Abstract: The invention relates to a method of transmitting an image portion, which method comprises, in a coding phase analyzing a coding context, adapting a parameter of a group of prediction functions that can be used for coding, forming a first predicted descriptor using a selected prediction function, and determining and transmitting a residue between the first predicted descriptor and the current descriptor. The method further includes a decoding phase comprising analyzing a decoding context, adapting a parameter of a group of prediction functions that can be used for decoding, forming a second predicted descriptor using a selected prediction function and combining the second predicted descriptor and the received residue to deliver a decoded version of the current descriptor.

Abstract: Successive images (F) of a video sequence are encoded in order in generate parameters which are included in an output flow (F) that is to be transmitted to a decoder. The encoding of certain images is effected in Inter mode relative to one or several previous images of the sequence. The output flow also includes long term marking commands for certain images and demarking commands for previously marked images. Each long-term marked image is kept in a memory by the decoder until a corresponding demarking command is received. Return information on the restoration of the images of the video sequence by the decoder is received by the encoder (1) and analyzed in order to identify an image that has been lost by the decoder. It is possible to encode a following image of the sequence in Inter mode in relation to a long-term marked image in response to identification of an image lost to the decoder.

Abstract: Successive images of a video image are encoded in order to generate parameters which are included in an output flow that is to be transmitted to a decoder. The encoding of certain images is carried out in inter mode in relation to one or several previous images of the sequence, said previous images being temporarily stored in an image memory. Return information on the restoration of the images of the video sequence by the decoder are received by the encoder and analyzed in order to evaluate the time lag of the return channel in relation to the transmission of the output flow. The encoder determines an amount of memory allocated to the image memory in the decoder according to the evaluated time lag and indicates said amount of memory to the decoder.

Abstract: The present invention relates to a method of storing pictures in a memory, a picture being divided into data blocks, said method comprising the step of: computing a transform of an input data block for producing a transformed data block comprising a set of n transformed elements, where n is an integer, entropy coding m first transformed elements of the transformed data block for producing an encoded data block, where m is an integer lower than n, computing a cost function on the basis of a weighted sum of a distortion value between the input data block and the encoded data block and a power consumption required for reading or writing the encoded data block in the memory, iterating the entropy coding and cost function computing steps for different values of m, and storing in the memory the encoded data block corresponding to the value of m that minimizes the cost function.

Abstract: The present invention relates to a method of post-processing a digital image (Im) comprising pixels, said digital image being encoded and decoded according to a technique of coding by blocks of pixels. Said method comprises a classification step (6) intended to allocate a class (Cli) to a block (Bj) of pixels of said digital image, a step of evaluating the degradation (5) of said digital image delivering a degradation measurement (DM) of said digital image, a filter selection step (9) intended to associate a filter (F1) with a pair of adjacent blocks (Bj, Bk) according to their respective classes (Clm, Cln) and the degradation measurement (DM) of said digital image, a filtering decision step (8) intended to deliver a filtering decision (Dec) for a pair of adjacent blocks (Bj, Bk) according to the degradation measurement (DM) and a filtering step (11) intended to filter a pair of adjacent blocks (Bj, Bk) by means of its associated filter (F1) delivering a filtered digital image (ImF).

Abstract: The present invention relates to a method of motion estimation for use in a device adapted to process a sequence of frames, a frame being divided into blocks of data samples. Said motion estimation method comprises a step of computing a residual error block associated with a motion vector candidate (MV) on the basis of a current block (cb) contained in a current frame (CF) and of a reference block (rb) contained in a reference frame (RF), said reference block having a same position in the reference frame as the current block has in the current frame. The motion vector candidate defines a relative position of a virtual block (vb) containing a first reference portion (rbp1) of the reference block with reference to said reference block.

Abstract: The present invention relates to a method of processing digital images comprising pixel blocks, said method comprising a step of detecting blocking artifacts (41) between two adjacent blocks (Bj,bk), and a step of filtering (43) the pair of adjacent blocks. The method according to the invention further comprises a filter decision step (42) based on a comparison between luminance values of the pixels of the two adjacent blocks and a reference function representing a difference of minimum luminance values that can be seen by an observer as a function of an average luminance area of the image in order to determine whether a difference of luminance between the blocks is either or not visible to an observer.

Abstract: The present invention relates to a method of encoding a sequence of pictures, a picture being divided into blocks of data, said encoding method comprising the steps of:—computing a residual error block from a difference between a current block contained in a current picture and a candidate area using of a prediction function,—computing an entropy of the residual error block,—computing an overall error between said current block and said candidate area,—estimating a power consumption of a video processing device adapted to implement said prediction function,—computing a rate-distortion value on the basis of the entropy, the overall error and the estimated power consumption of the video processing device, —applying the preceding steps to a set of candidate areas using a set of prediction functions in order to select a prediction function according to the rate-distortion value.

Abstract: The present invention relates to method of coding blocks of video data for a handheld apparatus comprising a battery. Said method comprising a step of computing a residual error block from the use of a set of prediction functions having different power consumption levels. It also comprises a step of enabling or disabling a prediction function of the set depending on its associated power consumption level for a predetermined level of the battery. It finally comprises a step of selecting a prediction function among a set of enabled prediction functions to code the residual error block.

Abstract: The present invention relates to a method of processing digital images (30) comprising data blocks, said method including a step of determining (31) a homogeneous region containing two adjacent blocks (Bj, Bk) whose continuous components (Lj, Lk) differ by a value lower than a predetermined threshold. It also includes a step of determining (32) a segment to be corrected (Sjk) which comprises a set of initial data on either side of a border separating the adjacent blocks. The method finally comprises a step of replacing (33) the set of initial data of the segment to be corrected by a set of corrected data (S?jk) chosen at random from various possible corrected data sets (34), an average value of a corrected set of data being substantially equal to an average value of the continuous components of the two adjacent blocks.

Abstract: The present invention relates to a method and an encoder for coding an input digital video signal comprising a luminance component with luminance values. The method comprises the steps of:- transforming said video sequence from the original spatial representation into fewer representation data comprising transformed luminance values;—performing a quantization on the representation data so as to obtain a reduced set of data. The invention is characterized in that the quantization step performs a quantization of the luminance component in an adaptive way according to a visible range of transformed luminance values of the luminance component.

Abstract: The invention relates to a method of detecting blocking artefacts within a sequence of digital images. The method comprises a step of high-pass filtering a portion of a digital image, intended to supply at least one card of discontinuity pixels. It also comprises a step of detecting blocking artefacts, intended to detect a first type (p1) of elementary blocking artefact and a second type (p2) of elementary blocking artefact from the at least one card of discontinuity pixels. The method finally comprises a step of correcting the blocking artefacts in accordance with their type (p1, p2).

Abstract: The invention relates to a method of processing a digital image encoded and decoded in accordance with a pixel-block encoding technique, suitable for supplying a motion vector per block of pixels and a quantization step per image. Said method comprises a step of selecting said decoded image if its quantization step is larger than a predetermined threshold, and a step of detecting pixel blocks having a secondary grid. Said detection step comprises a sub-step of detecting a uniform block of the decoded image, a sub-step of selecting a uniform block of non-zero motion and with an amplitude which is smaller than a predetermined amplitude threshold, and a sub-step of localizing a secondary grid within a uniform block selected as a function or its motion vector. Such a method has the advantage that the performance of a method of correcting block effects or evaluating the quality of said decoded image is enhanced.

Abstract: The invention relates to a method of coding an input digital video sequence corresponding to an original color image sequence, said method comprising at least a step for converting said video sequence from the spatial domain to less representation data, a quantization step, for transforming the converted signals thus obtained into a reduced set of data. According to the invention, said coding method also comprises, before said converting step, a pre-processing step, provided for determining if the input video sequence is in YUV color space, Y being the luminance component and U, V the chrominance components, and transforming said space into a less redundant color space by means of a non-linear transformation taking into account the possible lower quality finally obtained.

Abstract: A flexible tubular pipe comprising at least, from the inside outwards, an internal sealing sheath made of a polymer material, a cylindrical pressure vault having an external face and having an internal face placed over the internal sheath. The vault is a winding, in a helix with a short pitch and with a gap between turns, of an interlocked metal profile wire. At least one ply of tensile armour layers is wound with a long pitch. An external protective sealing sheath is made of a polymer. The fastener wire has the same height as the profile wire and is fastened below the neutral fiber of the profile wire. The ratio of the cross section of the profile wire to the cross section of the fastening wire is between 1 and 2 and the ratio of the moment of inertia Iyy of the profile wire to the moment of inertia Iyy of the fastening wire is between 1 and 2.

Abstract: The present invention relates to a method of measuring video quality. Said method comprises a step of determining (21) at least one reference level (JND) above which visual artifacts become noticeable to a group of subjects, with a corresponding predetermined artifact metric (M), from a set of reference sequences (RS) of digital pictures only comprising a corresponding artifact. The method of measuring video quality also comprises a step of measuring (22) at least one artifact level (L) of the input sequence (IS) with the corresponding predetermined artifact metric (M). It further comprises a step of computing (23) a video quality metric (OQM) of the input sequence from at least one ratio of the artifact level (L) to the reference level (JND) corresponding to a same predetermined artifact metric. Such a method of measuring video quality provides an objective quality metric.

Abstract: The invention concerns a process for decompression of compressed animated images with a method including treatment of images in blocks and containing a digital data recomposition phase defining predefined forms, a phase modeling the movement of these forms using a process of prediction, interpolation and temporal compensation, an image composition phase from reconstructed elements of JPEG or MPEG type motion, characterized by the fact that the form recomposition phase includes a process for separating fixed forms from mobile forms, a process for recording digital data corresponding to the fixed forms treated by a filter not separable from the processes implemented in the recomposition phase in a first specific memory unit and digital data corresponding to mobile forms in a second specific memory unit.

Abstract: The present invention relates to a method of processing digital images comprising pixel blocks, said method comprising a step of detecting blocking artifacts (41) between two adjacent blocks (Bj,bk), and a step of filtering (43) the pair of adjacent blocks. The method according to the invention further comprises a filter decision step (42) based on a comparison between luminance values of the pixels of the two adjacent blocks and a reference function representing a difference of minimum luminance values that can be seen by an observer as a function of an average luminance area of the image in order to determine whether a difference of luminance between the blocks is either or not visible to an observer.

Abstract: The present invention relates to a method of post-processing a digital image (Im) comprising pixels, said digital image being encoded and decoded according to a technique of coding by blocks of pixels. Said method comprises a classification step (6) intended to allocate a class (Cli) to a block (Bj) of pixels of said digital image, a step of evaluating the degradation (5) of said digital image delivering a degradation measurement (DM) of said digital image, a filter selection step (9) intended to associate a filter (F1) with a pair of adjacent blocks (Bj, Bk) according to their respective classes (Clm, Cln) and the degradation measurement (DM) of said digital image, a filtering decision step (8) intended to deliver a filtering decision (Dec) for a pair of adjacent blocks (Bj, Bk) according to the degradation measurement (DM) and a filtering step (11) intended to filter a pair of adjacent blocks (Bj, Bk) by means of its associated filter (F1) delivering a filtered digital image (ImF).

Abstract: The present invention relates to a method of measuring video quality. Said method comprises a step of determining (21) at least one reference level (JND) above which visual artifacts become noticeable to a group of subjects, with a corresponding predetermined artifact metric (M), from a set of reference sequences (RS) of digital pictures only comprising a corresponding artifact. The method of measuring video quality also comprises a step of measuring (22) at least one artifact level (L) of the input sequence (IS) with the corresponding predetermined artifact metric (M). It further comprises a step of computing (23) a video quality metric (OQM) of the input sequence from at least one ratio of the artifact level (L) to the reference level (JND) corresponding to a same predetermined artifact metric. Such a method of measuring video quality provides an objective quality metric.