AcuityView
An R package for representing a visual scene as it may be seen by an animal with less acute vision
Acuity (the ability of an animal to perceive detail) varies dramatically across species. Humans have some of the highest acuity in the animal kingdom, meaning that we perceive a great deal more spatial detail than the majority of animals. As a result, researchers may develop hypotheses about the potential function of a spatial pattern or signaling trait without first testing that it is resolvable by the relevant animal viewer.
- How does AcuityView Work?
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AcuityView provides a simple and powerful method for eliminating all of the spatial information from a scene that should not be resolvable by a viewer with a given acuity from a given distance. Importantly, AcuityView does NOT tell us what the animal perceives--no theoretical or experimental treatment can do that! Rather, it allows us to examine what visual information is and is not available to a given viewer.
In brief, AcuityView uses Fourier methods to eliminate spatial information from an image that is below the acuity of a given viewer from a specified viewing distance. An image is Fourier-transformed (FFT). The transform is a representation of the original image in frequency space. This transform is then multiplied (element by element) with the modulation transfer function (MTF) of the viewer. The product is then inverse-Fourier-transformed (iFFT) to create the converted image, which has now lost all detail finer than what can be perceived by a visual system with a chosen acuity.
- How do I access AcuityView?
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The AcuityView package is freely available using the R software and can be downloaded from the R CRAN. The source code for AcuityView has been archived using GitHub and is freely available from the Zenodo repository (https://doi.org/10.5281/zenodo.998916).
You can also implement AcuityView (in conjunction with many other image processing features) in ImageJ via the MICA Toolbox (http://www.empiricalimaging.com/knowledge-base/acuityview/)
AcuityView is also available inside the Pavo R Package, a powerful R package for working with spectral and spatial color data. AcuityView is now part of Pavo's Processing and Visualizing Data functionality.
EM Caves and S Johnsen. 2017. AcuityView: An R package for portraying the effects of visual acuity on scenes observed by an animal. Methods in Ecology and Evolution 9: 793-797. doi.org/10.1111/2041-210X.12911
