WO2025071283A1 - Procédé et dispositif de codage/décodage vidéo basés sur une détermination améliorée de modèle de compensation d'éclairage local - Google Patents

Procédé et dispositif de codage/décodage vidéo basés sur une détermination améliorée de modèle de compensation d'éclairage local Download PDF

Info

Publication number
WO2025071283A1
WO2025071283A1 PCT/KR2024/014632 KR2024014632W WO2025071283A1 WO 2025071283 A1 WO2025071283 A1 WO 2025071283A1 KR 2024014632 W KR2024014632 W KR 2024014632W WO 2025071283 A1 WO2025071283 A1 WO 2025071283A1
Authority
WO
WIPO (PCT)
Prior art keywords
information
lic
prediction
present
video
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/KR2024/014632
Other languages
English (en)
Korean (ko)
Inventor
류창우
최기호
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kaon Group Co Ltd
Kyung Hee University
Original Assignee
Kaon Group Co Ltd
Kyung Hee University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kaon Group Co Ltd, Kyung Hee University filed Critical Kaon Group Co Ltd
Priority to CN202480060927.6A priority Critical patent/CN121925853A/zh
Priority claimed from KR1020240130655A external-priority patent/KR20250046217A/ko
Publication of WO2025071283A1 publication Critical patent/WO2025071283A1/fr
Anticipated expiration legal-status Critical
Pending legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/102—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or selection affected or controlled by the adaptive coding
    • H04N19/103—Selection of coding mode or of prediction mode
    • H04N19/105—Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/102—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or selection affected or controlled by the adaptive coding
    • H04N19/132—Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/169—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding
    • H04N19/17—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding the unit being an image region, e.g. an object
    • H04N19/176—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding the unit being an image region, e.g. an object the region being a block, e.g. a macroblock
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/50—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding
    • H04N19/503—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding involving temporal prediction
    • H04N19/51—Motion estimation or motion compensation
    • H04N19/513—Processing of motion vectors
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/70—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals characterised by syntax aspects related to video coding, e.g. related to compression standards

Definitions

  • the present invention relates to video compression technology, and more particularly, to improvement of local illuminance compensation (LIC) technology included in prediction coding technology that contributes to improvement of compression performance in a video encoder and decoder.
  • LIC local illuminance compensation
  • the present invention may be in the same technical field as at least one of digital video compression technology standards known by the standard names such as MPEG-2, MPEG-4 Video, H.263, H.264/AVC, H.265/HEVC, H.266/VVC, VC-1, AV1, QuickTime, VP-9, VP-10, Motion JPEG, or in the technical field for improving the inherent efficiency of the standard, or in the technical field for improving or replacing the standard.
  • digital video compression technology standards known by the standard names such as MPEG-2, MPEG-4 Video, H.263, H.264/AVC, H.265/HEVC, H.266/VVC, VC-1, AV1, QuickTime, VP-9, VP-10, Motion JPEG, or in the technical field for improving the inherent efficiency of the standard, or in the technical field for improving or replacing the standard.
  • Digital video encoding and decoding are widely used in various digital video applications. For example, digital television broadcasting, transmission of video through communication networks, video calls/video conversations/video chats, recording and providing video content using optical media including VCD (video compact disc)/DVD (digital versatile disc)/Blu-Ray, all procedures for producing, editing, collecting, and distributing video content, and devices such as video shooting devices and camcorders for shooting and recording video for various reasons including personal, commercial, industrial, and security purposes, all depend on video encoding and decoding technologies.
  • VCD video compact disc
  • DVD digital versatile disc
  • Blu-Ray digital versatile disc
  • implementations that may be referred to as digital video encoders and decoders may form part of a wide range of devices, including digital televisions, digital broadcasting systems, wireless broadcasting systems, computers in the form of notebooks/desktops/tablets, e-book readers, digital cameras, digital recording devices, digital multimedia playback devices, video game devices/terminals/console, mobile phones (including smartphones) with multimedia playback capabilities, devices for video conferencing, and other devices related to the generation, recording, and provision of digital video.
  • the above digital video encoders and decoders can be implemented by a digital video compression standard that is widely used and understood by those skilled in the art.
  • the digital video compression standard can include at least one of compression standards known by standard names such as MPEG-2, MPEG-4 Video, H.263, H.264/AVC, H.265/HEVC, H.266/VVC, VC-1, AV1, QuickTime, VP-9, VP-10, and Motion JPEG.
  • Video encoders and decoders can be implemented to encode or decode digital video information more efficiently while complying with the above standards, or by improving or modifying the above standards. Attempts to modify the above standards can also lead to the derivation of new standards.
  • ECM enhanced compression model
  • JVET joint video experts team
  • the LIC technology refers to a technology that calculates a prediction residual by correcting (i.e., compensating) illuminance for a value of a prediction target block selected for predictive encoding in inter-picture predictive encoding (so-called inter encoding) and/or intra-picture predictive encoding (so-called intra encoding), and a decoding process corresponding to each of the above encoding methods, and in particular, it can mean that the compensation is performed locally, for example, on a block-by-block basis.
  • the present invention proposes an improved LIC implementation method to solve the above-described technical problems.
  • a method for decoding an encoded video bitstream includes the steps of extracting information related to local illumination compensation (LIC) for a current block from the bitstream, obtaining LIC information from the extracted information, determining at least one linear model based on the LIC information, generating a prediction sample for the current block by a LIC method using the linear model, and restoring the current block using the prediction sample, wherein the linear model may be characterized in that it is defined by at least one linear function or a quadratic function.
  • LIC local illumination compensation
  • the above LIC information may include model parameters including a reference sample value (Ref), a scale factor (Scale), a shift factor (Shift), and an offset factor (Offset), and the linear model may be characterized by being defined by an arithmetic expression that derives a predicted sample value (Pred) based on the model parameters.
  • Ref reference sample value
  • Scale scale factor
  • Shift shift factor
  • Offset offset factor
  • the above reference sample value may be characterized in that it is determined by a weighted sum of at least one prediction value derived through intra-screen and/or inter-screen prediction.
  • the above prediction value may be characterized in that it is derived by at least one of motion estimation and template matching.
  • At least one weight for deriving the above weighted sum may be characterized in that it is selected by an index from a predefined table.
  • At least one weight for deriving the above weighted sum may be characterized in that it is determined to give a greater weight to a value having a smaller information requirement cost calculated by a method including SAD (Sum of Absolute Differences), SATD (Sum of Absolute Transformed Differences), or MR-SAD (Mean-removal SAD) among each of the above predicted values.
  • the above LIC information may be characterized in that it comprises a parameter set including a coefficient of at least one model parameter, preferably the scale coefficient, the shift coefficient, and the offset coefficient, each of the coefficients, and each of the coefficients is selected from a list of at least one predetermined parameter set.
  • the list of the above parameter sets may be characterized in that they are selected by index from a predefined table.
  • the list of the above parameter sets may be characterized in that it is constructed from a candidate list including parameter sets of LICs used in surrounding blocks of the current block.
  • the list of parameter sets may be characterized in that it is configured based on the result of re-ordering the candidate list based on template matching.
  • the re-ordering may be performed based on the encoding information required cost calculated according to the template matching result, and according to one embodiment, the re-ordering may be performed in order of low cost.
  • the information required cost may be calculated by SAD, SATD, or MR-SAD, and the re-ordering may also be performed based on this cost.
  • the list of said parameter sets may be characterized by including at least one parameter set predicted in the same form as that adopted by the encoder, based on information obtained from a previously decoded bit string.
  • the step of obtaining the above LIC information may include a step of extracting information of available surrounding blocks and obtaining the LIC information from the extracted information when there is a boundary condition that blocks above or to the left of the current block cannot be used.
  • the above boundary conditions may be characterized by being specified by a high-level bitstream syntax.
  • the above linear model may be characterized by being defined by a combination of at least one linear function and at least one quadratic function.
  • the above linear model may be characterized by including at least one linear function expressed in the form of ⁇ *p[x]+ ⁇ , where the predicted value is p[x].
  • the above linear model may be characterized by including at least one quadratic function expressed in the form of ⁇ *(p[x]2)+ ⁇ *p[x]+ ⁇ , where the predicted value is p[x].
  • a method for encoding a video signal into a bit string includes the steps of extracting information related to local illumination compensation (LIC) for a current block based on a previously encoded video signal, and obtaining LIC information from the extracted information, determining at least one linear model based on the LIC information, generating a prediction sample for the current block using the linear model, encoding the current block using the prediction sample, and recording the encoding result in the bit string, wherein the linear model may be characterized in that it is defined by at least one linear function or a quadratic function.
  • LIC local illumination compensation
  • the above LIC information may include model parameters including a reference sample value (Ref), a scale factor (Scale), a shift factor (Shift), and an offset factor (Offset), and the linear model may be characterized by being defined by an arithmetic expression that derives a predicted sample value (Pred) based on the model parameters.
  • Ref reference sample value
  • Scale scale factor
  • Shift shift factor
  • Offset offset factor
  • the step of obtaining the above LIC information may include a step of extracting information of available surrounding blocks and obtaining the LIC information from the extracted information when there is a boundary condition that blocks above or to the left of the current block cannot be used.
  • a decoder device configured to decode a video bit-stream encoded by a computing device includes a processor, and a memory storing instructions executable by the processor, wherein the instructions are configured to include instructions for extracting information related to local illumination compensation (LIC) for a current block from the bit-stream, obtaining LIC information from the extracted information, determining at least one linear model based on the LIC information, generating a prediction sample for the current block by a LIC method using the linear model, and restoring the current block using the prediction sample, wherein the linear model may be defined by at least one linear function or a quadratic function.
  • LIC local illumination compensation
  • At least one of the following effects can be derived from video encoding and decoding: improvement of encoding efficiency, improvement of decoding efficiency, improvement of video quality, reduction of computational amount, reduction of software size, reduction of hardware size, and improvement of other performances related to encoding and decoding.
  • Figure 1 is a conceptual diagram of a video communication system according to one embodiment of the present invention.
  • FIG. 2 is a conceptual diagram of the arrangement of an encoder and decoder in a real-time video streaming environment according to one embodiment of the present invention.
  • Figure 3 is a conceptual diagram of a functional unit of a video decoder according to one embodiment of the present invention.
  • Figure 5 is a conceptual diagram of a frame type according to one embodiment of the present invention.
  • Figure 6 is a conceptual diagram showing the structure of a video encoder according to the H.266/VVC standard.
  • Figure 7 is a conceptual diagram showing the general structure of a LIC application method according to one embodiment of the present invention.
  • first, second, etc. may be used to describe various components, the components should not be limited by the terms. The terms are only used to distinguish one component from another.
  • first component could be referred to as the second component, and similarly, the second component could also be referred to as the first component, without departing from the scope of the present invention.
  • the term "and/or" includes any combination of a plurality of related listed items or any of a plurality of related listed items, and is non-exclusive unless otherwise indicated.
  • the listing of items in this application is merely an exemplary description to easily explain the spirit and possible implementation methods of the present invention, and therefore, is not intended to limit the scope of embodiments of the present invention.
  • a or B can mean “only A”, “only B”, or “both A and B”. In other words, as used herein, “A or B” can be interpreted as “A and/or B”. For example, as used herein, “A, B or C” can mean “only A”, “only B”, “only C”, or “any combination of A, B and C”.
  • a slash (/) or a comma can mean “and/or”.
  • A/B can mean “A and/or B”.
  • A/B can mean "only A”, “only B”, or “both A and B”.
  • A, B, C can mean "A, B, or C”.
  • At least one of A and B can mean “only A”, “only B” or “both A and B”. Additionally, as used herein, the expressions “at least one of A or B” or “at least one of A and/or B” can be interpreted identically to “at least one of A and B”.
  • At least one of A, B and C can mean “only A”, “only B”, “only C”, or “any combination of A, B and C”. Additionally, “at least one of A, B or C” or “at least one of A, B and/or C” can mean “at least one of A, B and C”.
  • the embodiments may be described or illustrated in terms of unit blocks that perform the described function or functions.
  • the blocks may be expressed as one or more devices, units, modules, parts, etc. in this application.
  • the blocks may be implemented in hardware by one or more logic gates, integrated circuits, processors, controllers, memories, electronic components, or information processing hardware implementation methods that are not limited thereto.
  • the blocks may be implemented in software by application software, operating system software, firmware, or information processing software implementation methods that are not limited thereto.
  • One block may be implemented by being separated into multiple blocks that perform the same function, or conversely, one block may be implemented to perform the functions of multiple blocks simultaneously.
  • the blocks may also be implemented by being physically separated or combined by any criterion.
  • the blocks may be implemented to operate in an environment where their physical locations are not specified and are separated from each other by a communication network, the Internet, a cloud service, or a communication method that is not limited thereto. All of the above implementation methods are within the scope of various embodiments that can be taken by a person skilled in the field of information and communication technology to implement the same technical idea, and therefore, any detailed implementation method should be interpreted as being included within the scope of the technical idea of the invention of the present application.
  • FIG. 1 is a conceptual diagram of a video communication system according to one embodiment of the present invention.
  • the video communication system (100) may be configured to include at least two terminals (110, 120) that are connected to each other through a network (105).
  • FIG. 1 may mean a block diagram for configuring a one-way video communication network.
  • a first terminal (110) among the terminals may encode the video data in order to transmit (111) the video data through a network (105).
  • a second terminal (120) among the terminals may be configured to receive (121) the encoded video data through a network and decode and display it.
  • each terminal 110, 120 may be configured to encode video data acquired by itself for video transmission (112, 122) to each other terminal via the network.
  • Each terminal may also be configured to receive (113, 123) and decode video data transmitted by another terminal via the network, and display the decoded video data.
  • each terminal (110, 120) shown in Fig. 1 may be exemplified as devices such as server computers, personal computers, portable computers, and smartphones, depending on the embodiment, but are not limited thereto, and may be any computing device generally used.
  • each terminal (110, 120) may mean a desktop computer, a laptop computer, a tablet PC, a mobile phone, a smart phone, a PDA (personal digital assistant), a workstation, an electronic calculator, a server computer, a cloud computer, a virtual computer, a quantum computer, or any other electronic, electrical, or quantum computing device implemented in a movable or non-movable form, and in particular, it may be interpreted as any device designed to operate as a terminal device according to an embodiment of the present invention among such devices, capable of operating as a terminal device according to an embodiment of the present invention, or capable of installing and/or executing a computer program that enables operating as a terminal device according to an embodiment of the present invention or performing a method corresponding to such
  • Each of the above terminals (110, 120) may be implemented by a plurality of functional units that are interconnected in various forms, such as a bus, a circuit, or a relationship between a routine and a subroutine, and configured to exchange information within each of the above terminals (110, 120).
  • the above terminals may be configured to include a processor (130) having a calculation function and a memory (140) connected to the processor.
  • the processor (130) described in this specification may mean one or more general-purpose computers or special-purpose computers, such as a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable array (FPA), a programmable logic unit (PLU), a microprocessor, or any other device capable of executing instructions and responding.
  • ALU arithmetic logic unit
  • FPA field programmable array
  • PLU programmable logic unit
  • microprocessor or any other device capable of executing instructions and responding.
  • processor (130) may include a plurality of processing elements and/or a plurality of types of processing elements.
  • a device may include a plurality of processors or one processor and one controller as the processor (130).
  • the processor (130) may be implemented by various processing configurations, such as a parallel processor or a multi-core processor.
  • the processor (130) may be configured to execute an operating system (OS) and one or more software executed on the operating system. In addition, the processor may access, store, manipulate, process, and generate data in response to the execution of the software.
  • the software may include a computer program, a code, an instruction, or a combination of one or more of these, and may configure a processing device to operate as desired or independently or collectively command a processing device.
  • the software may be permanently or temporarily embodied in any type of machine, component, physical device, virtual equipment, computer storage medium or device, or transmitted signal wave to be interpreted by the processor (130) or to provide instructions or data to the processor.
  • the software may be distributed among a plurality of computer systems connected to the network (105), such as the terminals (110, 120), and stored or executed in a distributed manner.
  • the software may also be implemented in the form of program commands that can be executed through various computer means and recorded or stored in the memory (140).
  • the memory (140) may be a computer-readable recording medium, and program commands, data files, data structures, etc. may be recorded singly or in combination in the computer-readable recording medium.
  • the program commands stored in the memory (140) may be based on a command system specifically designed and configured for the embodiment of the present invention, or may follow a command system known and available to those skilled in the art of computer software, for example, a command system exemplified by the assembly language, C, C++, Java, Python, etc. It should be understood that the command system and the program commands thereby include not only machine language codes created by a compiler, but also high-level language codes that can be executed by the device and/or the processor (130) according to one embodiment of the present invention using an interpreter, etc.
  • the computer-readable recording medium constituting the device according to one embodiment of the present invention may include a temporary or volatile recording medium that is maintained only while the processor is operating, such as a processor cache, a RAM, a flash memory, or a relatively nonvolatile or long-term recording medium, such as a magnetic media such as a hard disk, a floppy disk, and a magnetic tape, an optical media such as a CD-ROM, a DVD, a magneto-optical media such as a floptical disk, or a solid state memory, or a read-only recording medium such as a ROM arranged on hardware, and further, the hardware itself configured to perform an operation equivalent to a series of program commands by a hard-wired structure by circuit wiring, and since each step for performing the operation implementing the embodiment of the present invention can be viewed as being recorded by the connection and arrangement of the hardware components, the connection and arrangement method It is obvious to those skilled in the art that this can soon be seen as equivalent to the above memory
  • one hardware device may be configured to operate as a module composed of one or more of the software to perform the operations of the embodiments of the present invention, and vice versa.
  • all or part of the operations assigned to a certain functional unit may be implemented by one or more of the software stored in the device according to one embodiment of the present invention (preferably, in any one of the recording media belonging to the category of the memory) and configured to be executed by the processor, and in this case, such a functional unit may be referred to as a functional unit "included" in the processor.
  • the present invention is applicable to all environments for forming a one-way or two-way video communication network, and it should be understood that the network (105) can be formed by any means for transporting encoded video data between the terminals (110, 120).
  • the network (105) may mean a wired or wireless communication network.
  • the network may be configured to communicate information using any communication standard, and the communication standard may include packet-based communication.
  • the packet communication may be understood to mean including, for example, a packet known as TCP or UDP.
  • the wired communication method of the network (105) may be a method of connecting to an external communication network by a telephone line of the RJ-11 standard, an Ethernet cable belonging to various categories of the RJ-45 standard, other coaxial cables, metal cables, optical cables, and other various wired media.
  • the wireless communication method of the above network (105) may include, depending on the embodiment, a short-range wireless communication method including Bluetooth, Wi-Fi, Zigbee, and NFC (near field communication), or may include a long-range wireless communication method that may be referred to as a name of a wireless communication technology collectively called a generation name of communication standards such as Wibro, WiMax, Global Systems for Mobile Communications (GSM), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), Long-Term Evolution (LTE), New Radio (NR), and other 2G, 3G, 4G, 5G, and 6G, and a name of an international standard wireless communication standard such as IMT-2000, IMT-Adcanced, IMT-2020, and IMT-2030.
  • GSM Global Systems for Mobile Communications
  • CDMA Code Division Multiple Access
  • WCDMA Wideband Code Division Multiple Access
  • LTE Long-Term Evolution
  • NR New Radio
  • any conventional or newly developed wired or wireless communication means, method, standard, and protocol are applied to the implementation of the network (105), there is no problem in achieving the purpose of the present invention as long as it is a means configured to perform transmission and reception in an information and communication device such as the terminal (110, 120).
  • one network (105) can be configured in a mixed manner by one or more wired and/or wireless standards.
  • the network (105) may be understood to include a process of information transmission using a computer-readable recording medium.
  • the configuration of the network is not limited to a communication medium, and should be understood to include a process of temporarily storing and physically transporting in a computer-readable memory and/or recording medium.
  • the computer-readable recording medium used for the information transmission may be understood to mean, in particular, a relatively non-volatile or long-term recording medium such as a magnetic media such as a hard disk, a floppy disk, and a magnetic tape, an optical media such as a CD-ROM, a DVD, a magneto-optical media such as a floptical disk, or a solid state memory, which is mainly used as a means of transporting data between computing devices.
  • a relatively non-volatile or long-term recording medium such as a magnetic media such as a hard disk, a floppy disk, and a magnetic tape
  • an optical media such as a CD-ROM, a DVD
  • magneto-optical media such as a floptical disk
  • solid state memory which is mainly used as a means of transporting data between computing devices.
  • Any other means of information communication or transportation applied can be considered to fall within the scope of embodiments of the present invention as long as it has a structure that supports transmitting video data in an encoded state and decoding it. Accordingly, in addition to some of the examples listed above, all means of information communication or transportation known in the past or newly provided can fall within the scope of application of the present invention.
  • FIG. 2 is a conceptual diagram of the arrangement of an encoder and decoder in a real-time video streaming environment according to one embodiment of the present invention.
  • the streaming system (200) illustrated in FIG. 2 can be considered to be applied to, for example, a video data communication network including digital broadcasting, video telephony, and video conferencing.
  • a video data communication network including digital broadcasting, video telephony, and video conferencing.
  • the technical structure identical to or similar to the streaming system can be equally applied to a case where information is transmitted via a recording medium as described above.
  • the streaming system may include a video source (210) that generates a video stream.
  • the video source may include a digital video acquisition means (212), which may be, for example, a digital camera or other device, for acquiring uncompressed raw video.
  • the raw video stream (215) may have a huge capacity and may therefore be compressed by a video encoder (217) coupled or connected to the video source.
  • the above encoder (217) may be configured as a means including hardware, software, or a combination of the two, configured to implement an image encoding method and/or an implementation method thereof according to one embodiment of the present invention.
  • an encoded bit stream (219) with a reduced capacity compared to the original video stream can be output.
  • the bit stream (219) can be provided in real time for communication by a relay device, which may be referred to as a streaming server (220), for example, and/or can be stored in a recording medium (225) of the streaming server (220) for subsequent use.
  • the streaming system (200) may include at least one streaming client (230, 240) that connects to the streaming server (220) to receive the encoded bit string (229) in real time or obtain it later.
  • the streaming client may include a video decoder (232) that obtains the encoded bit string (229) (which may also be considered as a copy of the bit string (219) received by the streaming server), decodes the bit string (229), and outputs the resulting video data as video data in a form that can be displayed by a display (235) or other visual, auditory, or other sensory display means.
  • the functions for encoding and decoding video data are collectively called a coder-and-decoder, or video codec.
  • FIG. 3 is a conceptual diagram of a functional unit of a video decoder according to an embodiment of the present invention.
  • a receiving unit (310) can receive at least one encoded video data to be decoded by a decoder (305).
  • the encoded video data can be independent for each reception, and a decoding procedure of each independent video data can be independent from a decoding procedure of other video data.
  • the encoded video data can be received by the receiving unit (310) through a hardware or software connection (315) to a device storing the same, and as described above, the storing device may be a kind of streaming server located at the other end of a communication network, or may mean a physical recording medium, but is not limited thereto.
  • the above receiving unit (310) can receive the encoded video data together with other data accompanying it, such as encoded audio data or other auxiliary data, and each of the data can be separated from the video data and provided to an appropriate processing function unit (312) other than the video decoder.
  • a buffer memory (320) may be coupled between the receiving unit (310) and the decoder (305) in order to minimize delay and disconnection according to the network environment.
  • the buffer memory (320) may mean a computer-readable recording medium that temporarily stores the received video data and stably supplies it to a parser (330) corresponding to the input terminal of the decoder (305).
  • the buffer memory may be unnecessary.
  • the video decoder (305) may include the parser (330) as its input terminal to interpret the encoded video data.
  • the parser may perform a function of separating (parsing) a plurality of pieces of information stored in the form of a bit string in the encoded video data according to a predetermined rule, and, if necessary, performing an entropy decoding (335) of entropy-coded video data, thereby performing a function of reconstructing symbols (338), which are paragraphs of video encoding information.
  • the symbols (338) may include all information for controlling the operation of the decoder (305), and/or may further include information for controlling a device that is attached to the decoder (305) and can operate, such as a display device, such as a display. Control information for controlling the above display device may include information in a format called supplementary enhancement information (SEI) or video usability information (VUI).
  • SEI Supplemental Enhancement Information
  • VUI video usability information
  • the parser (330) may be configured to perform entropy decoding (335) of the encoded video data.
  • the entropy encoding method of the encoded video data may vary depending on the encoding standard, and decoding may be performed correspondingly.
  • Representative examples of the entropy encoding standard may include variable length coding, Huffman coding, and arithmetic coding, and each of the encoding methods may be a context-adaptive or context-sensitive method depending on the standard, and may be based on principles widely known to those skilled in the art.
  • the parser (330) may be configured to extract at least one partial image from the encoded video data.
  • the definition of the partial image may vary depending on the encoding standard, and depending on the standard, one or more of the examples listed below may correspond simultaneously and overlappingly.
  • the partial image may be defined as a unit such as a group of pictures (GOPs), pictures/frames, tiles, slices, macroblocks, blocks, subblocks, transform units (TUs), or prediction units (PUs).
  • the parser (330) may be configured to extract encoding information, such as transform coefficients, quantization parameters (QPs), and/or motion vectors, from the encoded video data.
  • the parser (330) may be configured to perform entropy decoding (335) and parsing operations on the video data received from the buffer memory, and to selectively decode symbols (338) representing the encoding information.
  • the parser (330) may be configured to selectively supply a specific symbol (338) to a specific decoding function unit within the decoder (305), such as an inverse quantization and inverse transform unit (340), an intra prediction unit (350), an inter prediction unit (355), or a loop filter unit (360). Control of such information supply can be determined by the information sequence contained in the encoded video, and may vary depending on the encoding standard, and is not limited within the scope of the embodiments of the present invention, and is not described in detail in this conceptual diagram.
  • the above decoder (305) may be composed of a plurality of conceptual functional units that receive and process the encoding information from the parser (330). It is obvious that these conceptual functional units may be combined with each other or further subdivided according to implementation needs. For example, they may be further separated for ease of implementation and integrated into one for efficiency of operation. In any case, each functional unit may be configured to perform close interaction with each other. However, despite the possibility of such integration or separation, the following will be described as a combination of conceptual functional units in order to illustrate a decoding procedure of video data applied as an embodiment of the present invention.
  • the above decoder may include an inverse quantization and inverse transformation unit (340).
  • the inverse quantization and inverse transformation unit (340) may be configured to receive encoding information including a method to be used for numerical transformation from the parser (330), a size of a block, quantization coefficients for recovering quantized information, and distinction information of a quantization matrix that simplifies and represents the quantized coefficients, and may be configured to output block values (341) that may be input to an aggregator (370) as a result of processing the encoding information.
  • the output values of the inverse quantization and inverse transformation unit (340) may include intra-prediction encoded block values.
  • the intra-predicted block values may mean values that can be decoded without using prediction information from a previously decoded partial image, for example, a previous frame, but using prediction information within a partial image currently being decoded, for example, a current frame.
  • the prediction information within the current partial image may be provided by the intra prediction unit (350).
  • the intra prediction unit (350) generates a block value having the same form as the block being decoded as the prediction information by using the image information of a spatially adjacent area derived from a partial image currently being decoded and of which decoding has been partially completed.
  • the partial image information may be provided (381) from a current image buffer, a so-called line buffer (380).
  • the merging unit (370) may be configured to merge the prediction information (351) generated by the intra prediction unit (350) with the block values (341) provided by the inverse quantization and inverse transformation unit (340), according to an embodiment.
  • the output values of the inverse quantization and inverse transformation unit (340) may include block values subjected to motion compensation as inter-prediction encoded block values, and in some cases, block values subjected to motion compensation.
  • the inter-prediction unit (355) may extract and use sample information (386) used for motion-based prediction from a reference picture buffer (385).
  • the information (356) derived by performing motion compensation on the sample information based on the symbols (338) included in the block values as the output values may be configured to be merged with the block values (341) provided by the inverse quantization and inverse transformation unit (340) by the merging unit (370).
  • the block values (341) may be referred to as so-called differential or residual values.
  • the position information in the memory used by the inter prediction unit (355) to extract the sample information from the reference image may be determined by a motion vector provided to the inter prediction unit (355) which is composed of a combination of symbols (338) for representing, for example, X, Y, and other specific points of the reference image.
  • the inter prediction unit (355) may also include a function capable of interpolating and using the sample values when a so-called 'subsampling' capable motion vector is provided, and may further include a function for predicting and reinforcing the value of the motion vector.
  • the output values (371) of the above merging unit (370) may be provided to the loop filter unit (360) and processed by various loop filtering methods.
  • the loop filter unit (360) may be configured to receive not only the block unit output (371) of the merging unit (370) but also the symbol (338) provided from the parser (330) and control its operation.
  • the output of the loop filter unit (360) may be output to an external display means such as the display device through an output connection (390), but may be stored (361) in a line buffer (380) for use in prediction for interpreting a subsequent intra or inter encoded block value, and may also be stored in a reference image buffer (385) through this.
  • Specific partial images such as frames, after their decoding is completed, can be utilized as reference images for performing predictive decoding in a subsequent decoding process.
  • One partial image such as a frame, can be gradually accumulated in a line buffer (380) and decoded, and when one frame is decoded, the contents of the line buffer (380) can be transferred (383) to the reference image buffer (385), and a new line buffer (380) can be allocated for decoding a new frame.
  • the above video decoder (305) may be configured to perform a decoding operation according to a predetermined video compression technique that may be documented by various international standard specifications or commercial standards.
  • the standards may include, for example, international standard recommendations such as H.264, H.265, and H.266 defined by the International Telecommunication Union Standardization Sub-Tier (ITU-T).
  • ITU-T International Telecommunication Union Standardization Sub-Tier
  • ISO International Organization for Standardization
  • IEC International Electrotechnical Conference
  • the encoded video data may comply with a specific bitstream syntax defined by the corresponding standard as defined in the video compression standard document and standard document, and specifically, by the profile and level specified within such document.
  • the complexity of the encoded video data may be limited to a certain level in order to comply with the profile and level.
  • a profile or level may be configured to limit a maximum picture size, a maximum decoding speed, and a maximum reference picture size.
  • the limitations may also, in some embodiments, be further limited via metadata signals for a hypothetical reference decoder (HRD) and HRD buffer management included in the encoded video data.
  • HRD hypothetical reference decoder
  • the receiver (310) may receive additional redundant data together with the encoded video.
  • the additional data may be considered as a part of the encoded video data.
  • the additional data may include information that may be used by the decoder (305) to properly decode the data, or to more accurately reconstruct an image that approximates the original image before encoding.
  • the additional data may be provided in the form of, for example, layers for temporal, spatial, or signal-to-noise ratio (SNR) enhancement, redundant slices, redundant pictures, and forward error correction codes.
  • SNR signal-to-noise ratio
  • FIG. 4 is a functional unit conceptual diagram of a video encoder according to one embodiment of the present invention.
  • the encoder (405) may be configured to receive original video information (402) from a video source (401) and perform encoding.
  • the above original video information (402) may have any suitable bit depth, for example, 8 bits, 10 bits, 12 bits, etc.
  • the original video information (402) may have any suitable color space, for example, R/G/B, Y/U/V, Y/Cb/Cr, etc.
  • the original video source may have any suitable sampling structure corresponding to the color space, for example, may have a format such as Y/Cb/Cr 4:2:0, Y/Cb/Cr 4:4:4.
  • the original video source having such a predetermined format may be provided to the encoder in the form of a digital video stream.
  • the original video information (402) can be obtained from a recording medium storing a previously prepared video original.
  • the original video information (402) can be obtained from an image acquisition device, such as a camera, that generates at least one video transmission stream included in the two-way video communication.
  • the video data including the above original video information (402) may be configured as a plurality of partial images configured to simulate motion by being played back in time order.
  • the partial images may be expressed as concepts such as pictures or frames, for example.
  • the partial images may include one or more samples depending on the type of sampling structure, color space, etc. being used. A person skilled in the art will understand that the sample and the pixel in a digital image are closely related terms. Hereinafter, the operation of the encoder will be described based on such samples.
  • the encoder (405) may be configured to encode and compress (partial) images constituting the original video information (402) in real time (or according to other temporal requirements required according to the implementation method) into the form of encoded video information.
  • control unit (450) may be a functional unit configured to control an appropriate encoding speed.
  • the control unit (450) may be configured to control other functional units and be functionally coupled to the following functional units as described below.
  • the parameters set by the control unit (450) may include parameters related to bitrate control, such as skip of the picture, quantizer, variable values for applying a picture quality optimization technique, and may also include values such as the size of the picture, the structure of a group of pictures (GOP), and the maximum search range of a motion vector.
  • GOP group of pictures
  • a person skilled in the art will be able to understand various other functions that the control unit (450) may have, and such other functions may be added or removed according to the design of a video encoder optimized for an individual system design.
  • the encoder (405) may be configured to operate in a structure such as a "coding loop" well known to those skilled in the art.
  • the coding loop may be configured with an internal encoder (so-called “source coder”) (410) which is responsible for receiving an image to be encoded and generating symbols based on at least one reference image that has been encoded in the past, and a local decoder (420) which is configured to be connected to the internal encoder.
  • the local decoder (420) may be configured to perform an operation to reproduce sample data to be generated by a decoder (490) located at an actual remote location that will receive encoded video information from the encoder (405) by receiving an output of the internal encoder (410).
  • the video data composed of sample data reconstructed by the internal decoder (420) may be configured to be input to the reference picture buffer of the encoder (405).
  • the internal decoder (420) is implemented to reproduce the result output by the encoder (405) and to be decoded by a remote decoder, so the video data recorded in the reference picture buffer may also be identical in bit units to the information of the reference picture buffer of the remote decoder. That is, the prediction function unit that may be included in the encoder (405) may read the same values as the sample values of the previous frame that the decoder will later refer to in the decoding process from the reference picture buffer of the encoder (405).
  • the principle of achieving matching of reference image buffers between the encoder (405) and the decoder (490) by means of the internal decoder (420) on the encoder (405) side is well known to those skilled in the art, and a method of responding to an environment in which such an environment is not guaranteed (e.g., information loss due to communication failure, etc.) can also follow what is well known to those skilled in the art.
  • the decoder of FIG. 3 may be considered as the "remote" decoder (490) described above.
  • the internal decoder (420) may be implemented excluding lossless encoding and decoding sections such as the parser (330) or the entropy decoding (335). This is because the internal encoder (405) is implemented to simply reproduce the operation of the decoder located at a remote location, and thus the symbols may be decoded directly without requiring a process of compressing and then decompressing the symbols. Accordingly, the functional sections preceding the parser and the entropy decoder as shown in FIG. 3 may not be provided or may be implemented at least partially.
  • any decoder function (excluding a parser and an entropy decoder) present in the decoder can naturally exist as a substantially identical function in the corresponding encoder (405).
  • the operation of the encoding function unit that may be included in the above encoder (405) may be considered as the reverse of the decoder function unit. Therefore, the embodiment may be explained by generally performing the operation of the decoder function unit in reverse. For example, a quantization and transform function unit corresponding to the inverse quantization and inverse transform unit may be provided, and an inter prediction encoding unit corresponding to the inter prediction unit may be provided. In addition, some additional explanations will be added.
  • the above internal encoder (410) may be configured to perform encoding on input image information, for example, an input frame, by a predictive encoding method executed by a predictive encoding unit (440) that operates by referencing at least one temporally previous encoded partial image, for example, frames, from a reference image buffer (430) from at least one reference image information, for example, video data designated as a reference frame.
  • the encoder (405) may be configured to encode a differential between blocks of samples constituting the input image and blocks of samples constituting the reference image.
  • the internal decoder (420) can decode video data that can be designated as the reference picture from symbols generated by the internal encoder (410). As described above, since the video data is identical to the decoding operation performed by the remote decoder, the video data used as the reference picture can be provided to the encoder (405) in a form in which some damage has occurred due to lossy compression, and this operation can be intended for operation consistency with the decoder.
  • the prediction encoding unit (440) may be configured to perform a prediction search operation within the encoder (405).
  • the prediction search operation may mean an operation corresponding to the inter prediction or intra prediction described in the description of the decoder.
  • the prediction unit may access the reference image buffer (430) to retrieve information, such as a motion vector, a block shape, and metadata that may include the motion vector, which are information indicating points of a reference image that can function as prediction reference information suitable for the new image information, and a sample block to be actually referenced.
  • the prediction encoding unit (440) may operate on the basis of the so-called "sample block by pixel block" in order to obtain appropriate prediction reference information.
  • at least one prediction reference information designating at least one reference image information stored in the reference image buffer (430) may be specified for the input image, as determined based on the search results obtained by the prediction encoding unit (440).
  • control unit (450) may be configured to manage the overall encoding operation of the internal encoder (410), including setting parameters used to encode video data.
  • the entropy encoding (460) may include various entropy coding techniques, such as variable length coding, Huffman coding, and arithmetic coding, for the symbols generated by the various functional units as described above, and each encoding method may be a context-adaptive or context-sensitive method according to the standard, and may also be based on principles widely known to those skilled in the art.
  • the entropy encoding (460) can typically achieve lossless compression, and thus may be configured to convert at least one symbol generated by the functional units into encoded video data.
  • the above control unit (450) can apply the type of encoding of a specific partial image during an encoding section to each partial image, such as a picture or a frame, when controlling the operation of the encoder (405).
  • the type can include what is classified as a “frame type” as follows.
  • Fig. 5 is a conceptual diagram of a frame type according to one embodiment of the present invention. The following description will be made with reference to Fig. 5.
  • An intra (“I") picture may mean a picture that can be encoded and decoded only with its own information without referring to other picture information in the video data by predictive encoding.
  • the "I” picture may be designated by names such as a key frame, an independent/instantaneous decoder referh (IDR) frame, and a clean random-access (CRA) frame according to a video encoding standard, and the "I” pictures designated by various names as described above may have various modifications and application methods as permitted by each standard and may be partially different from each other.
  • various application methods for implementing the "I” picture may be by various methods that are already known to those skilled in the art or may be newly provided.
  • a prediction (“P") picture may mean a picture that can be encoded and decoded through intra or inter prediction based on at least one prediction information and/or a motion vector that designates at least one reference picture to predict sample values of a block constituting the picture.
  • the "P" picture may be configured to refer to only one reference frame, or may be configured to refer to one or more reference frames, according to a video encoding standard. When referring to one or more reference frames, sample information and/or associated metadata derived from a plurality of reference pictures may be used for reconstructing a single block. However, in common cases, a picture designated as a "P" picture may be understood as a picture that performs reference only to a temporally preceding picture.
  • a bidirectional prediction (“B") picture may mean a picture that can be encoded and decoded through intra or inter prediction based on at least one prediction information and/or a motion vector that designates at least two reference pictures to predict sample values of blocks constituting the picture.
  • a picture designated as the "B" picture is distinguished from a picture designated as the "P" picture, and may be understood as a picture that performs a reference without being limited to a temporally preceding picture.
  • Video data may be spatially divided into a plurality of sample blocks in the process of encoding and decoding, and encoding may be performed in block units.
  • the block units may include, but are not limited to, sizes such as 4x4, 8x8, 4x8, or 16x16 in units of horizontal/vertical pixels, as is widely known.
  • the block may be encoded by a predictive encoding method with reference to any other (already encoded) blocks, as permitted and/or restricted by the type specified for each partial picture including the block.
  • the blocks of the "I" picture (510) may be encoded without using a predictive encoding method, or with reference to blocks already encoded in the same partial picture. That is, only the so-called intra prediction method may be used.
  • the "P" picture (520) may further refer to a reference picture encoded in at least one previous time unit, and thus inter prediction may also be used for encoding along with intra prediction.
  • a "B" picture (530) reference can be made not only to a previously encoded picture in the encoding order but also to a later reference picture in terms of time unit.
  • the above video encoder (405) may be configured to perform an encoding operation according to a predetermined video compression technique that may be documented by various international standard specifications or commercial standards. Examples of the above standards may include all of those described in the above decoder.
  • the transmitter (470) may buffer the encoded video data generated by the entropy encoding in order to provide/transmit the video data (ultimately to a remote decoder (490)) to a device storing the encoded video data via a hardware or software connection (495).
  • the transmitter (470) may receive and merge other data accompanying the encoded video data, for example, encoded audio data or other auxiliary data, from a separate source (480).
  • the transmitter (470) may be configured to further transmit additional data together with the encoded video.
  • the additional data may be considered as part of the encoded video data.
  • the additional data may include information that may be used by the decoder to properly decode the data, or to more accurately reconstruct an image that approximates the original image before encoding. Examples of the additional data may include all of the examples presented above with respect to the receiver (310) of the decoder.
  • the present invention can be implemented by a digital video compression standard widely used and understood by those skilled in the art as described above.
  • the digital video compression standard may include at least one of compression standards known by standard names such as MPEG-2, MPEG-4 Video, H.263, H.264/AVC, H.265/HEVC, H.266/VVC, VC-1, AV1, QuickTime, VP-9, VP-10, and Motion JPEG.
  • Fig. 6 is a conceptual diagram showing the structure of a video encoder according to the H.266/VVC standard. What is shown in Fig. 6 corresponds to the rough structure of a video encoder widely known as a standard code such as ITU-T H.266 and ISO/IEC 23090-3, and also under the name of MPEG-I Part 3 or the general name of versatile video coding (VVC).
  • a standard code such as ITU-T H.266 and ISO/IEC 23090-3
  • VVC versatile video coding
  • the video encoder (605) may be configured to receive uncompressed and unencoded original video data (601) as input and output an encoded bit stream (602).
  • the video data (601) may be supplied directly to a luma mapping unit (610a) in the case of intra encoding, or may be supplied to a luma mapping unit (610b) via an inter prediction unit (620) including motion vector extraction.
  • the mapped luma signal may be supplied to an output merger (606) alone, or by selecting (608) at least one of an intra prediction encoded signal via the intra prediction unit (625) or an inter prediction encoded signal output from the luma mapping unit (610b) via the inter prediction unit (620).
  • the result of the above output merger can be applied to a chroma scaling unit (615).
  • the operation of the luminance signal mapping unit (610) and the operation of the chroma scaling unit (615) are collectively referred to as a luma mapping/chroma scalaing (LMCS) process.
  • the reduced chroma signal can be provided to a transform unit (630), and the transform unit (630) can perform an adaptive color transform, particularly on the chroma signal.
  • the coefficient derived as a result of the transform is applied to a quantization unit (640) and quantized.
  • lossy compression is achieved, and the result of the lossy compression can be output as a bit string (602) through a multi-hypothesis CABAC (650), which is a lossless compression method.
  • the result of the lossy compression may enter a decoding procedure by going through inverse quantization (645), inverse transform (635), and luma signal expansion (617) processes to generate a coding loop.
  • the result of the luma signal expansion may be supplied to an internal merger (607) together with a result of selecting (608) at least one of the previously generated intra prediction encoding signal or inter prediction encoding signal.
  • the result of the internal merger may go through inverse luma mapping (617), and then may go through processing such as a deblocking filter (660), a sample adaptive offset (SAO) (670), and an adaptive loop filter (ALF) to reproduce an image quality improvement process in a decoder.
  • the result of reproducing the operation in the decoder as described above is applied to the reference image buffer (690) and can be reused for prediction encoding by the inter prediction unit (620).
  • the present invention can also be utilized by or in combination with the enhanced compression model (ECM), which is an implementation of a next-generation video codec being developed by the joint video experts team (JVET), an international standardization expert group, to improve H.266/VVC.
  • ECM enhanced compression model
  • JVET joint video experts team
  • JVET AC2025-v1 the improved compression model may include an improved intra prediction coding method, an improved inter prediction coding method, an improved transform and transform coefficient coding method, an improved adaptive loop filtering method, a bilateral filtering method, a new sample adaptive offset (SAO) method for image quality improvement, an extended entropy coding method, and an improved gradual decoding refresh (GDR) technique, and such techniques may be included in the present invention as background techniques for implementing the present invention.
  • SAO new sample adaptive offset
  • the present invention provides a method for applying an improved local illuminance compensation (LIC) technique that can be used in the video encoding and decoding field including the above-described embodiments, and a device to which such a method is applied.
  • LIC local illuminance compensation
  • FIG. 7 is a conceptual diagram showing the general structure of a LIC application method according to an embodiment of the present invention.
  • Weighted Prediction is applied in traditional video coding standards.
  • the WP is applied on a frame-by-frame basis, and is a technology that compensates for brightness changes in a reference block in order to accurately obtain a prediction value when encoding the current frame.
  • the WP is applied to both H.264/AVC and H.265/HEVC, and can be used by dividing it into an explicit mode and an implicit mode depending on whether or not a brightness compensation parameter is transmitted for each slice.
  • the above WP-based technology can compensate for the predicted value of the reference frame for the entire image by responding well to the brightness change between frames, but it cannot properly perform brightness compensation for local brightness changes due to technical limitations applied on a frame-by-frame basis.
  • the LIC technology is a technology that induces appropriate brightness compensation for local predicted brightness changes.
  • the above LIC is a technology for modeling (760) local brightness changes between a final prediction block (770) for a current block (710) and a final prediction block (770) by a function (750) that approximates between a value (730) based on a current block (710) and a value (740) based on a reference sample (720) between a template (715) adjacent to a current block (710) and a template (725) adjacent to a reference block (720).
  • the parameters of the function can be represented by a scale ⁇ and an offset ⁇ that form a linear equation, which can be expressed in the form of ⁇ *p[x]+ ⁇ as a linear equation for compensating for brightness changes, where p[x] can mean a reference sample pointed to by a motion vector (MV) (717) at a location x on a reference picture in an inter prediction method.
  • MV motion vector
  • the MV can be clipped considering an offset that takes into account the circular pixel space structure.
  • ⁇ and ⁇ can be derived based on the current block template and the reference block template, no signaling overhead is required for them, except when a LIC usage indication flag is signaled in the bitstream to indicate the usage of the LIC (preferably for the Advanced Motion Vector Prediction (AMVP) mode).
  • AMVP Advanced Motion Vector Prediction
  • the LIC technology presented in the present invention can be equally utilized for intra prediction, and for example, when a BV (block vector) is used instead of the MV (717) or the MV or the BV is derived from a decoder, the present invention does not exclude the possibility that a method based on the LIC technology can be equally applied.
  • an implementation method citing the method proposed in JVET Technical Contribution JVET-O0066 can be modified as follows and used for a block that is inter-coded between screens, for example, an inter-coded unit (inter-coded CU).
  • inter-coded CU inter-coded unit
  • neighboring samples in the intra aspect can be used to derive the LIC parameter. This allows the accuracy of LIC to be improved by utilizing information of intra-encoded neighboring blocks.
  • LIC can be disabled for blocks having less than 32 luminance samples. This reduces unnecessary operations and improves coding efficiency for small-sized blocks.
  • LIC parameter derivation in non-sub-block and affine mode, can be performed based on template block samples corresponding to the current CU instead of partial template block samples corresponding to the first 16x16 unit from the upper left. This allows more information to be utilized to improve the accuracy of LIC.
  • samples of a reference block template can be generated using MC (motion compensation) together with the MV of the corresponding block without rounding to integer pixel precision. This enables more precise prediction, thereby improving coding efficiency.
  • two sets of LIC parameters may be derived separately for L0 and L1 prediction samples.
  • the L0 and L1 prediction samples may mean respective samples obtained in two prediction directions used in the bi-directional prediction.
  • the L0 prediction sample may mean a prediction sample derived from a reference picture that is generally temporally earlier than the current picture. That is, it may represent prediction information obtained from a past frame.
  • the L1 prediction sample may mean a prediction sample derived from a reference picture that is generally temporally later than the current picture. That is, it may represent prediction information obtained from a future frame.
  • the L0 and L1 prediction samples may be obtained from different reference pictures, and they may be at different temporal positions.
  • the L0 and L1 prediction samples may be obtained from different reference pictures, and they may be at different temporal positions.
  • the same method can be repeatedly applied to derive the L0 and L1 LIC parameters.
  • the L0 LIC parameter is first derived by minimizing the difference between the L0 template prediction T0 and the template T, and the samples of T can be updated by subtracting the corresponding samples of T0.
  • the L1 parameter that minimizes the difference between the L1 template prediction T1 and the updated template can be calculated.
  • the L0 parameter can also be refined again in the same manner.
  • weights considering temporal characteristics of each direction can be applied. For example, if the L0 prediction sample is temporally closer to the current picture, a higher weight can be given to the L0 LIC parameter. Conversely, if the L1 prediction sample is closer, a higher weight can be given to the L1 LIC parameter. This allows for more effective utilization of temporal correlation.
  • the present invention proposes a method and device for enhancing compression performance by appropriately performing brightness compensation of LIC.
  • the above-described LIC-based method can be configured to find a reference block by utilizing a set template, and generate a change in brightness between a current block (e.g., CU) and the reference block as a linear model by utilizing an L-shaped template.
  • the linear model can be configured in the form of a linear function of ⁇ *p[x]+ ⁇ .
  • the p[x] can be defined as a reference value as a prediction pixel, and the ⁇ and ⁇ can represent a slope and a bias of the derived linear model.
  • two or more linear models can be used at the same time.
  • the method of deriving the linear model parameters is not limited to a first-order linear model, but can be set as a second-order or higher-order line fitting model. This can help model more complex brightness changes more accurately.
  • a LIC method using one first-order linear model can be provided.
  • a LIC method using two first-order linear models can be provided.
  • a LIC method using one first-order linear model and one second-order model can be provided. This method can help to support more accurate brightness compensation by supplementing complex brightness changes that are difficult to express with a first-order model with a second-order model.
  • a LIC method using two first-order linear models and one second-order model can be provided.
  • This method can help to provide more sophisticated brightness compensation by expressing most of the brightness changes with two first-order models and compensating for the remaining complex changes with the second-order model.
  • a LIC method using two first-order linear models and two second-order models can be provided.
  • This method can cope with the most complex forms of brightness changes, and can help provide more sophisticated brightness compensation by adaptively selecting the application area of each model.
  • a LIC method using at least one first-order linear model and at least one second-order model can be applied and provided.
  • the number of the first-order linear model and the second-order model can be adaptively determined within a range that compression efficiency and complexity allow, or a variable number can be signaled by a bit string.
  • a method can be used in which the number of primary and secondary models to be used is determined in a high-level bitstream syntax, the primary and secondary models to be used in the LIC method are determined accordingly, and the determined information is transmitted to a decoder via a bitstream.
  • the complexity of the model can be adaptively adjusted according to the characteristics of the image, thereby achieving an optimal balance between compression efficiency and computational complexity.
  • parameters of each model can be adaptively quantized and transmitted.
  • the slope and bias of the first model and the coefficients of the second model can be quantized with different precisions, so that important parameters can be transmitted more accurately and less important parameters can be transmitted concisely, thereby achieving a balance between bit rate and performance.
  • Rate-Distortion Optimization can be applied in the process of selecting the LIC model.
  • RDO Rate-Distortion Optimization
  • the linear model formula actually applied to derive linear model parameters based on a first-order function is as shown in the following mathematical formula 1.
  • the "Ref” may mean a reference pixel value used for prediction.
  • the "Scale” and the “Shift” may be values that approximate the ⁇ portion in the linear model ⁇ *p[x]+ ⁇
  • the "Offset” may mean a value that approximates ⁇ .
  • the ">>” operator symbol appearing in the above mathematical expression 1 may be understood as a right binary bit shift operation.
  • the “Ref” value may have the same meaning as a predicted value obtained in a motion estimation (ME) process.
  • a value in the form of a weighted sum derived from two or more predicted values found in the ME process may be used.
  • a value in the form of a weighted sum derived from two or more predicted values found through template matching may be used instead of the "Ref" value.
  • the weights to be multiplied by each prediction value may be stored in the form of a table.
  • the weights may be selected and used as an index for a pre-determined table, and information on the selected index may be configured to be transmitted to a decoder through a bit string or the like.
  • a larger weight when configuring to derive a value in the form of a weighted sum from two or more prediction values, a larger weight may be assigned to a value having a smaller information requirement cost calculated by a method including SAD (Sum of Absolute Differences), SATD (Sum of Absolute Transformed Differences), or MR-SAD (Mean-removal SAD) among the prediction values found through the ME and/or the template matching.
  • SAD Sud of Absolute Differences
  • SATD Sud of Absolute Transformed Differences
  • MR-SAD Magnetic-removal SAD
  • a parameter set can be configured by defining at least one parameter value required to configure the linear model as a set.
  • the "Scale”, “Shift”, and “Offset” can be made into one package to configure a parameter set, and it is obvious that even when the number or composition of the parameters is different, different parameters can be treated as a set.
  • the above parameter set may be shared in advance between the encoder and decoder through an encoding standard, or may be provided by a bit string (especially, a high-level bit string).
  • parameters when a LIC model is used in a surrounding block may be used as candidates to determine the parameter set.
  • parameter sets of a storage storing previously used LIC parameters may be configured as candidates.
  • the candidate set when configuring the candidate set, even if LIC is not used in a surrounding block, the candidate set may be configured by referring to other information used for intra-screen or inter-screen prediction.
  • the values and/or parameter sets of the candidate set may be arbitrarily added according to a predetermined order or information.
  • a template may be utilized to perform rearrangement of the order of the candidate set.
  • an optimal parameter set may be selected through RDO or the like, and an index thereof may be included in a bit string and transmitted to a decoder.
  • the decoder may be configured to form the candidate group in the same manner as the encoder, and to reconstruct the LIC parameter set used in the encoder by utilizing information transmitted through the bit string.
  • a candidate group found through template matching can be utilized as a LIC usage parameter set.
  • the above-described linear model can be transformed into a nonlinear model to improve prediction accuracy.
  • an equation such as the following mathematical expression 2 can be derived and used.
  • the “Ext” may correspond to the additional term, and may be determined as any one of the average of the "Ref", the square of the average, the average of the bit depth values (bitDepth), the square of the average of the bitDepth, or a value raised to an exponent of 2 considering a bit shift operation according to "Shift”.
  • the "Ext” may be the average of the template, the square of the average of the template, the average of the bitDepth of the template, the square of the average of the bitDepth of the template, or a value raised to an exponent of 2 considering a bit shift operation according to "Shift” calculated from the template.
  • the nonlinear model can be used alone or in combination with a linear model.
  • the nonlinear model can be used to completely replace the linear model, in which case prediction can be performed using only the nonlinear model instead of the existing linear model.
  • the nonlinear model and the linear model can be used together.
  • the method of determining which model to use can be divided into an explicit method and an implicit method.
  • information on the model to be used can be included in a bit string and transmitted to the decoder.
  • the implicit method can be used to determine whether to use a linear model or a nonlinear model.
  • the information of the blocks adjacent to the upper and left sides of the current block e.g., CU
  • the prediction mode, size, or characteristics of the residual signal of the upper and left blocks can be analyzed to select a model suitable for the current block. It is self-evident that various decoder-side mode derivation methods known in the past or newly provided can be commonly used or applied for model derivation in the above decoder.
  • linear model in the specification or claims of the present invention should be understood to correspond to a concept including the nonlinear model described above as one of its derived implementation methods.
  • the LIC-based method can be configured to find a reference block by utilizing a set template and generate a change in brightness between a current block (e.g., CU) and the reference block as a linear model by utilizing an L-shaped template.
  • the linear model can be configured in the form of a quadratic function of ⁇ *(p[x] 2 )+ ⁇ *p[x]+ ⁇ .
  • the p[x] can be defined as a reference value as a prediction pixel value, and ⁇ , ⁇ , and ⁇ can represent coefficients and constants of the derived linear model.
  • the p[x] can mean a value of a reference sample pointed to by an MV at a location x on a reference picture. Since the above ⁇ , ⁇ , and ⁇ can be derived based on the current block template and the reference block template, no signaling overhead is required for them except when a LIC usage indication flag is signaled within the bit string to indicate the usage of the LIC (preferably for AMVP mode).
  • a linear model formula actually applied to derive a linear model parameter based on a quadratic function may include at least one of the exemplary formulas represented by the following mathematical formulas 3 to 6.
  • the "Ref” value may mean a predicted pixel value obtained through ME.
  • the " ⁇ " operator symbol appearing in the above mathematical expression 6 may be understood as a left binary bit shift operation.
  • a value in the form of a weighted sum derived from two or more predicted values found in the ME process may be used.
  • a value in the form of a weighted sum derived from two or more predicted values found through template matching may be used instead of the "Ref" value.
  • the weights to be multiplied by each prediction value may be stored in the form of a table.
  • the weights may be selected and used as an index for a pre-determined table, and information on the selected index may be configured to be transmitted to a decoder through a bit string or the like.
  • a greater weight may be assigned to a value having a smaller cost calculated through SAD, SATD, etc. among the prediction values found through the ME and/or the template matching.
  • the "Scale”, “Shift”, and “Offset” can be made into a single package to form a parameter set.
  • the parameter set may be shared in advance between the encoder and the decoder through an encoding standard, or may be provided by a bit string (especially, a high-level bit string).
  • parameters when a LIC model is used in a surrounding block may be used as a candidate set to determine the parameter set.
  • a parameter set of a storage storing previously used LIC parameters may be included in the candidate set.
  • a parameter set determined by referring to other information used for intra-screen or inter-screen prediction may be included in the candidate set even if LIC is not used in the surrounding block.
  • the values and/or parameter sets of the candidate set may be arbitrarily added according to a predetermined order or information.
  • the order of the candidate group can be re-ordered using a template.
  • the re-ordering can be performed based on the encoding information required cost calculated based on the template, and according to one embodiment, the re-ordering can be performed in order of low cost.
  • the information required cost can be calculated by SAD, SATD, or MR-SAD, and the re-ordering can also be performed based on this cost.
  • an optimal parameter set may be selected through RDO or the like, and an index thereof may be included in a bit string and transmitted to a decoder.
  • the decoder may be configured to form the candidate group in the same manner as the encoder, and to reconstruct the LIC parameter set used in the encoder by utilizing information transmitted through the bit string.
  • a candidate group found through template matching can be utilized as a LIC usage parameter set.
  • a boundary condition may mean a situation in which a reconstructed pixel value of an adjacent block to a block currently being encoded or decoded cannot be utilized in the current block.
  • a boundary condition is generally referred to as a boundary condition because it mainly occurs at a boundary of an encoding unit, but is not necessarily limited to such a case.
  • the boundary condition may occur at a boundary of various encoding/decoding units, including, for example, a picture unit, a slice unit, a tile unit, a CTU (coding tree unit) unit, and/or a MER (motion estimation region) unit.
  • the boundary condition may be specified in units of processing units in consideration of hardware implementation. This means that boundary conditions can be defined based on processing units of a specific size or structure for efficient processing based on hardware (e.g., multi-processor processing).
  • the boundary condition may be specified through a high-level bitstream syntax. For example, boundary conditions may be specified in units of picture, slice, tile, CTU, and/or MER, and further, it may be possible to specifically specify specific boundary points that can induce occurrence of the boundary condition.
  • a linear model based on a reference sample (“Ref") for deriving a prediction sample (“Pred”) (for example, it may mean based on any one of Equations 1 to 6)
  • Pred a prediction sample
  • the "Scale”, "Shift”, and “Offset” values may be determined by utilizing only the upper or left value and/or template that can be utilized.
  • the "Scale”, “Shift”, and “Offset” values may be determined by utilizing only the value of the left block and/or template.
  • the values of the "Scale”, “Shift”, and “Offset” can be determined only by utilizing the values and/or template of the upper block.
  • the size or shape of the template can be dynamically adjusted according to the boundary conditions.
  • a replacement template utilizing temporal correlation can be used. That is, when the template of a spatially adjacent block cannot be used, pixels at the same position or at a position corrected by a motion vector of the previous frame can be used as a template.
  • a processing method in boundary conditions can be adaptively selected on a block-by-block basis, for example, according to the characteristics of the block (texture complexity, degree of movement, etc.).
  • the encoding method according to the present invention can be applied equally to an encoder and a decoder.
  • the encoding method according to the present invention can be first used as one of the methods for generating a sample value of a prediction block for performing intra-screen and/or inter-screen prediction in an encoder.
  • the decoder can generate a sample value of the same prediction block using a corresponding and/or symmetrical method, and obtain decoded samples by combining the differential value with such a prediction block.
  • such a decoding process can be implemented identically within the encoder to predict the state of the decoder.
  • the encoding method according to the present invention described above can be implemented through an encoder as a device.
  • the encoder as a device can be implemented in a form that maintains the conventional encoder structure exemplified through FIGS. 1 to 6 above or applies a predetermined change thereto.
  • the form of implementation is not necessarily limited to what has been exemplified, and any form of encoder structure that can function as a video encoder should be considered an encoder established by the present invention as long as it implements the technical idea of the present invention.
  • the method for decoding the encoding result according to the present invention described above can be implemented through a decoder as a device.
  • the decoder as a device can be implemented in a form that maintains the conventional decoder structure exemplified through FIGS. 1 to 6 above or applies a predetermined change thereto.
  • the form of implementation is not necessarily limited to what has been exemplified, and any form of decoder structure that can function as a video decoder is considered to be a decoder established by the present invention as long as it implements the technical idea of the present invention.
  • a bit stream encoded by the above-described method and device can be decoded by applying a method symmetrical and/or inverse to the encoding method.
  • at least one variable length coded phrase included in the encoded bit stream can be interpreted, and furthermore, in one embodiment, the variable length coding can be performed by an entropy coding method.
  • the technical details and application method of implementing such a decoding procedure can readily be understood from the above-described encoding procedure.
  • the encoder and/or decoder described in the present specification may correspond to a device including a processor and a memory, each of which may be implemented as a computing device.
  • the processor which may be included in the encoder and/or decoder described in the present specification, may mean one or more general-purpose computers or special-purpose computers, such as a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable array (FPA), a programmable logic unit (PLU), a microprocessor, or any other device capable of executing instructions and responding.
  • ALU arithmetic logic unit
  • FPA field programmable array
  • PLU programmable logic unit
  • the processor may include a plurality of processing elements and/or a plurality of types of processing elements.
  • a device may include a plurality of processors or one processor and one controller as the processor.
  • the processor may be implemented by various processing configurations, such as a parallel processor or a multi-core processor.
  • the processor may be configured to execute an operating system (OS) and one or more software programs running on the operating system. Additionally, the processor may access, store, manipulate, process, and generate data in response to execution of the software programs.
  • OS operating system
  • software programs running on the operating system. Additionally, the processor may access, store, manipulate, process, and generate data in response to execution of the software programs.
  • the software may include a computer program, code, instructions, or a combination of one or more of these, and may be configured to control the processor to perform a desired operation, and may be configured to issue instructions to the processor, either independently or collectively.
  • the software may be permanently or temporarily embodied in any type of machine, component, physical device, virtual equipment, computer storage medium or device, or transmitted signal wave, for interpretation by the processor or for providing instructions or data to the processor.
  • the software may also be distributed over network-connected computer systems, and stored or executed in a distributed manner.
  • the software may also be implemented in the form of program commands that can be executed through various computer means and recorded or stored in the memory.
  • the memory may be a computer-readable recording medium, and program commands, data files, data structures, etc. may be recorded singly or in combination in the computer-readable recording medium.
  • the program commands stored in the memory may be based on a command system specifically designed and configured for the embodiment of the present invention, or may follow a command system known and available to those skilled in the art of computer software, for example, a command system exemplified by the assembly language, C, C++, Java, Python, etc. It should be understood that the command system and the program commands thereby include not only machine language codes generated by a compiler, but also high-level language codes that can be executed by the device and/or the processor according to an embodiment of the present invention using an interpreter, etc.
  • the computer-readable recording medium constituting the device according to one embodiment of the present invention may include a temporary or volatile recording medium that is maintained only while the processor is operating, such as a processor cache, a RAM, a flash memory, or a relatively non-volatile or long-term recording medium, such as a magnetic media such as a hard disk, a floppy disk, and a magnetic tape, an optical media such as a CD-ROM, a DVD, a magneto-optical media such as a floptical disk, or a solid state memory, or may include a read-only recording medium, such as a ROM arranged on hardware, and further, hardware itself configured to perform operations equivalent to a series of program commands by a hard-wired structure by circuit wiring, and since each step for performing the operations implementing the embodiments of the present invention can be viewed as being recorded by the connection and arrangement of the hardware components, the connection and arrangement method is the memory and It is obvious to a person skilled in the art that they can be considered equivalent
  • a single hardware device may be configured to operate as a module composed of one or more of the software to perform the operations of the embodiments of the present invention, and vice versa.
  • all or part of the operations assigned to a certain functional unit may be implemented by one or more of the software stored in the device according to an embodiment of the present invention (preferably, in any one of the recording media belonging to the category of the memory) and configured to be executed by the processor, and in this case, such a functional unit may be referred to as a functional unit "included" in the processor.

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Compression Or Coding Systems Of Tv Signals (AREA)

Abstract

La présente invention concerne une technologie de compression vidéo et, plus spécifiquement, l'amélioration d'une technologie de compensation d'éclairement local (LIC) incluse dans une technologie de codage par prédiction contribuant à l'amélioration des performances de compression dans un codeur et un décodeur vidéo. Un procédé de décodage d'un flux binaire vidéo codé, selon un mode de réalisation de la présente invention, comprend les étapes suivantes : extraire, à partir d'un flux binaire, des informations relatives à la compensation d'éclairement locale (LIC) pour le bloc actuel, et acquérir des informations LIC à partir des informations extraites ; déterminer au moins un modèle linéaire sur la base des informations LIC ; générer un échantillon de prédiction pour le bloc actuel au moyen d'un procédé LIC utilisant le modèle linéaire ; et utiliser l'échantillon de prédiction de manière à restaurer le bloc actuel, le modèle linéaire étant défini comme étant soit une fonction linéaire, soit une fonction quadratique.
PCT/KR2024/014632 2023-09-26 2024-09-26 Procédé et dispositif de codage/décodage vidéo basés sur une détermination améliorée de modèle de compensation d'éclairage local Pending WO2025071283A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202480060927.6A CN121925853A (zh) 2023-09-26 2024-09-26 基于改进的局部亮度补偿模板确定的视频编码/解码方法及装置

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
KR20230129368 2023-09-26
KR10-2023-0129368 2023-09-26
KR10-2024-0130655 2024-09-26
KR1020240130655A KR20250046217A (ko) 2023-09-26 2024-09-26 개선된 국소적 조도 보상 템플릿 결정에 기반한 동영상 부호화/복호화 방법 및 장치

Publications (1)

Publication Number Publication Date
WO2025071283A1 true WO2025071283A1 (fr) 2025-04-03

Family

ID=95201888

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2024/014632 Pending WO2025071283A1 (fr) 2023-09-26 2024-09-26 Procédé et dispositif de codage/décodage vidéo basés sur une détermination améliorée de modèle de compensation d'éclairage local

Country Status (1)

Country Link
WO (1) WO2025071283A1 (fr)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20180016390A (ko) * 2015-06-09 2018-02-14 퀄컴 인코포레이티드 비디오 코딩을 위한 조명 보상 상태를 결정하는 시스템들 및 방법들
KR20180134764A (ko) * 2017-06-09 2018-12-19 한국전자통신연구원 영상 부호화/복호화 방법, 장치 및 비트스트림을 저장한 기록 매체
KR20190055819A (ko) * 2016-10-05 2019-05-23 퀄컴 인코포레이티드 조명 보상을 위해 템플릿 사이즈를 적응적으로 결정하는 시스템들 및 방법들
KR20210134034A (ko) * 2019-03-12 2021-11-08 인터디지털 브이씨 홀딩스 인코포레이티드 서브블록 기반 로컬 조명 보상을 이용한 비디오 인코딩 및 디코딩 방법 및 장치
KR20210138760A (ko) * 2019-03-25 2021-11-19 광동 오포 모바일 텔레커뮤니케이션즈 코포레이션 리미티드 이미지 요소 예측 방법, 인코더, 디코더 및 저장 매체

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20180016390A (ko) * 2015-06-09 2018-02-14 퀄컴 인코포레이티드 비디오 코딩을 위한 조명 보상 상태를 결정하는 시스템들 및 방법들
KR20190055819A (ko) * 2016-10-05 2019-05-23 퀄컴 인코포레이티드 조명 보상을 위해 템플릿 사이즈를 적응적으로 결정하는 시스템들 및 방법들
KR20180134764A (ko) * 2017-06-09 2018-12-19 한국전자통신연구원 영상 부호화/복호화 방법, 장치 및 비트스트림을 저장한 기록 매체
KR20210134034A (ko) * 2019-03-12 2021-11-08 인터디지털 브이씨 홀딩스 인코포레이티드 서브블록 기반 로컬 조명 보상을 이용한 비디오 인코딩 및 디코딩 방법 및 장치
KR20210138760A (ko) * 2019-03-25 2021-11-19 광동 오포 모바일 텔레커뮤니케이션즈 코포레이션 리미티드 이미지 요소 예측 방법, 인코더, 디코더 및 저장 매체

Similar Documents

Publication Publication Date Title
WO2020071830A1 (fr) Procédé de codage d'images utilisant des informations de mouvement basées sur l'historique, et dispositif associé
WO2020071829A1 (fr) Procédé de codage d'image basé sur l'historique, et appareil associé
WO2018212569A1 (fr) Procédé de traitement d'image basé sur un mode de prédiction intra et appareil associé
WO2015009036A1 (fr) Procédé et appareil de prédiction inter-couche en fonction d'informations de sous-couche temporelle
WO2021201515A1 (fr) Procédé et dispositif de codage/décodage d'image pour signalisation hls, et support d'enregistrement lisible par ordinateur dans lequel est stocké un flux binaire
WO2020005002A1 (fr) Procédé et dispositif de dérivation d'une zone de modèle en fonction d'une prédiction inter dans un système de codage d'image
WO2021107622A1 (fr) Procédé et appareil de codage d'image/de vidéo
WO2020180043A1 (fr) Procédé de codage d'image basé sur le lmcs et dispositif associé
WO2020180044A1 (fr) Procédé de codage d'images basé sur un lmcs et dispositif associé
WO2019225932A1 (fr) Procédé et appareil de décodage d'image à l'aide de dmvr dans un système de codage d'images
WO2025071283A1 (fr) Procédé et dispositif de codage/décodage vidéo basés sur une détermination améliorée de modèle de compensation d'éclairage local
WO2025071286A1 (fr) Procédé et appareil de codage/décodage de vidéo sur la base d'une détermination de modèle améliorée pour une compensation d'éclairement local
WO2025071287A1 (fr) Procédé et appareil de codage/décodage vidéo basé sur un filtre croisé de compensation de l'éclairement local amélioré
WO2023055176A1 (fr) Procédé et dispositif de codage d'image basé sur un affinement de vecteur de mouvement côté décodeur
WO2025014115A1 (fr) Procédé et appareil de codage et de décodage vidéo sur la base d'une prédiction de partitionnement géométrique
WO2021137588A1 (fr) Procédé et appareil de décodage d'image pour coder des informations d'image comprenant un en-tête d'image
WO2025211830A1 (fr) Procédé et dispositif améliorés d'estimation de mode de prédiction intra côté décodeur pour codage et décodage vidéo
WO2025084913A1 (fr) Procédé et dispositif de codage/décodage de vidéo sur la base d'une intra-prédiction
WO2021006651A1 (fr) Procédé de codage d'image sur la base d'un filtrage de déblocage, et appareil associé
WO2025063635A1 (fr) Procédé et dispositif améliorés pour la dérivation de l'intra-mode du coté du décodeur pour l'encodage et le décodage de la vidéo
WO2025230284A1 (fr) Procédé et appareil de codage et de décodage vidéo reposant sur une technologie de calcul de décodeur adaptatif
WO2025135813A1 (fr) Procédé et appareil de codage et de décodage vidéo basés sur une prédiction de partitionnement géométrique améliorée
WO2025198325A1 (fr) Procédé et dispositif de codage et de décodage vidéo à l'aide d'une structure de prédiction intra améliorée
WO2013062175A1 (fr) Procédé et dispositif pour codage adaptable de couche d'enrichissement
WO2025048317A1 (fr) Procédé et dispositif de rafraîchissement progressif amélioré de décodeur, pour codage et décodage vidéo

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 24872991

Country of ref document: EP

Kind code of ref document: A1

REG Reference to national code

Ref country code: BR

Ref legal event code: B01A

Ref document number: 112026007005

Country of ref document: BR