F. W. Campbell

Application of fourier analysis to the visibility of gratings

1. The contrast thresholds of a variety of grating patterns have been measured over a wide range of spatial frequencies. 2. Contrast thresholds for the detection of gratings who...

The effect of phase on the perception of compound gratings

The Dependence of the Visual Numerosity Limit on Orientation, Colour, and Grouping in the Stimulus

Visual numerosity judgements were made for tachistoscopically presented arrays of dots. The arrangement within the arrays was either linear or such that dots could be easily per...

Orientational selectivity of the human visual system

1. It is known that an object is less detectable when it is viewed against a background containing structures similar to the object. The effect of changing the orientation betwe...

A Demonstration of the Visual Importance and Flexibility of Spatial-Frequency Amplitude and Phase

To establish how little information the human visual system requires for recognition, common objects were digitally manipulated in the Fourier domain. The results demonstrate th...