first block set based on the distance between the current block and the blocks in the first block set, or based on the difference between the size of the current block and the size of the blocks in the first block set.

7. The video decoding apparatus according to claim 1, wherein, The first HoG is a synthetic HoG, the first weight is a synthetic weight, and the first HoG is a synthetic normalized HoG.

8. A video decoding method, comprising: A first block set is determined, wherein each block in the first block set selects a non-decoder-side intra-frame mode derivation (DIMD) merging mode for prediction; Obtain encoding information associated with the current block from the first block set, wherein the encoding information includes at least a prediction pattern; Derive the first HoG, wherein the first HoG is derived based on the prediction pattern; Determine a first weight associated with the first HoG, wherein the first weight associated with the first HoG is determined based on the encoding information; and A merged gradient histogram (MHoG) is obtained, wherein the MHoG is obtained by at least applying the first weight to the first HoG.

9. The method of claim 8, further comprising: A second set of blocks is determined, wherein each block in the second set selects a DIMD merging pattern for prediction; and The second HoG is derived, wherein the MHoG is obtained based at least on the first HoG or the second HoG.

10. The method of claim 9, further comprising: The current block is predicted based on one or more intra-frame prediction modes obtained according to the MHoG, wherein the first block set and the second block set are neighboring blocks associated with the current block.

11. The method according to claim 8, wherein, The encoding information includes a coded block flag (CBF) or a set of coefficients associated with the current block obtained from the prediction error.

12. The method according to claim 8, further comprising: The normalized HoG is derived, wherein the normalized HoG is obtained based on normalization information, and wherein the MHoG is also obtained based on the normalized HoG.

13. The method of claim 8, further comprising: The first block set is filtered based on the distance between the current block and the blocks in the first block set, or based on the difference between the size of the current block and the size of the blocks in the first block set.

14. The method according to claim 8, wherein, The first HoG is a synthetic HoG and the first weight is a synthetic weight.

15. The video decoding apparatus according to claim 1 or the method according to claim 8, wherein, The first HoG is a synthetic normalized HoG and the first weight is a synthetic weight.

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