Volume 81, Number 4, February 2008
Article Number 44001
Number of page(s) 5
Section Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics
Published online 18 January 2008
EPL, 81 (2008) 44001
DOI: 10.1209/0295-5075/81/44001

Quantum limits in image processing

V. Delaubert1, 2, N. Treps1, C. Fabre1, H. A. Bachor2 and P. Réfrégier3

1  Laboratoire Kastler Brossel, Université Pierre et Marie Curie-Paris 6, École Normale Supérieure, CNRS, CC74 4 Place Jussieu, 75252 Paris cedex 05, France
2  ARC Centre of Excellence for Quantum-Atom Optics, Australian National University Canberra, ACT 0200, Australia
3  Physics and Image processing group, Fresnel Institute, UMR 6133, Domaine Universitaire de Saint-Jérôme 13397 Marseille cedex 20, France

received 26 October 2007; accepted in final form 7 December 2007; published February 2008
published online 18 January 2008

We determine the limit to the maximum achievable sensitivity in the estimation of a scalar parameter from the information contained in an optical image in the presence of quantum noise. This limit, based on the Cramer-Rao bound and valid for any image processing protocol, is calculated for a shot noise limited image, for a locally squeezed light, and for a single-mode squeezed light in a well-defined "noise mode". In addition, we exhibit an image processing protocol that allows us to reach the limits in the different cases.

42.50.Dv - Nonclassical states of the electromagnetic field, including entangled photon states; quantum state engineering and measurements.
42.30.-d - Imaging and optical processing.
42.50.Lc - Quantum fluctuations, quantum noise, and quantum jumps.

© EPLA 2008