Inversing a non-monotonic look-up table

Abstract

A method and an encoder device for generating an inverted lookup table (LUT). The method may identify monotonic and / or non-monotonic parts of a non-monotonic LUT. The method may generate a first plurality of data points by measuring the non-monotonic LUT in ascending order. The method may generate a second plurality of data points by measuring the non-monotonic LUT in descending order. The method may compute an average value by averaging the first plurality of data points and the second plurality of data points. The method may generate the inverted LUT based on the average value.

Description

INVERSING A NON-MONOTONIC LOOK-UP TABLECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of European Patent Application No. 23307079.6 filed onNovember 29, 2023, the entire contents of which are incorporated herein by reference.BACKGROUND

[0002] A lookup-table (LUT) may be computed from the single-layer high dynamic range (SL-HDR) metadata (MD). Then, the LUT, also referred to herein as an LUT color correction (lutCC), may be used to compute standard dynamic range (SDR) with post int clip prevent (PICP).SUMMARY

[0003] An encoder device for generating an inverted lookup table (LUT). The encoder may identify monotonic and / or non-monotonic parts of a non-monotonic LUT. The encoder may generate a first plurality of data points by measuring the non-monotonic LUT in ascending order. The encoder may generate a second plurality of data points by measuring the non-monotonic LUT in descending order. The encoder may compute an average value by averaging the first plurality of data points and the second plurality of data points. The encoder may generate the inverted LUT based on the average value.

[0004] The first plurality of data points may comprise the values of the non-monotonic LUT along an abscissa and / or values of the non-monotonic LUT along the ordinate which correspond to the values of the non-monotonic LUT along the abscissa as they are measured in ascending order. The second plurality of data points may comprise the values of the non-monotonic LUT along the abscissa and / or values of the non-monotonic LUT along the ordinate which correspond to the values of the nonmonotonic LUT along the abscissa as they are measured in descending order.

[0005] The non-monotonic parts of the LUT may be replaced by line segments. The non-monotonic parts of the LUT may be replaced by a replacement function such that the resulting LUT is monotonic The first plurality of data points and the second plurality of data points may be stored.

[0006] Measuring the non-monotonic LUT in ascending order and / or measuring the non-monotonic LUT in descending order may be performed at the one or more points along sections of the LUT wherein the derivative at those one or more points will cancel out the LUT. The encoder may identify an input for computing a standard dynamic range (SDR) signal with a post int clip prevent (PICP). The encoder may generate an SDR signal with a PCIP based on the input and the generated inverted LUT.

[0007] This invention improves the inversion of non-monotonous LUTs by avoiding large gaps caused by previous solutions. Instead of walking the LUT to be inverted in increasing order to match a point in ordinates with abscissa, the invention herein provides for walking the LUT in both ascending and descending order. Then the methods described herein may take the average found at each extremity. In some examples, a LUT may be referred to herein as a LUT color correction (lutCC).BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1A is a system diagram illustrating an example communications system in which one or more disclosed embodiments may be implemented.

[0009] FIG. 1 B 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.

[0010] 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.

[0011] FIG. 1 D 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.

[0012] FIG. 2 depicts a unified standard dynamic range (SDR) round-trip variant for single-layer high dynamic range (SL-HDR) distribution.

[0013] FIG. 3 depicts a modified SDR post int clip prevent (PICP) computation, using inverse lookup table (LUT).

[0014] FIG. 4 depicts a plot of a monotonic LUT.

[0015] FIG. 5 depicts a plot of a non-monotonic LUT.

[0016] FIG. 6 depicts a plot with large gap in a trivially inversed LUT.

[0017] FIG. 7 depicts a plot of an original, non-monotonic LUT.

[0018] FIG. 8 depicts a plot of inverting the LUT after taking the first value when scanning in ascending order, descending order, and / or the average of both ascending and descending order.

[0019] FIG. 9 depicts the algorithm used to best handle non-monotonic LUT(s) that may need to be inverted.

[0020] FIG. 10 depicts a plot of a non-monotonic LUT to alter, with remarkable points.

[0021] FIG. 11 depicts a plot of an altered LUT with non-monotonic part replaced.

[0022] FIG. 12 depicts a plot of the inverse LUT corresponding to FIG. 11 .DETAILED DESCRIPTION

[0023] 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 access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tail unique-word DFT- Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block-filtered OFDM, filter bank multicarrier (FBMC), and the like.

[0024] 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 ON 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 (loT) 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 WTRU.

[0025] 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 singleelement, it will be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0026] 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 combination 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.

[0027] 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).

[0028] 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).

[0029] 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).

[0030] 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).

[0031] 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).

[0032] 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, CDMA2000 1 X, 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.

[0033] The base station 114b in FIG. 1 A 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.

[0034] 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 securityfunctions, such as user authentication. Although not shown in FIG. 1 A, 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.

[0035] 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 common 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.

[0036] 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. 1 A 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.

[0037] FIG. 1 B is a system diagram illustrating an example WTRU 102. As shown in FIG. 1 B, 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 subcombination of the foregoing elements while remaining consistent with an embodiment.

[0038] 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 transceiver120, which may be coupled to the transmit / receive element 122. While FIG. 1 B 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.

[0039] 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 will be appreciated that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0040] Although the transmit / receive element 122 is depicted in FIG. 1 B 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.

[0041] 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.

[0042] 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).

[0043] 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.

[0044] 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 will be appreciated that the WTRU 102 may acquire location information by way of any suitable location-determination method while remaining consistent with an embodiment.

[0045] 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.

[0046] 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 139 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)).

[0047] 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 communicatewith the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0048] 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.

[0049] 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 of users in the UL and / or DL, and the like. As shown in FIG. 1 C, the eNode-Bs 160a, 160b, 160c may communicate with one another over an X2 interface.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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 IPgateway (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.

[0055] Although the WTRU is described in FIGS. 1 A-1 D 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.

[0056] In representative embodiments, the other network 112 may be a WLAN.

[0057] 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.

[0058] When using the 802.11 ac 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.

[0059] 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.

[0060] 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 MHz 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).

[0061] Sub 1 GHz modes of operation are supported by 802.11 af and 802.11 ah. The channel operating bandwidths, and carriers, are reduced in 802.11 af and 802.11 ah relative to those used in 802.11 n, and 802.11ac. 802.11 af supports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11 ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11 ah 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).

[0062] WLAN systems, which may support multiple channels, and channel bandwidths, such as 802.11 n, 802.11 ac, 802.11 af, and 802.11 ah, 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 802.11 ah, 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.

[0063] In the United States, the available frequency bands, which may be used by 802.11 ah, are from 902 MHz to 928 MHz. In Korea, the available frequency bands are from 917.5 MHz to 923.5 MHz. InJapan, the available frequency bands are from 916.5 MHz to 927.5 MHz. The total bandwidth available for 802.11 ah is 6 MHz to 26 MHz depending on the country code.

[0064] FIG. 1 D 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.

[0065] 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).

[0066] 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).

[0067] 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.

[0068] 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. 1 D, the gNBs 180a, 180b, 180c may communicate with one another over an Xn interface.

[0069] The CN 115 shown in FIG. 1 D 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.

[0070] 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.

[0071] 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 asmanaging and allocating WTRU 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.

[0072] 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, 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.

[0073] 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.

[0074] In view of Figures 1A-1 D, and the corresponding description of Figures 1A-1 D, 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-ab, 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.

[0075] 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.

[0076] 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. Forexample, 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.

[0077] FIG. 2 depicts an example method 200 of computing a unified SDR round-trip variant for SL- HDR distribution. A LUT (e.g., LUT color correction (lutCC)) may be computed from the SL-HDR metadata (MD). Then, the LUT (e.g., lutCC) may compute an SDR with post int clip prevent (PICP). An SDR with PICP is a picture modified to avoid decoding problems due to the limitations of SL-HDR's decoder hardware. For example, as shown in FIG. 2, the "compute lutCC from MD” block in FIG. 2 of the inverse tone management (ITM) pipeline may correspond to the lutCC that is used to compute the SDR with PICP.

[0078] Referring to FIG. 2, at 204 the ITM pipeline may analyze the SDR YUV in signal. At this time, at 204, the ITM pipeline may also compute an ITM LUT. Analyzing YUV video may produce the ITM LUT. If needed, the ITM LUT may be produced from another signal flavor. At 208, the ITM pipeline may compute an inverse ITM LUT. At 212, the ITM pipeline may compute single layer high dynamic range (SL-HDR) luminance LUT (L-LUT) and / or beta LUT (B-LUT). At 216, the ITM pipeline may estimate metadata (MD) based on the SL-HDR L-LUT and / or B-LUT (e.g., in ST2108). At 220, the ITM pipeline may generate an MD ST2108 parameter. At 224, the ITM pipeline may compute LUT (e.g., lutCC) from the MD (e.g., the SL-HDR MD). At 228, the ITM pipeline may compute an SDR with PICP from the lutCC and / or the SDR input (e.g., SDRJn). As such, at 232, the ITM pipeline may generate a YUV SDR output with PICP.

[0079] FIG. 3 depicts an example 300 of a modified SDR with PICP computation that uses an inverse lookup table. At 304, an inverted LUT (e.g., invLUTCC) may be used to compute an SDR with PICP. For instance, at 308, using an inverted LUT (e.g., invLUTCC) to compute the SDR with PICP may be faster than using a non-inverter LUT. Without an inverse LUT, the solution may rely on walking the entire LUT for every pixel, (e.g. with complexity O(n)), rather than doing just one access to the inverse LUT, (e.g., with complexity 0(1)). At 312, an inverted LUT (e.g., invLUTCC) may be used to compute the SDR with PICP in view of the way the LUT (e.g., lutCC) is accessed in the computation block (e.g., an SDR with PICP is computed from the inverted lutCC and an SDR input (SDRJn)).

[0080] For instance, the system may receive a LUT. The system may invert the LUT to generate an inverted LUT. The system may compute an SDR with PICP based on the inverter LUT (invLutCC) and an SDR input (SDRJn). In some examples, the SDR input may be YUV values of the SDR input. As such, the system may generate a YUV SDR output with PICP.

[0081] Inverting a LUT may include taking every point of the ordinates and / or matching each point of the ordinates with a point on abscissa. An inverse lookup table (e.g., or reverse lookup table and / or inverse LUT) may allow the key associated with a given value to be found in an original lookup table. A LUT may include a list of value associations that behaves like a mathematical function. The LUT may be used to replace a complex calculation by a simpler operation of consultation.

[0082] FIG. 4 depicts a plot of a monotonic LUT. For the inversion to be possible, the LUT must be monotonic as depicted in FIG. 4. As shown in FIG. 4, only one point on the X axis (e.g., abscissa) may be mapped to the Y axis (e.g., ordinates).

[0083] However, in some cases, the lutCC is non-monotonic and may not be trivially inverted because several points of the X axis are mapped to the same point on the Y axis. FIG. 5 depicts a plot of a nonmonotonic LUT. As shown in FIG. 5, the points (x0, xx, x2) correspond to y0.

[0084] In examples, a system and / or method may process the first point in ascending order that matches (e.g., x0as shown in FIG. 5). However, by doing so, the resulting inverted LUT may have a large gap. This large gap may lead to a visible flicker when applied to the pixels, as shown in FIG. 6. FIG. 6 depicts a plot with large gap in a trivially inversed LUT.

[0085] The examples described herein (e.g., below) may improve the inversion of non-monotonic LUTs by avoiding large gaps caused by previous solutions. Instead of walking the LUT to be inverted in increasing order to match a point in ordinates with abscissa, the examples described herein may provide for walking the LUT in both ascending and descending order. Then the methods described herein may take the average found at each extremity.

[0086] Inverting a monotonic function or LUT may be performed. For example, there may be a one-to- one relation between input and output, as shown in FIG. 4. However, a non-monotonic function may have several points on the abscissa mapping to the same point in ordinate as shown in FIG. 5. Since inverting a function and / or LUT involves mapping each point on the ordinate axis to a value on the abscissa axis, a decision must be made on how to consider these multiple matches.

[0087] As proposed herein, the LUT may be scanned multiple times (e.g., twice). For example, the LUT may be scanned in ascending order, and the matched ya= LUT(xa) value may be stored (e.g., memorized). The LUT may then be scanned in descending order, and the matched yd = LUT(xd) value may be stored (e.g., memorized). The average of these values (e.g., the matched ya= LUT(xa) value and the matched yd = LUT(xd) value) may be calculated to generate the inverted LUT.

[0088] The LUT may be scanned once, (e.g. in ascending order or in descending order) and the matched ya= LUT(xa) value or yd = LUT(xd) value may then be stored (e.g., memorized). The inverted LUT may then be generated from the inverted LUT based on the generated data points.

[0089] FIG. 7 depicts a plot of an original, non-monotonic LUT. FIG. 8 depicts a plot of inverting the LUT after taking the first value when scanning in ascending order, scanning in the descending order, and then calculating the average of both ascending and descending order. The average of the values calculated in the ascending order and the descending order may be the method described herein. An example of software code that corresponds to this method (e.g., the algorithm used to best handle nonmonotonic LUT(s) that may need to be inverted) is depicted in FIG. 9. FIG. 9 depicts an example algorithm that may generate non-monotonic LUT(s) that need to be inverted.

[0090] When observing the results depicted in FIG. 8, it should be noted that all three methods (e.g., inverting the LUT after taking the first value when scanning in ascending order, descending order, and / or the average) yield the same result on the monotonic part of the curve.

[0091] Both the ascending and / or the descending curves may lead to a single large vertical jump. In this instance, two adjacent values may map to very different values, causing flicker. The average curve has two smaller vertical jumps which may be less likely to cause flicker.

[0092] The complexity of the average method may be twice that of either the ascending and / or the descending methods. The solution of walking the original LUT twice takes twice as slow to compute. Such a solution may be viable if few points need to be accessed through the inverted LUT.

[0093] The inverted LUT may have greater utility when used for a vast number of points. The LUT inversion is most likely to happen once and / or accessed many times in a tight loop. The resulting inverted LUT generated using the method of FIG. 8 may trade one large gap for two smaller gaps.

[0094] FIG. 10 depicts an example of a non-monotonic LUT. Featured in FIG. 10 are remarkable points (e.g. the minimum and maximum points of the LUT). The range Ymin to Ymax may cover the non-monotonic subpart of the LUT, because several points on X axis (abscissa) map to the Y axis (ordinates). For instance, both Xn and Xj map to Ymax. At the exterior of the Ymin-Ymax range the LUT range is monotonic. As described herein, a linear function ranging from (X1 ,Ymin) to (Xj.Ymax) may replace the non-monotonic part of the function.

[0095] As depicted in FIG. 11 , the non-monotonic part of the original LUT may be replaced so that the resulting function is monotonic. This way, the original LUT may then be inverted without gaps. FIG. 11 depicts that a straight line may be used to connect the endpoints of the gaps. The intent of connecting the gaps is to avoid having substantial changes in the inverted LUT.

[0096] FIG. 12 depicts an example of the inverse non-monotonic LUT corresponding to FIG. 11. The resulting inverse LUT may yield the smallest differences when walking the "former non-monotonic" section (depicted as a linear function in FIG. 12). If a video processing uses the non-monotonic part of the inverted LUT, flickering may be amplified. Flickering is undesirable. Imprecisions and / or rounding errors introduced by the video processing may be less amplified by this superior LUT inversion solution.

[0097] When a small change in the input of the LUT results in a big change on the output result, then any modification on the way the input point is computed may be screened with great care. Such screening may be necessary to ensure that the modification does not affect the output picture in a detrimental way. In some examples, the LUT may be altered (e.g., inverted) to make the vertical slope less vertical.

[0098] The example depicted in FIG. 8 may produce an inverted LUT which has two smaller gaps; in practice the inverted LUT may have multiple smaller gaps. The number of gaps may depend on the shape of the original LUT. The examples depicted in FIGs. 10-12, however, may not depend on other examples described herein. The examples depicted in FIGs. 10-12 may consider points where the derivative at that point cancels out. Taking the derivative at these points identifies points that may need to be connected by a straight line. Moreover, this solution may work with multiple non-invertible parts. This solution may not need to work on an altered LUT.

[0099] The examples described herein may be performed in the context of inverting a non-monotonic LUT used to process pixels of a video converted to SL-HDR1 . However, the methods described herein may apply to any processing that involves applying an inverse LUT when the original LUT is nonmonotonic. The examples described herein may be performed to produce SL-HDR1 straight from SDR, also called SL-ITM. When generating SL-HDR1 content directly from SDR, the L-LUT and / or B-LUT may be issued as MD along with the encoded picture. The L-LUT and B-LUT may be accessible for inspection. If these LUTs are non-monotonic, flicker may occur in the pixels. These pixels may need to be modified by the clipping prevention pass of the SL-HDR encoder.

[0100] This clipping prevention pass may not be mandatory to convert a video to SL-HDR. In some examples, clipping prevention may be implemented. Using the SL-HDR system on chip (SOC) decoder may add clipping artifacts to the reconstructed video.

Claims

CLAIMS1 . A method for generating an inverted lookup table (LUT), the method comprising: identifying monotonic and non-monotonic parts of a non-monotonic LUT; generating a first plurality of data points by measuring the non-monotonic LUT in ascending order; generating a second plurality of data points by measuring the non-monotonic LUT in descending order; computing an average value by averaging the first plurality of data points and the second plurality of data points; and generating the inverted LUT based on the average value.

2. The method of claim 1 , wherein the first plurality of data points comprise the values of the nonmonotonic LUT along an abscissa and values of the non-monotonic LUT along the ordinate which correspond to the values of the non-monotonic LUT along the abscissa as they are measured in ascending order; and wherein the second plurality of data points comprise the values of the non-monotonic LUT along the abscissa and values of the non-monotonic LUT along the ordinate which correspond to the values of the non-monotonic LUT along the abscissa as they are measured in descending order.

3. The method of claim 1 , wherein the non-monotonic parts of the LUT are replaced by line segments.

4. The method of claim 1 , wherein the non-monotonic parts of the LUT are replaced by a replacement function such that the resulting LUT is monotonic.

5. The method of claim 1 , further comprising: storing the first plurality of data points; and storing the second plurality of data points.

6. The method of claim 1 , wherein measuring the non-monotonic LUT in ascending order and measuring the non-monotonic LUT in descending order are performed at the one or more points along sections of the LUT wherein the derivative at those one or more points will cancel out the LUT.

7. The method of claim 1 , further comprising: identifying an input for computing a standard dynamic range (SDR) signal with a post int clip prevent (PICP); and generating an SDR signal with a PCIP based on the input and the generated inverted LUT.

8. An encoder comprising: a processor configured to: identify monotonic and non-monotonic parts of a non-monotonic LUT; generate a first plurality of data points by measuring the non-monotonic LUT in ascending order; generate a second plurality of data points by measuring the non-monotonic LUT in descending order; compute an average value by averaging the first plurality of data points and the second plurality of data points; and generate the inverted LUT based on the average value.

9. The encoder of claim 8, wherein the first plurality of data points comprise the values of the nonmonotonic LUT along an abscissa and values of the non-monotonic LUT along the ordinate which correspond to the values of the non-monotonic LUT along the abscissa as they are measured in ascending order; and wherein the second plurality of data points comprise the values of the non-monotonic LUT along the abscissa and values of the non-monotonic LUT along the ordinate which correspond to the values of the non-monotonic LUT along the abscissa as they are measured in descending order.

10. The encoder of claim 8, wherein the non-monotonic parts of the LUT are replaced by line segments.11 . The encoder of claim 8, wherein the non-monotonic parts of the LUT are replaced by a replacement function such that the resulting LUT is monotonic.

12. The encoder of claim 8, the processor further configured to: store the first plurality of data points; and store the second plurality of data points.

13. The encoder of claim 8, wherein measuring the non-monotonic LUT in ascending order and measuring the non-monotonic LUT in descending order are performed at the one or more points along sections of the LUT wherein the derivative at those one or more points will cancel out the LUT.

14. The encoder of claim 8, the processor further configured to: identify an input for computing a standard dynamic range (SDR) signal with a post int clip prevent (PICP); and generate an SDR signal with a PCIP based on the input and the generated inverted LUT.

15. A method comprising: identifying monotonic and non-monotonic parts of a non-monotonic LUT; generating a plurality of data points by measuring the non-monotonic LUT in ascending order; and generating the inverted LUT based on the plurality of data points generated by measuring the non-monotonic LUT in ascending order.

16. The method of claim 15, wherein the plurality of data points comprise the values of the nonmonotonic LUT along an abscissa and values of the non-monotonic LUT along the ordinate which correspond to the values of the non-monotonic LUT along the abscissa as they are measured in ascending order.

17. The method of claim 15, wherein the non-monotonic parts of the LUT are replaced by line segments.

18. The method of claim 15, wherein the non-monotonic parts of the LUT are replaced by a replacement function such that the resulting LUT is monotonic.

19. The method of claim 15, further comprising: storing the plurality of data points.

20. The method of claim 15, further comprising: identifying an input for computing a standard dynamic range (SDR) signal with a post int clip prevent (PICP); and generating an SDR signal with a PCIP based on the input and the generated inverted LUT.

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