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Etablissement Public De Diffusion Dit 'telediffusion De France'

L'etat Francais, Represente Par Le Secretaire D'etat Aux Postes Et

L'etat Francais Represente Par Le Secretaire D'etat

Albert Benveniste

Denis Penninckx

Ludovic Noirie

Olivier Audouin

Andre Gilloire

Frederic Cerou

Francis Kretz

George Moustakides

Christian Richard

Maria Manzanedo

Christian Chaure

Method of measuring the error rate of an optical transmission system and apparatus for implementing the method

A coding process for the adaptive prediction differential PCM type. An error signal e.sub.t is formed between a sample of signal y.sub.t to be coded and a prediction signal p.sub.t of said signal. The prediction signal p.sub.t is formed from restored signals y.sub.t and e.sub.t by two linear filtering operations, the first relating to N successive samples of y.sub.t and using coefficients A1.sub.t, A2.sub.t, . . . , AN.sub.t and the second relating to P successive samples of e.sub.t and using coefficients B1.sub.t, B2.sub.t, . . . , BP.sub.t, the coefficients A1.sub.t, A2.sub.t, . . . , AN.sub.t and B1.sub.t, B2.sub.t, . . . , BP.sub.t being sequentially adjusted at each time t so that the mean power of error signal e.sub.t is minimal. Instead of carrying out the prediction on the basis of signals y.sub.t and e.sub.t only according to the invention, use is also made of the real signal y.sub.t and the real error e.sub.t. A linear filtering of y.sub.t using the coefficients A1.sub.t, A2.sub.t, . . . , AN.sub.t, these coefficients affecting N successive samples of the signal y.sub.t, a linear filtering of e.sub.t using the coefficients B1.sub.t, B2.sub.t, . . . , BP.sub.t are performed. In addition, the quantities thus obtained are respectively weighted by two coefficients between 0 and 1 and not simultaneously zero.

Adaptive prediction differential PCM-type transmission apparatus and

A device for following and recursively estimating the local state of pict contours defined by lines of N points distributed in accordance with an orthogonal sampling structure, said points being defined by successive numerical samples. The invention also relates to a differential coded pulse modulation coder and a differential coded pulse modulation decoder.

Device for following and estimating the local state of picture contours

Growing community of inventors

Rennes, France

Albert Benveniste