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Akiyoshi's illusion pages
- JDGM 13y agoAbsolutely superb. And I'm doing an optical illusions special with my students this week too so this goldmine is perfectly timed. Thanks! My favourite are the colour ones. I stare and stare at them trying to isolate the bit that - for example - is actually grey but looks red, to see its "true" colour. That level of concentration...not really ever seeing the grey, but perhaps objects behind me in the room flying around Matilda-style.
- henrik_w 13y agoReally cool! Just to make sure there was nothing funny with the web page (not that I thought so, but still), I printed the Rotating Snakes picture on paper. Sure enough, they still appear to rotate, even on paper.
- pavel_lishin 13y agoYou might be interested to learn that cats can also perceive this illusion: http://geekologie.com/2013/03/cat-can-see-spinning-optical-illusion-tr.php http://geekologie.com/2013/03/cat-can-see-spinning-optical-i...
- makeset 13y agoHa! A cross-species evolutionary bug.
- WA 13y agoConsidering the tricks of palette shifting [1] and stuff that old computer and console games used to make computationally cheap animated backgrounds, does anyone know if there were computer games that used optical illusions for "computationally super-cheap animations"? [1] http://www.effectgames.com/effect/article.psp.html/joe/Old_School_Color_Cycling_with_HTML5 http://www.effectgames.com/effect/article.psp.html/joe/Old_S...
- bentcorner 13y agoI was thinking the same thing - my guess is that these illusions rely on particular visual patterns and colors that don't lend themselves well to video games. One thing I'm interested in is getting video games to take advantage of eye tracking and foveal vision for perf gains. I thought I saw a prototype somewhere that did this but I can't dig it up at the moment...
- zvrba 13y agoThe "Autumn color swamp" doesn't "work" for me. Sometimes the background appears to move, but most of the time, everything appears still..
- cosmotron 13y agoI believe this one works best when the page itself is moving (e.g. by scrolling).
- instakill 13y agoThis page is a headache waiting to happen.
- miahi 13y agoThis is one of my oldest bookmarks. It's not only that the professor shows the illusions, but he also shows his research and explains them.
- notthemessiah 13y agoThe linked research only describes phenomenological characteristics of illusions, so it doesn't strike me as an explanation. But it points to research that does attempt to explain the peculiarities of what conditions these illusions arise. For example, it seems to explain the effect of the brightness of the background on these motion illusions : First, an optimised stimulus can induce motion aftereffect on a stationary sinusoidal grating, which provides evidence for the activity of the visual motion mechanism. Second, perceived direction can be altered by background luminance. The local mean luminance seems crucial. On the basis of these findings, we propose that asymmetric responses of motion detectors to the jittering luminance gradient are the source of this illusion. A gradient model of motion detectors, which takes the image velocity as local temporal gradient over local spatial gradient, can predict such asymmetric responses if we assume imbalance in the positive and negative parts of temporal derivative filters. The asymmetry then depends on the DC offset of the stimulus, which explains the effect of the background luminance. From http://www.perceptionweb.com/abstract.cgi?id=v031085 http://www.perceptionweb.com/abstract.cgi?id=v031085