Film Grain Synthesis Using Multiple Correlated Patterns
The video coding system addresses the challenge of simulating film grain in compressed video by generating correlated patterns through random seeds, low-pass filtering, and autoregression, resulting in improved realism and reduced artifacts.
Patent Information
- Application Number
- JP2024558969
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-04-08
- Filing Date
- 2023-03-30
- Publication Date
- 2025-04-15
AI Technical Summary
Existing video coding systems struggle to effectively simulate film grain in compressed video signals, leading to artifacts and loss of original image quality.
The system generates a set of correlated film grain patterns using a common random seed, applies low-pass filters with different cutoff frequencies, and performs autoregression processes with varying coefficients to create film grain patterns. These patterns are then selected and applied to image blocks based on pixel values, allowing for mixing of patterns for adjacent pixels.
This approach enhances the realism of film grain simulation, reduces artifacts, and improves the overall quality of compressed video signals by accurately replicating the dynamic behavior of film grain across different exposure levels.
Smart Images

Figure 2025511362000001_ABST
Abstract
Description
[Technical field]
[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of European Provisional Patent Application No. 22305512.0, filed April 8, 2022, the disclosure of which is incorporated herein by reference in its entirety. [Background technology]
[0002] Video coding systems may be used to compress digital video signals to, for example, reduce the storage and / or transmission bandwidth required for such signals. Video coding systems may include, for example, block-based, wavelet-based, and / or object-based systems. Summary of the Invention
[0003] A system, method, and means are disclosed for performing film grain synthesis using correlated and / or mixed patterns. A device may divide an image into a plurality of blocks. The device may generate a set of correlated film grain patterns for a block of the plurality of blocks. The device may select a correlated film grain pattern from the set of correlated film grain patterns to apply to pixels of the block.
[0004] Generating the set of correlated film grain patterns may include generating each correlated film grain pattern in the set of correlated film grain patterns using a common random seed. Generating the set of correlated film grain patterns may include applying a low pass filter to the root noise pattern, each correlated film grain pattern of the set of correlated film grain patterns generated using a different cutoff frequency for the low pass filter. Generating the set of correlated film grain patterns may include performing an autoregressive process on the root noise pattern, each correlated film grain pattern of the set of correlated film grain patterns generated using a different autoregressive coefficient for the autoregressive process. Generating the set of correlated film grain patterns may include adding a set of randomly located grains from the first film grain pattern to the second film grain pattern.
[0005] The correlated film grain pattern may be selected based on pixel values associated with the pixels of the block. Selecting the correlated film grain pattern may include blending multiple correlated film grain patterns from a set of correlated film grain patterns for adjacent selected values. The correlated film grain pattern may be selected based on a target picture sample value, a horizontal local average, or a horizontal low pass filter. The correlated film grain pattern may be selected based on the target picture sample value. The target picture sample value may be mapped to a pattern index indicating the correlated film grain pattern to apply to the pixels of the block. The correlated film grain pattern may be a first size and the block may be a second size smaller than the first size.
[0006] The device can determine a first set of properties associated with first particles in the first emulsion layer and a second set of properties associated with second particles in the second emulsion layer. The device can model behavior of the first particles and the second particles at different exposure levels. The device can emulate scanning of the first particles and the second particles at a given resolution. The device can derive a first grain image from the first emulsion layer and a second grain image from the second emulsion layer. Generating the set of correlated film grain patterns can include repeatedly overlaying the first grain image and the second grain image.
[0007] The systems, methods, and means described herein may involve a decoder. In some embodiments, the systems, methods, and means described herein may involve an encoder. In some embodiments, the systems, methods, and means described herein may involve a signal (e.g., from an encoder and / or received by a decoder). A computer-readable medium may include instructions for causing one or more processors to perform the methods described herein. A computer program product may include instructions that, when executed by one or more processors, may cause the one or more processors to perform the methods described herein. [Brief description of the drawings]
[0008] [Figure 1A] FIG. 1 is a system diagram illustrating an example communication system in which one or more disclosed embodiments may be implemented. [Figure 1B] 1B is a system diagram illustrating an example wireless transmit / receive unit (WTRU) that may be used within the communications system shown in FIG. 1A, in accordance with one embodiment. [Figure 1C]FIG. 1B is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communication system shown in FIG. 1A, according to one embodiment. [Figure 1D] FIG. 1B is a system diagram illustrating a further exemplary RAN and a further exemplary CN that may be used within the communication system shown in FIG. 1A, according to one embodiment. [Diagram 2] 1 illustrates an exemplary video encoder. [Diagram 3] 1 illustrates an exemplary video decoder. [Figure 4] 1 illustrates an example of a system in which various aspects and embodiments may be implemented. [Diagram 5] 1 shows an exemplary flow chart of film grain compositing. [Figure 6] 13 shows an example of a file grain pattern for film grain synthesis. [Figure 7] 13 shows an example of generating block offsets for film grain compositing. [Figure 8] An example of selecting a block sample pattern is shown below. [Figure 9] 1 shows an example of pixel-based template selection and associated correlation patterns. [Figure 10] 13 shows an example of selecting a pattern for film grain compositing without sub-blocks. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0009] A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawings, in which:
[0010] 1A is a diagram illustrating an example communications system 100 in which one or more disclosed embodiments may be implemented. Communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcasts, etc., to multiple wireless users. Communications system 100 may enable multiple wireless users to access such content through sharing of system resources, including wireless bandwidth. For example, the communications system 100 may use 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.
[0011] 1A, communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, RAN 104 / 113, CN 106 / 115, public switched telephone network (PSTN) 108, Internet 110, and other networks 112, although it will be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of 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 "STA," may be configured to transmit and / or receive wireless signals and may include user equipment (UE), mobile stations, fixed or mobile subscriber units, subscription-based units, pagers, mobile phones, personal digital assistants (PDAs), smartphones, laptops, netbooks, personal computers, wireless sensors, hotspots or Mi-Fi devices, Internet of Things (IoT) devices, watches or other wearables, head mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in industrial and / or automated processing chain contexts), consumer electronic devices, devices operating in commercial and / or industrial wireless networks, etc. Any of the UEs 102a, 102b, 102c, and 102d may be interchangeably referred to as a WTRU.
[0012] The communication system 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 other networks 112. By way of example, the base stations 114a, 114b may be a base station transceiver station (BTS), a Node B, an eNode B, a Home Node B, a Home eNode B, a gNB, an NR Node B, a site controller, an access point (AP), a wireless router, etc. Although the base stations 114a, 114b are each illustrated as a single element, it will be understood that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.
[0013] 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), a relay node, 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 cells (not shown). These frequencies may be licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide wireless service coverage for a particular geographic area, which may be relatively fixed or may change over time. A cell may be further 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 transceiver for each sector of the cell. In one 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, using beamforming to transmit and / or receive signals in a desired spatial direction.
[0014] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d via 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).
[0015] More specifically, as noted above, the communications system 100 may be a multiple access system, but may use one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base stations 114a and the WTRUs 102a, 102b, 102c in the RAN 104 / 113 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 communications 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 Uplink Packet Access (HSUPA).
[0016] In one 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).
[0017] In one 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).
[0018] In one 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, e.g., using dual connectivity (DC) principles. Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions sent to and from multiple types of base stations (e.g., eNBs and gNBs).
[0019] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement a wireless technology such as IEEE 802.11 (i.e., Wireless Fidelity, WiFi), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access, WiMAX), CDMA2000, CDMA2000 1X, 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), or the like.
[0020] 1A may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in a localized area, such as an office, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a road, etc. 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 one 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 establish a picocell or a femtocell using a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.). 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 need to access the Internet 110 via the CN 106 / 115.
[0021] The RAN 104 / 113 may communicate with the CN 106 / 115, which may be any type of network configured to provide voice, data, application, and / or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have various quality of service (QoS) requirements, such as, for example, different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 / 115 may provide call control, billing services, mobile location-based services, prepaid 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 communicate directly or indirectly with other RANs that use 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 utilize NR radio technology, the CN 106 / 115 may also communicate with another RAN (not shown) using GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.
[0022] The CN 106 / 115 may also act as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network providing 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 transmission control protocol (TCP), user datagram protocol (UDP), and / or internet protocol (IP) of the TCP / IP Internet protocol suite. The networks 112 may include wired and / or wireless communication 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 use the same RAT as the RANs 104 / 113 or a different RAT.
[0023] 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 a base station 114a, which may employ a cellular-based wireless technology, and a base station 114b, which may employ an IEEE 802 wireless technology.
[0024] Figure 1B is a system diagram illustrating an example WTRU 102. As shown in Figure 1B, the WTRU 102 may include, among other things, 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. It will be understood that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.
[0025] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, etc. 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. Although FIG. 1B illustrates the processor 118 and the transceiver 120 as separate components, it will be understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.
[0026] The transmit / receive element 122 may be configured to transmit or receive signals to or from a base station (e.g., 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 one 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.
[0027] 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.
[0028] The transceiver 120 may be configured to modulate signals transmitted by the transmit / receive element 122 and demodulate signals received by the transmit / receive element 122. As mentioned above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate via multiple RATs, such as, for example, NR and IEEE 802.11.
[0029] The processor 118 of the WTRU 102 may be coupled to and may receive user-entered data from a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an 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 non-removable memory 130 and / or 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, etc. 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 home computer (not shown).
[0030] The processor 118 may receive power from the power source 134 and may be configured to distribute and / or control the power to other components in the WTRU 102. The power source 134 may be any suitable device for providing power to the WTRU 102. For example, the power source 134 may include one or more dry batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.
[0031] The processor 118 may also be coupled to a GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or in lieu of, information from the GPS chipset 136, the WTRU 102 may receive location information from a base station (e.g., base stations 114a, 114b) over the air interface 116 and / or determine its location based on the timing of signals received from two or more nearby base stations. It will be appreciated that the WTRU 102 may obtain location information by way of any suitable position determination method while remaining consistent with an embodiment.
[0032] 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 electronic compass, a satellite transceiver, a digital camera (for photos and / or videos), 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, which 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.
[0033] The WTRU 102 may include a full-duplex radio where transmission and reception of some or all of the signals associated with a particular subframe (e.g., for both the UL (e.g., for transmission) and the downlink (e.g., for reception) may be parallel 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., via a separate processor (not shown) or via the processor 118). In one embodiment, the WRTU 102 may include a half-duplex radio for transmission and reception of either some or all of the signals (e.g., associated with a particular subframe for either the UL (e.g., for transmission) or the downlink (e.g., for reception)).
[0034] 1C is a system diagram illustrating the RAN 104 and the CN 106, according to one embodiment. As mentioned above, the RAN 104 may employ E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also communicate with the CN 106.
[0035] The RAN 104 may include eNodeBs 160a, 160b, 160c, although it will be understood that the RAN 104 may include any number of eNodeBs while remaining consistent with an embodiment. The eNodeBs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In an embodiment, the eNodeBs 160a, 160b, 160c may implement MIMO technology. Thus, the eNodeB 160a may, for example, use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.
[0036] Each of the eNodeBs 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, etc. As shown in FIG 1C, the eNodeBs 160a, 160b, 160c may communicate with one another via an X2 interface.
[0037] 1C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. Although each of the foregoing elements is illustrated as part of the CN 106, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.
[0038] The MME 162 may be connected to each of the eNodeBs 162a, 162b, 162c in the RAN 104 via an S1 interface and may function as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, activating / deactivating bearers, selecting a particular serving gateway during initial attachment of the WTRUs 102a, 102b, 102c, etc. 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.
[0039] The SGW 164 may be connected to each of the eNodeBs 160a, 160b, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to and from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring the user plane during inter-eNodeB handover, triggering paging when DL data is available to the WTRUs 102a, 102b, 102c, and managing and storing the context of the WTRUs 102a, 102b, 102c.
[0040] The SGW 164 may be connected to a 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.
[0041] 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 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 other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.
[0042] Although the WTRU is depicted in FIGS. 1A-1D as a wireless terminal, in certain representative embodiments, it is contemplated that such a terminal may use a wired communications interface (e.g., temporarily or permanently) with the communications network.
[0043] In an exemplary embodiment, the other network 112 may be a WLAN.
[0044] A WLAN in infrastructure Basic Service Set (BSS) mode may have an Access Point (AP) of the BSS and one or more stations (STAs) associated with the AP. The AP may have access or interface to a Distribution System (DS) or another type of wired / wireless network that carries traffic into and / or out of the BSS. Traffic originating from outside the BSS to the STA may arrive through the AP and be delivered to the STA. Traffic originating from the STA to a destination outside the BSS may be sent to the AP to be delivered to the respective destination. Traffic between STAs within the BSS may be sent, for example, through the AP, where the source STA may send traffic to the AP, which may deliver the traffic to the destination STA. Traffic between STAs within the BSS may be considered and / or referred to as peer-to-peer traffic. Peer-to-peer traffic may be sent between (e.g., directly between) the source STA and the destination STA using a direct link setup (DLS). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and STAs (e.g., all of the STAs) within or using the IBSS may communicate directly with each other. The IBSS mode of communication may be referred to herein as an "ad-hoc" communication mode.
[0045] When using an 802.11ac infrastructure mode of operation or a similar mode of operation, an AP may transmit a beacon on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., a 20 MHz wide bandwidth) or a width that is dynamically set via signaling. The primary channel may be the operating channel of the BSS, but may be used by STAs to establish a connection with the AP. In certain representative embodiments, for example, in an 802.11 system, Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) may be implemented. With CSMA / CA, STAs (e.g., all STAs), 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.
[0046] A High Throughput (HT) STA may use a 40 MHz wide channel for communication, which may be formed, for example, through a combination of a primary 20 MHz channel and adjacent or non-adjacent 20 MHz channels.
[0047] A Very High Throughput (VHT) STA may support 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. A 40 MHz and / or 80 MHz channel may be formed by combining multiple contiguous 20 MHz channels. A 160 MHz channel may be formed by combining eight 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, after channel encoding, the data may pass through a segment parser that may split the data into two streams. Inverse Fast Fourier Transform (IFFT) processing and time domain processing may be performed separately on each stream. The streams may be mapped to two 80 MHz channels and the data may be transmitted by the transmitting STA. At the receiver of the receiving STA, the operations described above for the 80+80 configuration may be reversed and the combined data may be transmitted to the Medium Access Control (MAC).
[0048] Sub-1 GHz operating modes are supported by 802.11af and 802.11ah. Channel operating bandwidths and carriers are reduced in 802.11af and 802.11ah compared to those used in 802.11n and 802.11ac. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in 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 communication, such as MTC devices in macro coverage areas. MTC devices may have limited capabilities, including certain capabilities, for example, support for (e.g., support only for) certain and / or limited bandwidths. MTC devices may include batteries with above-threshold battery life (e.g., to maintain very long battery life).
[0049] WLAN systems that may support multiple channels and channel bandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include a channel that may be designated as a primary channel. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be configured and / or limited by the STAs among all STAs operating in the BSS that support the smallest bandwidth operating mode. In an 802.11ah embodiment, the primary channel may be 1 MHz wide for STAs (e.g., MTC-type devices) that support (e.g., only) the 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) configuration may depend on the status of the primary channel. For example, if the primary channel is active due to a STA (that only supports the 1 MHz mode of operation) transmitting to the AP, the entire available frequency band may be considered active even though most of the frequency band may remain dormant and available.
[0050] In the United States, the available frequency bands that can be used by 802.11ah are 902MHz to 928MHz. In South Korea, the available frequency bands are 917.5MHz to 923.5MHz. In Japan, the available frequency bands are 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz depending on the country code.
[0051] 1D is a system diagram illustrating the RAN 113 and the CN 115, according to one embodiment. As mentioned above, the RAN 113 may employ NR radio technology and communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also communicate with the CN 115.
[0052] The RAN 113 may include gNBs 180a, 180b, 180c, although it will be understood 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 an embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, the gNBs 180a, 108b may utilize beamforming to transmit signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a may transmit and / or receive wireless signals to and from the WTRU 102a, for example, using multiple antennas. In one 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 an unlicensed spectrum, while the remaining component carriers may be on a licensed spectrum. In one embodiment, the gNBs 180a, 180b, 180c may implement Coordinated Multi-Point (CoMP) technology. For example, the WTRU 102a may receive coordinated transmissions from the gNBs 180a and 180b (and / or gNB 180c).
[0053] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with 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 the gNBs 180a, 180b, 180c using subframes or transmission time intervals (TTIs) of different or scalable lengths (e.g., including different numbers of OFDM symbols and / or lasting different lengths of absolute time).
[0054] 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 a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c without accessing another RAN (e.g., eNodeBs 160a, 160b, 160c, etc.). In a standalone configuration, the WTRUs 102a, 102b, 102c may utilize one or more of the gNBs 180a, 180b, 180c as mobility anchor points. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using signals in unlicensed bands. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate with and connect to a gNB 180a, 180b, 180c while also communicating with and connecting to another RAN, such as an eNodeB 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement DC principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNodeBs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the eNodeBs 160a, 160b, 160c may act as mobility anchors for the WTRUs 102a, 102b, 102c, and the gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.
[0055] 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 for network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data to User Plane Functions (UPFs) 184a, 184b, routing of control plane information to Access and Mobility Management Functions (AMFs) 182a, 182b, etc. As shown in FIG. 1D, the gNBs 180a, 180b, 180c may communicate with each other via an Xn interface.
[0056] 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. Although each of the foregoing elements is illustrated as part of the CN 115, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.
[0057] 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 function as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, supporting network slicing (e.g., handling different PDU sessions with different requirements), selecting a particular SMF 183a, 183b, managing registration areas, terminating NAS signaling, mobility management, etc. Network slicing may be used by the AMF 182a, 182b to customize the CN support of the WTRUs 102a, 102b, 102c based on the type of service utilizing the 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, etc. 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.
[0058] The SMFs 183a, 183b may be connected to the AMFs 182a, 182b in the CN 115 via an N11 interface. The SMFs 183a, 183b may also be connected to the UPFs 184a, 184b in the CN 115 via an N4 interface. The SMFs 183a, 183b may select and control the UPFs 184a, 184b and configure the routing of traffic through the UPFs 184a, 184b. The SMFs 183a, 183b may perform other functions such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notification, etc. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.
[0059] The UPFs 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 UPFs 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, etc.
[0060] The CN 115 may facilitate communication with other networks. For example, the CN 115 may include or 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 other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to local data networks (DNs) 185a, 185b through the UPFs 184a, 184b via an N3 interface to the UPFs 184a, 184b and an N6 interface between the UPFs 184a, 184b and the DNs 185a, 185b.
[0061] 1A-1D and the corresponding description thereof, one or more or all of the functions described herein with respect to one or more of the WTRUs 102a-d, base stations 114a-b, eNodeBs 160a-c, MME 162, SGW 164, PGW 166, gNBs 180a-c, AMFs 182a-b, UPFs 184a-b, SMFs 183a-b, DNs 185a-b, and / or any other devices 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.
[0062] The emulation device may be designed to perform one or more tests of other devices in a lab environment and / or an operator network environment. For example, one or more emulation devices may perform one or more or all functions while fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to test other devices in the communication network. One or more emulation devices may perform one or more or all functions while temporarily implemented / deployed as part of a wired and / or wireless communication network. The emulation device may be directly coupled to another device for testing purposes and / or may perform the tests using terrestrial wireless communication.
[0063] The one or more emulation devices may perform one or more functions, inclusive, while not being implemented / deployed as part of a wired and / or wireless communication network. For example, the emulation devices may be utilized in test scenarios in a test lab and / or in an undeployed (e.g., test) wired and / or wireless communication network to perform testing of one or more components. The one or more emulation devices may be test equipment. Direct RF coupling and / or wireless communication via RF circuitry (which may include, for example, one or more antennas) may be used by the emulation devices to transmit and / or receive data.
[0064] This application describes various aspects, including tools, features, examples, models, techniques, and the like. Many of these aspects are described with specificity and often in a potentially limiting manner to at least illustrate their individual characteristics. However, this is for purposes of clarity of description and does not limit the applicability or scope of the aspects. In fact, all of the different aspects may be combined and interchanged to provide further aspects. Moreover, these aspects may likewise be combined and interchanged with aspects described in prior applications.
[0065] Aspects described and contemplated in this application may be implemented in many different forms. Figures 5-9 described herein may provide some examples, but other examples are contemplated. Discussion of Figures 5-9 is not intended to limit the scope of implementations. At least one of the above aspects generally relates to video encoding and decoding, and at least one other aspect generally relates to transmitting a generated or encoded bitstream. These and other aspects 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 described methods, and / or a computer-readable storage medium having stored thereon a bitstream generated according to any of the described methods.
[0066] In this application, the terms "reconstructed" and "decoded" may be used interchangeably, the terms "pixel" and "sample" may be used interchangeably, and the terms "image", "picture", and "frame" may be used interchangeably.
[0067] Various methods are described herein, each of which includes one or more steps or acts for achieving the described method. Unless a specific order of steps or acts is required for proper operation of the method, the order and / or use of specific steps and / or acts may be modified or combined. Additionally, terms such as "first", "second", etc. may be used in various embodiments to modify elements, components, steps, operations, etc., such as, for example, "first decode" and "second decode". The use of such terms does not imply any ordering to the modified operations, unless specifically required. Thus, in this embodiment, the first decode need not be performed before the second decode, but may occur, for example, before, during, or during a period of overlap with the second decode.
[0068] Various methods and other aspects described herein may be used to modify modules, such as the decoding modules, of the video encoder 200 and decoder 300, as shown in Figures 2 and 3. Moreover, the subject matter disclosed herein may apply to any type, format, or version of video coding, whether described in a standard or recommendation, whether existing or developed in the future, and to extensions of any such standards and recommendations, for example. Unless otherwise indicated or technically impossible, aspects described herein may be used individually or in combination.
[0069] In the embodiments described in this application, various numerical values are used, such as 1, 2, 4, 7, 8, 16, 32, 64, etc. These and other specific values are for purposes of illustrating the embodiments, and the described aspects are not limited to these specific values.
[0070] 2 illustrates an example video encoder 200. Although variations of the example encoder 200 are contemplated, the encoder 200 is described below for purposes of clarity without describing all anticipated variations.
[0071] Before encoding, the video sequence may undergo encoding pre-processing (201), such as applying a color transformation to the input color picture (e.g., converting from RGB 4:4:4 to YCbCr 4:2:0) or performing a remapping of the input picture components to obtain a signal distribution that is more resilient to compression (e.g., using histogram equalization of one of the color components). Metadata (which may include, for example, film grain parameters determined by the pre-processing described herein) may be associated with the pre-processing and attached to the bitstream.
[0072] In the encoder 200, a picture is coded by the encoder elements, as described below. The picture to be coded is divided (202) and processed, for example, in coding units (CUs). Each unit is coded, for example, using either intra-mode or inter-mode. When a unit is coded in intra-mode, it performs intra prediction (260). In inter-mode, motion estimation (275) and motion compensation (270) are performed. The encoder decides (205) whether to use intra-mode or inter-mode to code the unit, and indicates the decision, for example, by a prediction mode flag. A prediction residual is calculated (210), for example, by subtracting the prediction block from the original image block.
[0073] The prediction residual is then transformed (225) and quantized (230). The quantized transform coefficients, as well as the motion vectors and other syntax elements, are entropy coded (245) to output a bitstream. The encoder can skip the transform and apply quantization directly to the untransformed residual signal. The encoder can bypass both the transform and quantization, i.e., the residual is coded directly without applying the transform or quantization processes.
[0074] The encoder decodes the coded block to provide a reference for further prediction. To decode the prediction residual, the quantized transform coefficients are dequantized (240) and inverse transformed (250). The decoded prediction residual and the predicted block are combined (255) to reconstruct an image block. An in-loop filter (265) is applied to the reconstructed picture to perform, for example, deblocking / Sample Adaptive Offset (SAO) filtering to reduce coding artifacts. The filtered image is stored in a reference picture buffer (280).
[0075] 3 illustrates an example of a video decoder. In the exemplary decoder 300, the bitstream is decoded by decoder elements as described below. The video decoder 300 generally performs a decoding path that is the inverse of the encoding path described in FIG. 2. Furthermore, the encoder 200 generally performs video decoding as part of the video data encoding.
[0076] In particular, the decoder input includes a video bitstream, which may be generated by the video encoder 200. The bitstream is first entropy decoded (330) to obtain transform coefficients, motion vectors, and other coded information. Picture partition information indicates how the picture is partitioned. Thus, the decoder may partition the picture according to the decoded picture partition information (335). To decode the prediction residual, the transform coefficients are dequantized (340) and inverse transformed (350). The decoded prediction residual and the predicted block are combined (355) to reconstruct an image block. The predicted block may be obtained from intra prediction (360) or from motion-compensated prediction (i.e., inter prediction) (375) (370). An in-loop filter (365) is applied to the reconstructed image. The filtered image is stored in a reference picture buffer (380).
[0077] The decoded picture may further undergo post-decoding processing (385), such as an inverse color conversion (e.g., from YCbCr 4:2:0 to RGB 4:4:4) or inverse remapping that performs the inverse of the remapping process performed in the pre-encoding processing (201). The post-decoding processing may use metadata derived in the pre-encoding processing and signaled in the bitstream. In an embodiment, the decoded image (e.g., after application of an in-loop filter (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.
[0078] FIG. 4 illustrates an example of a system in which various aspects and embodiments described herein may be implemented. System 400 may be embodied as a device including various components described below and configured to implement one or more of the aspects described herein. Examples of such devices include various electronic devices, such as, but not limited to, personal computers, laptop computers, smartphones, tablet computers, digital multimedia set-top boxes, digital television receivers, personal video recording systems, connected appliances, and servers. The elements of system 400, singly or in combination, may be embodied in a single integrated circuit (IC), multiple ICs, and / or separate components. For example, in at least one embodiment, the processing and encoder / decoder elements of system 400 are distributed across multiple ICs and / or separate components. In various embodiments, system 400 is communicatively coupled to one or more other systems or other electronic devices, for example, via a communication bus or through dedicated input and / or output ports. In various embodiments, system 400 is configured to implement one or more of the aspects described herein.
[0079] The system 400 is configured to execute instructions loaded therein, for example, to implement various aspects described herein. The system 400 includes at least one processor 410. The processor 410 may include embedded memory, input / output interfaces, and various other circuits 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). The system 400 includes a storage device 440, which may include non-volatile memory and / or volatile memory, including, but not limited to, electrically erasable programmable read-only memory (EEPROM), read-only memory (ROM), programmable read-only memory (PROM), random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), flash, magnetic disk drive, and / or optical disk drive. The storage device 440 may include, by way of non-limiting example, an internal storage device, an attached storage device (including removable and non-removable storage devices), and / or a network-accessible storage device.
[0080] The system 400 includes an encoder / decoder module 430 configured to process data to provide, for example, encoded or decoded video, and the encoder / decoder module 430 may include its own processor and memory. The encoder / decoder module 430 represents a module that may be included in a device to perform encoding and / or decoding functions. As is known, a device may include one or both of an encoding module and a decoding module. It is noted that the encoder / decoder module 430 may be implemented as a separate element of the system 400 or may be incorporated in the processor 410 as a combination of hardware and software known to those skilled in the art.
[0081] Program code to be loaded into the processor 410 or the encoder / decoder 430 to implement various aspects described herein may be stored in the storage device 440 and then loaded into the memory 420 for execution by the processor 410. According to various embodiments, one or more of the processor 410, the memory 420, the storage device 440, and the encoder / decoder module 430 may store one or more of various items during performance of the processes described herein. Such stored items may include, but are not limited to, input video, decoded video or portions of decoded video, bitstreams, matrices, variables, and intermediate or final results from the processing of equations, expressions, operations, and computational logic.
[0082] In some embodiments, memory internal to the processor 410 and / or the encoder / decoder module 430 is used to store instructions and provide working memory for processing required during encoding or decoding. However, in other embodiments, memory external to the processing device (e.g., the processing device can be either the processor 410 or the encoder / decoder module 430) is used for one or more of these functions. The external memory may be the memory 420 and / or the storage device 440, e.g., dynamic volatile memory and / or non-volatile flash memory. In some embodiments, an external non-volatile flash memory is used, e.g., to store the television's operating system. In at least one embodiment, a high-speed external dynamic volatile memory, such as a RAM, is used as working memory for video encoding and decoding operations.
[0083] Inputs to the elements of system 400 may be provided through various input devices, as shown in block 445. Such input devices may include, but are not limited to, (i) a radio frequency (RF) section that receives, for example, RF signals transmitted over the air by a broadcast station, (ii) a component (COMP) input terminal (or 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 include composite video, not shown in FIG. 4.
[0084] In various embodiments, the input devices of block 445 have associated respective input processing elements as known in the art. For example, the RF section may be associated with appropriate elements to (i) select a desired frequency (also referred to as selecting a signal or band-limiting a signal to a frequency band), (ii) downconvert the selected signal, (iii) band-limit again to a narrower frequency band to select a signal frequency band, which in a particular embodiment may be referred to (for example) as a channel, (iv) demodulate the downconverted and band-limited signal, (v) perform error correction, and / or (vi) demultiplex to select a desired stream of data packets. The RF section of various embodiments includes one or more elements for performing these functions, such as a frequency selector, a signal selector, a band limiter, a channel selector, a filter, a downconverter, a demodulator, an error corrector, and a demultiplexer. The RF section may include, for example, a tuner that performs various of these functions, including downconverting a received signal to a lower frequency (e.g., an intermediate frequency or a frequency close to baseband) or to baseband. In one embodiment of a set-top box, the RF section and its associated input processing elements perform frequency selection by receiving, filtering, downconverting, and refiltering RF signals transmitted over a wired (e.g., cable) medium to a desired frequency band. Various embodiments rearrange the order of the above-described (and other) elements, remove some of these elements, and / or add other elements to perform similar or different functions. Adding elements can include inserting elements between existing elements, such as, for example, inserting amplifiers and analog-to-digital converters. In various embodiments, the RF section includes an antenna.
[0085] The USB and / or HDMI terminals may include respective interface processors for connecting the system 400 to other electronic devices via USB and / or HDMI connections. It should be appreciated that various aspects of the input processing, e.g., Reed-Solomon error correction, may be implemented, for example, in a separate input processing IC or in the processor 410, as desired. Similarly, aspects of the USB or HDMI interface processing may be implemented, for example, in a separate interface IC or in the processor 410, as desired. The demodulated, error corrected, and demultiplexed streams are provided to various processing elements, including, for example, the processor 410 and an encoder / decoder 430 operating in combination with memory and storage elements that process the data streams as desired for presentation on an output device.
[0086] The various elements of system 400 may be provided within an integrated housing in which the various elements may be interconnected and transmit data between them using a suitable connection arrangement 425, such as an internal bus known in the art, including an Inter-IC (I2C) bus, hardwired, and printed circuit boards.
[0087] System 400 includes a communication interface 450 that enables communication with other devices over a communication channel 460. Communication interface 450 may include, but is not limited to, a transceiver configured to transmit and receive data over communication channel 460. Communication interface 450 may include, but is not limited to, a modem or a network card, and communication channel 460 may be implemented in a wired and / or wireless medium, for example.
[0088] Data is streamed or otherwise provided to system 400 in various embodiments using a wireless network such as a Wi-Fi network, e.g., IEEE 802.11 (IEEE refers to the Institute of Electrical and Electronics Engineers). The Wi-Fi signal in these embodiments is received via communication channel 460 and communication interface 450 adapted for Wi-Fi communication. Communication channel 460 in these embodiments is typically connected to an access point or router that provides access to external networks, including the Internet, to enable streaming applications and other over-the-top communications. Other embodiments provide streamed data to system 400 using a set-top box that delivers data via an HDMI connection in input block 445. Still other embodiments provide streamed data to system 400 using an RF connection in input block 445. As noted above, various embodiments provide data in a non-streaming manner. Additionally, various embodiments use wireless networks other than Wi-Fi, e.g., cellular networks or Bluetooth networks.
[0089] The system 400 can provide output signals to various output devices, including a display 475, speakers 485, and other peripheral devices 495. The display 475 in various embodiments includes, for example, one or more of a touch screen display, an organic light emitting diode (OLED) display, a curved display, and / or a foldable display. The display 475 can be for a television, a tablet, a laptop, a mobile phone, or another device. Furthermore, the display 475 can be integrated with other components (e.g., as in a smartphone) or can be separate (e.g., an external monitor for a laptop). The other peripheral devices 495 in various embodiments include one or more of a stand-alone digital video disc (or digital versatile disc) (DVD for both terms), a disc player, a stereo system, and / or a lighting system. Various embodiments use one or more peripheral devices 495 that provide functionality based on the output of the system 400. For example, a disc player performs the function of playing the output of the system 400.
[0090] In various embodiments, control signals are communicated between system 400 and display 475, speaker 485, or other peripheral devices 495 using signaling such as AV.Link, Consumer Electronics Control (CEC), or other communication protocols that allow control between devices with or without user intervention. Output devices may be communicatively coupled to system 400 via dedicated connections through respective interfaces 470, 480, and 490. Alternatively, output devices may be connected to system 400 via communication interface 450 using communication channel 460. Display 475 and speaker 485 may be integrated into a single unit with other components of system 400 in an electronic device such as, for example, a television. In various embodiments, display interface 470 includes a display driver, such as, for example, a timing controller (TCon) chip.
[0091] Display 475 and speakers 485 may 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 embodiments in which display 475 and speakers 485 are external components, output signals may be provided via dedicated output connections including, for example, an HDMI port, a USB port, or a COMP output.
[0092] These embodiments may be performed by the processor 410, or by computer software implemented by hardware, or by a combination of hardware and software. As a non-limiting example, these embodiments may be implemented by one or more integrated circuits. The memory 420 may be of any type suitable for the technology environment, and may be implemented using any suitable data storage technology, such as, as non-limiting examples, optical memory devices, magnetic memory devices, semiconductor-based memory devices, fixed memories, and removable memories. The processor 410 may be of any type suitable for the technology environment, and may include, as non-limiting examples, one or more of a microprocessor, a general-purpose computer, a special-purpose computer, and a processor based on a multi-core architecture.
[0093] Various implementations involve decoding. As used herein, “decoding” may encompass all or a portion of the processes performed on a received encoded sequence to result in a final output suitable for, for example, a display. In various embodiments, such processes include processes typically performed by a decoder, such as one or more of entropy decoding, inverse quantization, inverse transform, and differential decoding. In various embodiments, such processes also, or alternatively, include processes performed by a decoder of various implementations described herein. For example, the WTRU may divide an image into a number of blocks. The WTRU may generate a set of correlated film grain patterns for a block of the number of blocks. The WTRU may select a correlated film grain pattern from the set of correlated film grain patterns to apply to pixels of the block. Generating the set of correlated film grain patterns may include generating each correlated film grain pattern in the set of correlated film grain patterns using a common random seed. Generating the set of correlated film grain patterns may include applying a low pass filter to the root noise pattern, each correlated film grain pattern of the set of correlated film grain patterns being generated using a different cutoff frequency for the low pass filter. Generating the set of correlated film grain patterns may include performing an autoregressive process on the root noise pattern, each correlated film grain pattern of the set of correlated film grain patterns being generated using a different autoregressive coefficient for the autoregressive process. Generating the set of correlated film grain patterns may include adding a set of randomly positioned grains from the first film grain pattern to the second film grain pattern.
[0094] As a further example, in one embodiment, "decoding" refers to entropy decoding only, in another embodiment, "decoding" refers to differential decoding only, and in another embodiment, "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 to the broader decoding process as a whole will be clear based on the context of the specific description and will be well understood by one of ordinary skill in the art.
[0095] Various implementations involve encoding. Similar to the above discussion regarding “decoding,” “encoding” as used herein can encompass, for example, all or a portion of the processes performed on an input video sequence to produce an encoded bitstream. In various embodiments, such processes include one or more of processes typically performed by an encoder, such as partitioning, differential encoding, transforming, quantizing, and entropy encoding. In various embodiments, such processes also or alternatively include processes performed by an encoder in various implementations described herein. For example, the WTRU can partition an image into a number of blocks. The WTRU can generate a set of correlated film grain patterns for a block of the multiple blocks. The WTRU can select a correlated film grain pattern from the set of correlated film grain patterns to apply to pixels of the block. Generating the set of correlated film grain patterns can include generating each correlated film grain pattern in the set of correlated film grain patterns using a common random seed. Generating the set of correlated film grain patterns may include applying a low pass filter to the root noise pattern, each correlated film grain pattern of the set of correlated film grain patterns being generated using a different cutoff frequency for the low pass filter. Generating the set of correlated film grain patterns may include performing an autoregressive process on the root noise pattern, each correlated film grain pattern of the set of correlated film grain patterns being generated using a different autoregressive coefficient for the autoregressive process. Generating the set of correlated film grain patterns may include adding a set of randomly positioned grains from the first film grain pattern to the second film grain pattern.
[0096] As a further example, in one embodiment, "encoding" refers to only entropy encoding, while in another embodiment, "encoding" refers to only differential encoding, while in another embodiment, "encoding" refers to a combination of differential and entropy encoding. Whether the phrase "encoding process" is intended to refer specifically to a subset of operations or to the broader encoding process as a whole will be clear based on the context of the specific description and will be well understood by one of ordinary skill in the art.
[0097] It should be noted that the coding syntax for syntax elements used herein, e.g., intensity interval, grain parameter, block offset, scaling factor, etc., are descriptive terms, and therefore do not exclude the use of other syntax element names.
[0098] Where a figure is presented as a flow diagram, it should be understood that the figure also provides a block diagram of the corresponding apparatus. Similarly, where a figure is presented as a block diagram, it should be understood that the figure also provides a flow diagram of the corresponding method / process.
[0099] The implementations and aspects described herein may be implemented, for example, in a method or process, an apparatus, a software program, a data stream, or a signal. Even if discussed in the context of only a single implementation form (e.g., discussed only as a method), the implementation of the discussed features may also be implemented in other forms (e.g., an apparatus or a program). An apparatus may be implemented, for example, in appropriate hardware, software, and firmware. A method may be implemented, for example, in a processor, which generally refers to a processing device and includes, for example, a computer, a microprocessor, an integrated circuit, or a programmable logic device. Processors also include communication devices, such as, for example, computers, cellular phones, portable / personal digital assistants ("PDAs"), and other devices that facilitate communication of information between end users.
[0100] References to "one example" or "an example" or "one implementation" or "an implementation," as well as other variations thereof, mean that a particular feature, structure, characteristic, etc. described in connection with an embodiment is included in at least one embodiment. Thus, the appearances of the phrases "in one example" or "in an example" or "in one implementation" or "in an implementation" in various places throughout this application, as well as any other variations, are not necessarily all referring to the same embodiment.
[0101] Additionally, the application may refer to "determining" various information. Determining information may include, for example, one or more of estimating information, calculating information, predicting information, or retrieving information from a memory. Obtaining may include receiving, retrieving, constructing, generating, and / or determining.
[0102] Additionally, the application may refer to "accessing" various information. Accessing information may include, for example, one or more of receiving information, retrieving information (e.g., from a memory), storing information, moving information, copying information, calculating information, determining information, predicting information, or estimating information.
[0103] Additionally, the application may refer to "receiving" various information. Receiving, like "accessing," is intended to be a broad term. Receiving information may include, for example, one or more of accessing information or retrieving information (e.g., from a memory). Furthermore, "receiving" generally involves in some manner an operation, such as, for example, storing information, processing information, transmitting information, moving information, copying information, erasing information, calculating information, determining information, predicting information, or estimating information.
[0104] For example, in the case of "A / B," "A and / or B," and "at least one of A and B," it should be understood that the use of any of the following " / ," "and / or," and "at least one of" is intended to encompass the selection of only the first enumerated alternative (A), or the selection of only the second enumerated alternative (B), or the selection of both alternatives (A and B). As a further example, in the case of "A, B, and / or C" and "at least one of A, B, and C," such language is intended to encompass the selection of only the first enumerated alternative (A), or the selection of only the second enumerated alternative (B), or the selection of only the third enumerated alternative (C), or the selection of only the first and second enumerated alternatives (A and B), or the selection of only the first and third enumerated alternatives (A and C), or the selection of only the second and third enumerated alternatives (B and C), or the selection of all three alternatives (A and B and C). This can be expanded as many times as the items listed, as would be apparent to one of ordinary skill in this and related arts.
[0105] Also, as used herein, the term "signaling" means to indicate something, among other things, to a corresponding decoder. The encoder signal may include, for example, the number of intensity intervals, the number of model values, grain parameters, grain ID, scaling factors, etc. In this way, in one embodiment, the same parameters are used on both the encoder and decoder sides. Thus, for example, the encoder may transmit a particular parameter to the decoder so that the decoder can use the same particular parameter (explicit signaling). Conversely, if the decoder already has the particular parameter as well as other parameters, it may use signaling without transmitting, simply to allow the decoder to know and select the particular parameter (implicit signaling). By avoiding transmitting any actual function, bit savings are realized in various embodiments. It should be understood that signaling may be achieved in various ways. For example, in various embodiments, one or more syntax elements, flags, etc. are used to signal information to a corresponding decoder. Although the above relates to the verb form of the term "signal", the term "signal" may also be used as a noun in this specification.
[0106] As will be apparent to one of ordinary skill in the art, implementations may generate a variety of signals formatted to carry information that may be, for example, stored or transmitted. Information may include, for example, instructions for performing a method or data generated by one of the described implementations. For example, a signal may be formatted to carry a bit stream of the described embodiments. Such a signal may be formatted, for example, as an electromagnetic wave (e.g., using a radio frequency portion of the spectrum) or as a baseband signal. Formatting may include, for example, encoding a data stream and modulating a carrier wave with the encoded data stream. The information that the signal carries may be, for example, analog information or digital information. The signal may be transmitted by a variety of different wired or wireless links, as is well known. The signal may be stored in, accessed from, or received from a processor-readable medium.
[0107] Many examples are described herein. Features of the examples may be provided alone or in any combination across various claim categories and types. Furthermore, 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 embodied in a bitstream or signal that includes information generated as described herein. The information may enable a decoder to decode the bitstream, encoder, bitstream, and / or decoder according to any of the described embodiments. For example, features described herein may be implemented by generating and / or transmitting and / or receiving and / or decoding a bitstream or signal. For example, features described herein may be implemented as a method, process, apparatus, medium storing instructions, medium storing data, or signal. For example, features described herein may be implemented by a TV, a set-top box, a mobile phone, a tablet, or other electronic device that performs decoding. A TV, set-top box, mobile phone, tablet, or other electronic device may display (e.g., using a monitor, screen, or other type of display) the resulting image (e.g., an image from the residual reconstruction of the video bitstream). A TV, set-top box, mobile phone, tablet, or other electronic device may receive a signal that includes the encoded image and perform decoding.
[0108] The synthesis of film grain may be blended with the target picture. The synthesis of film grain may result in one or more of hiding artifacts present in a picture decoded from a compressed video stream, or creating a similar appearance to the original picture in which film grain is present (e.g., if the picture is denoised for better compression efficiency, or if the compression itself removes film grain). Film grain synthesis may be associated with post-processing (e.g., or image processing) that may be unrelated to, for example, decoding, encoding, or transcoding.
[0109] 5 shows an example flow chart of film grain synthesis. Film grain synthesis may generate or retrieve (e.g., from a database such as film stock scans) a set of film grain patterns of a given size A (e.g., 64×64), as shown in 502; a noise picture to be generated and blended with a target picture may be divided into blocks (e.g., coding blocks) of size B (e.g., size B may be 16×16), which may be smaller than size A, as shown in 504; for each block of size B (e.g., each block of size B), a random size B selection of a position is determined based on a set of samples of a virtual size A (e.g., a pseudo-random offset such that a block of size B taken from this offset within the pattern of size A can remain within the boundaries of that pattern), as shown in 506. ), a pattern may be selected for each block, as shown at 508; within a size B block, samples from multiple patterns from the set of film grain patterns may be mixed (e.g., one source pattern per 8×8 sub-block, or one per sample), and the same location selection rules (e.g., same offsets) described herein may be applied (e.g., source patterns may depend on local averages of collocated picture samples), or other processes may include one or more of (e.g., for one color component), such as similar scaling depending on picture sample values (e.g., as shown at 510), deblocking of transition boundaries (e.g., including size B block boundaries, as shown at 510), and / or the like. The selected pattern may be blended with the target picture (e.g., as shown at 512).
[0110] As shown in FIG. 5, a noise picture may be constructed from one or more film grain patterns (e.g., using a collection of master film patterns, where each pattern may be 64×64), for example, by randomly selecting a block of patterns. Block and sub-block may be used interchangeably herein. A picture (e.g., an image) may be divided into blocks (e.g., 16×16). For a block (e.g., each block), a different random offset in the pattern space may be selected. Within a block, multiple patterns may be used (e.g., for different pixels within the block). The random offset in the pattern space may be constant for a given block (e.g., as shown in FIG. 8 and FIG. 9), for example, which may allow for the use of aligned (e.g., correlated) patterns. In such a case, artifacts may be reduced when switching from one pattern to another within the same block (e.g., by keeping the offset constant, all patterns in the block are aligned). The offset may vary for subsequent blocks. Smoothing the transition from one block to another may involve deblocking, as described herein.
[0111] Figure 6 shows examples of film grain patterns for film grain synthesis. As shown in Figure 6, a set of film grain patterns of a given size A (e.g., 64x64) can be generated or retrieved (e.g., from a database such as film stock scans).
[0112] Figure 7 shows an example of generating block offsets for film grain synthesis. As shown in Figure 7, a noise picture can be generated and blended with the target picture. A selection of random size B locations can be generated from a set of virtual size A of samples.
[0113] Figure 8 shows an example of selecting a pattern for block samples. As shown in Figure 8, samples from multiple patterns from a set of film grain patterns may be mixed.
[0114] Multiple patterns can be used based on the behavior of film grain particles depending on the exposure. Films may be made from multiple emulsions of different grain sizes (e.g., sensitive to different amounts of light) to cover the full dynamic range of the film. For example, a black and white film may contain three layers, and a color film may be made from nine layers (e.g., three for each primary color dye). The physical grains may be too small to be visible (e.g., for scanning, where many grains may contribute to a single pixel). The grain characteristics may affect the final result and create different appearances depending on the exposure. Within the picture, this may result in different appearances depending on the lightness (e.g., sample value).
[0115] Film grain synthesis techniques may or may not use multiple film grain patterns (e.g., as described herein) within color components of the same picture. For example, film grain synthesis may use a single pattern per picture and color component. Pattern and block sizes may differ from the examples described herein. For example, the pattern size may be 64×64 for luma and 32×32 for chroma in 4:2:0 mode, while the block size may be 32×32 for luma and 16×16 for chroma in 4:2:0 mode. Film grain synthesis (e.g., based on film grain synthesis supplemental enhancement information (SEI)) may use multiple patterns within color components of a given picture, as described herein. The pattern selection (e.g., and scaling factor) for a given 8×8 sub-block may be based on the 8×8 average of the co-located picture samples of the current color component. This local 8x8 average to select the pattern (eg, and scaling factor) can be costly and may use a 7 line buffer.
[0116] The film grain pattern may be selected on a pixel basis. In other words, different film grain patterns (e.g., different film grain patterns to apply to blocks) may be selected within a picture depending on pixel values (e.g., pixel luminance values or color component intensity values). Figure 9 shows an example of pixel-based template selection and associated correlation patterns. Pixel-based selection may be performed during pattern generation.
[0117] Pixel-based pattern selection (e.g., varying the selected film grain pattern depending on a pixel value, e.g., a pixel luminance value or a color component intensity value) may change the pattern for neighboring pixels, which may reduce the film grain pattern spatial consistency (e.g., spatial correlation).
[0118] In some examples, changes on the 8×8 sub-blocks may be synchronized (e.g., by changing the pattern based on the average of color component intensities across the 8×8 sub-blocks) and the transitions may be smoothed using deblocking, which may use at least a 7-line buffer to calculate the average across the 8 lines, which may be costly (e.g., from a hardware perspective, since using line buffers may involve using a large amount of memory).
[0119] Pixel-based pattern selection may avoid the use of line buffers while maintaining multiple patterns to simulate grain characteristics (e.g., grain size) that vary with pixel values, such as color component intensity values. This may better simulate authentic film grain (e.g., to maintain an original appearance or to fulfill artistic intent). However, pixel-based pattern selection may not preserve spatial correlation (e.g., because patterns for adjacent pixels may be different).
[0120] Correlated (e.g., aligned) patterns may be generated to represent different grain characteristics (e.g., grain size), for example, to preserve spatial correlation in pixel-based pattern selection. In one example, correlated patterns may be generated by smoothing the same root pattern with different smoothing strengths or by using incremental generation (e.g., Monte Carlo simulation). In such cases, spatial consistency (e.g., spatial correlation) may be preserved when different correlated patterns are selected for adjacent pixels.
[0121] It may be possible to use multiple grain patterns for color components in the same picture without the need to use a line buffer. Patterns may be correlated and / or blended. For example, as shown in FIG. 6, generated and / or retrieved patterns (e.g., a set of film grain patterns) may be correlated and / or blended with each other. One or more patterns may then be selected from the set of correlated patterns. In some examples, pattern selection may involve blending patterns (e.g., blending multiple correlated patterns from a set of correlated patterns) for adjacent selected values to create (e.g., smooth) a transition, as shown in FIG. 8. In some examples, both techniques (e.g., correlation / blending patterns and blending patterns) may be used together. Pattern selection may be current line dependent (e.g., only current line dependent) (e.g., may not utilize a line buffer to change patterns on a line-by-line basis), as shown in FIG. 10. Pattern selection may be determined for the first n lines of a sub-block, as shown in FIG. 8, and subsequent lines of the sub-block may reuse the same determination.
[0122] If sub-block based modifications (e.g., all sub-block based modifications) are removed (e.g., pattern selection and scaling factors are sample based), then deblocking on sub-block boundaries as described herein may not be used.
[0123] The correlation patterns may be generated using low-pass filtering. The correlation patterns may be generated by low-pass filtering the same high-frequency root noise pattern with different cutoff frequencies. The patterns may be decorrelated due to different random seeds being used to generate each pattern (e.g., due to different fill patterns of discrete cosine transform (DCT) coefficients). This may be corrected using one or more of: generating the patterns (e.g., all patterns) using the same random seed (e.g., a common random seed); generating a full 64×64 array of random samples (e.g., the same for all patterns); zeroing out coefficients with frequencies higher than the horizontal or vertical cutoff frequency that characterizes the generated pattern; or applying a two-dimensional inverse discrete cosine transform (iDCT2). In some examples, the full 64×64 array may not be filled, or may be filled only about the highest frequency cutoff. A low-pass filtering process (e.g., other than iDCT2) may be used to generate the correlation patterns. In one example, a smooth decay may be used instead of zeroing out the coefficients. In one example, an inverse fast Fourier transform (iFFT) may be used instead of the iDCT.
[0124] The correlation patterns may be generated using other techniques driven by a common underlying random pattern. For example, the correlation patterns may be generated by the same random pattern (e.g., a common root noise pattern) that undergoes an autoregressive process or other filtering techniques (e.g., low-pass filtering) with coefficients or parameters (e.g., autoregressive coefficients or filter cutoff frequencies) that vary for each pattern. The randomization (e.g., for generating grain pictures from grain patterns) may be associated with a random offset (e.g., as shown in FIG. 5). The offset may be different for each size B block (e.g., 16×16) in the picture. In one example, random sign inversion may be applied, which may add diversity (e.g., the random offset may be kept constant for each block).
[0125] The correlated patterns may be generated using iterative noise generation. If different patterns represent different particle densities, an iterative process may be used (e.g., by adding N grains at random locations from one pattern to the next, as in a Monte Carlo simulation). In some examples, the transition (e.g., change) may be smoother if a small number of grains are added or removed at random locations from one pattern to the next (e.g., adding a layer with N grains associated with a second pattern on top of a first layer associated with the first pattern).
[0126] The correlation patterns may be generated using physical capture or simulation. The correlation patterns may be generated by capturing physical phenomena (e.g., photographs of the same area of the film at different intervals during the development process, or photographs with the film exposed to different amounts of light). A computer model may be used to determine the location and / or characteristics of the grains in the emulsion layers (e.g., each emulsion layer). The computer model may model (e.g., may then model) the grain behavior at different exposure levels and emulate a scan at a given resolution. The correlation patterns may be generated by repeatedly overlaying different grain images from one pattern onto the next pattern. These grain images may be obtained from separate photographs of the emulsion layers that may be stacked to form a film. The photographs may be processed to generate exposure levels (e.g., all used exposure levels).
[0127] Patterns assigned to adjacent intensities may be mixed. Even for uncorrelated patterns, if the pattern selection is based on a spatially smooth characteristic (e.g., the target picture sample intensity), a smooth transition between patterns may be achieved by interpolating between adjacent patterns (e.g., with respect to the selected characteristic). For example, if P1 is the pattern selected for intensity I1 and P2 is the pattern selected for I2, an interpolated pattern P may be generated for intensities I between I1 and I2 as follows:
[0128]
number
[0129] If the selection values are not smooth enough, this technique may not prevent sharp transitions. If the selection changes too frequently, there may not be a smooth transition, and providing spatial consistency may not help to create a smooth transition. This technique may be extended to blend more than two adjacent patterns, for example, three or four adjacent patterns.
[0130] Correlated patterns can be generated and blended for adjacent intensities. Even with correlated patterns, the number of patterns may be fewer (e.g., much fewer) than the possible selection characteristics (e.g., intensities), so pattern transitions may be visible if the target picture contains smooth variations of the selection characteristics (e.g., smooth intensity gradients). In such cases, interpolation between adjacent patterns may be used as described herein.
[0131] The correlated and / or blended patterns may be selected without the use of a line buffer. To avoid the use of a line buffer, the selection may not use a metric that involves multiple picture lines. The selection may be sample-based, based on a horizontal (e.g., horizontal only) local average (e.g., 3×1, 8×1 average), or based on a horizontal low-pass filter. For example, the selection may be a direct mapping of target picture sample values to a pattern index (e.g., a look-up table). The pattern index may indicate the correlation pattern to apply to a given pixel of the block.
[0132] FIG. 10 shows an example of selecting a pattern for film grain compositing without sub-blocks.
[0133] Uncorrelated patterns may be selected without a line buffer. For uncorrelated patterns, spatial consistency may be provided by aligning the selection on a subblock basis. To avoid the use of a line buffer, the selection may be determined once for samples of the first line of a subblock, and the selection may be reused for subsequent lines of the subblock. This may result in a tradeoff of line buffer for pattern index buffer.
[0134] The uncorrelated pattern can be selected with a reduced number of line buffers. Using a reduced number of line buffers N (e.g., 1), the selection value can be derived from at most N+1 first lines of the subblock (e.g., 8×2 average), and the selection value can be reused for subsequent lines of the subblock. In some examples, the subblock size can be M×(N+1), and the pattern can be allowed to change N+1 lines (e.g., every N+1 lines), which can provide limited spatial consistency when N is small (e.g., 1).
[0135] Features (one or more) related to deblocking (e.g., deblocking only) on size B block boundaries are provided herein. If subblock-based modifications (e.g., all subblock-based modifications) are removed (e.g., pattern selection and scaling factors are sample-based), deblocking on subblock boundaries may not be used (e.g., may no longer be required). In one example, if a size B block is 16×16 and a subblock is 8×8, 16×16 horizontal right / left edges (e.g., only 16×16 horizontal right / left edges) may be deblocked (e.g., instead of 8×8). Vertical pre-deblocking by changing the pattern every 8 lines may be replaced by traditional deblocking (e.g., when a small number of line buffers are affordable) or by overlapping. In such cases, the block offset alignment to 8 lines may be relaxed. In some examples, changing the pattern every 16 lines may be provided, which may constrain the block offset to a multiple of 16 lines.
[0136] Although the features and elements are described above in certain combinations, one skilled in the art will understand that each feature or element may 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 embodied 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, read-only memory (ROM), random-access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks and digital 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
1. A device, comprising: a processor, the processor comprising: Divide the image into multiple blocks, generating a set of correlated film grain patterns for a block of the plurality of blocks; A device configured to select a correlated film grain pattern from the set of correlated film grain patterns to apply to pixels of the block.
2. 2. The device of claim 1 , wherein the processor being configured to generate the set of correlated film grain patterns comprises the processor being configured to generate each correlated film grain pattern in the set of correlated film grain patterns using a common random seed.
3. 2. The device of claim 1, wherein the processor being configured to generate the set of correlated film grain patterns comprises the processor being configured to apply a low pass filter to a root noise pattern, each correlated film grain pattern in the set of correlated film grain patterns being generated using a different cutoff frequency for the low pass filter.
4. 2. The device of claim 1, wherein the processor being configured to generate the set of correlated film grain patterns comprises the processor being configured to perform an autoregressive process on a root noise pattern, each correlated film grain pattern in the set of correlated film grain patterns being generated using different autoregressive coefficients for the autoregressive process.
5. The device of claim 1 , wherein the correlated film grain pattern is selected based on pixel values associated with the pixels of the block.
6. 2. The device of claim 1 , wherein the processor being configured to generate the set of correlated film grain patterns comprises the processor being configured to add a set of randomly positioned grains from a first film grain pattern to a second film grain pattern.
7. 2. The device of claim 1, wherein the processor being configured to select the correlated film grain pattern comprises the processor being configured to blend multiple correlated film grain patterns from the set of correlated film grain patterns for adjacent selection values.
8. The device of claim 1 , wherein the correlated film grain pattern is selected based on a target picture sample value, a horizontal local average, or a horizontal low pass filter.
9. 10. The device of claim 8, wherein the correlated film grain pattern is selected based on a target picture sample value, the target picture sample value being mapped to a pattern index that indicates the correlated film grain pattern to apply to the pixels of the block.
10. The processor, determining a first set of properties associated with first particles in the first emulsion layer and a second set of properties associated with second particles in the second emulsion layer; modeling the behavior of the first particles and the second particles at different exposure levels; emulating a scan of the first particle and the second particle at a given resolution; 2. The device of claim 1, further configured to derive a first grain image from the first emulsion layer and a second grain image from the second emulsion layer, wherein the processor configuring to generate the set of correlated film grain patterns includes the processor configured to iteratively overlay the first grain image and the second grain image.
11. The device of claim 1 , wherein the correlated film grain pattern is a first size and the blocks are a second size smaller than the first size.
12. 1. A method comprising: Dividing an image into a number of blocks; generating a set of correlated film grain patterns for a block of the plurality of blocks; selecting a correlated film grain pattern from the set of correlated film grain patterns for application to pixels of the block.
13. The method of claim 12 , wherein generating the set of correlated film grain patterns comprises generating each correlated film grain pattern in the set of correlated film grain patterns using a common random seed.
14. 13. The method of claim 12, wherein generating the set of correlated film grain patterns includes applying a low pass filter to a root noise pattern, each correlated film grain pattern in the set of correlated film grain patterns being generated using a different cutoff frequency of the low pass filter.
15. 13. The method of claim 12, wherein generating the set of correlated film grain patterns includes performing an autoregressive process on a root noise pattern, each correlated film grain pattern in the set of correlated film grain patterns being generated using different autoregressive coefficients for the autoregressive process.
16. The method of claim 12 , wherein the correlated film grain pattern is selected based on pixel values associated with the pixels of the block.
17. The method of claim 12 , wherein generating the set of correlated film grain patterns includes adding a set of randomly positioned grains from a first film grain pattern to a second film grain pattern.
18. The method of claim 12 , wherein selecting the correlated film grain pattern comprises blending multiple correlated film grain patterns from the set of correlated film grain patterns for adjacent selected locations.
19. The method of claim 12 , wherein the correlated film grain pattern is selected based on a target picture sample value, a horizontal local average, or a horizontal low pass filter.
20. 20. The method of claim 19, wherein the correlated film grain pattern is selected based on a target picture sample value, the target picture sample value being mapped to a pattern index that indicates the correlated film grain pattern to apply to the pixels of the block.
21. determining a first set of properties associated with first particles in the first emulsion layer and a second set of properties associated with second particles in the second emulsion layer; modeling the behavior of the first particles and the second particles at different exposure levels; emulating a scan of the first particle and the second particle at a given resolution; 13. The method of claim 12, further comprising: deriving a first grain image from the first emulsion layer and a second grain image from the second emulsion layer, and generating the set of correlated film grain patterns comprises iteratively overlaying the first grain image and the second grain image.
22. The method of claim 12 , wherein the correlated film grain pattern is a first size and the blocks are a second size that is smaller than the first size.