Combination of intra template matching prediction and local illumination compensation with dedicated template matching metrics

Abstract

Video encoding and / or decoding may be performed using a combination of intra template matching prediction (ITMP) and local illumination compensation (LIC) with dedicated template matching metrics. In examples, template matching metric (e.g., a number and / or types of template matching metrics) may be based on an indication, such as an ITMP-LIC flag. In examples, the number and / or types of template matching metrics may be based on a sequence parameter set (SPS) indication, such as an SPS ITMP-LIC flag. In examples, a template matching metric may be computed (e.g., approximatively computed), allowing computations to be shared and / or reused between the approximate computation of a template matching metric and the computation of another template matching metric. ITMP-LIC and fusion may be combined.

Description

IDVC_ 2023P01112WO PATENT COMBINATION OF INTRA TEMPLATE MATCHING PREDICTION AND LOCAL ILLUMINATION COMPENSATION WITH DEDICATED TEMPLATE MATCHING METRICS CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of European Provisional Patent Application No.23307377.4 filed December 22, 2023 and European Provisional Patent Application No.24305037.4 filed January 9, 2024, the contents of which are incorporated by reference herein. BACKGROUND

[0002] Video coding systems may be used to compress digital video signals, e.g., to reduce the storage and / or transmission bandwidth needed for such signals. Video coding systems may include, for example, block-based, wavelet-based, and / or object-based systems. SUMMARY

[0003] Systems, methods, and instrumentalities are disclosed for performing video encoding / decoding using a combination of intra template matching prediction (ITMP), local illumination compensation (LIC) with one or more dedicated template matching metrics, fusion, and / or sub-pel precision filtering.

[0004] In examples, a video decoding device may be configured to perform one or more of the following. For example, the video decoding device may determine that an intra template matching prediction (ITMP) local illumination compensation (LIC) is enabled for a current block (e.g., a first block). The video decoding device may determine that the ITMP LIC is enabled based on whether an ITMP LIC enablement indication flag is on. The ITMP enablement indication flag may be configured to indicate whether an ITMP is enabled or disabled.

[0005] Based on the determination that the ITMP-LIC is enabled for the first block, the video decoding device may perform an ITMP search (e.g., a first ITMP search) using a first template matching metric. The video decoding device may decode the first block based on the first ITMP search.

[0006] The video decoding device may determine that the ITMP-LIC is disabled for another block (e.g., a second block). Based on the determination that the ITMP-LIC is disabled for the second block, the video decoding device may perform another ITMP search (e.g., a second ITMP search) using a second templateIDVC_ 2023P01112WO PATENT matching metric. The video decoding device may decode the second block based on the second ITMP search.

[0007] The first template matching metric may be associated with a mean removed (MR) sum of absolute difference (SAD) between a first template of a scanned reconstructed block and a template of the first block. The second template matching metric may be associated with an SAD between a second template of the scanned reconstructed block and the template of the second block.

[0008] The video decoding device may decode the current block based on the ITMP search.

[0009] The video decoding device may determine (e.g., further determine) that sub-pel precision filtering is enabled. For example, the video decoding device may determine that sub-pel precision filtering is enabled for the first block and / or determine that the sub-pel precision filtering is disabled for the second block.

[0010] Based on the determination that the sub-pel filtering is enabled for the first block, the video decoding device may predict the first block based on at least one of a sub-pel precision index or a sub-pel direction index. Based on the determination that the sub-pel filtering is disabled for the second block, the video decoding device may skip the prediction of the current block based on the sub-pel precision index or the sub-pel direction index.

[0011] A computer-readable medium for video decoding may include one or more instructions for causing one or more processors to perform the method described herein.

[0012] In examples, a video encoding device may be configured to perform one or more of the following. For example, the video encoding device may determine to enable an ITMP-LIC for a current block (e.g., a first block). Based on the determination to enable the ITMP-LIC for the first block, the video encoding device may perform an ITMP search (e.g., a first ITMP search) for the first block using a first template matching metric. The video encoding device may encode the first block based on the first ITMP search.

[0013] The video encoding device may determine to disable the ITMP-LIC for another block (e.g., a second block). Based on the determination to disable the ITMP-LIC for the second block, the video encoding device may perform another ITMP search (e.g., a second ITMP search) for the second block using a second template matching metric. The video encoding device may encode the second block based on the second ITMP search.

[0014] As described herein, the first template matching metric may be associated with a mean removed (MR) sum of absolute difference (SAD) between a first template of a scanned reconstructed block and a template of the first block. The second template matching metric may be associated with an SAD between a second template of the scanned reconstructed block and the template of the second block.IDVC_ 2023P01112WO PATENT

[0015] In examples, the video encoding device may determine (e.g., further determine) to enable sub- pel precision filtering for the first block. Based on the determination to enable the sub-pel filtering for the first block, the video encoding device may include, in video data, at least one of a sub-pel precision index or a sub-pel direction index.

[0016] In examples, the video encoding device may determine (e.g., further determine) to disable the sub-pel precision filtering for the second block. Based on the determination to disable the sub-pel filtering for the second block, the video encoding device may skip the inclusion of the sub-pel precision index or the sub-pel direction index in the video data.

[0017] The video encoding device may include a first ITMP-LIC indication in video data. The first ITMP- LIC indication may be configured to indicate that the ITMP-LIC is enabled for the first block. In examples, the first ITMP-LIC indication may be a first ITMP enablement indication flag.

[0018] The video encoding device may include a second ITMP-LIC indication in video data. The second ITMP-LIC indication may be configured to indicate that the ITMP-LIC is disabled for the second block. In examples, the second ITMP-LIC indication may be a second ITMP enablement indication flag.

[0019] In examples, a computer-readable medium for video encoding may include one or more instructions for causing one or more processors to perform the method described herein.

[0020] In examples, video data may include information representative of a current block ended according to the method described herein.

[0021] A (e.g., single) template matching metric may be based on an indication, such as an ITMP-LIC flag. One or more numbers and / or types of template matching metrics may be based on the indication (e.g., the ITMP-LIC flag). The indication, such as the ITMP-LIC flag, may be signaled at sequence parameter set (SPS) level. For example, the numbers and / or types of template matching metrics may be based on an SPS ITMP-LIC flag. A template matching metric may be computed (e.g., approximatively computed), allowing one or more computations to be shared and / or reused between the computation (e.g., approximate computation) of a (e.g., one) template matching metric and the computation (e.g., approximate computation) of another template matching metric. ITMP-LIC and fusion may be combined. ITMP-LIC and sub-pel precision filtering may be combined.

[0022] A video decoding device (e.g., a decoder) may be configured to implement a method, which may include one or more of the following. The video decoding device may determine whether an ITMP-LIC is enabled for a current block. Based on a determination that the ITMP-LIC is enabled, the video decoding device may perform an ITMP search using a first template matching metric. Based on a determination that the ITMP-LIC is disabled, the video decoding device may perform the ITMP search using a secondIDVC_ 2023P01112WO PATENT template matching metric. The video decoding device may decode the current block based on the ITMP search.

[0023] In examples, the first template matching metric may be, or may include, a mean removed (MR) sum of absolute difference (SAD) between a first template of a scanned reconstructed block and a template of the current block. In examples, the second template matching metric may be, or may include, an SAD between a second template of the scanned reconstructed block and the template of the current block. In examples, the first template and the second template may be identical.

[0024] The video decoding device may determine whether a fusion is enabled. If the fusion is enabled, the video decoding device may predict the current block based on an ITMP fusion index. If the fusion is disabled, the video decoding device may not use the fusion based on an ITMP fusion index for predicting the current block.

[0025] The video decoding device may determine whether sub-pel precision filtering is enabled. If the sub-pel precision filtering is enabled, the video decoding device may predict the current block based on at least one of a sub-pel precision index or a sub-pel direction index. If the sub-pel precision filtering is disabled, the video decoding device may skip the sub-pel precision filtering based on the sub-pel precision index or the sub-pel direction index for predicting the current block.

[0026] A video encoding device (e.g., an encoder) may be configured to implement a method, which may include one or more of the following. The video encoding device may enable ITMP-LIC for a current block. The video encoding device may obtain an ITMP search using a first template matching metric. The video encoding device may obtain the ITMP search using a second template matching metric. The video encoding device may encode the current block based on the ITMP search.

[0027] In examples, the first template matching metric may be, or may include, an MR-SAD between a first template of a scanned reconstructed block and a template of the current block. In examples, the second template matching metric may be, or may include, an SAD between a second template of the scanned reconstructed block and the template of the current block.

[0028] The video encoding device may enable a fusion. If the fusion is enabled, the video encoding device may include, in video data, an ITMP fusion index. If the fusion is disabled, the video encoding device may skip the inclusion of the ITMP fusion index in the video data.

[0029] The video encoding device may enable sub-pel precision filtering. If the sub-pel filtering is enabled, the video encoding device may include, in video data, at least one of a sub-pel precision index or a sub-pel direction index. If the sub-pel filtering is disabled, the video encoding device may skip the inclusion of the sub-pel precision index or the sub-pel direction index in the video data.IDVC_ 2023P01112WO PATENT BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG.1A is a system diagram illustrating an example communications system in which one or more disclosed embodiments may be implemented.

[0031] FIG.1B is a system diagram illustrating an example wireless transmit / receive unit (WTRU) that may be used within the communications system illustrated in FIG.1A according to an embodiment.

[0032] FIG.1C is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communications system illustrated in FIG.1A according to an embodiment.

[0033] FIG.1D is a system diagram illustrating a further example RAN and a further example CN that may be used within the communications system illustrated in FIG.1A according to an embodiment.

[0034] FIG.2 illustrates an example video encoder.

[0035] FIG.3 illustrates an example video decoder.

[0036] FIG.4 illustrates an example of a system in which various aspects and examples may be implemented.

[0037] FIG.5 illustrates an example of three types of matchings between a template of a ^^ ൈ ^^reconstructed block inside a search area covering a reconstructed part of a current frame and the templateof the current ^^ ൈ ^^ block.

[0038] FIG.6 illustrates an example of a search area for the current ^^ ൈ ^^ block to be predicted viaintra template matching prediction (ITMP).

[0039] FIG.7 illustrates an example of extracting training examples.

[0040] FIG.8 illustrates an example of a 5-tap spatial component of a filter to be applied to a reference block in a linear filter model sub-mode of ITMP.

[0041] FIG.9 illustrates an example of extracting training examples.

[0042] FIG.10 illustrates an example of decoding of the current block predicted by ITMP if a (e.g., single) template-matching metric involved in the ITMP search is based on an ITMP-LIC flag, which may be read during the parsing of the syntax of the current block.

[0043] FIG.11 illustrates an example of decoding a current block predicted by ITMP if the number and / or types of template-matching metrics involved in the ITMP search are based on an ITMP-LIC flag, which may be read during the parsing of the syntax of the current block.IDVC_ 2023P01112WO PATENT

[0044] FIG.12 illustrates an example of decoding a current block predicted by ITMP if the number and / or types of template-matching metrics involved in the ITMP search are based on a sequence parameter set (SPS) ITMP-LIC flag.

[0045] FIG.13 illustrates an example of different approximations of a mean removed (MR) sum ofabsolute difference (SAD) between a template of a given ^^ ൈ ^^ reconstructed block and the template ofthe current ^^ ൈ ^^ block.

[0046] FIG.14 illustrates an example of computations of approximate MR-SAD, including MRSADୟୠ୭^^,ୟ୮୮୰୭^,^, MRSAD୪^^^,ୟ୮୮୰୭^,^, and / or MRSADୟ୮୮୰୭^,^.

[0047] FIG.15 illustrates an example of decoding a current block predicted by ITMP using a combination of a (e.g., single) template matching metric based on an ITMP-LIC flag and approximate computation of template matching metrics.

[0048] FIGs.16A-B illustrate an example of decoding a current block predicted by ITMP if the combination between ITMP-LIC and fusion is allowed.

[0049] FIGs.17A-B illustrate an example of decoding a current block predicted by ITMP if the combination between ITMP-LIC and sub-pel is allowed.

[0050] FIGs.18A-B illustrate an example of decoding a current block predicted by ITMP if the combination between ITMP-LIC, fusion, and sub-pel is allowed.

[0051] FIG.19 illustrates an example of decoding a current block predicted by ITMP where the use of LIC is determined by the comparison between two template matching metrics.

[0052] FIGs.20A-B illustrate an example of decoding a current block predicted by ITMP where the use of LIC is determined by the comparison between two template matching metrics and the combination between ITMP-LIC and sub-pel is allowed. DETAILED DESCRIPTION

[0053] A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawings.

[0054] FIG.1A is a diagram illustrating an example communications system 100 in which one or more disclosed embodiments may be implemented. The communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communications system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communications systems 100 may employ one or more channel access methods, such as code division multiple accessIDVC_ 2023P01112WO PATENT (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tail unique-word DFT-Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block-filtered OFDM, filter bank multicarrier (FBMC), and the like.

[0055] As shown in FIG.1A, the communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a RAN 104 / 113, a CN 106 / 115, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a “station” and / or a “STA”, may be configured to transmit and / or receive wireless signals and may include a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. Any of the WTRUs 102a, 102b, 102c and 102d may be interchangeably referred to as a UE.

[0056] The communications systems 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106 / 115, the Internet 110, and / or the other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node-B, an eNode B, a Home Node B, a Home eNode B, a gNB, a NR NodeB, a site controller, an access point (AP), a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0057] The base station 114a may be part of the RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and / or the base station 114b may be configured to transmit and / or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combinationIDVC_ 2023P01112WO PATENT of licensed and unlicensed spectrum. A cell may provide coverage for a wireless service to a specific geographical area that may be relatively fixed or that may change over time. The cell may further be divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., one for each sector of the cell. In an embodiment, the 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 desired spatial directions.

[0058] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0059] More specifically, as noted above, the communications system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station 114a in the RAN 104 / 113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 115 / 116 / 117 using wideband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High-Speed Downlink (DL) Packet Access (HSDPA) and / or High-Speed UL Packet Access (HSUPA).

[0060] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro).

[0061] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR Radio Access , which may establish the air interface 116 using New Radio (NR).

[0062] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, for instance using dual connectivity (DC) principles. Thus, the air interface utilized by WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions sent to / from multiple types of base stations (e.g., a eNB and a gNB).IDVC_ 2023P01112WO PATENT

[0063] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA20001X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like.

[0064] The base station 114b in FIG.1A may be a wireless router, Home Node B, Home eNode B, or access point, for example, and may utilize any suitable RAT for facilitating wireless connectivity in a localized area, such as a place of business, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a roadway, and the like. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR etc.) to establish a picocell or femtocell. As shown in FIG.1A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not be required to access the Internet 110 via the CN 106 / 115.

[0065] The RAN 104 / 113 may be in communication with the CN 106 / 115, which may be any type of network configured to provide voice, data, applications, and / or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have varying quality of service (QoS) requirements, such as differing throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like. The CN 106 / 115 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not shown in FIG.1A, it will be appreciated that the RAN 104 / 113 and / or the CN 106 / 115 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 / 113 or a different RAT. For example, in addition to being connected to the RAN 104 / 113, which may be utilizing a NR radio technology, the CN 106 / 115 may also be in communication with another RAN (not shown) employing a GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0066] The CN 106 / 115 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or the other networks 112. The PSTN 108 may include circuit- switched telephone networks that provide plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use commonIDVC_ 2023P01112WO PATENT communication protocols, such as the transmission control protocol (TCP), user datagram protocol (UDP) and / or the internet protocol (IP) in the TCP / IP internet protocol suite. The networks 112 may include wired and / or wireless communications networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 / 113 or a different RAT.

[0067] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links). For example, the WTRU 102c shown in FIG.1A may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0068] FIG.1B is a system diagram illustrating an example WTRU 102. As shown in FIG.1B, the WTRU 102 may include a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138, among others. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0069] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. While FIG.1B depicts the processor 118 and the transceiver 120 as separate components, it will be appreciated that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0070] The transmit / receive element 122 may be configured to transmit signals to, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In an embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals, for example. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF and light signals. It willIDVC_ 2023P01112WO PATENT be appreciated that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0071] Although the transmit / receive element 122 is depicted in FIG.1B as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0072] The transceiver 120 may be configured to modulate the signals that are to be transmitted by the transmit / receive element 122 and to demodulate the signals that are received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11, for example.

[0073] The processor 118 of the WTRU 102 may be coupled to, and may receive user input data from, the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or organic light-emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from, and store data in, any type of suitable memory, such as the non-removable memory 130 and / or the removable memory 132. The 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. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0074] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control the power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 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, and the like.

[0075] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or in lieu of, the information from the GPS chipset 136, the WTRU 102 may receive location information over the air interface 116 from a base station (e.g., base stations 114a, 114b) and / or determine its location based on the timing of the signals being received from two or more nearby base stations. It willIDVC_ 2023P01112WO PATENT be appreciated that the WTRU 102 may acquire location information by way of any suitable location- determination method while remaining consistent with an embodiment.

[0076] The processor 118 may further be coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functionality and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (for photographs and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a Virtual Reality and / or Augmented Reality (VR / AR) device, an activity tracker, and the like. The peripherals 138 may include one or more sensors, the sensors may be one or more of a gyroscope, an accelerometer, a hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

[0077] The WTRU 102 may include a full duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for both the 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 either hardware (e.g., a choke) or signal processing via a processor (e.g., a separate processor (not shown) or via processor 118). In an embodiment, the WRTU 102 may include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for either the UL (e.g., for transmission) or the downlink (e.g., for reception)).

[0078] FIG.1C is a system diagram illustrating the RAN 104 and the CN 106 according to an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0079] The RAN 104 may include eNode-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the eNode-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the eNode-B 160a, for example, may use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a.

[0080] Each of the eNode-Bs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling ofIDVC_ 2023P01112WO PATENT users in the UL and / or DL, and the like. As shown in FIG.1C, the eNode-Bs 160a, 160b, 160c may communicate with one another over an X2 interface.

[0081] The CN 106 shown in FIG.1C 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 are depicted as part of the CN 106, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0082] The MME 162 may be connected to each of the eNode-Bs 162a, 162b, 162c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, and the like. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and / or WCDMA.

[0083] The SGW 164 may be connected to each of the eNode Bs 160a, 160b, 160c in the RAN 104 via the S1 interface. The SGW 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring user planes during inter- eNode B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing contexts of the WTRUs 102a, 102b, 102c, and the like.

[0084] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0085] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers.

[0086] Although the WTRU is described in FIGS.1A-1D as a wireless terminal, it is contemplated that in certain representative embodiments that such a terminal may use (e.g., temporarily or permanently) wired communication interfaces with the communication network.

[0087] In representative embodiments, the other network 112 may be a WLAN.IDVC_ 2023P01112WO PATENT

[0088] A WLAN in Infrastructure Basic Service Set (BSS) mode may have an Access Point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have an access or an interface to a Distribution System (DS) or another type of wired / wireless network that carries traffic in to and / or out of the BSS. Traffic to STAs that originates from outside the BSS may arrive through the AP and may be delivered to the STAs. Traffic originating from STAs to destinations outside the BSS may be sent to the AP to be delivered to respective destinations. Traffic between STAs within the BSS may be sent through the AP, for example, where the source STA may send traffic to the AP and the AP may deliver the traffic to the destination STA. The traffic between STAs within a BSS may be considered and / or referred to as peer-to- peer traffic. The peer-to-peer traffic may be sent between (e.g., directly between) the source and destination STAs with a direct link setup (DLS). In certain representative embodiments, the DLS may use an 802.11e DLS or an 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and the STAs (e.g., all of the STAs) within or using the IBSS may communicate directly with each other. The IBSS mode of communication may sometimes be referred to herein as an “ad- hoc” mode of communication.

[0089] When using the 802.11ac infrastructure mode of operation or a similar mode of operations, the AP may transmit a beacon on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., 20 MHz wide bandwidth) or a dynamically set width via signaling. The primary channel may be the operating channel of the BSS and may be used by the STAs to establish a connection with the AP. In certain representative embodiments, Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) may be implemented, for example in in 802.11 systems. For CSMA / CA, the STAs (e.g., every STA), including the AP, may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0090] High Throughput (HT) STAs may use a 40 MHz wide channel for communication, for example, via a combination of the primary 20 MHz channel with an adjacent or nonadjacent 20 MHz channel to form a 40 MHz wide channel.

[0091] Very High Throughput (VHT) STAs may support 20MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. The 40 MHz, and / or 80 MHz, channels may be formed by combining contiguous 20 MHz channels. A 160 MHz channel may be formed by combining 8 contiguous 20 MHz channels, or by combining two non-contiguous 80 MHz channels, which may be referred to as an 80+80 configuration. For the 80+80 configuration, the data, after channel encoding, may be passed through a segment parser that may divide the data into two streams. Inverse Fast Fourier Transform (IFFT) processing, and time domain processing, may be done on each stream separately. The streams may be mapped on to the two 80 MHzIDVC_ 2023P01112WO PATENT channels, and the data may be transmitted by a transmitting STA. At the receiver of the receiving STA, the above described operation for the 80+80 configuration may be reversed, and the combined data may be sent to the Medium Access Control (MAC).

[0092] Sub 1 GHz modes of operation are supported by 802.11af and 802.11ah. The channel operating bandwidths, and carriers, are reduced in 802.11af and 802.11ah relative to those used in 802.11n, and 802.11ac.802.11af supports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non- TVWS spectrum. According to a representative embodiment, 802.11ah may support Meter Type Control / Machine-Type Communications, such as MTC devices in a macro coverage area. MTC devices may have certain capabilities, for example, limited capabilities including support for (e.g., only support for) certain and / or limited bandwidths. The MTC devices may include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).

[0093] WLAN systems, which may support multiple channels, and channel bandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include a channel which may be designated as the primary channel. The primary channel may have a bandwidth equal to the largest common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA, from among all STAs in operating in a BSS, which supports the smallest bandwidth operating mode. In the example of 802.11ah, the primary channel may be 1 MHz wide for STAs (e.g., MTC type devices) that support (e.g., only support) a 1 MHz mode, 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 sensing and / or Network Allocation Vector (NAV) settings may depend on the status of the primary channel. If the primary channel is busy, for example, due to a STA (which supports only a 1 MHz operating mode), transmitting to the AP, the entire available frequency bands may be considered busy even though a majority of the frequency bands remains idle and may be available.

[0094] In the United States, the available frequency bands, which may be used by 802.11ah, are from 902 MHz to 928 MHz. In Korea, the available frequency bands are from 917.5 MHz to 923.5 MHz. In Japan, the available frequency bands are from 916.5 MHz to 927.5 MHz. The total bandwidth available for 802.11ah is 6 MHz to 26 MHz depending on the country code.

[0095] FIG.1D is a system diagram illustrating the RAN 113 and the CN 115 according to an embodiment. As noted above, the RAN 113 may employ an NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115.IDVC_ 2023P01112WO PATENT

[0096] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, gNBs 180a, 108b may utilize beamforming to transmit signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a, for example, may use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum while the remaining component carriers may be on licensed spectrum. In an embodiment, the gNBs 180a, 180b, 180c may implement Coordinated Multi-Point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[0097] The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using transmissions associated with a scalable numerology. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using subframe or transmission time intervals (TTIs) of various or scalable lengths (e.g., containing varying number of OFDM symbols and / or lasting varying lengths of absolute time).

[0098] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c without also accessing other RANs (e.g., such as eNode-Bs 160a, 160b, 160c). In the standalone configuration, WTRUs 102a, 102b, 102c may utilize one or more of gNBs 180a, 180b, 180c as a mobility anchor point. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration WTRUs 102a, 102b, 102c may communicate with / connect to gNBs 180a, 180b, 180c while also communicating with / connecting to another RAN such as eNode-Bs 160a, 160b, 160c. For example, WTRUs 102a, 102b, 102c may implement DC principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously. In the non-standalone configuration, eNode-Bs 160a, 160b, 160c may serve as a mobility anchor for WTRUs 102a, 102b, 102c and gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for servicing WTRUs 102a, 102b, 102c.IDVC_ 2023P01112WO PATENT

[0099] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, support of network slicing, dual connectivity, interworking between NR and E- UTRA, routing of user plane data towards User Plane Function (UPF) 184a, 184b, routing of control plane information towards Access and Mobility Management Function (AMF) 182a, 182b and the like. As shown in FIG.1D, the gNBs 180a, 180b, 180c may communicate with one another over an Xn interface.

[0100] The CN 115 shown in FIG.1D 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 are depicted as part of the CN 115, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0101] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and may serve as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, support for network slicing (e.g., handling of different PDU sessions with different requirements), selecting a particular SMF 183a, 183b, management of the registration area, termination of NAS signaling, mobility management, and the like. Network slicing may be used by the AMF 182a, 182b in order to customize CN support for WTRUs 102a, 102b, 102c based on the types of services being utilized WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for machine type communication (MTC) access, and / or the like. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as WiFi.

[0102] The SMF 183a, 183b may be connected to an AMF 182a, 182b in the CN 115 via an N11 interface. The SMF 183a, 183b may also be connected to a UPF 184a, 184b in the CN 115 via an N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b and configure the routing of traffic through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions, such as managing and allocating UE IP address, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notifications, and the like. A PDU session type may be IP-based, non-IP based, Ethernet- based, and the like.

[0103] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet- switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b,IDVC_ 2023P01112WO PATENT 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, and the like.

[0104] The CN 115 may facilitate communications with other networks. For example, the CN 115 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to a local Data Network (DN) 185a, 185b through the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0105] In view of Figures 1A-1D, and the corresponding description of Figures 1A-1D, one or more, or all, of the functions described herein with regard to one or more of: WTRU 102a-d, Base Station 114a-b, eNode-B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF 182a-b, UPF 184a-b, SMF 183a-b, DN 185a-b, and / or any other device(s) described herein, may be performed by one or more emulation devices (not shown). The emulation devices may be one or more devices configured to emulate one or more, or all, of the functions described herein. For example, the emulation devices may be used to test other devices and / or to simulate network and / or WTRU functions.

[0106] The emulation devices may be designed to implement one or more tests of other devices in a lab environment and / or in an operator network environment. For example, the one or more emulation devices may perform the one or more, or all, functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network in order to test other devices within the communication network. The one or more emulation devices may perform the one or more, or all, functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The emulation device may be directly coupled to another device for purposes of testing and / or may performing testing using over-the-air wireless communications.

[0107] The one or more emulation devices may perform the one or more, including all, functions while not being implemented / deployed as part of a wired and / or wireless communication network. For example, the emulation devices may be utilized in a testing scenario in a testing laboratory and / or a non-deployed (e.g., testing) wired and / or wireless communication network in order to implement testing of one or more components. The one or more emulation devices may be test equipment. Direct RF coupling and / or wireless communications via RF circuitry (e.g., which may include one or more antennas) may be used by the emulation devices to transmit and / or receive data.IDVC_ 2023P01112WO PATENT

[0108] This application describes a variety of aspects, including tools, features, examples, models, approaches, etc. Many of these aspects are described with specificity and, at least to show the individual characteristics, are often described in a manner that may sound limiting. However, this is for purposes of clarity in description, and does not limit the application or scope of those aspects. Indeed, all of the different aspects may be combined and interchanged to provide further aspects. Moreover, the aspects may be combined and interchanged with aspects described in earlier filings as well.

[0109] The aspects described and contemplated in this application may be implemented in many different forms. FIGS.5-15 described herein may provide some examples, but other examples are contemplated. The discussion of FIGS.5-15 does not limit the breadth of the implementations. At least one of the aspects generally relates to video encoding and decoding, and at least one other aspect generally relates to transmitting a bitstream generated or encoded. These and other aspects may be implemented as a method, an apparatus, a computer readable storage medium having stored thereon instructions for encoding or decoding video data according to any of the methods described, and / or a computer readable storage medium having stored thereon a bitstream generated according to any of the methods described.

[0110] In the present application, the terms “reconstructed” and “decoded” may be used interchangeably, the terms “pixel” and “sample” may be used interchangeably, the terms “image,” “picture” and “frame” may be used interchangeably.

[0111] Various methods are described herein, and each of the methods comprises one or more steps or actions for achieving the described method. Unless a specific order of steps or actions is required for proper operation of the method, the order and / or use of specific steps and / or actions may be modified or combined. Additionally, terms such as “first”, “second”, etc. may be used in various examples to modify an element, component, step, operation, etc., such as, for example, a “first decoding” and a “second decoding”. Use of such terms does not imply an ordering to the modified operations unless specifically required. So, in this example, the first decoding need not be performed before the second decoding, and may occur, for example, before, during, or in an overlapping time period with the second decoding.

[0112] Various methods and other aspects described in this application may be used to modify modules, for example, decoding modules, of a video encoder 200 and decoder 300 as shown in FIG.2 and FIG.3. Moreover, the subject matter disclosed herein may be applied, for example, to any type, format or version of video coding, whether described in a standard or a recommendation, whether pre-existing or future- developed, and extensions of any such standards and recommendations. Unless indicated otherwise, or technically precluded, the aspects described in this application may be used individually or in combination.

[0113] Various numeric values are used in examples described the present application, such as chroma format (e.g., 4:2:0, 4:2:2, 4:4:4), block sizes or coding unit sizes (e.g., height, width), partition dimensions,IDVC_ 2023P01112WO PATENT number of search areas, number of sub areas or regions, search step sizes, number of reconstructed blocks, number of entries in a list, precision, number of directions, number of modes, number of candidates, number of samples, number of references, bit depth, number of filter taps, bit values, sub-block sizes, number of parameters, flag values, multiplier values, constant values, range values, etc. These and other specific values are for purposes of describing examples and the aspects described are not limited to these specific values.

[0114] FIG.2 is a diagram showing an example video encoder. Variations of example encoder 200 are contemplated, but the encoder 200 is described below for purposes of clarity without describing all expected variations.

[0115] Before being encoded, the video sequence may go through pre-encoding processing (201), for example, applying a color transform to the input color picture (e.g., conversion from RGB 4:4:4 to YCbCr 4:2:0), or performing a remapping of the input picture components in order to get a signal distribution more resilient to compression (for instance using a histogram equalization of one of the color components). Metadata may be associated with the pre-processing and attached to video data (e.g., the bitstream).

[0116] In the encoder 200, a picture is encoded by the encoder elements as described below. The picture to be encoded is partitioned (202) and processed in units of, for example, coding units (Cus). Each unit is encoded using, for example, either an intra or inter mode. When a unit is encoded in an intra mode, it performs intra prediction (260). In an inter mode, motion estimation (275) and compensation (270) are performed. The encoder decides (205) which one of the intra mode or inter mode to use for encoding the unit, and indicates the intra / inter decision by, for example, a prediction mode flag. Prediction residuals are calculated, for example, by subtracting (210) the predicted block from the original image block.

[0117] The prediction residuals are then transformed (225) and quantized (230). The quantized transform coefficients, as well as motion vectors and other syntax elements, such as picture partitioning information, are entropy coded (245) to output a bitstream. The encoder can skip the transform and apply quantization directly to the non-transformed residual signal. The encoder can bypass both transform and quantization, e.g., the residual is coded directly without the application of the transform or quantization processes.

[0118] The encoder decodes an encoded block to provide a reference for further predictions. The quantized transform coefficients are de-quantized (240) and inverse transformed (250) to decode prediction residuals. Combining (255) the decoded prediction residuals and the predicted block, an image block is reconstructed. In-loop filters (265) are applied to the reconstructed picture to perform, for example, deblocking / SAO (Sample Adaptive Offset) / ALF (Adaptive Loop Filtering) filtering to reduce encoding artifacts. The filtered image is stored at a reference picture buffer (280).IDVC_ 2023P01112WO PATENT

[0119] FIG.3 is a diagram showing an example of a video decoder. In example decoder 300, video data (e.g., a bitstream) is decoded by the decoder elements as described below. Video decoder 300 generally performs a decoding pass reciprocal to the encoding pass as described in FIG.2. The encoder 200 also generally performs video decoding as part of encoding video data.

[0120] In particular, the input of the decoder includes video data, such as a video bitstream, which may be generated by video encoder 200. The video data (e.g., the bitstream) is first entropy decoded (330) to obtain transform coefficients, prediction modes, motion vectors, and other coded information. The picture partition information indicates how the picture is partitioned. The decoder may therefore divide (335) the picture according to the decoded picture partitioning information. The transform coefficients are de- quantized (340) and inverse transformed (350) to decode the prediction residuals. Combining (355) the decoded prediction residuals and the predicted block, an image block is reconstructed. The predicted block may be obtained (370) from intra prediction (360) or motion-compensated prediction (e.g., inter prediction) (375). In-loop filters (365) are applied to the reconstructed image. The filtered image is stored at a reference picture buffer (380). In some examples (e.g., for a given picture) the contents of the reference picture buffer 380 on the decoder 300 side may be identical to the contents of the reference picture buffer 280 on the encoder 200 side (e.g., for the same picture).

[0121] The decoded picture may further go through post-decoding processing (385), for example, an inverse color transform (e.g., conversion from YcbCr 4:2:0 to RGB 4:4:4) or an inverse remapping performing the inverse of the remapping process performed in the pre-encoding processing (201). The post-decoding processing can use metadata derived in the pre-encoding processing and signaled in the video data (e.g., the bitstream). In an example, the decoded images (e.g., after application of the in-loop filters (365) and / or after post-decoding processing (385), if post-decoding processing is used) may be sent to a display device for rendering to a user.

[0122] FIG.4 is a diagram showing an example of a system in which various aspects and examples described herein may be implemented. System 400 may be embodied as a device including the various components described below and is configured to perform one or more of the aspects described in this document. Examples of such devices, include, but are not limited to, various electronic devices such as personal computers, laptop computers, smartphones, tablet computers, digital multimedia set top boxes, digital television receivers, personal video recording systems, connected home appliances, and servers. Elements of system 400, singly or in combination, may be embodied in a single integrated circuit (IC), multiple Ics, and / or discrete components. For example, in at least one example, the processing and encoder / decoder elements of system 400 are distributed across multiple Ics and / or discrete components. In various examples, the system 400 is communicatively coupled to one or more other systems, or otherIDVC_ 2023P01112WO PATENT electronic devices, via, for example, a communications bus or through dedicated input and / or output ports. In various examples, the system 400 is configured to implement one or more of the aspects described in this document.

[0123] The system 400 includes at least one processor 410 configured to execute instructions loaded therein for implementing, for example, the various aspects described in this document. Processor 410 may include embedded memory, input output interface, and various other circuitries as known in the art. The system 400 includes at least one memory 420 (e.g., a volatile memory device, and / or a non-volatile memory device). System 400 includes a storage device 440, which can 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, magnetic disk drive, and / or optical disk drive. The storage device 440 may include an internal storage device, an attached storage device (including detachable and non-detachable storage devices), and / or a network accessible storage device, as non-limiting examples.

[0124] System 400 includes an encoder / decoder module 430 configured, for example, to process data to provide an encoded video or decoded video, and the encoder / decoder module 430 can include its own processor and memory. The encoder / decoder module 430 represents module(s) that may be included in a device to perform the encoding and / or decoding functions. As is known, a device can include one or both of the encoding and decoding modules. Additionally, encoder / decoder module 430 may be implemented as a separate element of system 400 or may be incorporated within processor 410 as a combination of hardware and software as known to those skilled in the art.

[0125] Program code to be loaded onto processor 410 or encoder / decoder 430 to perform 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. In accordance with various examples, one or more of processor 410, memory 420, storage device 440, and encoder / decoder module 430 can store one or more of various items during the performance of the processes described in this document. Such stored items can include, but are not limited to, the input video, the decoded video or portions of the decoded video, the video data, the bitstream, matrices, variables, and intermediate or final results from the processing of equations, formulas, operations, and operational logic.

[0126] In some examples, memory inside of the processor 410 and / or the encoder / decoder module 430 is used to store instructions and to provide working memory for processing that is needed during encoding or decoding. In other examples, however, a memory external to the processing device (for example, the processing device may be either the processor 410 or the encoder / decoder module 430) is used for one orIDVC_ 2023P01112WO PATENT more of these functions. The external memory may be the memory 420 and / or the storage device 440, for example, a dynamic volatile memory and / or a non-volatile flash memory. In several examples, an external non-volatile flash memory is used to store the operating system of, for example, a television. In at least one example, a fast external dynamic volatile memory such as a RAM is used as working memory for video encoding and decoding operations.

[0127] The input to the elements of system 400 may be provided through various input devices as indicated in block 445. Such input devices include, but are not limited to, (i) a radio frequency (RF) portion that receives an RF signal transmitted, for example, 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. Other examples, not shown in FIG. 4, include composite video.

[0128] In various examples, the input devices of block 445 have associated respective input processing elements as known in the art. For example, the RF portion may be associated with elements suitable for (i) selecting a desired frequency (also referred to as selecting a signal, or band-limiting a signal to a band of frequencies), (ii) downconverting the selected signal, (iii) band-limiting again to a narrower band of frequencies to select (for example) a signal frequency band which may be referred to as a channel in certain examples, (iv) demodulating the downconverted and band-limited signal, (v) performing error correction, and / or (vi) demultiplexing to select the desired stream of data packets. The RF portion of various examples includes one or more elements to perform these functions, for example, frequency selectors, signal selectors, band-limiters, channel selectors, filters, downconverters, demodulators, error correctors, and demultiplexers. The RF portion can include a tuner that performs various of these functions, including, for example, downconverting the received signal to a lower frequency (for example, an intermediate frequency or a near-baseband frequency) or to baseband. In one set-top box example, the RF portion and its associated input processing element receives an RF signal transmitted over a wired (for example, cable) medium, and performs frequency selection by filtering, downconverting, and filtering again to a desired frequency band. Various examples rearrange the order of the above-described (and other) elements, remove some of these elements, and / or add other elements performing similar or different functions. Adding elements can include inserting elements in between existing elements, such as, for example, inserting amplifiers and an analog-to-digital converter. In various examples, the RF portion includes an antenna.

[0129] The USB and / or HDMI terminals can include respective interface processors for connecting system 400 to other electronic devices across USB and / or HDMI connections. It is to be understood that various aspects of input processing, for example, Reed-Solomon error correction, may be implemented, forIDVC_ 2023P01112WO PATENT example, within a separate input processing IC or within processor 410 as necessary. Similarly, aspects of USB or HDMI interface processing may be implemented within separate interface Ics or within processor 410 as necessary. The demodulated, error corrected, and demultiplexed stream is provided to various processing elements, including, for example, processor 410, and encoder / decoder 430 operating in combination with the memory and storage elements to process the datastream as necessary for presentation on an output device.

[0130] Various elements of system 400 may be provided within an integrated housing. Within the integrated housing, the various elements may be interconnected and transmit data therebetween using suitable connection arrangement 425, for example, an internal bus as known in the art, including the Inter- IC (I2C) bus, wiring, and printed circuit boards.

[0131] The system 400 includes communication interface 450 that enables communication with other devices via communication channel 460. The communication interface 450 can include, but is not limited to, a transceiver configured to transmit and to receive data over communication channel 460. The communication interface 450 can include, but is not limited to, a modem or network card and the communication channel 460 may be implemented, for example, within a wired and / or a wireless medium.

[0132] Data is streamed, or otherwise provided, to the system 400, in various examples, 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). The Wi-Fi signal of these examples is received over the communications channel 460 and the communications interface 450 which are adapted for Wi-Fi communications. The communications channel 460 of these examples is typically connected to an access point or router that provides access to external networks including the Internet for allowing streaming applications and other over-the-top communications. Other examples provide streamed data to the system 400 using a set-top box that delivers the data over the HDMI connection of the input block 445. Still other examples provide streamed data to the system 400 using the RF connection of the input block 445. As indicated above, various examples provide data in a non-streaming manner. Additionally, various examples use wireless networks other than Wi-Fi, for example a cellular network or a Bluetooth® network.

[0133] The system 400 can provide an output signal to various output devices, including a display 475, speakers 485, and other peripheral devices 495. The display 475 of various examples includes one or more of, for example, a touchscreen display, an organic light-emitting diode (OLED) display, a curved display, and / or a foldable display. The display 475 may be for a television, a tablet, a laptop, a cell phone (mobile phone), or other device. The display 475 can also be integrated with other components (for example, as in a smart phone), or separate (for example, an external monitor for a laptop). The other peripheral devices 495 include, in various examples, one or more of a stand-alone digital video disc (orIDVC_ 2023P01112WO PATENT digital versatile disc) (DVD, for both terms), a disk player, a stereo system, and / or a lighting system. Various examples use one or more peripheral devices 495 that provide a function based on the output of the system 400. For example, a disk player performs the function of playing the output of the system 400.

[0134] In various examples, control signals are communicated between the system 400 and the display 475, speakers 485, or other peripheral devices 495 using signaling such as AV.Link, Consumer Electronics Control (CEC), or other communications protocols that enable device-to-device control with or without user intervention. The output devices may be communicatively coupled to system 400 via dedicated connections through respective interfaces 470, 480, and 490. Alternatively, the output devices may be connected to system 400 using the communications channel 460 via the communications interface 450. The display 475 and speakers 485 may be integrated in a single unit with the other components of system 400 in an electronic device such as, for example, a television. In various examples, the display interface 470 includes a display driver, such as, for example, a timing controller (T Con) chip.

[0135] The display 475 and speakers 485 can alternatively be separate from one or more of the other components, for example, if the RF portion of input 445 is part of a separate set-top box. In various examples in which the display 475 and speakers 485 are external components, the output signal may be provided via dedicated output connections, including, for example, HDMI ports, USB ports, or COMP outputs.

[0136] The examples may be carried out by computer software implemented by the processor 410 or by hardware, or by a combination of hardware and software. As a non-limiting example, the examples may be implemented by one or more integrated circuits. The memory 420 may be of any type appropriate to the technical environment and may be implemented using any appropriate data storage technology, such as optical memory devices, magnetic memory devices, semiconductor-based memory devices, fixed memory, and removable memory, as non-limiting examples. The processor 410 may be of any type appropriate to the technical environment, and can encompass one or more of microprocessors, general purpose computers, special purpose computers, and processors based on a multi-core architecture, as non-limiting examples.

[0137] Various implementations involve decoding. “Decoding”, as used in this application, can encompass all or part of the processes performed, for example, on a received encoded sequence in order to produce a final output suitable for display. In various examples, such processes include one or more of the processes typically performed by a decoder, for example, entropy decoding, inverse quantization, inverse transformation, and differential decoding. In various examples, such processes also, or alternatively, include processes performed by a decoder of various implementations described herein, for example, determining whether an intra template matching prediction (ITMP) with local illuminationIDVC_ 2023P01112WO PATENT compensation (LIC) is enabled for a current block; based on a determination that the ITMP-LIC is enabled, performing an ITMP search using a first template matching metric; based on a determination that the ITMP- LIC is disabled, performing the ITMP search using a second template matching metric; decoding the current block based on the ITMP search; merging at least one of a first list associated with a mean removed (MR) sum of absolute difference (SAD) or a second list associated with a sum of absolute transform difference (SATD); obtaining a prediction of the current block based on the ITMP, etc.

[0138] As further examples, in one example “decoding” refers only to entropy decoding, in another example “decoding” refers only to differential decoding, and in another example “decoding” refers to a combination of entropy decoding and differential decoding. Whether the phrase “decoding process” is intended to refer specifically to a subset of operations or generally to the broader decoding process will be clear based on the context of the specific descriptions and is believed to be well understood by those skilled in the art.

[0139] Various implementations involve encoding. In an analogous way to the above discussion about “decoding”, “encoding” as used in this application can encompass all or part of the processes performed, for example, on an input video sequence in order to produce an encoded bitstream. In various examples, such processes include one or more of the processes typically performed by an encoder, for example, partitioning, differential encoding, transformation, quantization, and entropy encoding. In various examples, such processes also, or alternatively, include processes performed by an encoder of various implementations described in this application, for example, enabling an ITMP-LIC for a current block; obtaining an ITMP search using a first template matching metric; obtaining the ITMP search using a second template matching metric; encoding the current block based on the ITMP search; merging at least one of a first list associated with a MR SAD or a second list associated with a SATD; obtaining a prediction of the current block based on the ITMP, etc.

[0140] As further examples, in one example “encoding” refers only to entropy encoding, in another example “encoding” refers only to differential encoding, and in another example “encoding” refers to a combination of differential encoding and entropy encoding. Whether the phrase “encoding process” is intended to refer specifically to a subset of operations or generally to the broader encoding process will be clear based on the context of the specific descriptions and is believed to be well understood by those skilled in the art.

[0141] Note that syntax elements as used herein, such as intra_tmp_flag, intra_tmp_fusion_flag, intra_tmp_fusion_idx, intra_tmp_idx, intra_tmp_filter_flag, intra_tmp_sub_pel_precision_idx, intra_tmp_sub_pel_direction_idx, intra_tmp_lic_flag, intra_tmp_lic_index, predBlock, resBlock, recBlock, etc. are descriptive terms. As such, they do not preclude the use of other syntax element names.IDVC_ 2023P01112WO PATENT

[0142] When a figure is presented as a flow diagram, it should be understood that it also provides a block diagram of a corresponding apparatus. Similarly, when a figure is presented as a block diagram, it should be understood that it also provides a flow diagram of a corresponding method / process.

[0143] The implementations and aspects described herein may be implemented in, for example, a method or a process, an apparatus, a software program, a data stream, or a signal. Even if only discussed in the context of a single form of implementation (for example, discussed only as a method), the implementation of features discussed can also be implemented in other forms (for example, an apparatus or program). An apparatus may be implemented in, for example, appropriate hardware, software, and firmware. The methods may be implemented in, for example, a processor, which refers to processing devices in general, including, for example, a computer, a microprocessor, an integrated circuit, or a programmable logic device. Processors also include communication devices, such as, for example, computers, cell phones, portable / personal digital assistants (“PDAs”), and other devices that facilitate communication of information between end-users.

[0144] Reference to “one example” or “an example” or “one implementation” or “an implementation”, as well as other variations thereof, means that a particular feature, structure, characteristic, and so forth described in connection with the example is included in at least one example. Thus, the appearances of the phrase “in one example” or “in an example” or “in one implementation” or “in an implementation”, as well any other variations, appearing in various places throughout this application are not necessarily all referring to the same example.

[0145] Additionally, this application may refer to “determining” various pieces of information. Determining the information can include one or more of, for example, estimating the information, calculating the information, predicting the information, or retrieving the information from memory. Obtaining may include receiving, retrieving, constructing, generating, and / or determining.

[0146] Further, this application may refer to “accessing” various pieces of information. Accessing the information can include one or more of, for example, receiving the information, retrieving the information (for example, from memory), storing the information, moving the information, copying the information, calculating the information, determining the information, predicting the information, or estimating the information.

[0147] Additionally, this application may refer to “receiving” various pieces of information. Receiving is, as with “accessing”, intended to be a broad term. Receiving the information can include one or more of, for example, accessing the information, or retrieving the information (for example, from memory). Further, “receiving” is typically involved, in one way or another, during operations such as, for example, storing the information, processing the information, transmitting the information, moving the information, copying theIDVC_ 2023P01112WO PATENT information, erasing the information, calculating the information, determining the information, predicting the information, or estimating the information.

[0148] It is to be appreciated that the use of any of the following “ / ”, “and / or”, and “at least one of”, for example, in the cases of “A / B”, “A and / or B” and “at least one of A and B”, is intended to encompass the selection of the first listed option (A) only, or the selection of the second listed option (B) only, or the selection of both options (A and B). As a further example, in the cases of “A, B, and / or C” and “at least one of A, B, and C”, such phrasing is intended to encompass the selection of the first listed option (A) only, or the selection of the second listed option (B) only, or the selection of the third listed option (C) only, or the selection of the first and the second listed options (A and B) only, or the selection of the first and third listed options (A and C) only, or the selection of the second and third listed options (B and C) only, or the selection of all three options (A and B and C). This may be extended, as is clear to one of ordinary skill in this and related arts, for as many items as are listed.

[0149] Also, as used herein, the word “signal” refers to, among other things, indicating something to a corresponding decoder. Encoder signals may include, for example, residual signals, metadata, coding or motion representation modes (e.g., ITMP-related flags, LIC-related flags), partitioning modes, reference pictures, motion vector predictors (MVPs), motion vector differences (MVDs), indices, candidate lists, etc. In this way, in an example the same parameter is used at both the encoder side and the decoder side. Thus, for example, an encoder may transmit (explicit signaling) a particular parameter to the decoder so that the decoder can use the same particular parameter. Conversely, if the decoder already has the particular parameter as well as others, then signaling may be used without transmitting (implicit signaling) to simply allow the decoder to know and select the particular parameter. By avoiding transmission of any actual functions, a bit savings is realized in various examples. It is to be appreciated that signaling may be accomplished in a variety of ways. For example, one or more syntax elements, flags, and so forth are used to signal information to a corresponding decoder in various examples. While the preceding relates to the verb form of the word “signal”, the word “signal” can also be used herein as a noun.

[0150] As will be evident to one of ordinary skilled in the art, implementations may produce a variety of signals formatted to carry information that may be, for example, stored or transmitted. The information can include, for example, instructions for performing a method, or data produced by one of the described implementations. For example, a signal may be formatted to carry the bitstream of a described example. Such a signal may be formatted, for example, as an electromagnetic wave (for example, using a radio frequency portion of spectrum) or as a baseband signal. The formatting may include, for example, encoding a data stream and modulating a carrier with the encoded data stream. The information that the signal carries may be, for example, analog or digital information. The signal may be transmitted over aIDVC_ 2023P01112WO PATENT variety of different wired or wireless links, as is known. The signal may be stored on, or accessed or received from, a processor-readable medium.

[0151] Many examples are described herein. Features of examples may be provided alone or in any combination, across various claim categories and types. Further, examples may include one or more of the features, devices, or aspects described herein, alone or in any combination, across various claim categories and types. For example, features described herein may be implemented in a bitstream or signal that includes information generated as described herein. The information may allow a decoder to decode a bitstream, the encoder, bitstream, and / or decoder according to any of the embodiments described. For example, features described herein may be implemented by creating and / or transmitting and / or receiving and / or decoding a bitstream or signal. For example, features described herein may be implemented a method, process, apparatus, medium storing instructions, medium storing data, or signal. For example, features described herein may be implemented by a TV, set-top box, cell phone, tablet, or other electronic device that performs decoding. The TV, set-top box, cell phone, tablet, or other electronic device may display (e.g., using a monitor, screen, or other type of display) a resulting image (e.g., an image from residual reconstruction of the video bitstream). The TV, set-top box, cell phone, tablet, or other electronic device may receive a signal including an encoded image and perform decoding.

[0152] Intra Template Matching Prediction (ITMP) mode may refer to an intra prediction mode that predicts a current block, e.g., by copying the reconstructed block in a current frame whose L-shaped template best matches an L-shaped template of the current block. The match between the L-shaped template of a given reconstructed block and the L-shaped template of the current block may be measured via a predefined metric, e.g., sum of absolute difference (SAD).

[0153] An encoder may search, e.g., within a search range covering a reconstructed part of the current frame, for the template closest to the template of the current block according to a metric, e.g., a predefined metric. The block associated with the template retained by the search may be used as a prediction of the current block. The encoder may signal in video data (e.g., in bitstream) the usage of ITMP. A decoder may perform the same search and / or the same prediction process performed by the encoder, for example, if ITMP is selected to predict the same current block.

[0154] ITMP may be implemented in a video coding tool. ITMP may involve one or more (e.g., multiple) candidates. Prediction (e.g., at the encoder) may involve sorting one or more positions of the searched reconstructed blocks in a list, e.g., according to the template matching SADs. The index in the list of the position of the selected reconstructed block for prediction may be signaled in the video data (e.g., the bitstream), for example, if ITMP is selected to predict the given block. An ITMP search, one or more ITMPIDVC_ 2023P01112WO PATENT sub-modes, and / or signaling of ITMP may be based on (e.g., built upon) one or more candidate characteristics.

[0155] An ITMP search may be implemented based on one or more prerequisites. In some examples(e.g., for the current ^^ ൈ ^^ block to be predicted), one or more (e.g., three) types of matching betweenthe template of a ^^ ൈ ^^ reconstructed block inside the search area covering a reconstructed part of thecurrent frame and the template of the current block may exist. As shown in FIG.5, a first type of matchingmay involve a SAD between the above portion (1005) of the template of the ^^ ൈ ^^ reconstructed block(1004) and the above portion (1001) of the template of the current ^^ ൈ ^^ block (1000), where the SADmay be denoted as SADୟୠ୭^^. A second type of matching may involve a SAD between the left portion (1007) of the template of (1004) and the left portion (1003) of the template of (1000), where the SAD may be denoted as SAD୪^^^. A third type of matching may involve a SAD between the template gathering (1005), (1006), and (1007) of (1004) and the template gathering (1001), (1002), and (1003) of (1000), where the SAD may be denoted as SAD^^୪୪.

[0156] In some examples (e.g., for the current ^^ ൈ ^^ block to be predicted), the definition of thesearch area may be based on ^^ and ^^, e.g., as shown by example in FIG.6. The search area may be decomposed into one or more sub-areas (e.g., six sub-areas). For example, as shown in FIG.6, six sub- areas may be denoted as R1 to R6.

[0157] FIG.5 illustrates an example of three types of matchings between the template of a ^^ ൈ ^^reconstructed block (1004) inside the search area covering a reconstructed part of the current frame andthe template of the current ^^ ൈ ^^ block (1000).

[0158] FIG.6 illustrates an example of a search area for the current ^^ ൈ ^^ block to be predicted viaITMP.

[0159] A hierarchical search may be performed, for example, for computation saving. An ITMP search(e.g., for the current ^^ ൈ ^^ block to be predicted) including in computing a template matching SAD for areconstructed block belonging to the search area, e.g., scanning by step ^^ ∈ ℕ∗ pixelshorizontally / vertically, may be skipped (e.g., not be performed). An ITMP search may, e.g., instead od and / or additionally, be defined hierarchically. An ITMP search may be, for example, decomposed into a sparse search and / or a (e.g., subsequent) refined search.

[0160] A sparse search may scan regions (e.g., six regions) in an order, such as R4, R5, R6, R1, R2, and R3, e.g., as shown by example in FIG.6. Scanning may be performed in a region (e.g., in each region), for example, by stepping three (3) pixels horizontally / vertically, for a (e.g., each) scanned reconstructed block. One or more values may be computed for SADୟୠ୭^^, SAD୪^^^, and SAD^^୪୪between the template of the scanned reconstructed block and the template of the current block. The sparse searchIDVC_ 2023P01112WO PATENT may sort in a list ℒୟୠ୭^^the positions within the current frame of the (e.g., six (6)) scanned reconstructed blocks with SADୟୠ୭^^(e.g., the smallest SADୟୠ୭^^) in ascending order. A position within the current frame of a reconstructed block may refer to one or more coordinates of the pixel at the top-left of the reconstructed block in the current frame. The sparse search may (e.g., also) sort in a list ℒ୪^^^the positions within the current frame of the (e.g., six (6)) scanned reconstructed blocks with SAD୪^^^(e.g., the smallest SAD୪^^^) in ascending order. The sparse search may (e.g., also) sort in a list ℒ^^୪୪the positions within the current frame of the (e.g., 30) scanned reconstructed blocks with SAD^^୪୪(e.g., the smallest SAD^^୪୪) in ascending order.

[0161] A refined search may perform scanning, for example, by stepping a pixel horizontally / vertically within a reduced range around a position (e.g., for each position stored in ℒ^^୪୪). A value may be computed for SAD^^୪୪between the template of the scanned reconstructed block and the template of the current block, for example, for a (e.g., each) scanned reconstructed block. A refined search may sort in a list ℒ̅^^୪୪the positions within the current frame of the scanned reconstructed blocks with SAD^^୪୪(e.g., the smallest SAD^^୪୪) in ascending order. The size of ℒ̅^^୪୪may be 19. The (e.g., same) process may be repeated by replacing ℒ^^୪୪by ℒୟୠ୭^^, SAD^^୪୪by SADୟୠ୭^^, and / or ℒ̅^^୪୪by ℒ̅ୟୠ୭^^. The size of ℒ̅ୟୠ୭^^may be equal to three (3). The (e.g., same) process may be repeated by replacing ℒ^^୪୪by ℒ୪^^^, SAD^^୪୪by SAD୪^^^, and / or ℒ̅^^୪୪by ℒ̅୪^^^. The size of ℒ̅୪^^^may be equal to three (3).

[0162] A refined search may result in one or more (e.g., at most the last six (6)) positions in ℒ̅^^୪୪beingoverwritten by the positions in ^ℒ̅ୟୠ୭^^, ℒ̅୪^^^^. The term at most may indicate that, if a redundancy existsbetween a position in ℒ̅^^୪୪ and a position in ^ℒ̅ୟୠ୭^^, ℒ̅୪^^^^, a redundant position in ^ℒ̅ୟୠ୭^^, ℒ̅୪^^^^ maybe ignored , e.g., instead of and / or in addition to, overwriting. The list ℒ̅^^୪୪may correspond to the list of (e.g., 19) positions within the current frame of reconstructed blocks retained by the ITMP search.

[0163] At an encoder, the hierarchical search may be run (e.g., as described herein) for a given block predicted by ITMP. At a decoder, the hierarchical search may be performed identically (e.g., with exception) for the given block predicted by ITMP. At a decoder, provided the read syntax of ITMP (e.g., as described herein), an analysis may be performed to determine whether ℒ̅ୟୠ୭^^and ℒ̅୪^^^appear in the portion of ℒ̅^^୪୪that is effectively used. Based on the determination, ℒ̅ୟୠ୭^^and ℒ̅୪^^^may not be created and / or the above-mentioned computations of SADୟୠ୭^^and SAD୪^^^may be ignored, for example, if ℒ̅ୟୠ୭^^and ℒ̅୪^^^do not appear in the portion of ℒ̅^^୪୪that is effectively used.

[0164] One or more (e.g., multiple) sub-modes may exist. A sub-mode may include picking a (e.g., single) position of reconstructed block from ℒ̅^^୪୪and using the reconstructed block as a prediction of theIDVC_ 2023P01112WO PATENT current block. ITMP may include one or more (e.g., three) other sub-modes. ITMP sub-modes may include, for example, one or more of the following: fusion, sub-pel precision, and / or linear filter model.

[0165] A single ITMP sub-mode may be characterized by a (e.g., single) reconstructed block whose position is selected from ℒ̅^^୪୪, becoming a prediction of the current block.

[0166] A fusion ITMP sub-mode may be characterized by combining one or more (e.g., multiple) reconstructed blocks whose positions are selected from ℒ̅^^୪୪, yielding a final prediction of the current block.

[0167] A sub-pel precision ITMP sub-mode may be characterized by using a (e.g., single) reconstructed block for predicting the current block and using sub-pel precision with ½-pel precision, ¼-pel precision, and / or ¾-pel precision, each with multiple (e.g., eight (8)) possible directions.

[0168] A linear filter model ITMP sub-mode may be characterized by using a (e.g., single) reconstructed block for predicting the current block and / or using a linear filter that may be learned between the template of the (e.g., single) reconstructed block and the template of the current block. The learned linear filter may be applied to the copy of the (e.g., single) reconstructed block, yielding a final prediction of the current block.

[0169] In a fusion sub-mode of ITMP, fusion may be configured via filtering (e.g., as described herein) and / or fusion may be configured via blending (e.g., as described herein).

[0170] In some examples of fusion via filtering, a number ^^ of candidate reconstructed blocks (e.g.,^^ ^ 5 candidate reconstructed blocks) may be selected and filtered to generate a prediction (e.g., finalprediction) of a given block to be predicted. Fusion via filtering may be expressed, for example, in accordance with Eq. (1): predBlock ൌ ∑^ି^ ^ୀ^ ^^^ ∗ refBlock^ ^ ^^^ ∗ midValue (1)where predBlock may denote a final prediction of a given block. For ^^ ∈ ^0,^^ െ 1^, refBlock^ maydenote the selected reconstructed block of index ^^. In some examples, midValue may be equal to 512 for bit-depth 10.

[0171] Filter coefficients ^^^ , ^^ ∈ ^0,^^^ may be learned, for example, by minimizing the Mean SquaredError (MSE) between the filtered version of ^^ templates of the ^^ selected reconstructed blocks and thetemplate of the current block. As illustrated by example in FIG.7, the current ^^ ൈ ^^ block (1200) may bepredicted by collecting (e.g., as a training example), for a sample position in the template (1201) of (1200), the set of collocated samples {(1205), (1208), (1211), (1214), (1217)} belonging respectively to theIDVC_ 2023P01112WO PATENT template (1204) of the selected reconstructed block (1203), the template (1207) of the selected reconstructed block (1206), the template (1210) of the selected reconstructed block (1209), the template (1213) of the selected reconstructed block (1212), and the template (1216) of the selected reconstructed block (1215), e.g., along with the collocated target sample (1202) belonging to the template (1201) of (1200). The filter coefficients may be learned, for example, by minimizing the MSE between the output of the filtering of {(1205), (1208), (1211), (1214), (1217)} and the associated target sample (1202) over one or more (e.g., all) the collected training examples.

[0172] FIG.7 illustrates an example of extracting training examples. A (e.g., each) training example may correspond to a pair of a set of collocated samples inside ^^ templates of the ^^ selected ^^ൈ^^ reconstructed blocks and the collocated target sample inside the template of the current ^^ൈ^^ block, for example, to learn the filter coefficients.

[0173] In some examples of fusion via blending, a number ^^ of candidate reconstructed blocks (e.g., ^^ ^ 5 candidate reconstructed blocks) may be selected and blended to generate a prediction (e.g., a finalprediction) of a given block. Fusion via blending may be expressed, for example, in accordance with Eq. (2): predBlock ൌ ^∑^ି^ ^ୀ^ ^^^ ∗ refBlock^ ^ 32^ ≫ 6 (2)where predBlock may denote the prediction (e.g., the final prediction) of the given block. For ^^ ∈^0,^^ െ 1^, refBlock^ may denote the selected reconstructed block of index ^^.

[0174] For ^^ ∈ ^0,^^ െ 1^, SAD^ may denote a template matching SAD associated with refBlock^.The blending coefficient ^^^may be equal to an integerized form of the normalization ratio SAD^⁄ ൫∑^ି^ ^ୀ^ SAD^ ൯. Integerization of the normalization ratio in fusion via blending may be similar (e.g.,used in Decoder Side Intra Mode Derivation (DIMD).

[0175] A linear filter model may be used. For a given block to be predicted, the filter applied to the reference block, e.g., being the copy of the selected reconstructed block (e.g., the selected single reconstructed block), may include a 5-tap plus sign shape spatial component and a bias term. The input to the spatial 5-tap component of the filter may include a center I sample in the reference block, which may be at a corresponding location with the sample in the given block to be predicted, and above / north (N), below / south (S), left / west (W) and right / east(E) neighbors, for example, as depicted in FIG.8.

[0176] FIG.8 illustrates an example of a 5-tap spatial component of a filter to be applied to a reference block in a linear filter model sub-mode of ITMP.IDVC_ 2023P01112WO PATENT

[0177] A bias term B may represent a scalar offset between input and output. A bias term B may be set to a (e.g., middle) luma value (e.g., 512 for bit-depth 10). At a spatial location in the given block to be predicted collocated with C, the output of the filter may be calculated, for example, in accordance with Eq. (3): predVal = ^^^C + ^^^N + ^^ଶS + ^^ଷE + ^^ସW + ^^ହB (3)

[0178] Filter coefficients ^^^ , ^^ ∈ ^0,5^ may be learned, for example, by minimizing the MSE betweenthe filtered version of the template of the selected reconstructed block and the template of the currentblock. As illustrated by example in FIG.9, the current ^^ ൈ ^^ block (1100) may be predicted by collecting(e.g., as training examples), for a position C in the template (1103) of the selected ^^ ൈ ^^ reconstructedblock (1102), the pair of the set of samples {N, C, S, E, W} (1105) inside (1103), and / or the collocated target sample (1106) inside the template (1101) of (1100). The filter coefficients may be learned, for example, by minimizing the MSE between the output of the filtering of {N, C, S, E, W} and the associated target sample, over one or more (e.g., all) the collected training examples. The pattern (1105) may go out of the bounds of position C in the template (1103). Position C in the template (1103) may be supplemented with the one or more samples (1104). A sample in (1104) may be, for example, reconstructed or padded from neighboring samples, e.g., depending on availability.

[0179] FIG.9 illustrates an example of extracting training examples. A (e.g., each) training example may correspond to a pair of a set of samples {N, C, S, E, W} inside the template of the selected ^^ൈ^^ reconstructed block and the collocated target sample inside a template of the current ^^ൈ^^ block, for example, to learn the filter coefficients.

[0180] Signaling may be provided for ITMP. There may be one or more conditions for using ITMP. In some examples, ITMP may be used for natural and screen content. ITMP may be enabled for Coding Units (CUs), e.g., with height less than 64 and width less than 64.

[0181] ITMP may be signaled at the CU level (e.g., through a dedicated flag such as an intra_tmp_flag), for example, if DIMD is not used for a current CU. One or more other intra prediction modes may be inferred to be unused, for example, if ITMP is used. ITMP may be signaled, for example, as shown in Table 1, e.g., if the DIMD flag is false. Table 1 – Example of signaling ITMP …IDVC_ 2023P01112WO PATENT intra_tmp_flag if (intra_tmp_flag) { intra_tmp_fusion_flag if (intra_tmp_fusion_flag) { intra_tmp_fusion_idx } else { intra_tmp_idx intra_tmp_filter_flag if (!intra_tmp_filter_flag) { intra_tmp_sub_pel_precision_idx if (intra_tmp_sub_pel_precision_idx != 0) { intra_tmp_sub_pel_direction_idx } } } } …

[0182] An ITMP flag may be indicated, for example, as intra_tmp_flag. ITMP may be selected to predict the current block, for example, if the value of intra_tmp_flag is one (1). ITMP may not be selected to predict the current block, for example, if the value of intra_tmp_flag is zero (0).

[0183] An ITMP-fusion flag may be indicated, for example, as intra_tmp_fusion_flag. If the value of intra_tmp_fusion_flag is 1, the fusion sub-mode may be used to predict the current block. The fusion sub- mode may be skipped (e.g., not be used) to predict the current block, for example, if the value of intra_tmp_fusion_flag is zero (0).

[0184] An ITMP fusion index belonging to [|0, 5|] may be indicated, for example, as intra_tmp_fusion_idx. Fusion via blending may be used, for example, for intra_tmp_fusion_idx in [|0, 2|]. Fusion via filtering may be used, for example, for intra_tmp_fusion_idx in [|3, 5|]. For a given block to be predicted, in ℒ̅^^୪୪, the indices of the positions of the selected reconstructed blocks involved in the fusion may (e.g., always) be consecutives. The index in ℒ̅^^୪୪of the position of the first selected reconstructed block involved in the fusion may be the (e.g., only) index signaled via intra_tmp_fusion_idx. 5*intra_tmp_fusion_idx may be the index in ℒ̅^^୪୪of the position of the first selected reconstructed block involved in the fusion via blending, for example, if intra_tmp_fusion_idx in [|0, 2|].5*(intra_tmp_fusion_idx –IDVC_ 2023P01112WO PATENT 3) may be the index in ℒ̅^^୪୪of the position of the first selected reconstructed block involved in the fusion via filtering, for example, if intra_tmp_fusion_idx in [|3, 5|].

[0185] In a sub-mode (e.g., a single sub-mode) intra_tmp_idx may be an index in ℒ̅^^୪୪of the position of the (e.g., single) reconstructed block for prediction. Index intra_tmp_idx may belong to [|0, 18|].

[0186] An indication, such as an ITMP-linear-filter-model flag, may be indicated, for example, as intra_tmp_filter_flag. The linear filter model sub-mode may be used to predict the current block, for example, if the value of intra_tmp_filter_flag is one (1). The linear filter model sub-mode may be skipped (e.g., not be used) to predict the current block, for example, if the value of intra_tmp_filter_flag is zero (0).

[0187] The sub-pel precision sub-mode may be used to predict the current block, for example, if the value of intra_tmp_sub_pel_precision_idx is not equal to 0. The sub-pel precision sub-mode may be skipped (e.g., not be used) to predict the current block, for example, if the value of intra_tmp_sub_pel_precision_idx is equal to 0. In examples, in Table 1, the eleventh line (e.g., if (intra_tmp_sub_pel_precision_idx !} 0) {) may not necessarily mean that, for instance, at the decoder side, intra_tmp_sub_pel_precision_idx is read (e.g., entirely read) from video data (e.g., the bitstream) before testing whether intra_tmp_sub_pel_precision_idx is equal to 0. For example, at the decoder side, an indication, such as a flag (e.g., a single flag) may be read from video data (e.g., the bitstream) to determine whether intra_tmp_sub_pel_precision_idx is equal to 0. If intra_tmp_sub_pel_precision_idx is not equal to 0, one or more other flags may be read from the video data (e.g., the bitstream) to get the remainder of the value of intra_tmp_sub_pel_precision_idx. For example, intra_tmp_sub_pel_direction_idx may be read from the video data (e.g., the bitstream). In examples, in Table 1, the eleventh line (e.g., if (intra_tmp_sub_pel_precision_idx !} 0) {) may not necessarily mean that, for instance, at the encoder side, intra_tmp_sub_pel_precision_idx is written (e.g., entirely written) to video data (e.g., the bitstream) before testing whether intra_tmp_sub_pel_precision_idx is equal to 0. For example, at the encoder side, an indication, such as a flag (e.g., a single flag), may be written to the video data (e.g., the bitstream) to indicate whether intra_tmp_sub_pel_precision_idx is equal to 0. If intra_tmp_sub_pel_precision_idx is not equal to 0, one or more other flags may be written to the video data (e.g., the bitstream) to indicate remainder of the value of intra_tmp_sub_pel_precision_idx. For example, intra_tmp_sub_pel_direction_idx may be written to the video data (e.g., the bitstream).

[0188] As shown by example in Table 1, the fusion sub-mode may not be combined with the (e.g., single) sub-mode, the linear filter model sub-mode, and / or the sub-pel precision sub-mode. The linear filter model and / or sub-pel precision sub-modes may work (e.g., only work) as extensions of the (e.g., single) sub-mode. The linear filter model sub-mode may not be combined with the sub-pel precision sub-mode.IDVC_ 2023P01112WO PATENT

[0189] ITMP may be combined with Local Illumination Compensation (LIC).

[0190] LIC may be an inter prediction technique modeling local illumination variation between the current block and the reference block compensated via motion for prediction. The local illumination variation may be estimated from the template of the reference block and the template of the current block. The parameters of the model may be denoted by a scale α and an offset β, which may be used to form a linear equation α*p[x] + β to compensate illumination changes. p[x] may be a reference sample pointed to by Motion Vector (MV) at a location x on reference picture. The MV may be clipped with a wraparound offset taken into consideration, for example, if wrap around motion compensation is enabled. Values for α and β may be derived, for example, based on the template of the reference block and the template of the current block. For example, the value of α and β may be derived and signaling of α and β may be skipped (e.g., signaling overhead may therefore be skipped for α and β). An indication, such as an LIC flag, may be signaled for Advanced Motion Vector Prediction (AMVP) mode, for example, to indicate the use of LIC.

[0191] Local illumination compensation may be used for uni-prediction inter CUs, for example, with one or more of the following modifications: one or more intra neighbor samples may be used in LIC parameter derivation; LIC may be disabled for one or more blocks, e.g., including less than 32 luma samples; LIC parameter derivation may be performed (e.g., for non-subblock and / or affine modes) based on one or more template block samples corresponding to the current CU (e.g., instead of and / or in addition to partial template block samples corresponding to first top-left 16x16 unit); and / or one or more samples of the template of the reference block may be generated using motion compensation with the block MV without rounding to integer-pel precision.

[0192] For a given block predicted via ITMP, LIC may be applied to the selected reconstructed block used for prediction. LIC usage may be signaled through an indication, such as a CU-level flag, for example, if ITMP is used for predicting a given block. The usage of LIC and the usage of the linear filter model sub- mode (e.g., as described herein) may be mutually exclusive for a given CU. The usage of LIC and the usage of the fusion sub-mode (e.g., as described herein) may be mutually exclusive.

[0193] An adaptive template for LIC linear model computation may be used and / or one or more (e.g., multiple) linear models may be used to increase compression efficiency, e.g., for screen content coding.

[0194] Signaling of ITMP may be adapted to a combination of ITMP and LIC, for example, as shown by example in Table 2, e.g., if the DIMD flag is false. Table 2 – Example of signaling ITMP combined with LIC …IDVC_ 2023P01112WO PATENT intra_tmp_flag if (intra_tmp_flag) { intra_tmp_fusion_flag if (intra_tmp_fusion_flag) { intra_tmp_fusion_idx } else { intra_tmp_idx intra_tmp_filter_flag if (!intra_tmp_filter_flag) { intra_tmp_lic_flag if (intra_tmp_lic_flag && isItmpLicExtension) { intra_tmp_lic_index } if (!intra_tmp_lic_flag) { intra_tmp_sub_pel_precision_idx if (intra_tmp_sub_pel_precision_idx != 0) { intra_tmp_sub_pel_direction_idx } } } } } …

[0195] An IMTP-LIC flag may be indicated, for example, by intra_tmp_lic_flag. LIC may be used to predict the current block, for example, if the value of the ITMP-LIC flag is one (1). LIC may be skipped (e.g., not be used) to predict the current block, for example, if the value of the ITMP-LIC flag is zero (0).

[0196] An indication whether multiple linear models are activated may be provided, for example, by isItmpLicExtension, which may have Boolean values.

[0197] An ITMP-LIC index belonging to [|0, 3|] may be indicated, for example, by intra_tmp_lic_index. Values of intra_tmp_lic_index may indicate which of multiple (e.g., four (4)) LIC models is used.IDVC_ 2023P01112WO PATENT

[0198] Intra Block Copy (IBC) mode may be implemented as a block level prediction mode. At the encoder side, for a given block, block matching may find a block vector (e.g., an optimal block vector) and / or motion vector. A block vector may indicate the displacement from the current block to a reference block, which may already be reconstructed inside the current picture. The (e.g., optimal) block vector may be signaled to the decoder. In some examples, IBC may be specific to screen content coding, such as ITMP. In some examples, IBC may (e.g., also) be enabled in natural content coding, such as ITMP. A combination of IBC and LIC may be allowed.

[0199] An LIC transform may be applied to the reconstructed block whose position is selected from the list resulting from the ITMP search. A current block may be predicted via ITMP combined with LIC. For example, a template matching metric during the search for reconstructed blocks dedicated to ITMP-LIC may be used as the template matching metric used during the search for reconstructed blocks dedicated to ITMP sub-modes other than ITMP-LIC. An LIC transform applied to a reconstructed block may return a predicted block recovering discrepancies of statistics (e.g., discrepancies in offset and scale) between the reconstructed block (e.g., the initial reconstructed block) and the current block. The template matching metric involved in the search for reconstructed blocks dedicated to ITMP-LIC may (e.g., therefore) omit the recovered statistics.

[0200] Compression efficiency may be improved, for example, using template matching metrics during the search for reconstructed blocks dedicated to ITMP-LIC. A (e.g., single) template matching metric may be based on an indication, such as an ITMP-LIC flag. The number and / or types of template matching metrics may be based on the indication, such as the ITMP-LIC flag. The number and / or types of template matching metrics may be based on a sequence parameter set (SPS) indication, such as an SPS ITMP-LIC flag.

[0201] A (e.g., single) template matching metric may be based on an indication, e.g., an ITMP-LIC flag. For example, a (e.g., single) template-matching metric ruling an ITMP search for reconstructed blocks may be based on the ITMP-LIC flag read during the parsing of the syntax of a given block to be predicted using ITMP.

[0202] FIG.10 shows an example of decoding a current block predicted by ITMP where a (e.g., single) template matching metric may be based on an indication, such as an ITMP-LIC flag. As shown in FIG.10, the SPS ITMP-LIC flag on may indicate that the combination of ITMP and LIC is allowed in the hybrid block-based video codec of interest.

[0203] At 1300, decoding of the current block predicted by ITMP may begin.IDVC_ 2023P01112WO PATENT

[0204] At 1301, a determination may be made whether the ITMP-LIC flag read during the parsing of the syntax of the current block is on. The method may proceed to 1302 if the ITMP-LIC flag is on or to 1303 if the ITMP-LIC flag is off.

[0205] At 1302, the ITMP search may use the template matching metric ℳ^, returning the list ℒ̅^^୪୪,^of positions of reconstructed blocks, which may be sorted in ascending order of ℳ^values. For example, ℳ^may be the Mean Removed (MR)-SAD between the template of a scanned reconstructed block and the template of the current block.

[0206] At 1303, the ITMP search may use the template matching metric ℳୠୟ^^, returning the list ℒ̅^^୪୪,ୠୟ^^of positions of reconstructed blocks, which may be sorted in ascending order of ℳୠୟ^^values. For example, ℳୠୟ^^may be the SAD between the template of a scanned reconstructed block and the template of the current block.

[0207] At 1304, the current block may be predicted via ITMP using ℒ̅^^୪୪ ൌ ITMPLIC flag ? ℒ̅^^୪୪,^ ∶ℒ̅^^୪୪,ୠୟ^^, yielding predBlock.

[0208] At 1305, the reconstructed residual block resBlock may be decoded.

[0209] At 1306, following the reconstruction of the current block, e.g., recBlock ൌ predBlock ^resBlock, the decoding of the current block may end.

[0210] FIG.10 illustrates an example of decoding of the current block predicted by ITMP if the (e.g., single) template-matching metric involved in the ITMP search is based on the ITMP-LIC flag. The ITMP-LIC flag may be read during the parsing of the syntax of the current block. The SPS ITMP-LIC flag on may indicate that the combination of ITMP and LIC is allowed in the hybrid block-based video codec.

[0211] The number and / or type of template matching metrics may be based on an indication, such as the ITMP-LIC flag. For example, the number of template matching metrics and / or the types of template matching metrics ruling an ITMP search for reconstructed blocks may be based on the ITMP-LIC flag. The ITMP-LIC flag may be read during the parsing of the syntax of a given block to be predicted via ITMP.

[0212] FIG.11 shows an example of decoding a current block predicted by ITMP. As illustrated in FIG. 11, the number and / or type of template matching metrics may be based on an indication, such as an ITMP- LIC flag. As shown in FIG.11, the SPS ITMP-LIC flag on may indicate that the combination of ITMP and LIC is allowed in the hybrid block-based video codec of interest.

[0213] At 1400, the decoding of the current block predicted by ITMP may begin.

[0214] At 1401, a determination may be made whether the ITMP-LIC flag read during the parsing of the syntax of the current block is on. The method may proceed to {1402, 1403, 1404}, for example, if the ITMP- LIC flag is on or may proceed to 1405 if the ITMP-LIC flag is off.IDVC_ 2023P01112WO PATENT

[0215] At 1402, the ITMP search may use the template matching metric ℳ^, returning the list ℒ̅୮ୟ୰^,^of positions of reconstructed blocks, which may be sorted in ascending order of ℳ^values. For example, ℳ^may be the MR-SAD between the template of a scanned reconstructed block and the template of the current block.

[0216] At 1403, the ITMP search may use the template matching metric ℳ^, returning the list ℒ̅୮ୟ୰^,^of positions of reconstructed blocks, which may be sorted in ascending order of ℳ^values. For example, ℳ^may be the Sum of Absolute Transform Difference (SATD) between the template of a scanned reconstructed block and the template of the current block.

[0217] At 1404, the ITMP search may use the template matching metric ℳ ∗௧ି^, ^^ ∈ ℕ , returning thelist ℒ̅୮ୟ୰^,^ି^of positions of reconstructed blocks, which may be sorted in ascending order of ℳ௧ି^values. For example, ℳ௧ି^may be the MR-SATD between the template of a scanned reconstructed block and the template of the current block.

[0218] The results of {1402, 1403, 1404}, ℒ̅୮ୟ୰^,^, ℒ̅୮ୟ୰^,^, …, ℒ̅୮ୟ୰^,^ି^may be merged into a list (e.g., a final list) ℒ̅^^୪୪,୫^୰^^. In some examples, the merge may concatenate ℒ̅୮ୟ୰^,^, ℒ̅୮ୟ୰^,^, …, ℒ̅୮ୟ୰^,^ି^. In some examples, the merge may interleave positions from ℒ̅୮ୟ୰^,^, positions from ℒ̅୮ୟ୰^,^, …, positions from ℒ̅୮ୟ୰^,^ି^. In some examples, the merge may concatenate a truncated version of ℒ̅୮ୟ୰^,^, a truncated version of ℒ̅୮ୟ୰^,^, …, a truncated version of ℒ̅୮ୟ୰^,^ି^.

[0219] At 1405, the ITMP search may use the template matching metric ℳୠୟ^^, returning the list ℒ̅^^୪୪,ୠୟ^^of positions of reconstructed blocks, which may be sorted in ascending order of ℳୠୟ^^values. In some examples, ℳୠୟ^^may be the MSE between the template of a scanned reconstructed block and the template of the current block. In some examples, ℳୠୟ^^may be the SAD between the template of a scanned reconstructed block and the template of the current block.

[0220] At 1406, the current block may be predicted via ITMP using ℒ̅^^୪୪ൌITMPLIC flag ? ℒ̅^^୪୪,୫^୰^^ ∶ ℒ̅^^୪୪,ୠୟ^^, yielding predBlock.

[0221] At 1407, the reconstructed residual block resBlock may be decoded.

[0222] At 1408, following the reconstruction of the current block, e.g., recBlock ൌ predBlock ^resBlock, the decoding of the current block may end.

[0223] FIG.11 illustrates an example of decoding a current block predicted by ITMP if the number and / or types of template-matching metrics involved in the ITMP search are based on an indication, such as an ITMP-LIC flag. The ITMP-flag may be read during the parsing of the syntax of the current block. TheIDVC_ 2023P01112WO PATENT SPS ITMP-LIC flag on may indicate that the combination of ITMP and LIC is allowed in the hybrid block- based video codec.

[0224] FIG.11 may be adapted (e.g., straightforwardly adapted) to the case where the ITMP-LIC flag is off during the decoding of the current block predicted by ITMP. One or more (e.g., multiple) template matching metrics may be used to create one or more (e.g., multiple) lists of positions of reconstructed blocks. The lists may (e.g., each) be sorted, for example, in ascending order of an associated metric value. The lists may be merged into a list (e.g., a final list).

[0225] The number and / or types of template matching metrics may be based on an indication, such as the SPS ITMP-LIC flag. For example, the number of template matching metrics and / or the types of template matching metrics ruling the ITMP search for reconstructed blocks for a given block to be predicted via ITMP may be based on the SPS ITMP-flag.

[0226] FIG.12 shows an example of decoding a current block predicted by ITMP if number and / or types of template matching metrics are based on the SPS ITMP-LIC flag.

[0227] At 1500, a determination may be made whether the SPS ITMP-LIC flag is on. The method may proceed to 1501 to 1508, for example, if the SPS ITMP-LIC flag is on or proceed to 1509 to 1513 if the SPS ITMP-LIC flag is off.

[0228] At 1501, the decoding of the current block predicted by ITMP may begin, e.g., based on the SPS ITMP-LIC flag being on.

[0229] At 1502, the ITMP search may use the template matching metric ℳ^, returning the list ℒ̅୮ୟ୰^,^of positions of reconstructed blocks, which may be sorted in ascending order of ℳ^values. For example, ℳ^may be the MR-SAD between the template of a scanned reconstructed block and the template of the current block.

[0230] At 1503, the ITMP search may use the template matching metric ℳ^, returning the list ℒ̅୮ୟ୰^,^of positions of reconstructed blocks, which may be sorted in ascending order of ℳ^values. For example, ℳ^may be the SATD between the template of a scanned reconstructed block and the template of the current block.

[0231] At 1504, the ITMP search may use the template matching metric ℳ ∗௧ି^, ^^ ∈ ℕ , returning thelist ℒ̅୮ୟ୰^,^ି^of positions of reconstructed blocks, which may be sorted in order of ℳ௧ି^values. For example, ℳ௧ି^may be the MR-SATD between the template of a scanned reconstructed block and the template of the current block.IDVC_ 2023P01112WO PATENT

[0232] At 1505, ℒ̅୮ୟ୰^,^, ℒ̅୮ୟ୰^,^, …, ℒ̅୮ୟ୰^,^ି^may be merged into a final list ℒ̅^^୪୪. In some examples, the merge may concatenate ℒ̅୮ୟ୰^,^, ℒ̅୮ୟ୰^,^, …, ℒ̅୮ୟ୰^,^ି^. In some examples, the merge may interleave positions from ℒ̅୮ୟ୰^,^, positions from ℒ̅୮ୟ୰^,^, …, positions from ℒ̅୮ୟ୰^,^ି^.

[0233] At 1506, the current block may be predicted via ITMP using ℒ̅^^୪୪, yielding predBlock.

[0234] At 1507, the reconstructed residual block resBlock may be decoded.

[0235] At 1508, following the reconstruction of the current block, e.g., recBlock ൌ predBlock ^resBlock, the decoding of the current block may end.

[0236] At 1509, the decoding of the current block predicted by ITMP may begin, e.g., based on the SPS ITMP-LIC flag being off.

[0237] At 1510, the ITMP search may use the template matching metric ℳୠୟ^^, returning the list ℒ̅^^୪୪of positions of reconstructed blocks, which may be sorted in ascending order of ℳୠୟ^^values. For example, ℳୠୟ^^may be the SAD between the template of a scanned reconstructed block and the template of the current block.

[0238] At 1511, the current block may be predicted via ITMP using ℒ̅^^୪୪, yielding predBlock.

[0239] At 1512, the reconstructed residual block resBlock may be decoded.

[0240] At 1513, following the reconstruction of the current block, e.g., recBlock ൌ predBlock ^resBlock, the decoding of the current block may end.

[0241] FIG.12 illustrates an example of decoding a current block predicted by ITMP if the number and / or types of template-matching metrics involved in the ITMP search are based on an indication, such as an SPS ITMP-LIC flag. The SPS ITMP-LIC flag on may indicate that the combination of ITMP and LIC is allowed in the hybrid block-based video codec.

[0242] FIG.12 may be adapted (e.g., straightforwardly adapted) to the case where the SPS ITMP-LIC flag is off. One or more (e.g., multiple) template matching metrics may be used to create one or more (e.g., multiple) lists of positions of reconstructed blocks during the decoding of the current block predicted by ITMP. A (e.g., each) list may be sorted, for example, in ascending order of the associated metric value. The lists may be merged into a final list.

[0243] The foregoing examples may be applied in a variety of scenarios. The applications may be configured to use the example described herein, where a (e.g., single) template matching metric may be based on the ITMP-LIC flag. The applications may be configured to use the example described herein, where the number and / or types of template matching metrics may be based on the ITMP-LIC flag. The applications may be configured to use the example described herein, where the number and / or types ofIDVC_ 2023P01112WO PATENT template matching metrics may be based on the SPS ITMP-LIC flag. The examples described herein may differ from one another in the choices of the template matching metrics for building the list ℒ̅^^୪୪of positions of reconstructed blocks used to predict the current block via ITMP. Accordingly, the applications described herein may be applied (e.g., straightforwardly applied) to the other examples (e.g., the number and / or types of template matching metrics may be based on the ITMP-LIC flag and / or based on the SPS ITMP-LIC flag).

[0244] In some examples, a template matching metric may be computed (e.g., approximatively computed). The approximation may bring speed-ups by sharing computations between an approximate computation of a template matching metric and a (e.g., approximate) computation of another template matching metric.

[0245] FIG.13 shows an example of different approximations of the MR-SAD between the template of a given ^^ ൈ ^^ reconstructed block (1601) and the template of the current ^^ ൈ ^^ block (1600). Thetemplate of (1601) may be decomposed into an above part ^^^,^, a left part ^^^,^, and / or an above-left part ^^^,^^. The template of (1600) may be split into an above part ^^^,^, a left part ^^^,^, and / or an above-left part ^^^,^^. ^^^and ^^^may denote the means of, respectively, the template of (1601) and the template of (1600). ^^^,^, ^^^,^, and ^^^,^^may denote the means of, respectively, ^^^,^, ^^^,^, and ^^^,^^. ^^^,^, ^^^,^, and ^^^,^^ may denote the means of, respectively, ^^^,^, ^^^,^ , and ^^^,^^. ‖ . ‖^ may denote the l1-norm ofits input block, e.g., the sum of the absolute values of its samples. MRSAD^^ୟୡ^may be a computation (e.g., the exact computation) of the MR-SAD between the template of (1601) and the template of (1600). 44recisi, ^^ ∈ ^0,3^, may be four exemplar approximations of MRSAD^^ୟୡ^. In 44recisi, for (1601),(e.g., only two) separate means ^^^,^and ^^^,^may be calculated. For (1600), (e.g., only two) separate means ^^^,^and ^^^,^may be calculated. The MR-SAD between the template of (1601) and the template of (1600) may be computed by parts, the part of the MR-SAD involving ^^^,^^and ^^^,^^reusing the means ^^^,^and ^^^,^.illustrates an example of different approximations of the MR-SAD between the template of a given ^^ൈ^^ reconstructed block and the template of the current ^^ൈ^^ block.

[0247] For example, the template matching metric approximations described in FIG.13 may be adapted (e.g., straightforwardly adapted) to the case where the MR-SAD is replaced by the MR-SATD.

[0248] The examples described herein may be applied to a video coding tool. As described herein, ITMP may be implemented with multiple (e.g., three) types of matchings between the template of a reconstructed block and the template of the current block. Computations may be re-used through the computations of the three types of matchings, for example, using template matching metric approximation.IDVC_ 2023P01112WO PATENT

[0249] FIG.14 shows an example of computations of MRSADୟୠ୭^^,ୟ୮୮୰୭^,^between above portion ofthe template of a given ^^ ൈ ^^ reconstructed block (1701) and the above portion of the template of thecurrent ^^ ൈ ^^ block (1700), MRSAD୪^^^,ୟ୮୮୰୭^,^ between left portion of the template of (1701) and theleft portion of the template of (1700), and MRSADୟ୮୮୰୭^,^between template of (1701) and the template of (1700) in ITMP.

[0250] FIG.14 illustrates an example of computations of an approximate MR-SAD, denoted MRSADୟୠ୭^^,ୟ୮୮୰୭^,^, between above portion of the template of a given reconstructed block (1701) and the above portion of the template of the current block (1700), an approximate MR-SAD, denoted MRSAD୪^^^,ୟ୮୮୰୭^,^, between left portion of the template of (1701) and the left portion of the template of (1700), and an approximate MR-SAD, denoted MRSADୟ୮୮୰୭^,^, be between template of (1701) and the template of (1700), in ITMP.

[0251] A combination of the example described herein (e.g., where a (e.g., single) template matching metric may be based on an indication, such as an ITMP-LIC flag) and approximate computation of template matching metrics may be illustrated in FIG.15. The descriptions from 1800 to 1806 in FIG.15 may be similar to the descriptions from 1300 to 1306 in FIG.10, although in 1802, ℳ^becomes MRSADୟ୮୮୰୭^,^and45recisi803, ℳୠୟ^^becomes SAD.

[0252] FIG.15 illustrates an example of decoding a current block predicted by ITMP using a combination of a (e.g., single) template matching metric based on the ITMP-LIC flag and approximate computation of template matching metrics. As indicated in FIG.15, the SPS ITMP-LIC flag on may indicate that the combination of ITMP and LIC is allowed in the hybrid block-based video codec.

[0253] ITMP-LIC and fusion may be combined.

[0254] In some examples, fusion may be performed via blending.

[0255] For example (e.g., in ITMP-LIC combined with the fusion via blending), (e.g., each of) the ^^ ^ 5selected reconstructed blocks may be transformed via LIC using the parameters learned from the templateof the selected reconstructed block and the template of a given block to be predicted. The ^^ ^ 5 LICtransformed blocks may be blended to generate a prediction (e.g., a final prediction) of the given block to be predicted. The fusion via blending may be implemented, for example, in accordance with Eq. (4): predBlock ൌ ^∑^ି^ ^ୀ^ ^^^ ∗ ^^^^ ∗ refBlock^ ^ ^^^^ ^ 32^ ≫ 6 (4)IDVC_ 2023P01112WO PATENTwhere predBlock may denote the final prediction of the given block to be predicted. For ^^ ∈ ^0,^^ െ 1^,refBlock^ may denote the selected reconstructed block of index ^^. For ^^ ∈ ^0,^^െ 1^, ^^^ and ^^^ maydenote the LIC parameters learned from the template of the selected reconstructed of index ^^ and thetemplate of the given block to be predicted.

[0256] Blending coefficients may be derived from the template matching metric values involved in theITMP search. For example, the blending coefficients ^^^^, ^^^, … , ^^^ି^^ may be derived from the templatematching metric values of the associated selected involved in the blending.

[0257] For example, the one or more examples shown in FIG.10 may be applicable. FIG.10 shows an example of decoding a current block predicted by ITMP where a (e.g., single) template matching metric is based on an indication, such as an ITMP-LIC flag. Continuing with the example, the MR-SAD between the template of a reconstructed block and the template of the current block may be used as a template matching metric during the ITMP search, for example, if the ITMP-LIC flag is on. In the case of thecombination of ITMP-LIC and the fusion via blending, for ^^ ∈ ^0,^^െ 1^, let MRSAD^ denote thetemplate matching MR-SAD associated with refBlock^. The blending coefficient ^^^may be equal to anintegerized form of the normalization ratio MRSAD^⁄ ൫∑^ି^ ^ୀ^ MRSAD^ ൯.

[0258] Blending coefficients may be derived from the template matching metric values involved in theITMP search. For example, the blending coefficients ^^^^, ^^^, … , ^^^ି^^ may be derived from the templatematching metric values of the associated selected reconstructed blocks involved in the blending.

[0259] For example, the one or more examples shown in FIG.10 may be applicable. FIG.10 shows an example of decoding a current block predicted by ITMP where a (e.g., single) template matching metric is based on an indication, such as an ITMP-LIC flag. Continuing with the example, the MR-SAD between the template of a reconstructed block and the template of the current block may be used as a template matching metric during the ITMP search, for example, if the ITMP-LIC flag is on. In the case of thecombination of ITMP-LIC and the fusion via blending, for ^^ ∈ ^0,^^െ 1^, let MRSAD^ denote thetemplate matching MR-SAD associated with refBlock^. The blending coefficient ^^^may be equal to anintegerized form of the normalization ratio MRSAD^⁄ ൫∑^ି^ ^ୀ^ MRSAD^ ൯.

[0260] One or more blending coefficients may be derived. For example, one or more blending coefficients may be derived from the template matching metric applied to an LIC transformed template. The template of a selected reconstructed block (e.g., for one or more (e.g., each of the) ^^ selected reconstructed blocks involved in the blending) may be transformed via LIC, e.g., using the one or more LIC parameters learned from the template of the selected reconstructed block and / or the template of the current block to be predicted. The template matching metric used during the ITMP search may beIDVC_ 2023P01112WO PATENT computed, e.g., between the LIC transformed version of the template of the one or more (e.g., each of) ^^ selected reconstructed blocks and the template of the current block. The blending coefficients may be derived from the ^^ template matching metrics incorporating the LIC transforms.

[0261] In examples, fusion may be performed via filtering.

[0262] For example, in ITMP-LIC combined with the fusion via filtering, the one or more (e.g., each of)^^ ^ 5 selected reconstructed blocks may be transformed via LIC, e.g., using the one or more parameterslearned from the template of the selected reconstructed block and / or the template of a given block to bepredicted. The ^^ ^ 5 LIC transformed blocks may be filtered, e.g., to generate a prediction (e.g., a finalprediction) of the given block to be predicted. The fusion via filtering may be implemented, for example, in accordance with Eq. (5): predBlock ൌ ∑^ି^ ^ୀ^ ^^^ ∗ ^^^^ ∗ refBlock^ ^ ^^^^ ^ ^^^ ∗ midValue (5)where predBlock may denote the prediction (e.g., the final prediction) of the given block to be predicted.For ^^ ∈ ^0,^^ െ 1^, refBlock^ may denote the selected reconstructed block of index ^^. For ^^ ∈^0,^^ െ 1^. ^^^ and ^^^ may denote the LIC parameters learned from the template of the selectedindex ^^ and the template of the given block to be predicted.

[0263] Filter coefficients ^^^ , ^^ ∈ ^0,^^^ may be learned, for example, by minimizing the Mean SquaredError (MSE) between the filtered version of ^^ LIC transformed templates of the ^^ selected reconstructed blocks and the template of the current block. For example, the collection of the one or more training examples and / or the one or more learning of the filter coefficients may be configured as illustrated in FIG. 11. In addition to and / or alternative to the collection of the one or more training examples and / or the one or more learning of the filter coefficients configured as illustrated in FIG.11, before the collection of the training examples, for one or more (e.g., each of the) selected reconstructed blocks, the template may be transformed via LIC, e.g., using the one or more LIC parameters learned from the template of the selected reconstructed block and / or the template of the current block.

[0264] In examples, ITMP fusion mode may be combined with ITMP-LIC prediction mode and / or fusion may be combined with the filtering process used in ITMP, described herein.

[0265] In examples described herein, a differentiated IntraTMP search space may be employed for an ITMP mode example (e.g., a regular ITMP mode example) and / or for the ITMP-LIC flag. At encoder side, the use of ITMP-LIC prediction mode, e.g., in addition to the regular ITMP mode, may imply that the encoder may be configured to perform one or more (e.g., multiple) types of IntraTMP search processes, e.g., to select the ITMP prediction mode (e.g., the best ITMP prediction) mode between the regular ITMPIDVC_ 2023P01112WO PATENT and ITMP-LIC modes. Such configuration may multiply the number of IntraTMP searches by the number of different metrics used to determine ITMP-LIC prediction blocks.

[0266] The ITMP search space may be specialized for the ITMP-LIC mode and be made different from the search space used for the regular ITMP prediction block search. The specialization of the ITMP search space may take one or more (e.g., all or part) of the following forms.

[0267] The regular ITMP search may be configured (e.g., assumed) to include a sparse search pass (e.g., a first sparse search pass), followed by a block vector refinement pass, as illustrated in FIG.15 (e.g., 1802).

[0268] The sparse search may be configured in a different way for ITMP-LIC prediction, e.g., compared to regular ITMP. For example, the number ^^^^୪୪of elements may be kept in order in MRSAD ascending order that may differ from the number of elements issued from the sparse search of the regular ITMP mode.

[0269] The size of elements ^^^obtained in MRSAD based search, e.g., based on left-template matching procedure, may also be different between ITMP-LIC and regular ITMP modes.

[0270] The size of elements ^^^obtained in MRSAD based search, e.g., based on above-template matching procedure, may also be different between ITMP-LIC and regular ITMP modes.

[0271] The sparse search process, e.g., dedicated to the ITMP-LIC prediction mode, may consider a set of candidate positions different from the set of positions considered during the sparse search stage of the regular ITMP prediction mode. A coarser search may take place for ITMP-LIC mode. For example, a subset of positions considered during regular ITMP sparse search may be considered, e.g., during the sparse search for ITMP-LIC prediction mode.

[0272] During the refinement process, amount (e.g., specific amount) of positions evaluated during the refinement process, e.g., dedicated to the ITMP-LIC, may be considered during the refinement process for ITMP-LIC mode, e.g., compared to regular ITMP mode.

[0273] In examples, refinement may be skipped (e.g., no refinement may take place) during the ITMP search process, e.g., dedicated to the ITMP-LIC mode and / or during an ITMP search process, e.g., that is different from the regular ITMP search process.

[0274] For a current coding block (e.g., CU), the signaling of ITMP may be adapted such that the combination of ITMP, LIC, and / or fusion is allowed. For example, for the current CU, if the combination of ITMP, LIC, and / or fusion is allowed and one or more (e.g., multiple) linear models are not (e.g., cannot be) combined with fusion, the signaling of ITMP may be as illustrated in Table 3. For example, the DIMD flag may be (e.g., may assumed to be) false.IDVC_ 2023P01112WO PATENT Table 3 - Example of signaling ITMP combined with LIC, where the combination ITMP, LIC, and fusion is allowed but the combination of one or more (e.g., multiple) linear models and fusion is not allowed. … intra_tmp_flag if (intra_tmp_flag) { intra_tmp_fusion_flag if (intra_tmp_fusion_flag) { intra_tmp_fusion_idx intra_tmp_lic_flag } else { intra_tmp_idx intra_tmp_filter_flag if (!intra_tmp_filter_flag) { intra_tmp_lic_flag if (intra_tmp_lic_flag && isItmpLicExtension) { intra_tmp_lic_index } if (!intra_tmp_lic_flag) { intra_tmp_sub_pel_precision_idx if (intra_tmp_sub_pel_precision_idx != 0) { intra_tmp_sub_pel_direction_idx } } } } } …

[0275] In examples, for the current CU, if the combination of ITMP, LIC, and / or fusion is allowed, but one or more (e.g., multiple) linear models are not (e.g., cannot be) combined with fusion, the signaling of ITMP may be as illustrated in Table 4. The DIMD flag may be (e.g., may assumed to be) false.IDVC_ 2023P01112WO PATENT Table 4 – Example of signaling ITMP combined with LIC, where the combination ITMP, LIC, and / or fusion is allowed but the combination of one or more (e.g., multiple) linear models and fusion is not allowed. … intra_tmp_flag if (intra_tmp_flag) { intra_tmp_fusion_flag if (intra_tmp_fusion_flag) { intra_tmp_lic_flag intra_tmp_fusion_idx } else { intra_tmp_idx intra_tmp_filter_flag if (!intra_tmp_filter_flag) { intra_tmp_lic_flag if (intra_tmp_lic_flag && isItmpLicExtension) { intra_tmp_lic_index } if (!intra_tmp_lic_flag) { intra_tmp_sub_pel_precision_idx if (intra_tmp_sub_pel_precision_idx != 0) { intra_tmp_sub_pel_direction_idx } } } } } …

[0276] As examples, for the current CU, if the combination of ITMP, LIC, and / or fusion is allowed, and one or more (e.g., multiple) linear models may be (e.g., can be) combined with fusion, the signaling of ITMP may be as illustrated in Table 5. The DIMD flag may be (e.g., may assumed to be) false,IDVC_ 2023P01112WO PATENT Table 5 – Example of signaling ITMP combined with LIC, where the combination ITMP, LIC, and / or fusion is allowed, and the combination of one or more (e.g., multiple) linear models and fusion is allowed. … intra_tmp_flag if (intra_tmp_flag) { intra_tmp_fusion_flag if (intra_tmp_fusion_flag) { intra_tmp_fusion_idx intra_tmp_lic_flag if (intra_tmp_lic_flag && isItmpLicExtension) { intra_tmp_lic_index } } else { intra_tmp_idx intra_tmp_filter_flag if (!intra_tmp_filter_flag) { intra_tmp_lic_flag if (intra_tmp_lic_flag && isItmpLicExtension) { intra_tmp_lic_index } if (!intra_tmp_lic_flag) { intra_tmp_sub_pel_precision_idx if (intra_tmp_sub_pel_precision_idx != 0) { intra_tmp_sub_pel_direction_idx } } } } } …IDVC_ 2023P01112WO PATENT

[0277] The intra_tmp_lic_flag, illustrated in Tables 3, 4, and / or 5, may share the same Context Binary Arithmetic Coding (CABAC) context index. In examples, the intra_tmp_lic_flag, illustrated in Tables 3, 4, and / or 5, may have different CABAC context indices.

[0278] A combination of the one or more examples described herein (e.g., where a (e.g., single) template matching metric may be based on an indication, such as an ITMP-LIC flag) and a combination of ITMP-LIC and fusion may be illustrated in FIGs.16A-B.

[0279] FIGs.16A-B illustrate an example of decoding a current block predicted by ITMP where a (e.g., single) template matching metric may be based on an indication, such as an ITMP-LIC flag and where ITMP-LIC and fusion may be combined. In FIGs.16A-B, symbol (*) may create a connection between the two parts of FIGs.16A-B. Similarly, symbols (**), (***), (****), and / or (*****) may create a corresponding connection between the two parts of FIGs.16A-B.

[0280] As illustrated in FIG.16A, at 1900, decoding of the current block predicted by ITMP may begin.

[0281] As illustrated in FIG.16A, at 1901, a determination may be made whether the ITMP-LIC flag read during the parsing of the syntax of the current block is on. The method may proceed to 1902 if the ITMP- LIC flag is on or to 1912 if the ITMP-LIC flag is off.

[0282] As illustrated in FIG.16A, at 1902, the ITMP search may use the template matching metric MR- SAD, e.g., returning the list ℒ̅^^୪୪,^of positions of reconstructed blocks, which may be sorted in ascending order of MR-SAD values.

[0283] As illustrated in FIG.16A, at 1903, a determination may be made whether the ITMP-FUSION flag read during the parsing of the syntax of the current block is on. The method may proceed to 1904 if the ITMP-FUSION flag is on or to 1910 if the ITMP-FUSION flag is off.

[0284] As illustrated in FIG.16A, at 1904, the LIC parameters ^^^^^,^^^^^^∈^^,^ି^^may be learned for the ^^ reconstructed blocks, e.g., having positions of starting from indexintra_tmp_fusion_idx ^ 2 ? 5 ∗ intra_tmp_fusion_idx : 5 ∗ (3 - intra_tmp_f–sion_idx), using the templateof a selected reconstructed block and the template of the current block to be predicted.intra_tmp_fusion_idx ^ 2 may indicate that fusion via blending is used. intra_tmp_fusion_idx ^ 2 mayindicate that fusion via filtering is used.

[0285] As illustrated in FIG.16A, at 1905, a determination may be made whether intra_tmp_fusion_idx read during the parsing of the syntax of the current block is smaller than 2. The method may proceed to 1906 if intra_tmp_fusion_idx is smaller than 2 or to 1907 if intra_tmp_fusion_idx is strictly larger than 2.IDVC_ 2023P01112WO PATENT

[0286] As illustrated in FIG.16A, at 1906, the blending coefficients ^^^^^^∈^^,^ି^^may be derived from the MR-SAD between the LIC transformed template of each of the ^^ reconstructed blocks and the template of the current block to be predicted.

[0287] As illustrated in FIG.16A, at 1907, the filtering coefficients ^^^^^^∈^^,^ି^^may be learned by extracting training examples from the LIC transformed template of each of the ^^ reconstructed blocks and the template of the current block to be predicted.

[0288] As illustrated in FIG.16B, at 1908, for ^^ ∈ ^0,^^ െ 1^, the LIC transform of parameters ^^^^ ,^^^^may be applied to the selected reconstructed block of index ^^. The ^^ resulting LIC transformed blocks may be blended with one or more blending coefficients ^^^^^^∈^^,^ି^^, e.g., to generate a prediction predBlock of the current block, as described herein.

[0289] As illustrated in FIG.16B, at 1909, for ^^ ∈ ^0,^^ െ 1^, the LIC transform of parameters ^^^^ ,^^^^may be applied to the selected reconstructed block of index ^^. The ^^ resulting LIC transformed blocks may be filtered with filtering coefficients ^^^^^^∈^^,^ି^^, e.g., to generate a prediction predBlock of the current block.

[0290] As illustrated in FIG.16A, at 1910, the LIC parameters ^^^,^^^ may be learned for the reconstructed block having position of index intra_tmp_idx in ℒ̅^^୪୪,^, e.g., using the template of this reconstructed block and the template of the current block.

[0291] As illustrated in FIG.16A, at 1911, the LIC transform of parameters ^^^,^^^ may be applied to the (e.g., copy of the) reconstructed block having position intra_tmp_idx in ℒ̅^^୪୪,^, e.g., yielding a prediction predBlock of the current block.

[0292] As illustrated in FIG.16A, at 1912, the ITMP search may use the template matching metric SAD, returning the list ℒ̅^^୪୪,ୠୟ^^of positions of reconstructed blocks, e.g., which may be sorted in ascending order of SAD values.

[0293] As illustrated in FIG.16A, at 1913, the current block may be predicted via ITMP using ℒ̅^^୪୪. Depending on the ITMP-FUSION flag read during the parsing of the syntax of the current block, fusion may be used for this prediction.

[0294] As illustrated in FIG.16B, at 1914, the reconstructed residual block resBlock may be decoded.

[0295] As illustrated in FIG.16B, at 1915, following the reconstruction of the current block, e.g.,recBlock ൌ predBlock ^ resBlock, the decoding of the current block may end.

[0296] ITMP-LIC and sub-pel may be combined.IDVC_ 2023P01112WO PATENT

[0297] For example, for a given block to be predicted, the selected reconstructed block may be transformed via LIC, e.g., using one or more parameters learned from the template of the selected reconstructed block and / or the template of the given block. Sub-pel filtering may be applied to the resulting LIC transformed block, e.g., yielding a prediction of this given block.

[0298] For the current CU, the signaling of ITMP may be adapted such that the combination of ITMP, LIC, and / or sub-pel is allowed. In examples, for the current CU, if the combination of ITMP, LIC, and / or sub-pel is allowed and multiple linear models are incapable of being combined with sub-pel, the signaling of ITMP may be as illustrated in Table 6. For example, the DIMD flag may be false, e.g., may assumed to be false. Table 6 – Example of signaling ITMP combined with LIC, where the combination ITMP, LIC, and / or sub-pel is allowed but the combination of multiple linear models and sub-pel is not allowed. … intra_tmp_flag if (intra_tmp_flag) { intra_tmp_fusion_flag if (intra_tmp_fusion_flag) { intra_tmp_fusion_idx } else { intra_tmp_idx intra_tmp_filter_flag if (!intra_tmp_filter_flag) { intra_tmp_lic_flag intra_tmp_sub_pel_precision_idx if (intra_tmp_sub_pel_precision_idx != 0) { intra_tmp_sub_pel_direction_idx } if (intra_tmp_lic_flag && isItmpLicExtension && intra_tmp_sub_pel_precision_idx == 0) { intra_tmp_lic_index } }IDVC_ 2023P01112WO PATENT } } …

[0299] In examples, for the current CU, if the combination of ITMP, LIC, and / or sub-pel is allowed, but multiple linear models are incapable of being combined with sub-pel, the signaling of ITMP may be as illustrated in Table 7. For example, the DIMD flag may be false, e.g., may assumed to be false. Table 7 – Example of signaling ITMP combined with LIC, where the combination ITMP, LIC, and / or sub-pel is allowed but the combination of multiple linear models and sub-pel is not allowed. … intra_tmp_flag if (intra_tmp_flag) { intra_tmp_fusion_flag if (intra_tmp_fusion_flag) { intra_tmp_fusion_idx } else { intra_tmp_idx intra_tmp_filter_flag if (!intra_tmp_filter_flag) { intra_tmp_sub_pel_precision_idx if (intra_tmp_sub_pel_precision_idx != 0) { intra_tmp_sub_pel_direction_idx } intra_tmp_lic_flag if (intra_tmp_lic_flag && isItmpLicExtension && intra_tmp_sub_pel_precision_idx == 0) { intra_tmp_lic_index } } } }IDVC_ 2023P01112WO PATENT …

[0300] In examples, for the current CU, if the combination of ITMP, LIC, and / or sub-pel is allowed and multiple linear models may be combined with sub-pel, the signaling of ITMP may be as illustrated in Table 8. For example, the DIMD flag may be false, e.g., may assumed to be false. Table 8 – Example of signaling ITMP combined with LIC, where the combination ITMP, LIC, and / or sub-pel is allowed and the combination of multiple linear models and sub-pel is allowed. … intra_tmp_flag if (intra_tmp_flag) { intra_tmp_fusion_flag if (intra_tmp_fusion_flag) { intra_tmp_fusion_idx } else { intra_tmp_idx intra_tmp_filter_flag if (!intra_tmp_filter_flag) { intra_tmp_sub_pel_precision_idx if (intra_tmp_sub_pel_precision_idx != 0) { intra_tmp_sub_pel_direction_idx } intra_tmp_lic_flag if (intra_tmp_lic_flag && isItmpLicExtension) { intra_tmp_lic_index } } } } …IDVC_ 2023P01112WO PATENT

[0301] A combination of the example described herein (e.g., where a (e.g., single) template matching metric may be based on an indication, such as an ITMP-LIC flag) and a combination of ITMP-LIC and sub- pel may be illustrated in FIGs.17A-B.

[0302] FIGs.17A-B illustrate an example of decoding a current block predicted by ITMP if the combination between ITMP-LIC and sub-pel is allowed. For example, FIGs.17A-B show an example of decoding a current block predicted by ITMP where a (e.g., single) template matching metric may be based on an indication, such as an ITMP-LIC flag and where ITMP-LIC and sub-pel may be combined. In FIGs. 17A-B, symbol (*) may create a connection between the two parts of FIGs.17A-B. Similarly, symbol (**) may create a connection between the two parts of FIGs.17A-B.

[0303] As illustrated in FIG.17A, at 2000, decoding of the current block predicted by ITMP may begin.

[0304] As illustrated in FIG.17A, at 2001, a determination may be made whether an ITMP-LIC indication, such as an ITMP-LIC flag, read during the parsing of the syntax of the current block is on. The method may proceed to 2002 if the ITMP-LIC flag is on or to 2007 if the ITMP-LIC flag is off.

[0305] As illustrated in FIG.17A, at 2002, the ITMP search may use the template matching metric MR- SAD, returning the list ℒ̅^^୪୪,^of positions of reconstructed blocks, which may be sorted in ascending order of MR-SAD values.

[0306] As illustrated in FIG.17A, at 2003, the LIC parameters^^^,^^^may be learned for the reconstructed block having position of index intra_tmp_idx in ℒ̅^^୪୪,^, using the template of this reconstructed block and the template of the current block to be predicted.

[0307] As illustrated in FIG.17A, at 2004, the LIC transform of parameters ^^^,^^^ may be applied to the (e.g., copy of the) reconstructed block having position intra_tmp_idx in ℒ̅^^୪୪,^, yielding licTrBlock.

[0308] As illustrated in FIG.17A, at 2005, a determination may be made whether intra_tmp_sub_pel_precision_idx is not equal to 0, e.g., by reading a flag during the parsing of the syntax of the current block. The method may proceed to 2006 if intra_tmp_sub_pel_precision_idx is not equal to 0. If intra_tmp_sub_pel_precision_idx is equal to 0, 2006 may be skipped and a prediction ofthe current block may be predBlock ൌ licTrBlock.

[0309] As illustrated in FIG.17A, at 2006, the sub-pel filtering defined by intra_tmp_sub_pel_precision_idx and intra_tmp_sub_pel_direction_idx read during the parsing of the syntax of the current block may be applied to licTrBlock, yielding a prediction predBlock of the current block.IDVC_ 2023P01112WO PATENT

[0310] As illustrated in FIG.17A, at 2007, the ITMP search may use the template matching metric SAD, returning the list ℒ̅^^୪୪,ୠୟ^^of positions of reconstructed blocks, which may be sorted in ascending order of SAD values.

[0311] As illustrated in FIG.17A, at 2008, the current block may be predicted via ITMP using ℒ̅^^୪୪. Depending on whether intra_tmp_sub_pel_precision_idx is not equal to 0, e.g., by reading a flag during the parsing of the syntax of the current block, sub-pel may be used for this prediction.

[0312] As illustrated in FIG.17B, at 2009, the reconstructed residual block resBlock may be decoded.

[0313] As illustrated in FIG.17B, at 2010, following the reconstruction of the current block, e.g.,recBlock ൌ predBlock ^ resBlock, the decoding of the current block may end.

[0314] Given the examples of combinations of ITMP-LIC and fusion and the examples of combinations of ITMP-LIC and sub-pel described herein, ITMP-LIC, fusion, and sub-pel may be combined (e.g., straightforwardly combined).

[0315] For the current CU, the signaling of ITMP may be adapted such that the combination of ITMP, LIC, fusion, and sub-pel is allowed. For instance, for the current CU, if the combination of ITMP, LIC, fusion, and sub-pel is allowed, but multiple linear models can be combined with neither fusion nor sub-pel, the signaling of ITMP may be as illustrated in Table 9. For example, the DIMD flag may be false, e.g., may be assumed to be false. Table 9 – Example of signaling ITMP combined with LIC, where the combination ITMP, LIC, fusion, and sub-pel is allowed but multiple linear models can be combined with neither fusion nor sub-pel. … intra_tmp_flag if (intra_tmp_flag) { intra_tmp_fusion_flag if (intra_tmp_fusion_flag) { intra_tmp_fusion_idx intra_tmp_lic_flag } else { intra_tmp_idx intra_tmp_filter_flag if (!intra_tmp_filter_flag) { intra_tmp_lic_flagIDVC_ 2023P01112WO PATENT intra_tmp_sub_pel_precision_idx if (intra_tmp_sub_pel_precision_idx != 0) { intra_tmp_sub_pel_direction_idx } else { if (intra_tmp_lic_flag && isItmpLicExtension) { intra_tmp_lic_index } } } } } …

[0316] In examples, the two syntax elements shown intra_tmp_lic_flag in Table 9 may share the same Context Binary Arithmetic Coding (CABAC) context index. In examples, the two shown intra_tmp_lic_flag in Table 9 may have different CABAC context indices.

[0317] A combination of the example described herein (e.g., where a (e.g., single) template matching metric may be based on an indication, such as an ITMP-LIC flag) and a combination of ITMP-LIC, fusion, and sub-pel may be illustrated in FIGs.18A-B.

[0318] FIGs.18A-B illustrate an example of decoding a current block predicted by ITMP if the combination between ITMP-LIC, fusion, and sub-pel is allowed. For example, FIGs.18A-B illustrate an example of decoding a current block predicted by ITMP where a (e.g., single) template matching metric may be based on an indication, such as an ITMP-LIC flag and where ITMP-LIC, fusion, and sub-pel may be combined. In FIGs.18A-B, symbol (*) may create a connection between the two parts of FIGs.18A-B. Similarly, symbols (**), (***), (****), and / or (*****) may create connections between the two parts of FIGs. 18A-B. FIGs.18A-B may be constructed by adding the portion shown in dotted box in FIG.18A to FIGs. 16A-B.

[0319] The use of LIC during the prediction of a current block to be predicted may be determined. For example, the use of LIC during the prediction of a current block to be predicted may be determined by comparing a first template matching metric between a template of a selected reconstructed block and a template of the current block and a second template matching metric between a template of the selected reconstructed block and a template of the current block.IDVC_ 2023P01112WO PATENT

[0320] In examples, a template matching metric may be computed. For example, at the decoder side, a first template matching metric ℳୠୟ^^between a template of a selected reconstructed block and a template of the current block may be computed. A second template matching metric ℳ^between a template of a selected reconstructed block and a template of the current block may be computed. An indication isLicUsed may be based on ℳୠୟ^^and ℳ^. The indication, such as the isLicUsed being true (e.g., 1) may mean that LIC applies to the selected reconstructed block. The indication, such as the isLicUsed, being false (e.g., 0) may mean that LIC may be skipped (e.g., does not apply) to the selected reconstructedblock. In examples, an indication, such as a isLicUsed, may be configured as isLicUsed ൌ ℳ^ ^^^ℳୠୟ^^. In examples, ^^ may be configured as ^^ ൌ 2. In examples, ^^ may be configured as ^^ ൌ 3. Inexamples, an indication, such as a isLicUsed, may be configured as isLicUsed ൌ ℳ^ ^൫^^^ℳୠୟ^^^ ≫ ^^൯. In examples, ^^ and ^^ may be configured as ^^ ൌ 5 and ^^ ൌ 2. In examples, ^^ and ^^may be configured as ^^ ൌ 7 and ^^ ൌ 3. In examples, an indication, such as a isLicUsed, may beconfigured as isLicUsed ൌ ℳ^ ^ ^^ℳୠୟ^^. In examples, ^^ may be configured as ^^ ൌ 4. In examples, ^^may be configured as ^^ ൌ 7. In examples, an indication, such as a isLicUsed, may be configured asisLicUsed ൌ ℳ^ ^ ൫^^^ℳୠୟ^^^ ≫ ^^൯. In examples, ^^ and ^^ may be configured as ^^ ൌ 24 and ^^ ൌ4. In examples, an indication, such as isLicUsed ൌ ൫^^^ℳ^ ^ ^^^ ≫ ^^൯ ^ ൫^^^ℳୠୟ^^ ^ ^^^ ≫ ^^൯. Inexamples, ^^, ^^, ^^, ^^, ^^, ^^^^^^ ^^ may beൌ 4, ^^ ൌ 18, ^^ ൌ 0,^^ ൌ 2.In examples, ^^, ^^, ^^, ^^, ^^, ^^^^^^ ^^ may be configured as ^^ ൌ 17,^^ ൌ 7, ^^ ൌ 6, ^^ ൌ 11, ^^ ൌ 3,^^ ൌ0.

[0321] FIG.19 illustrates an example of decoding a current block predicted by ITMP, e.g., where the use of LIC during the prediction of the current block via ITMP may be determined by comparing template matching metrics (e.g., comparing between two template matching metrics). For example, a first template matching metric may be compared between a template of a selected reconstructed block and a template of the current block. And a second template matching metric may be compared between a template of the selected reconstructed block and a template of the current block.

[0322] As illustrated in FIG.19, at 2100, decoding of the current block predicted by ITMP may begin.

[0323] At 2101, the ITMP search may use the template matching metric ℳୠୟ^^, returning the list ℒ̅^^୪୪,ୠୟ^^of positions of reconstructed blocks, which may be sorted in ascending order of ℳୠୟ^^values.This may also return the associated template matching metrics ^ℳୠୟ^^,^^^∈^^,^ି^^ in which, for ^^ ∈^0,^^ െ 1^, ℳୠୟ^^,^ may be the value of ℳୠୟ^^ between the template of the reconstructed block ofposition of index ^^ in ℒ̅^^୪୪,ୠୟ^^and the template of the current block. For example, ℳୠୟ^^may be the SADIDVC_ 2023P01112WO PATENT between the template of a scanned reconstructed block and the template of the current block. For example,^^ ൌ 19.

[0324] At 2102, the template matching metric ℳ^, ୧୬^୰ୟ_^୫୮_୧^^between the template of the reconstructed block of position of index ^^^^^^^^^^_^^^^^^_^^^^^^ in ℒ̅^^୪୪,ୠୟ^^and the template of the current block may be computed. For example, ^^^^^^^^^^_^^^^^^_^^^^^^ may refer to the index of the position of the selected reconstructed block in ℒ̅^^୪୪,ୠୟ^^read during the parsing of the syntax of the current block. For example, ℳ^may be the MR-SAD between the template of a scanned reconstructed block and the template of the current block.

[0325] At 2103, the value isLicUsedintra_tmp_idxof isLicUsed for the selected reconstructed block of position of index ^^^^^^^^^^_^^^^^^_^^^^^^ in ℒ̅^^୪୪,ୠୟ^^may be defined as isLicUsedintra_tmp_idxൌℳ^,intra_tmp_idx ^ ^^ℳୠୟ^^,intra_tmp_idx. For instance, ^^ ൌ 2. In examples, ^^ ൌ 5.

[0326] At 2104, a determination may be made whether isLicUsedintra_tmp_idxis true. The method may proceed to 2105 to 2106, for example, if isLicUsedintra_tmp_idxis true or proceed to 2107 if isLicUsedintra_tmp_idxis false.

[0327] At 2105, the LIC parameters^^^,^^^may be learned for the reconstructed block having position of index intra_tmp_idx in ℒ̅^^୪୪,ୠୟ^^, e.g., using the template of this reconstructed block and the template of the current block to be predicted.

[0328] At 2106, the LIC transform of parameters ^^^,^^^ may be applied to the (e.g., copy of the) reconstructed block having position of index intra_tmp_idx in ℒ̅^^୪୪,ୠୟ^^, e.g., yielding a prediction predBlock of the current block.

[0329] At 2107, predBlock may be the (e.g., copy of the) reconstructed block of position of index intra_tmp_idx in ℒ̅^^୪୪,ୠୟ^^.

[0330] At 2108, the reconstructed residual block resBlock may be decoded.

[0331] At 2109, following the reconstruction of the current block, e.g., recBlock ൌ predBlock ^resBlock, the decoding of the current block may end.

[0332] The use of LIC during the prediction of a current block determined. For example, the use of LIC during the prediction of a current block may be determined by comparing one or more template matching metrics. A first template matching metric may be compared between a template of a selected reconstructed block and a template of the current block. A second template matching metric may be compared between a template of the selected reconstructed block and a template of the current block. The first templateIDVC_ 2023P01112WO PATENT matching metric and the second template matching metric may be combined (e.g., straightforwardly combined) with fusion.

[0333] For example, at the decoder side, for the current block to be predicted, if fusion applies, the one or more processes described herein may apply to a reconstructed block involved in the prediction of the current block via fusion. A first template matching metric ℳୠୟ^^between a template of the selected reconstructed block involved in the prediction via fusion and a template of the current block may be computed. A second template matching metric ℳ^between a template of the selected reconstructed block involved in the prediction via fusion and a template of the current block may be computed. An indication, such as isLicUsed, may be based on ℳୠୟ^^and ℳ^. The indication isLicUsed being true (e.g., 1) may mean that LIC applies to the selected reconstructed block involved in the prediction via fusion. The indication isLicUsed being false (e.g., 0) may mean that LIC may be skipped (e.g., does not apply) to the selected reconstructed block involved in the prediction via fusion.

[0334] The use of LIC during the prediction of a current block determined. For example, the use of LIC during the prediction of a current block may be determined by comparing one or more template matching metrics. A first template matching metric may be compared between a template of a selected reconstructed block and a template of the current block. A second template matching metric may be compared between a template of the selected reconstructed block and a template of the current block. The first template matching metric and the second template matching metric may be combined (e.g., straightforwardly combined) with the sub-pel precision filtering.

[0335] For example, at the decoder side, a first template matching metric ℳୠୟ^^between a template of a selected reconstructed block and a template of the current block may be computed. A second template matching metric ℳ^between a template of a selected reconstructed block and a template of the current block may be computed. An indication, such as isLicUsed, may be based on ℳୠୟ^^and / or ℳ^. The indication isLicUsed being true (e.g., 1) may mean that LIC applies to the selected reconstructed block. The indication isLicUsed being false (e.g., 0) may mean that LIC may be skipped (e.g., does not apply) to the selected reconstructed block. If intra_tmp_sub_pel_precision_idx read during the parsing of the syntax of the current block is not equal to 0 (e.g., 1), the sub-pel precision filtering may apply to the potentially LIC transformed version of the selected reconstructed block, yielding the final prediction of the current block. If intra_tmp_sub_pel_precision_idx read during the parsing of the syntax of the current block is equal to 0, the potentially LIC transformed version of the selected reconstructed block may correspond to the final prediction of the current block.

[0336] FIGs.20A-B illustrate an example of decoding a current block predicted by ITMP where the use of LIC, e.g., during the prediction of the current block via ITMP, is determined by comparing between twoIDVC_ 2023P01112WO PATENT template matching metrics (e.g., a first template matching metric between a template of a selected reconstructed block and a template of the current block and a second template matching between a template of the selected reconstructed block and a template of the current block). The ITMP-LIC may be combined with the sub-pel precision filtering (e.g., if the sub-pel is allowed). In FIGs.20A-B, symbol (*) may create a connection between the two parts of FIGs.20A-B.

[0337] As illustrated in FIG.20A, at 2200, decoding of the current block predicted by ITMP may begin.

[0338] As illustrated in FIG.20A, at 2201, the ITMP search may use the template matching metric ℳୠୟ^^, returning the list ℒ̅^^୪୪,ୠୟ^^of positions of reconstructed blocks, which may be sorted in ascending order of ℳୠୟ^^values. This may also return the associated template matching metrics ^ℳୠୟ^^,^^^∈^^,^ି^^in which, for ^^ ∈ ^0,^^ െ 1^, ℳୠୟ^^,^ may be the value of ℳୠୟ^^ between the template of thereconstructed block of position of index ^^ in ℒ̅^^୪୪,ୠୟ^^and the template of the current block. In examples, ℳୠୟ^^may be the SATD between the template of a scanned reconstructed block and the template of the current block. In examples, ℳୠୟ^^may be the SAD between the template of a scanned reconstructed block and the template of the current block. For example, ^^ ൌ 19. In examples, ^^ ൌ 21.

[0339] As illustrated in FIG.20A, at2202, the template matching metric ℳ^, ୧୬^୰ୟ_^୫୮_୧^^between the template of the reconstructed block of position of index ^^^^^^^^^^_^^^^^^_^^^^^^ in ℒ̅^^୪୪,ୠୟ^^and the template of the current block may be computed. For example, ^^^^^^^^^^_^^^^^^_^^^^^^ may refer to the index of the position of the selected reconstructed block in ℒ̅^^୪୪,ୠୟ^^read during the parsing of the syntax of the current block. For example, ℳ^may be the MR-SAD between the template of a scanned reconstructed block and the template of the current block.

[0340] As illustrated in FIG.20A, at 2203, the value isLicUsedintra_tmp_idxof isLicUsed for the selected reconstructed block of position of index ^^^^^^^^^^_^^^^^^_^^^^^^ in ℒ̅^^୪୪,ୠୟ^^may be defined as isLicUsedintra_tmp_idx ൌ ℳ^,intra_tmp_idx ^ ^^ℳୠୟ^^,intra_tmp_idx. For instance, ^^ ൌ 2. In examples, ^^ ൌ 5.made whether isLicUsedintra_tmp_idxis true. The method may proceed to 2205, for example, if isLicUsedintra_tmp_idxis true or proceed to 2207 if isLicUsedintra_tmp_idxis false.

[0342] As illustrated in FIG.20A, at 2205, the LIC parameters ^^^,^^^ may be learned for the reconstructed block having position of index intra_tmp_idx in ℒ̅^^୪୪,ୠୟ^^, e.g., using the template of this reconstructed block and the template of the current block to be predicted.

[0343] One or more processes 2202, 2203, 2204, 2205 may be described the same way as processes 2102, 2103, 2104, and 2105 illustrated in FIG.19.IDVC_ 2023P01112WO PATENT

[0344] As illustrated in FIG.20A, at 2206, the LIC transform of parameters ^^^,^^^ may be applied to the (e.g., copy of the) reconstructed block having position of index intra_tmp_idx in ℒ̅^^୪୪,ୠୟ^^, e.g., yielding intBlock.

[0345] As illustrated in FIG.20A, at 2207, intBlock may be the (e.g.0 copy of the) reconstructed block of position of index intra_tmp_idx in ℒ̅^^୪୪,ୠୟ^^.

[0346] As illustrated in FIG.20B, at 2208, a determination may be made whether intra_tmp_sub_pel_precision_idx is not equal to 0 (e.g., 1), e.g., by reading an indication, such as a flag, during the parsing of the syntax of the current block. The method may proceed to 2209 if intra_tmp_sub_pel_precision_idx is not equal to 0 (e.g., 1). If intra_tmp_sub_pel_precision_idx isequal to 0, 2209 may be skipped and a prediction of the current block may be predBlock ൌ intBlock.

[0347] As illustrated in FIG.20B, at 2209, the sub-pel filtering defined by intra_tmp_sub_pel_precision_idx and intra_tmp_sub_pel_direction_idx, e.g., read during the parsing of the syntax of the current block, may be applied to intBlock, yielding a prediction predBlock of the current block.

[0348] As illustrated in FIG.20B, at 2210, the reconstructed residual block resBlock may be decoded.

[0349] As illustrated in FIG.20B, at 2211, following the reconstruction of the current block, e.g.,recBlock ൌ predBlock ^ resBlock, the decoding of the current block may end.

[0350] One or more processes illustrated in FIGs.10-20B (e.g., involving dedicated template matching metrics for ITMP-LIC) may be straightforwardly applied to dedicated template matching metrics for IBC-LIC. For example, FIG.10 illustrating an example of decoding a current block predicted by ITMP where a (e.g., single) template matching metric is based on an indication, such as an ITMP-LIC flag, may be applied (e.g., straightforwardly applied) to an example of decoding a current block predicted by IBC where a (e.g., single) template matching metric is based on an indication, such as an IBC-LIC flag.

[0351] Although features and elements are described above in particular combinations, one of ordinary skilled in the art will appreciate that each feature or element can be used alone or in any combination with the other features and elements. In addition, the methods described herein may be implemented in a computer program, software, or firmware incorporated in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted over wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, a read only memory (ROM), a random access memory (RAM), a register, 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 disks, and digitalIDVC_ 2023P01112WO PATENT versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

IDVC_ 2023P01112WO PATENT Claims 1. A video decoding device comprising: a processor configured to: determine that an intra template matching prediction (ITMP) local illumination compensation (LIC) is enabled for a first block; based on the determination that the ITMP-LIC is enabled for the first block, perform a first ITMP search using a first template matching metric; decode the first block based on the first ITMP search; determine that the ITMP-LIC is disabled for a second block; based on the determination that the ITMP-LIC is disabled for the second block, perform a second ITMP search using a second template matching metric; and decode the second block based on the second ITMP search.

2. The video decoding device of claim 1, wherein the first template matching metric is associated with a mean removed (MR) sum of absolute difference (SAD) between a first template of a scanned reconstructed block and a template of the first block and the second template matching metric is associated with an SAD between a second template of the scanned reconstructed block and the template of the second block.

3. The video decoding device of claim 1 or claim 2, wherein the processor is further configured to: determine that a sub-pel precision filtering is enabled for the first block; based on the determination that the sub-pel filtering is enabled for the first block, predict the first block based on at least one of a sub-pel precision index or a sub-pel direction index; determine that the sub-pel precision filtering is disabled for the second block; and based on the determination that the sub-pel filtering is disabled for the second block, skip the prediction of the second block based on the sub-pel precision index or the sub-pel direction index.

4. The video decoding device of any one of claims 1-3, wherein to determine that the ITMP LIC is enabled for the first block comprises the processor being configured to: determining that an ITMP LIC enablement indication flag is on.IDVC_ 2023P01112WO PATENT 5. A method for video decoding, the method comprising: determining that an intra template matching prediction (ITMP) local illumination compensation (LIC) is enabled for a first block; based on the determination that the ITMP-LIC is enabled for the first block, performing a first ITMP search using a first template matching metric; decoding the first block based on the first ITMP search; determining that the ITMP-LIC is disabled for a second block; based on the determination that the ITMP-LIC is disabled, performing a second ITMP search using a second template matching metric; and decoding the second block based on the second ITMP search.

6. The method of claim 5, wherein the first template matching metric is associated with a mean removed (MR) sum of absolute difference (SAD) between a first template of a scanned reconstructed block and a template of the first block and the second template matching metric is associated with an SAD between a second template of the scanned reconstructed block and the template of the second block.

7. The method of claim 5 or claim 6, wherein the method further comprises: determining that a sub-pel precision filtering is enabled for the first block; based on the determination that the sub-pel filtering is enabled for the first block, predicting the first block based on at least one of a sub-pel precision index or a sub-pel direction index; determining that a sub-pel precision filtering is disabled for the second block; and based on the determination that the sub-pel filtering is disabled for the second block, skipping the prediction of the second block based on the sub-pel precision index or the sub-pel direction index.

8. The method of any one of claims 5-7, wherein determining that the ITMP LIC is enabled for the first block comprises: determining that an ITMP-LIC enablement indication flag is on.

9. A video encoding device comprising: a processor configured to: determine to enable an intra template matching prediction (ITMP) local illumination compensation (LIC) for a first block; based on the determination to enable the ITMP-LIC for the first block, perform a first ITMP search for the first block using a first template matching matric;IDVC_ 2023P01112WO PATENT encode the first block based on the first ITMP search; determine to disable the ITMP-LIC for a second block; based on the determination to disable the ITMP-LIC for the second block, perform a second ITMP search for the second block using a second template matching matric; and encode the second block based on the second ITMP search.

10. The video encoding device of claim 9, wherein the first template matching metric is associated with a mean removed (MR) sum of absolute difference (SAD) between a first template of a scanned reconstructed block and a template of the first block and the second template matching metric is associated with an SAD between a second template of the scanned reconstructed block and the template of the second block.

11. The video encoding device of claim 9 or claim 10, wherein the processor is further configured to: determine to enable a sub-pel precision filtering for the first block; based on the determination to enable the sub-pel filtering, include, in video data, at least one of a sub-pel precision index indication that is configured to indicate a sub-pel precision index or a sub-pel direction index indication that is configured to indicate a sub-pel direction index; determine to disable the sub-pel precision filtering for the second block; and based on the determination to disable the sub-pel filtering for the second block, skip the inclusion of at least one of the sub-pel precision index indication or the sub-pel direction index indication in the video data.

12. The video encoding device of any one of claims 9-11, wherein the processor is configured to: include, in the video data, a first ITMP-LIC indication that is configured to indicate that the ITMP- LIC is enabled for the first block; and include, in the video data, a second ITMP-LIC indication that is configured to indicate that the ITMP-LIC is disabled for the second block.

13. A method for video encoding, the method comprising: determining to enable an intra template matching prediction (ITMP) local illumination compensation (LIC) for a first block;IDVC_ 2023P01112WO PATENT based on the determination to enable the ITMP-LIC for the first block, performing a first ITMP search for the first block using a first template matching matric; encoding the first block based on the first ITMP search; determining to disable the ITMP-LIC for a second block; based on the determination to disable the ITMP-LIC for the second block, performing a second ITMP search for the second block using a second template matching matric; and encoding the second block based on the second ITMP search.

14. The method of claim 13, wherein the first template matching metric is associated with a mean removed (MR) sum of absolute difference (SAD) between a first template of a scanned reconstructed block and a template of the first block and the second template matching metric is associated with an SAD between a second template of the scanned reconstructed block and the template of the second block.

15. The method of claim 13 or claim 14, wherein the method further comprises: determining to enable a sub-pel precision filtering for the first block; based on the determination to enable the sub-pel filtering, including, in video data, at least one of a sub-pel precision index indication that is configured to indicate a sub-pel precision index or a sub-pel direction index indication that is configured to indicate a sub-pel direction index; determining to disable the sub-pel precision filtering for the second block; and based on the determination to disable the sub-pel filtering for the second block, skipping the inclusion of at least one of the sub-pel precision index indication or the sub-pel direction index indication in the video data.

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