The Distribution of Observer Detection Thresholds and the Concept of the Contrast Signal-to-Noise Ratio
A recent experiment was performed at Memphis State University to study the detection of four-bar (square-wave), 7:1 aspect-ratio targets in the presence of noise. The targets were presented on a video display to which broadband white noise was added. In addition, the experimental parameters of target spatial frequency and target contrast were varied. Eighty-four observers participated in the experiment, recording almost 3000 observations. Analysis of the experimental data has led to two important results. The first (and foremost) result is that the threshold of detection for observers is distributed log-normally. The second result is the formulation of a transformation (based on the concept of "contrast signal-to-noise") which normalizes observer detection responses with respect to different target-to-background contrasts.
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Master of Science (M.S.)
College of Engineering
Electrical Engineering and Communication Sciences
Length of Campus-only Access
Masters Thesis (Open Access)
Dissertations, Academic -- Engineering; Engineering -- Dissertations, Academic
Pickard, Jack Warren, "The Distribution of Observer Detection Thresholds and the Concept of the Contrast Signal-to-Noise Ratio" (1989). Retrospective Theses and Dissertations. 4201.