Virtual Robots Fooled By Visual Illusions

Roland Piquepaille alerts us to research out of University College London in which virtual robots, trained to "see" as we do, were duped by optical illusions the same way humans are. Here's one of the illusions the software system fell for.

Comments

Re:That's not an optical illusion

[cathector]

no, it's not a difference in lighting.
the central squares are in fact the same color on your monitor, (pretty close to hex: 647316).

this is very similar to this famous color constancy illusion.

More exactly : diffent surrounding...

[DrYak]

...that's a difference in surrounding lightning.

Human visual system (as most other senses) work not by absolute values (i.e.: it doesn't see that the color '#c0ff20' or whatever), but mainly by comparing the signal with signals from the surrounds.
Thus what we technically see is that on the left object the central case looks much more "greener" than its surrounding, in the right object, the central case is "much more orange" than the surrounding. In fact, when the mask is enable, the colours do change from the point of view of the visual system : we were seeing contrast with two different surrounding, now we see a contrast with a third surround (mostly black). We see three different contrasts, even if from the computer's point of view the color is them same (the same RGB triplet / same intensity on your CRT/LCD)

If the scientist are trying to build efficient visual systems, they are probably mimicking this "works-by-comparing" method that the nature is using.
That's why we can recognise the same object, during day, during night, with weird lights, displayed on the screen (worse colour gamut) or on a print out (even worse color range). Because the relative difference stay the same, even if the colour as-seen-by-a-computer change.

The same is valid for any other sens, or in fact, any other information that is processed by neurons. Everything works by comparing (across several signals, across time, etc.). There's no such thing as "an absolute value" in the information carried by neurons.

That's also why all those "but the human eye can only x thousands of colors" (usually mocking the latest 32bit, 48bit, floating point or whatever color depth), are fundamentally wrong.
Yes, the human visual system can only distinguish a hundred or so colors.... ...WHEN those colors are ISOLATED. (i.e: putting the name "red" "orange" "purple" on a color you see alone).
When two colors are put next to each other, the human brain can suddenly distinguish much more subtle variations (each color would be considered as "brown" when seen alone, but next to each other, you can use thousands of different shade of brown and the eye will still see the difference).

That's also why radiologist are fond of high contrast / big depth screens : because all those difference in shades of grey *can* be distinguished and *are* revellent for the diagnosis when displaying X-Ray pictures.