Patent ID: 6741666
Filing Date: 2004-05-25
Classification: G06F,H03M,H04N

Abstract:
Method for the analysis filtering of an original digital signal including original samples representing physical quantities, original samples of the digital signal being transformed by successive calculation steps into high and low frequency output samples, any sample calculated at a given step being calculated by a predetermined function of original samples, and/or previously calculated samples, the samples being ordered by increasing rank, characterized in that:the signal is processed by successive input blocks of samples (BE1, BE2), the calculations made on an input block under consideration taking into account only the original or calculated samples belonging to the input block under consideration, the input block under consideration (BE1) and the following input block (BE2) overlap over a predetermined number of original samples, the start limit of the input block under consideration is formed between a first original sample and a first output sample, passing successively, from a previous sample to a following sample calculated as a function of the previous sample, the following sample having a rank equal to or greater than the previous sample, the end limit of the input block under consideration is formed between a second original sample and a second output sample, passing successively from a previous sample to a following sample, calculated as a function of the previous sample, the following sample having a rank equal to or less than the previous sample, the end limit of the input block under consideration and the start limit of the following input block are such that there does not exist any compatibility sample having a rank strictly less than the rank of the sample belonging to the start image of the following input block and to the same row as the compatibility sample, and at the same time a rank strictly greater than the rank of the sample belonging to the end limit of the input block under consideration and to the same row as the compatibility sample, output blocks (BS1, BS2) are formed, each output block corresponding respectively to an input block, two consecutive output blocks overlap over output samples having the same ranks as the original samples on which the input blocks corresponding to the output blocks under consideration overlap.