You can't belive your eyes

Faram · Post by **Faram** » 2002-09-29 04:46pm

A light check in the shadow is the same gray as a dark check outside the shadow.

Post by **Kuja** » 2002-09-29 04:52pm

Uh, it's called a shadow.

Post by **Kuja** » 2002-09-29 04:53pm

waitaminute.....*looks closer.....WTF?!?!

2000AD · Post by **2000AD** » 2002-09-29 04:55pm

They aren't the same shade though.

salm · Post by **salm** » 2002-09-29 04:55pm

nice one!

2000AD · Post by **2000AD** » 2002-09-29 04:57pm

just WTF is meant to be happening?

Post by **Kuja** » 2002-09-29 04:57pm

Is this some kind of mind-bending psychiatric shit??!

Post by **Mr Bean** » 2002-09-29 04:58pm

The Letters are the same shade of Grey
Just because somthing is dark does not make it the same color

IE in a Dark room, a Yellow truck is still yellow, even without light

Grand Admiral Thrawn · Post by **Grand Admiral Thrawn** » 2002-09-29 04:58pm

I don't get it...

Faram · Post by **Faram** » 2002-09-29 04:59pm

From the webpage:

The visual system needs to determine the color of objects in the world. In this case the problem is to determine the gray shade of the checks on the floor. Just measuring the light coming from a surface (the luminance) is not enough: a cast shadow will dim a surface, so that a white surface in shadow may be reflecting less light than a black surface in full light. The visual system uses several tricks to determine where the shadows are and how to compensate for them, in order to determine the shade of gray "paint" that belongs to the surface.

The first trick is based on local contrast. In shadow or not, a check that is lighter than its neighboring checks is probably lighter than average, and vice versa. In the figure, the light check in shadow is surrounded by darker checks. Thus, even though the check is physically dark, it is light when compared to its neighbors. The dark checks outside the shadow, conversely, are surrounded by lighter checks, so they look dark by comparison.

A second trick is based on the fact that shadows often have soft edges, while paint boundaries (like the checks) often have sharp edges. The visual system tends to ignore gradual changes in light level, so that it can determine the color of the surfaces without being misled by shadows. In this figure, the shadow looks like a shadow, both because it is fuzzy and because the shadow casting object is visible.

The "paintness" of the checks is aided by the form of the "X-junctions" formed by 4 abutting checks. This type of junction is usually a signal that all the edges should be interpreted as changes in surface color rather than in terms of shadows or lighting.

As with many so-called illusions, this effect really demonstrates the success rather than the failure of the visual system. The visual system is not very good at being a physical light meter, but that is not its purpose. The important task is to break the image information down into meaningful components, and thereby perceive the nature of the objects in view.

2000AD · Post by **2000AD** » 2002-09-29 05:00pm

But the thing says that the SQUARES marked A and B are the same colour, not the letters

salm · Post by **salm** » 2002-09-29 05:01pm

Mr Bean wrote:The Letters are the same shade of Grey
Just because somthing is dark does not make it the same color

IE in a Dark room, a Yellow truck is still yellow, even without light

no the squares are supposed to be the same shade.
there´s no dark room in this picture it´s just a bunch of pixles and the square A and Square B are the same shades

*shoots up photoshop to check*

salm · Post by **salm** » 2002-09-29 05:03pm

yup, both squares are R: 107 G: 107 B: 107

aerius · Post by **aerius** » 2002-09-29 05:04pm

I just photoshoped it, the squares are indeed the same colour.

salm · Post by **salm** » 2002-09-29 05:06pm

aerius wrote:I just photoshoped it, the squares are indeed the same colour.

HAAAHAAA
FIRST!

Faram · Post by **Faram** » 2002-09-29 05:13pm

Some more

Classic the lines are straight :

The color of the dots?

Faram · Post by **Faram** » 2002-09-29 05:14pm

Nice post inflating tread ain't it?

Post by **Kuja** » 2002-09-29 05:15pm

The lines are horizontal. Your eyes just see them wrong because of the blocks.

The dots are all white. The black is an OI.

salm · Post by **salm** » 2002-09-29 05:19pm

they dots colors range from R: 248 G: 248 B: 248 to R: 255 G: 255 B: 255

so, no they´re not all white. some of them are white some of them are very light shades of gray

Post by **Sea Skimmer** » 2002-09-29 05:20pm

Faram · Post by **Faram** » 2002-09-29 05:24pm

Just could not resit making this my #100 post

ArmorPierce · Post by **ArmorPierce** » 2002-09-29 05:43pm

huh? what exactly am I suppose to be looking at?

Post by **Kuja** » 2002-09-29 05:45pm

Nothing like that could exist in- (aide whispers in ear) the PRESIDENT??!?!

Oops

ArmorPierce · Post by **ArmorPierce** » 2002-09-29 05:49pm

the letters its because of the shadow isn't it as for the seecond ones, that one is a good one the letters its because of the shadow isn't it as for the seecond ones they are all white and what are the lines slanted and strait?

Wait... on closer inspection I'm able to tell that all the lines are strait and not slanted.

Asst. Asst. Lt. Cmdr. Smi · Post by **Asst. Asst. Lt. Cmdr. Smi** » 2002-09-29 08:50pm

I'm a fan of the ones by Escher, but they're a different kind of optical illusion. They don't rely on different shades of grey to fool the eye.