Naslov
Speckle noise in bar-code scanning systems-power spectral density and SNR

Autori
Marom, E. ; Krešić-Jurić, Saša ; Bergstein, L.

Izvornik
Applied optics (0003-6935) 42 (2003), 2; 161-174

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
specle noise ; bar-code ; power spectral density

Sažetak
Laser-based flying-spot scanners are strongly affected by speckle that is intrinsic to coherent illumination of diffusing targets. In such systems information is usually extracted by processing the derivative of a photodetector signal that results from collecting over the detector’s aperture the scattered light of a laser beam scanning a bar code. Because the scattered light exhibits a time-varying speckle pattern, the signal is corrupted by speckle noise. In this paper we investigate the power spectral density and total noise power of such signals. We also analyze the influence of speckle noise on edge detection and derive estimates for a signal-to-noise ratio when a laser beam scans different sequences of edges. The theory is illustrated by applying the results to Gaussian scanning beams for which we derive closed form expressions.

Izvorni jezik
Engleski

Znanstvena područja
Matematika

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