Tesi di LAUREA SPECIALISTICA Titolo Acoustic Imaging in the RaySpace: Application to Environment Inference Data 2012-04-23 Autore/i Sandrini, Giorgio Relatore Sarti, A. Relatore Markovic, D. Full text non disponibile Abstract This work is part of the environment-aware processing, a eld of recent interest that promises to signicantly push the boundaries of audio signal processing. The environment-aware processing uses information arising from the environmental response to enable the acoustic systems to become aware of their own characteristics and geometry and those of the environment that they operate in. This information allows advanced and innovative space-time processing solutions. In particular the thesis addresses the problem of inference from acoustic measurements on the geometric characteristics of the environment. Recently a number of techniques for localization of reective surfaces appeared in literature. These techniques exploit dierent information extracted from acoustic measurements to infer the position of the reectors in the environment. Usually the extracted information, combined with some a priori knowledge, defines a non-linear constraint on reector position. Using multiple constraints (e.g changing the hardware position) a cost function is formulated whose minimization yields the estimated line or plane (for 2D or 3D geometries) on which the reflector lies. In this work we take a slightly different approach for the localization of reective surfaces. Instead of extracting information related to a specific geometric constraint, we are interested in looking at the acoustic scene, i.e. obtaining an overview of what is happening in dierent positions in space, and successively estimating the environment geometry from a number of such acoustic snapshots. Therefore, we want to imitate, to a certain extent, the procedures used in computer vision to reconstruct the environment geometry taking visual snapshots from dierent points of view. The acoustical snapshots are dened using a non-linear transformation applied to acoustic measurements that maps the data in a space in which the geometric primitives are represented by linear constraints. Unlike most of other methods, the acoustic observation of the environment allows us to nd not only the line on which the reector lies but also its extension. This property can turn useful in irregular, complex environments where occlusions and limited visibility of acoustic reflectors are present. Furthermore, the representation of acoustic measurements dened in this work can potentially be used also to infer on radiometric properties of the environment (e.g. radiation pattern and reflection coefficients) and therefore it has a number of potential other applications.