摘要:
The invention proposes a digital signal coding method including a step of analysing (E1) the digital signal (IM) into a plurality of frequency sub-band signals distributed according to at least two different frequency bands, at least one first sub-band signal having a lower frequency and at least one second sub-band signal having a higher frequency, characterised in that it includes, for each second sub-band signal, the steps of: dividing (E4) the second sub-band signals into blocks (Bi,n), selecting (E9) blocks to be coded by setting to a predetermined value, according to a selection criterion, coding the blocks selected by setting to the predetermined value.
摘要:
According to the invention, the method of primary processing of a first set of primary data (IM,f) representing physical quantities includes: a set division step (200A to 202) during which the first set of data is divided into sub-sets of first data, and for each first sub-set of data: a step (205 to 207) of “constructing” a global contractive mapping of the first type, for the said first sub-set of data, whose fixed point constitutes an approximation of all or part of this sub-set. The set of parameters (ai, b) thus determined constitutes a primary representation of the said first set of data.
摘要:
The method for primary processing according to the invention takes into account a minimum dimension and a partition of a set of data into so-called “initial elementary” subsets (Ki). It includes: a) for each elementary subset which size is larger than the minimum dimension, one iteration of: a division suitability estimation step, and when appropriate, a step of “supplementary partitioning” of the said subset, b) a “construction” step of a global multidimensional mapping and non-linear mapping, the restrictions of the global mapping to the elementary subsets (Ki) being composed of elementary mappings, the fixed point of the global mapping constituting an approximation of all or part of this set, the set of parameters (ai, b) determined by the restrictions constituting an approximation of the said set of data.
摘要:
A method and device that operates in accordance with the method are provided for primary processing a set of data (IM, f) representing physical quantities. The method comprises a step of constructing a global contractive mapping of a first type for the set of data, the fixed point of which constitutes an approximation of all or part of this set. At least one mapping belonging to the group of mappings consisting of multi-dimensional mappings and non-linear mappings is employed to construct the global contractive mapping. A next step includes determining parameters (ai, b) of the global contractive mapping so as to allow the use of a method of successive approximations converging towards the fixed point of the global contractive mapping. The determined set of parameters (ai, b) constitutes a primary representation of the set of data.
摘要:
In order to progressively transmit a digital image (IM), a method for coding the image comprises the division (E1) of the image into vectors (V.sub.m,n), the selection (E2) of a code vector (VC.sub.d) associated with an index (A.sub.d) for each of the image vectors, and the replacement (E2) of the image vectors by the indices associated with the selected code vectors, in order to produce a plane of indices (PI) representing the image. The method comprises the steps of sub-sampling (E3) the plane of indices (PI) into sub-planes of indices (SPI.sub.1 to SPI.sub.F) respectively comprising indices selected from the plane of indices, and ordering (E4) the sub-planes of indices according to a predetermined order before transmitting them.