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People resolve the relative position of two targets (this object is to the left of that one) with very high accuracy. A displacement of less than 1/3rd of the width of a cone can be detected. The ability to make such fine position discriminations depends on the neural analysis of light that is spread across the cone photoreceptor mosaic. This position resolution is called vernier acuity.

The main purpose of this toolbox is to perform calculations that clarify the information available to the nervous system to perform relative position estimates. A secondary value is that the limits of relative position (vernier) acuity has implications for the design of image display devices and printers.

This repository uses ISETBIO to characterize a vernier task. The ISETBIO tools model the stimulus (scene radiance) on a display, the physiological optics, the cone photoreceptor absorptions, eye movements, the cone photocurrent responses, and computational classification methods. We model how well a computational observer can judge the relative position of various stimuli based on cone absorptions and cone photocurrent. We illustrate how the available information depends on viewing conditions, such as the luminance levels, stimulus duration, eye movements, physiological optics, and cone mosaic properties.

P.S. The definition and discussion of vernier acuity as a hyperacuity on wikipedia is misleading or perhaps even wrong. When this software and wiki page are complete, we should link to that page and offer readers this computational explanation.