WO2015052064A1 - Procédé de codage et de décodage de données flottantes d'un bloc d'images et dispositifs associés - Google Patents

Procédé de codage et de décodage de données flottantes d'un bloc d'images et dispositifs associés Download PDF

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WO2015052064A1
WO2015052064A1 PCT/EP2014/071112 EP2014071112W WO2015052064A1 WO 2015052064 A1 WO2015052064 A1 WO 2015052064A1 EP 2014071112 W EP2014071112 W EP 2014071112W WO 2015052064 A1 WO2015052064 A1 WO 2015052064A1
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block
image
prediction
coding
residual error
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PCT/EP2014/071112
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English (en)
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Dominique Thoreau
Mikael LE PENDU
Yannick Olivier
Christine Guillemot
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Thomson Licensing
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    • 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
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
    • H03M7/00—Conversion of a code where information is represented by a given sequence or number of digits to a code where the same, similar or subset of information is represented by a different sequence or number of digits
    • H03M7/14—Conversion to or from non-weighted codes
    • H03M7/24—Conversion to or from floating-point codes
    • 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
    • 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
    • H04N19/134—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or criterion affecting or controlling the adaptive coding
    • H04N19/146—Data rate or code amount at the encoder output
    • H04N19/147—Data rate or code amount at the encoder output according to rate distortion criteria
    • 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
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/189—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the adaptation method, adaptation tool or adaptation type used for the adaptive coding
    • H04N19/19—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the adaptation method, adaptation tool or adaptation type used for the adaptive coding using optimisation based on Lagrange multipliers

Definitions

  • the invention relates to the general domain of image coding. More specifically, the invention relates to a method for coding to a coded data signal an image block whose data are represented by floating values and a method for decoding a stream of coded data representative of an image block whose data are represented by floating values. The invention also relates to methods for coding and decoding a sequence of images and devices implementing these methods.
  • Intra-image prediction is used to improve the compression of a sequence of images. It comprises, for a current image block, the generation of a prediction image block and the coding of a difference, also called residual image block, between the current image block and the prediction image block. The more the prediction image block is correlated with the current image block, the lower the number of bits required to code the current image block and therefore the more efficient the compression.
  • Examples of such methods include those defined by the MPEG-4 AVC/H.264 standard described in the ISO/I EC 14496-10 document, or those defined by the HEVC (High Efficiency Video Coding) standard described in the document (B. Bross, W.J. Han, G. J. Sullivan, J. R. Ohm, T. Wiegand JCTVC-K1003, "High Efficiency Video Coding (HEVC) text specification draft 9," Oct 201 2.).
  • HEVC High Efficiency Video Coding
  • C p is one of the R, G or B components of a pixel, with M and E representing mantissa and exponent respectively.
  • RGBE with E meaning exponent
  • OpenEXR RGB half float cf K. Myszkowski, R Mantiuk, G Krawczyk “High Dynamic Range video,” Synthesis Lectures on Computer Graphics and Animation, Morgan & Claypool Publishers 2008
  • RGBE with E meaning exponent
  • OpenEXR RGB half float cf K. Myszkowski, R Mantiuk, G Krawczyk “High Dynamic Range video,” Synthesis Lectures on Computer Graphics and Animation, Morgan & Claypool Publishers 2008
  • a mantissa comprising Nm bits which enables the mantissa values to extend between 0 and 2 Nm -1 , and
  • the values expressed with a floating representation composed of 1 sign bit, Nm mantissa bits and Ne exponent bits can vary from 0 to:
  • the invention relates to a method for coding, to a coded data signal, an image block whose image data are represented by floating values.
  • Each floating value being expressed by a mantissa and an exponent, the method is characterised in that it comprises the following steps:
  • said exponent value thus determined is coded without loss.
  • said exponent value is predicted by a prediction value and the difference between the prediction value and the exponent value is coded.
  • the prediction value is defined from a causal neighbouring area formed of at least one image block previously processed by said method.
  • the causal neighbourhood is formed of a block belonging to the image to which the block to be coded belongs and/or of at least one block belonging to at least one other image different from the image to which the image block to be coded belongs.
  • the method comprises a step of selecting a coding mode for the image block to be coded from a set of coding modes during which step the coding mode selected is that which minimises a compromise between a minimum reconstruction error for this image block coded and then decoded according to this coding mode and a minimum coding cost taking into account the coding cost according to this mode of coding the exponent's unique value and the cost of coding the mantissas of the floating values representing the image data of the prediction residual error block.
  • the invention also relates to a method for decoding a coded data signal representative of an image block whose data are represented by floating values. Each floating value being expressed by a mantissa and an exponent, the method is characterised in that it comprises the following steps:
  • the invention relates to a coded data signal representative of an image block whose data are represented by floating values.
  • Each item of floating data being expressed by a mantissa and an exponent, the signal is characterised in that it comprises at least one item of coded data describing a single exponent value for floating values and at least one other item of coded data describing the mantissas of floating values representing the image data of the prediction error block of the image block.
  • the invention relates to a device for coding, to a coded data signal, an image block whose image data are represented by floating values.
  • a device for coding to a coded data signal, an image block whose image data are represented by floating values.
  • Each floating value being expressed by a mantissa and an exponent, the device is characterised in that it comprises the following means for:
  • the invention relates to a device for decoding a coded data signal representative of an image block whose data are represented by floating values.
  • a coded data signal representative of an image block whose data are represented by floating values.
  • Each floating value being expressed by a mantissa and an exponent, the device is characterised in that it comprises the following means for:
  • - Fig. 1 depicts an example of the definition of an image block according to the HEVC standard
  • Fig. 2 depicts a diagram showing the steps of a method for coding an image block whose image data are represented by floating values
  • Fig. 3 depicts a diagram showing the steps of a method for coding an exponent value
  • Fig. 4 depicts an example of the causal neighbourhood of an image block
  • Fig. 5 depicts a diagram showing the steps of an embodiment of the method for decoding a coded data signal
  • FIG. 6 depicts an example of the internal architecture of a device. 5. Detailed description of the invention
  • the invention relates to a method for coding an image block B c ⁇ whose data are represented by floating values to a coded data signal F, a method for decoding a coded data signal F representative of an image block B c whose data are represented by floating values and a coded data signal F representative of a prediction error block relative to an image block B c whose data are represented by floating values.
  • An image block is from an image which itself may be from a sequence of images.
  • An image block comprises pixels or image points with each of which at least one item of image data represented by one (or several) floating value(s) is associated.
  • An item of image data is, for example, an item of luminance data or an item of chrominance data.
  • image block hereafter includes any set of image data to which a transform is possibly applied. Though it is usual to use square- or rectangular-shaped blocks, the invention is in no way limited to these shapes and indeed any shape may be used.
  • an image block may be a macroblock to which a DCT (Discrete Cosinus Transform) or any other transform such as wavelet decomposition is applied.
  • an image block in the sense of the invention, corresponds to a Transform Unit (TU).
  • TU Transform Unit
  • the HEVC standard defines a recursive partitioning of an image into prediction units (PU) and each PU can in turn be decomposed into several transform units TU.
  • Each unit TU is then encoded by applying a suitable transform.
  • a unit PU can thus be encoded using various transforms depending on the partitioning of this PU into TUs.
  • each TU is an image block in the sense of the invention.
  • a Coding Unit CU is subdivided into 4 CUs and one of these CUs is subdivided into 4 PUs.
  • a PU can then be encoded either by applying a single TU transform to this PU, for example an 8x8 DCT, or by applying a TU transform to each half of this PU, for example by applying a TU transform twice to each half of this PU, for example by applying a 4x8 or 8x4 DCT twice, or by applying a TU transform to each quarter of this PU, for example by applying a TU transform four times to each quarter of this PU, for example by applying a 4x4 DCT four times.
  • the steps for determining and coding the exponent and the coding of the mantissas of the floating values representing the image data of the image block to be coded are executed by the colour component of this space.
  • motion data comprises the motion vectors and possibly the reference image indexes enabling a reference image to be identified in the reconstructed image sequence. It can also comprise an item of information indicating the type of interpolation that must be applied to a reference image block to derive a prediction block.
  • prediction block includes any set of image data used to predict an image block.
  • a prediction block is obtained from an image block of the same image as the image to which the image block that it predicts belongs (spatial prediction or intra-image prediction) or from one or several image blocks belonging to one (mono-directional prediction) or several (bi-directional prediction) different images (temporal prediction or inter-image prediction) of the image to which the image block that it predicts belongs.
  • residual error block includes any set of image data obtained after extraction of other data. This term is synonymous with the term “residues”.
  • prediction residual error block therefore includes any set of image data obtained by subtracting a prediction block from an image block that it predicts.
  • a transform may be applied to a residual error block.
  • a DCT Discrete Cosine Transform
  • Such transforms "transform" data of a residual error block, for example luminance and/or chrominance residual data, into a "block of transformed data” also called “block of frequency data” or "block of coefficients".
  • the block of coefficients generally comprises a low- frequency coefficient known under the name of direct current coefficient or DC coefficient and high-frequency coefficients known under the name of AC coefficients.
  • the method for coding an image block B c comprises the following steps:
  • a coded data signal F is obtained.
  • This stream comprises an item of coded data Ec describing a unique exponent value relative to the floating values which represent the image data of this prediction residual error block and an item of coded data Ec describing the mantissas of the floating values of the image data of this prediction residual error block.
  • This item of coded data Ec is composed of several items of information, each describing the mantissa of a floating value of an item of data of this block.
  • the exponent value Exp res represents the maximum value of pixel exponents of the prediction residual error block B res .
  • Exp ns ar gmax ⁇ ex P res ' ) ⁇ where exp res (i, j) is the exponent value for a pixel of indices i and j of the prediction residual error block B res .
  • the invention is not limited to a particular determination of this exponent but extends to any possible approach such as the exponent mean or median value, to give just a few of examples.
  • the exponent value Exp res is coded without loss.
  • the exponent value is coded using Fixed Length Coding
  • This embodiment is particularly advantageous due to its simplicity of implementation into an image sequence coding scheme, since it is sufficient to transmit the Fixed Length Code to the decoder so that this decoder can find the exponent value Exp res associated with the prediction residual error block
  • the exponent value Exp res is coded by Variable Length Coding (VLC), using a Huffman-type coder or any other entropic coder well known to those skilled in the art, including, notably, those used in standards such as H264/AVC.
  • VLC Variable Length Coding
  • step 40 shown in Fig. 3, the exponent value Exp res is predicted (step 41 ) by a prediction value Exp pred , a so-called difference value denoted Exp diff is then calculated (step 42) by extracting the prediction value Exp pred from the exponent value Exp res , and this difference ExV d iff is coded (step 43) giving rise to an item of coded data Ec added to the coded data signal F.
  • the difference Exp diff is coded without loss.
  • this difference is coded using Fixed Length Coding (FLC).
  • FLC Fixed Length Coding
  • this difference Exp diff is coded via the intermediary of a Variable Length Coder (VLC), a Huffman-type coder or any other entropic coder well known to those skilled in the art, including, notably, those used in standards such as H264/AVC.
  • VLC Variable Length Coder
  • Huffman-type coder Huffman-type coder
  • any other entropic coder well known to those skilled in the art, including, notably, those used in standards such as H264/AVC.
  • the prediction value Exp pred is defined from a block that belongs to an image, called a reference image, other than the image to which image block B c belongs.
  • this block is co-located with the image block B c , that is to say located in the same spatial position.
  • the reference image block is designated by a motion vector which, in a coding/decoding scheme, is transmitted to the decoder.
  • the prediction value Exp pred is defined from a causal neighbourhood V res formed of at least one block B? es previously processed by the method.
  • Each block B? es corresponds to a prediction residual error block of an image block and is thus associated with a unique exponent value Exp ⁇ x determined, for example, according to step 30.
  • a neighbourhood is qualified as causal when it is formed of available data blocks.
  • a neighbourhood is causal if the decoder is able to form this neighbourhood from data that it has previously decoded.
  • the decoder is capable of obtaining the block(s) B? es as well as its/their associated values which are required to form the neighbourhood V res .
  • the use of a neighbourhood is particularly advantageous in a context of transmitting the signal F between a coder and a decoder, because the decoder is then able to obtain a prediction value of the exponent value without any data being transmitted by the coder, as soon as the coder and decoder have the same rule for obtaining this prediction value.
  • the causal neighbourhood V res is formed of at least one block belonging to the image to which the block to be processed belongs.
  • Fig. 4 illustrates an example of a causal neighbourhood.
  • the neighbourhood is formed by three blocks denoted B es , 5r es , 5 r 3 es with which the exponent values Exp es , Exp? es , Exp? es are associated respectively.
  • a causal neighbouring area V res is formed of at least one block belonging to at least one other image different to the image to which the image block to be coded belongs.
  • This other image may be a reference image used for the estimation of motion data in a coding scheme or an image pointed to by a motion vector.
  • At least one of the blocks which belongs to the reference image is co-located with the image block Be, that is to say located in the same spatial position.
  • At least one of the blocks which belongs to the reference image is designated by a motion vector which, in a coding/decoding scheme, is transmitted to the decoder.
  • the prediction value Exp pred is defined from the prediction residual error.
  • the prediction value Exp pred is defined from a median-type predictor defined by the following equation:
  • Exp P red median(Exp? es ) pour n E ⁇ 1, ... , N] where N is a prediction residual error block number.
  • the prediction value Exp pred is defined from a mean-type predictor defined by the following equation:
  • the prediction value Exp pred is defined from a maximum-type predictor defined by the following equation:
  • the prediction value Exp pred is defined from a set of reconstructed data.
  • these data are reconstructed by a decoder and form what is commonly called a causal zone.
  • the prediction value Exp pred is defined from a median-type predictor defined by the following equation:
  • Exp pred median ( ⁇ Exp n ⁇ pou r n E ⁇ 1, ... , N]
  • Exp n median xp" (i, j) ⁇ i e ⁇ l ,..., L ⁇ ei j e ⁇ ,. ,., ⁇ ⁇ and where L and M are dimensions of a block of index n and exp" (i, j) is the exponent value for a pixel (i,j) belonging to a block n of the neighbourhood used to predict the exponent. This block n was previously reconstructed.
  • the prediction value Exp pred is defined from a maximum-type predictor defined by the following equation:
  • Exppred arg maX ⁇ P" V ur fi £ ⁇ l, ...,JV ⁇
  • Exp n arg max ⁇ exp"( , j) ⁇ i e ⁇ l,..., h ⁇ et j ⁇ ⁇ l,..., ⁇ and where L and M are dimensions of a block of index n and exp" (i, j) is the exponent value for a pixel (i,j) belonging to a block n of the neighbourhood used to predict the exponent. This block n was previously reconstructed.
  • this set of reconstructed data may be formed of pixels used to construct a prediction block.
  • the invention is not limited to a particular set of reconstructed data.
  • step 41 used to define the prediction value Exp pred , can be combined with each other to obtain a spatial prediction or a temporal prediction or a spatio- temporal prediction.
  • the invention is not limited to a particular type of method for coding the mantissas M res of the floating values representing the image data of the prediction residual error block B res , nor is it limited to any known coding method using, for example, a transform such as a DCT, DST (Discrete Sinus Transform) or wavelet, nor those using DPCM-type coding (Differential pulse- code modulation) (" Differential pulse-code modulation from ⁇ available at: httpi /qps-tscupces/GTAV/Torres/Teaching/IVC-Notes/dpcm enqlish.pdf) nor that used in the H264 standard ("Advanced video coding for generic audiovisual services" available at: http://www.itu.int/rec/T-REC-H.264-201304- I) known as I PCM (Intra Pulse Code Modulation), to give just a few of examples. It is also well known that these various coders use quantisers
  • Fig. 5 represents a method for decoding a coded data signal F representative of an image block whose data are represented by floating values.
  • the method comprises the following steps: - decoding (51 ) from the coded data signal F an exponent value relative to a prediction residual error block relative to the image block;
  • the floating values representing the data of the prediction residual error blocks to be decoded are obtained, for example, using equation (1 ).
  • the exponent value of the prediction residual error block is obtained by decoding an item of coded data Ec from the coded data signal F.
  • the Ec data are decoded according to either a fixed- or variable-length code.
  • the Ec data represent the exponent value of the prediction residual error block.
  • the Ec data represent a value called the difference value which corresponds to the difference Exp diff between the exponent value Exp res of the image block which was coded and a prediction value Exp pred of this exponent value.
  • the prediction value Exp pred is then obtained from a causal neighbourhood in a manner identical to step 41 described above.
  • the exponent value Exp res is then decoded (reconstructed) by summing this prediction value Exp pred with the decoded item of Ec data
  • the mantissas of floating values representing the image data of the prediction residual error block are a set of integer values which is coded, according to the invention, by a coding method which uses, for example, a transform.
  • a decoding method which is the inverse of this coding method is then used to decode the coded data of signal F in order to find the mantissas of these floating values.
  • the invention is not limited to a particular method for decoding integral data.
  • each image is divided into image blocks, each image block is coded according to one of the methods described in relation to Fig. 2 to 4 and the coded data signal comprises as many items of data (Ec, Mc) as it does image blocks to be coded.
  • the coded data signal F can then be decoded according to one of the methods described in relation to Fig. 5, with the aim of decoding (reconstructing) an image and possibly a sequence of images.
  • the method for coding an image block B c also comprises a step (step 60) of selecting a coding mode for the residual error block from a set of coding modes.
  • the set of coding modes may include several methods to determine a unique exponent value for the floating values representing the image data of the prediction residual error block (step 30) and/or several predictors of this unique exponent value (step 41 ) and/or several coders to code the difference between this unique exponent value and a prediction value (step 43) and/or several coders to code the mantissas of the floating values representing the image data of the prediction residual error block (step 50).
  • a coding mode in the set may also be a combination of one of these specific coders and predictors.
  • a prediction residual error block is coded according to one of the coding modes i of the set and a coding cost Csti is then determined.
  • the coding cost Csti takes into account the cost of coding MB ⁇ sj the mantissas of the floating values representing the image data of the prediction residual error block, the cost of coding Exp d c ff i the difference ExV d iff calculated by extracting the prediction value Exp pred from the exponent value Exp res and the cost of coding Hdr cst i the syntax elements which enable the decoder to decode the image block B c , such as an index to designate a specific prediction mode or a motion vector.
  • the coding cost Cst j relative to a coding mode i of the image block B c is given by:
  • the adjustment of parameter A, called Lagrangian is widely known.
  • the best choice of coding mode, of index (i opt ) is made by selecting the mode which leads to the best compromise between a minimum coding cost for the exponent value and the mantissas of floating values representing the image data of the prediction residual error image, and a minimum reconstruction error of the image block.
  • the optimal coding cost is defined by:
  • the metric sse rec i is a square error calculated between the image block B c and the coded/decoded block according to a coding mode (i).
  • the modules shown are functional units that may or may not correspond to physically distinguishable units.
  • these modules or some of them can be grouped together in a single component or circuit, or constitute functions of the same software.
  • some modules may be composed of separate physical entities.
  • the prediction and/or coding devices compatible with the invention can be implemented according to a purely hardware embodiment, for example in the form of a dedicated component (for example in an ASIC (Application Specific Integrated Circuit) or FPGA (Field-Programmable Gate Array) or VLSI (Very Large Scale Integration)) or of several electronic components integrated into a device or even in the form of a mixture of hardware elements and software elements.
  • ASIC Application Specific Integrated Circuit
  • FPGA Field-Programmable Gate Array
  • VLSI Very Large Scale Integration
  • Fig. 6 describes an example of the internal architecture of a device configured to implement at least one of the methods for coding an image block which are described in relation to Fig. 2, 3 and 4, and at least one of the methods for decoding a coded data signal which are described in relation to Fig. 5.
  • Device 600 comprises the following elements, interconnected by a digital address and data bus 601 :
  • a calculation unit 603 (also called a central processing unit);
  • the calculation unit 603 can be implemented by a (possibly dedicated) microprocessor, a (possibly also dedicated) microcontroller, etc.
  • the memory 605 can be implemented in a volatile and/or non-volatile form such as a RAM (random access memory), a hard disc, an EPROM (erasable programmable ROM), etc.
  • means 603, 604 and possibly 605 cooperate with each other in order to determine a unique exponent value for the floating values representing the image data of a residual error block which is from an image block to be coded, in order to code said exponent value thus determined and in order to code the mantissas of the floating values representing the image data of the residual error block by spatial and/or temporal prediction.
  • means 603, 604 and possibly 605 then cooperate with each other in order to decode an exponent value from the coded data signal for a residual error block relative to an image block to be decoded, in order to decode the mantissas of the floating values representing the image data of the residual error block from the coded data signal by spatial and/or temporal prediction and in order to reconstruct the floating values representing the image data of the residual error block to be decoded from said exponent value and said mantissas thus decoded.
  • the two embodiments above may also be combined so that the device 600 is designed both to code and decode a residual error block relative to an image block to be coded.
  • the devices described above are also designed to code and decode an image and/or a sequence of images.
  • Information regarding image data, image sequence data and/or image block data are possibly received via the interface 604 and connection 602 or these data can be obtained from the memory 605.
  • the data signal F may be saved in the memory 605 and/or transmitted to an item of remote equipment via the interface 604 and connection 602.
  • the invention is not limited to the embodiment examples mentioned above. In particular, those skilled in the art may apply any variant to the stated embodiments and combine them to benefit from their various advantages.
  • the invention is in no way limited by the mode of coding the mantissas.
  • the invention can be used with a DCT, a DST, a Hadarmard transform or a wavelet transform.

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Abstract

La présente invention concerne un procédé et un dispositif permettant de coder, en un signal de données codées, un bloc d'images dont les données d'images sont représentées par des valeurs flottantes. Chaque valeur flottante étant exprimée par une mantisse et un exposant, le procédé est caractérisé en ce qu'il comprend les étapes suivantes consistant à : – déterminer (10) un bloc de prédiction (Bpred) pour le bloc d'images destiné à être codé ; – déterminer (20) un bloc d'erreur résiduelle de prédiction (Bres) en extrayant ledit bloc de prédiction du bloc d'images destiné à être codé ; – déterminer (30) une valeur exponentielle unique (Expres) pour les valeurs flottantes représentant les données d'images du bloc d'erreur résiduelle de prédiction (Bres), – coder (40) ladite valeur exponentielle ainsi déterminée (Expres) pour le bloc d'erreur résiduelle de prédiction (Bres), et – coder (50) les mantisses (Mres) des valeurs flottantes représentant les données d'images du bloc d'erreur résiduelle de prédiction (Bres) par une prédiction spatiale et/ou temporelle. L'invention concerne également un procédé et un dispositif permettant de décoder le signal de données codées.
PCT/EP2014/071112 2013-10-07 2014-10-02 Procédé de codage et de décodage de données flottantes d'un bloc d'images et dispositifs associés WO2015052064A1 (fr)

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FR1359689 2013-10-07
FR1359689 2013-10-07
FR1452220A FR3010605A1 (fr) 2014-03-18 2014-03-18 Procede de codage et de decodage de donnes flottantes d'un bloc d'image et dispositifs associes
FR1452220 2014-03-18

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CN114885166B (zh) * 2018-12-29 2024-04-12 华为技术有限公司 编码器，解码器和使用压缩mv存储的对应方法
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WO2020258057A1 (fr) * 2019-06-25 2020-12-30 深圳市大疆创新科技有限公司 Procédé, appareil et dispositif de traitement vidéo

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