Equivalent-noise model for contrast detection and discrimination.

Models for the detection and the discrimination of low-contrast signals by human observers typically assume that the observer is limited by the filtering action of the visual system and by the noisy character of its processing. For some models both the filtering and the noise can be represented by a noise in the stimulus domain, the input equivalent noise of the model. We derive some formulas for computing this noise, describe the calculation of a sample, and discuss some implications of this approach.