**Abstract**
The intensity of a polarized speckle pattern
obeys a negative exponential probability density function. This distribution
implies a signal-to-noise-ratio (SNR) unity since the standard deviation
equals the mean intensity. However, if the logarithmic response of the
retinal photoreceptors is taken into account, the first order statistics
of the pattern is transformed in such a way that the SNR becomes a function
of the mean intensity. The results developed here are closely connected
with the masking effect of speckle in vision experiments. In particular,
it contributes to explain why the resolving power of the human visual system
with speckled imagery decreases as the mean luminance increases. |