An Optical Illusion

[Renegade]

I was working on a kind of tiling problem, I wanted to visually compare some sizes, and mocked up 4 bars in Photoshop:

[attachimg=#]

In the top corner you can see 4 vertical bars, and 4 bars behind them.

Anyways, just a stupid little thing that I though might amuse someone.

[f0dder]

Cute

[mouser]

What am I supposed to see?

[worstje]

In the top corner you can see 4 vertical bars, and 4 bars behind them.

[mouser]

I guess the idea was we are supposed to perceive 4 *horizontal* bars behind the vertical ones.  Didn't really happen for me. meh.

[mahesh2k]

I want to go creative with this, add more 4 more black bars and let this be visualizer. 

[Renegade]

I want to go creative with this, add more 4 more black bars and let this be visualizer. 

[attachimg=#]

[mahesh2k]

[tomos]

I guess the idea was we are supposed to perceive 4 *horizontal* bars behind the vertical ones.  Didn't really happen for me. meh.

I saw it as 4 grey bars initially - the black bars were in the foreground.
But when I read your response mouser I looked at it again (the first image) and was able to "push" the black bars into the background (which I think is how you see it).

Damn, if I look at that image too long my eyes start dancing...

[mwb1100]

The bars behind bars effect didn't really hit me either, but what I see is that the light colored  squares around the black bars have a definitely different hue than the light colored squares in the rest of the image (I'm assuming that they in fact have the same color).  Maybe it's my laptop monitor, but I'm surprised no one else mentioned the effect.

[bob99]

Helps me if I tilt the screen to look perpendicular at it and remove my glasses.  I have the progressive bi-focals and just a slight up or down movement can change the focus.

[tomos]

The bars behind bars effect didn't really hit me either, but what I see is that the light colored  squares around the black bars have a definitely different hue than the light colored squares in the rest of the image (I'm assuming that they in fact have the same color).  Maybe it's my laptop monitor, but I'm surprised no one else mentioned the effect.

no, that's a known effect - the hue/tone depends on the surrounding colour(s).
I'm not sure if colour "changes" this way too, I think so though.