A graph that is made by perceiving it – Mind Hacks
The distinction sensitivity operate exhibits how our sensitivity to contrasts is affected by spatial frequency. You can check it utilizing gratings of alternating gentle and darker shade. Ian Goodfellow has this neat remark:
It’s a graph that makes itself! The picture is the uncooked information, and by interacting along with your visible system, you understand a discontinuity which illustrates the boundaries of your notion.
Spatial frequency means how usually issues change in area. High spatial frequency modifications means plenty of small element. Spatial frequency is surprisingly necessary to our visible system – plenty of primary options of the visible world, like orientation or movement, are processed first in line with which spatial frequency the knowledge is out there at.
Spatial frequency is behind the Einstein-Marilyn phantasm, whereby you see Albert Einstein if the picture is massive or shut up, and Marilyn Monroe if the picture is small / seen from a distance (strive it! You’ll need to stroll away out of your display screen to see it change).
Depending on distance, totally different spatial frequencies are simpler to see, and if these spatial frequencies encode totally different data then you may make a hybrid picture which switches as you alter your distance from it.
Spatial frequency is additionally why, once you’re flying over the ocean, you may see waves which seem to not transfer. Although you imaginative and prescient is delicate sufficient to see the wave, the movement delicate a part of your visible system isn’t pretty much as good on the high quality spatial frequencies – which creates a pure phantasm of static waves.
The distinction sensitivity picture on the head of this publish varies distinction high to backside (low to excessive) and spatial frequency left to proper (low to excessive). The level at which the bars cease trying distinct picks out a ridge which rises (to a most at about about 10 cycles per levels of angle) after which drops off. Where this ridge is will range relying in your explicit visible system and what distance you view the picture at. It is the final word individualised information visualisation – it picks out the actual sensitivity of your individual visible system, in actual time. It’s even interactive, immediately adjusting for momentary modifications in parameters like brightness!
More on hybrid pictures (together with some neat examples): Oliva, A., Torralba, A., & Schyns, P. G. (2006, July). Hybrid pictures. In ACM Transactions on Graphics (TOG) (Vol. 25, No. three, pp. 527-532). ACM.
More on the visible system, together with the distinction sensitivity operate: Frisby, J. P., & Stone, J. V. (2010). Seeing: The computational method to organic imaginative and prescient. The MIT Press.