understanding of the stability of the image restoration process. Note that the deconvolution method (Lannes [*et al.*]{} 1987) respects the photometry of the target, which is necessary for many applications, such as the determination of color indices of binary stars for example (cf §6).

[**6. Astrophysical programs**]{}

10000 In this section, we describe are some of the scientific subjects which are being studied with PISCO at Pic du Midi. Other programs which aimed at imaging complex objects (asteroids and stellar enveloppes) have been impossible to do because of bad weather conditions.

10000 [*– Orbits of binary stars*]{}

10000 The study of binaries is a well suited program for speckle cameras as the bibliography of the last two decades can easily show (CHARA project, McAlister and Hartkopf, 1984, 1988, Hartkopf [*et al.*]{}, 1996).

A long term program aims at measuring the position of close binaries to determine the orbits and derive the masses of the components using the parallaxes measured by Hipparcos (Carbillet [*et al.*]{}, 1996, Aristidi [*et al.*]{}, 1997, Aristidi [*et al.*]{}, 1998). New orbital elements have already been recalculated for 8 double stars from these observations (Aristidi [*et al.*]{}, 1998).

We noticed that PISCO was very efficient for binary 