Journal: Proceedings of the Royal Society B: Biological Sciences
Article Title: How to generate and test hypotheses about colour: insights from half a century of guppy research
doi: 10.1098/rspb.2022.2492
Figure Lengend Snippet: Illustrations showing the potential blurring effects of acuity and motion. Defocus and motion blur were done using MATLAB functions fspecial (for filter definition) and imfilter (to apply the filter to the image). Structural colours show weakly in this photograph; see electronic supplementary material, figures S1 and S2 for effects on structural colours and more details. ( a ) Six guppies seen at short distance (as in typical guppy courtship). ( b ) The same guppies seen at a distance (as by a predator). ( c ) Motion blur during the sigmoid courtship display in which the body is rapidly rotated along the body long axis, blurring vertically. This also has a strong effect on the structural colours because they only reflect strongly in certain directions, causing a strong flicker. ( d ) Motion blur when foraging or fleeing a predator, blurring horizontally. This kind of motion results in a lot less structural colour flicker because the long axis is not rotated very much, if at all. Note the loss of colour and luminance contrast due to acuity limits and note the very different appearances due to motion in different directions. Similar effects occur for structural colours (electronic supplementary material, figures S1 and S2). Guppies and their predators gather very different visual information.
Article Snippet: Defocus and motion blur were done using MATLAB functions fspecial (for filter definition) and imfilter (to apply the filter to the image).
Techniques: