Abstract: A method for detecting (DET) a signal in a communication system including a plurality of communication channels, from a plurality of noisy values respectively representative of the transmission through the communication channels, is provided. The propagation in the communication channels is characterized by at least one variable. The set of values that can be taken by the variable is divided into a plurality of ranges. The method includes receiving (E4) the signals respectively transmitted in the plurality of communication channels, and detecting (E20) a signal corresponding to a value of the variable lying within one of the plurality of ranges by comparing, with a predetermined threshold, a value taken by a correlator linked to the range in question and calculated as a function of the noisy values. A channel estimation method, a detection device, a channel estimation device and a computer program are also described.

Abstract: Disclosed is a method for constructing a digital hologram to be displayed by of a display system. The display system includes a light modulator producing a light beam and a convergent optical device designed to make the light beam converge towards a focal point. The scene is defined by a set of luminous elements. The construction method includes a step of determining values respectively associated with the pixels of the digital hologram by summing the light contributions respectively produced by the luminous elements with weighting, for each of the light contributions, by a correction coefficient depending on the area of the intersection of a surface between the convergent optical device and the focal point, and a pencil of light having a predetermined angular opening and transmitted through the convergent optical device from the luminous element producing the light contribution concerned. An associated holographic system is also described.

Abstract: The invention concerns a method for converting an input image comprising an input luminance component made of elements into an output image comprising an output luminance component made of elements, the respective ranges of the output luminance component values and input luminance component element values being of different range extension. the method comprises for the input image: computing a value of a general variable representative of at least two input luminance component element values; transforming each input luminance component element value into a corresponding output luminance component element value according to the computed general variable value; and converting the input image using the determined output luminance component element values.

Abstract: Disclosed is a method and a device for coding a sequence including first and second digital holograms representing respective scenes, the digital holograms being represented by a set of wavelets each defined by a multiplet of coordinates in multidimensional space. The first and second holograms are represented by first and second coefficients respectively associated with wavelets. The coding method includes the following steps: for each second coefficient, determining a remainder by a difference between the second coefficient concerned, associated with a first wavelet defined by a given multiplet, and the first coefficient) associated with a second wavelet defined by a multiplet having as its image the multiplet by a transform in the multidimenisonal space; coding the determined remainders. The transform is determined by analysis of variation between the first scene represented by the first digital hologram and the second scene represented by the second digital hologram.

Abstract: Proposed is a method for encoding an image of a video sequence, the image including at least two components, including a component representative of the luminance and a component representative of the chrominance, each component being partitioned into blocks, wherein the method involves encoding at least one block of the chrominance component using a BDPCM mode.

Abstract: Disclosed is a method for processing an input hologram HE associated with an input plane, to obtain an output hologram displayable on a holographic screen placed in a plane called the output plane of a display system, viewable from a viewing plane of the system. The method includes: receiving the input hologram and a position of the input plane; obtaining a first transfer matrix representative of a propagation between the input plane and the viewing plane; obtaining a second transfer matrix representative of a propagation between the viewing plane and the output plane; calculating an overall matrix of transfer of a light field emitted by the input hologram, between the input plane and the output plane, by taking the product of the two matrices; and converting the input hologram into the output hologram by applying an operator dependent of the input hologram and on the screen.

Abstract: Disclosed is a method for encoding data corresponding to a video sequence, into a spatial resolution scalable binary flow, including a base layer and enhancement layer. The method includes, for a frame of the sequence: obtaining, from the frame, a first frame, partitioning the first frame into blocks, each block having a given size, and encoding a block of the first frame to generate the base layer; obtaining, from the frame, a second frame; partitioning the second frame into blocks by inferring the initial size of a block from the size of a corresponding block in the first frame, the block of the second frame having an initial spatial resolution; determining a spatial encoding resolution associated with the block from a set of predetermined spatial resolutions; and coding data representative of the at block, based on the determined spatial encoding resolution, to generate an enhancement layer.

Abstract: A pilot sequence includes pilot vectors to be transmitted in a communication channel. A method of determining the pilot sequence comprises determining an orthogonal basis of a real vector space that is an image of a matrix having, respectively as columns, the partial derivatives of the model vector with respect to the different real parameters; and constructing the pilot vectors using the determined orthogonal basis, by grouping the orthogonal vectors of the orthogonal basis in at least one pair and by producing, for each of the at least one pair comprising a first vector and a second vector, a pilot vector by summation of the first vector and a product of the second vector by an imaginary number.

Abstract: The invention relates to a method for decoding an image based on a base layer (Cbase) and enhancement information (Iam), said method comprising the following steps: decoding said base layer (Cbase) in order to obtain at least one base component (Ydecbase, Udecbase, Vdecbase), oversampling the at least one base component (Ydecbase, Udecbase, Vdecbase) in order to obtain at least one oversampled component (Ysurech, Usurech, Vsurech), decoding the enhancement information (Iam) by means of a part (B) at least of artificial neural network in order to obtain enhancement values (Vam), reconstructing the image based on the at least one oversampled component (Ysurech, Usurech, Vsurech) and the enhancement values (Vam). The invention also relates to associated encoding method, electronic decoding device, electronic encoding device and signal.

Abstract: A method for interpolating a sound field captured by a plurality of N microphones each outputting the encoded sound field in a form including at least one captured pressure and an associated pressure gradient vector. Such a method includes an interpolation of the sound field at an interpolation position outputting an interpolated encoded sound field as a linear combination of the N encoded sound fields each weighted by a corresponding weighting factor. The interpolation includes an estimation of the N weighting factors at least from: the interpolation position; a position of each of the N microphones; the N pressures captured by the N microphones; and an estimated power of the sound field at the interpolation position.

Abstract: A method for decoding a digital image from encoded data representative of the image. The image is divided into blocks processed in a defined order. The method includes, for a current block having a predetermined number (Mv) of lines and number (Mh) of columns: decoding coefficients of the current block from coded data; decoding an index representative of an identifier of a transform among a plurality of transforms and identifying the transform, a transform being expressed as a vertical subtransform of size Mv*Mv and a horizontal subtransform of size Mh*Mh; transforming the current block into a decoded block transformed, from the transform obtained, by successive application of the vertical subtransform and then the horizontal subtransform or respectively of the horizontal subtransform and then the vertical subtransform; and reconstructing the image from the transformed decoded block. The transforming includes: a modified use of core sub-transform coefficients, their absolute values being retained.

Abstract: A method for encoding or decoding at least one image, an image being split into blocks of elements. The method includes, for at least one block: splitting the block into at least two areas; and processing at least one of the areas. The processing includes scanning the elements of the area according to a predetermined scanning order, and for at least one scanned element, called a current element: selecting at least one predictor element previously encoded or decoded according to a prediction function; and predicting the current element: from the at least one predictor element, if the at least one predictor element belongs to the area; or from at least one replacement value, otherwise.

Abstract: A method for forming an image sequence that is an output sequence, from an input image sequence, is provided. The input image sequence has an input spatial resolution and an input temporal resolution. The output sequence has an output temporal resolution equal to the input temporal resolution and an output spatial resolution equal to a predetermined fraction 1/N of the input spatial resolution by an integer number N higher than or equal to 2. The method, implemented for a sub-sequence of the input frame sequence that is a current input sub-sequence and including a preset number of images, includes: obtaining a temporal frequency that is an image frequency, associated with the current input sub-sequence; processing the current input sub-sequence to obtain an output sub-sequence; and inserting the output sub-sequence and the associated image frequency into an output container.

Abstract: A method for predicting a three-dimensional representation in a three-dimensional scene, using one or more two-dimensional representations, obtained from at least one image generated by a camera. The method includes obtaining a forest of regression trees, and for the at least one image: extracting a 2D representation associated with one or more positions within the image; predicting a 3D representation, corresponding to the extracted 2D representation, using the regression tree forest includes a set of possible associations between at least one 2D representation and a 3D representation, each possible association resulting from a predictive model; evaluating one or more of the possible associations of the regression tree forest, according to a predetermined confidence criterion; and updating the regression tree forest including a deactivation of one or more possible associations, depending on the evaluation of the possible associations.

Abstract: A method for estimating a camera pose in a frame of reference of a three-dimensional scene, including: obtaining an image of colour intensities of the scene; extracting points of interest, which are invariant by geometric transformation of the image; forming patches in the image, each including an extracted point of interest; predicting 3D locations of the points of interest by applying an automatic prediction system, trained by a training set including patches from images acquired from plural points of view, an image being associated with a 2D position of its point of interest in a frame of reference of the image and with a 3D position of its point of interest in the frame of reference of the scene; estimating the pose of a camera, by mapping the 2D positions of the points of interest and reprojections in the current image frame of reference of the predicted 3D locations.

Abstract: Disclosed is a method for generating a digital hologram representing a 3D scene including an object, an object being defined by points and their associated intensity. For each object, a prior step of calculating an “omnidirectional” angular spectrum of the light field emitted by an object in the scene on the surface of a geometric solid centered on the object, a surface of the solid being sampled according to a predetermined grid, a sample of the grid being associated with a vector frequency; for the scene, the following steps: —obtaining a pose of an observer in the world frame of reference; —deriving the hologram from the scene as a function of the pose obtained from the “multidirectional” angular spectra calculated for each object. The step of calculating an angular spectrum of the light field for each object of the scene takes into account predetermined viewing directions.

Abstract: A method for estimating a wireless communication channel between a transmitter and a receiver, including a plurality of paths for propagation of a wave, at least one of the transmitter and the receiver being formed of a plurality of antennas. The method includes: for at least one path, determining a characteristic matrix, which depends on a first element representative of at least one propagation direction associated with the path, and a second element representative of a propagation distance associated with the path; and estimating the communication channel from the at least one obtained characteristic matrix.

Abstract: A method for decoding an encoded data stream representative of at least one image, which is divided into blocks. The decoding method includes, for a current block: evaluating a plurality of value hypotheses of at least one description element of the current block, by calculating a likelihood measurement per hypothesis; calculating a disparity in the likelihood measurements obtained; determining at least one parameter of a decoder based on the calculated disparity; decoding, using the determined decoder, complementary information for identifying at least one of the hypotheses; and identifying at least one of the hypotheses using the decoded complementary information and obtaining a value of the at least one description element for the current block, from the at least one identified hypothesis.

Abstract: A method for determining the amplitude of a movement performed by a member of an articulated body comprises: obtaining a segment representative of the positioning of the member in a given reference frame at the end of said movement, generating a three-dimensional model of the member, positioned in said reference frame by means of the obtained segment, obtaining a cloud of three-dimensional points representing the member in said reference frame at the end of said movement, based on depth information provided by a sensor, said depth information defining a three-dimensional scene comprising at least a part of the articulated body including said member, repositioning the model of the member so as to minimize a predetermined error criterion between the obtained cloud of points and said model, and determining the amplitude of the movement, based on the new positioning of the model of the member.

Abstract: A method is described for converting an input image into an output image, the output image including an output luminance component made of elements. The method includes: obtaining an input luminance component from the input image; determining the output luminance component, the respective ranges of the output luminance component element values and input luminance component element values being of different range extension, the determining step including: —determining a first intermediate luminance component from the input luminance component and an exponent, —obtaining a mapping profile allowing for mapping a luminance component based on the input luminance component into the output luminance component, —determining a second intermediate luminance component from the input luminance component and the obtained mapping profile, —determining the output luminance component from the first and second intermediate luminance components; and converting the input image into the output image.