Wednesday, March 24, 2010

Ambiguous chromatic motion

Image and video hosting by TinyPicI had no idea that it was so easy to embed an animated GIF file into a PowerPoint display. Now the only choice is whether to use GIFs like this in the next presentation, or steal one from a Substantial blog. Which would keep the audience awake? It is a hard pancake.

It's 'chromatic' because all 5 colours are supposed to be calibrated to the same luminance, taking away the luminance-contrast cues that normally dominate our perception of motion and leaving purely hue-contrast cues (which the brain processes in a different way). Though the calibration is not likely to survive being screen-grabbed and then reproduced on whatever motley computers different people are using. 'Ambiguous' because there are two superimposed gratings moving in opposite directions. Whichever of the gratings has greater chromatic contrast, it resolves the ambiguity and produces a dominant sense of motion.

You could do the same thing with brightly-coloured sugar confectionary Peeps if you had two superimposed patterns, one multicoloured pattern of Peeps occupying the White squares of a large chessboard (as it were) and the other occupying the Black squares, and you took a series of photographs, moving the black-square pattern one step leftward after each photograph and the white-square pattern one step rightward.

This is left as an exercise for the reader.

17 comments:

merc said...

"Every time you make a powerpoint Edward Tufte kills a kitten"

cantng, not really counting, repeatedly.

Jennifer said...

tease

Another Kiwi said...

moving the black-square pattern one step leftward after each photograph and the white-square pattern one step rightward.

This is left as an exercise for the reader.

OR you might not be knob and not do it.

mikey said...

[Shiver]

I think I understand. It's like when you're sitting in a hole in the middle of the night and there are illum flares drifting down and the shadows are moving and the light is changing all the time and you're trying SO HARD to see if some movement is something or someBODY and you don't wanna look like an idiot and open up on ghosts but you don't want to sit there and stare at the shifting shadows and rationalize doing nothing until the sappers cut your throat, so you try to figure out how you're supposed to tell movement from bullshit when the shadows are swaying and then, just as you have a handle on what's happening in front of you, somewhere down the line a trip flare fires and 2nd platoon lights 'em up and it turns out to be an old woman trying to salvage some scrap metal when nobody's looking and you think "man, fuckers fucked now" and that's when the sappers hit your perimeter...

mikey said...

My suggestion?

People should stay in at night and watch tv.

merc said...

merc does not play well with others (A.K. you know this...why, why always with the tortures?).

sumsole, literally anyone, anyone at all.

Another Kiwi said...

It is the price, Merc.

merc said...

Talk to ma Lion, talk to ma Lion...

Another Kiwi said...

He just growls and claws the carpets somnething wicked

mikey said...

'Cause see, it's DARK!

ckc (not kc) said...

...it resolves the ambiguity...

yeah, sure it does...

dissolves the acuity
revolves the ambergris
resorts to ambience.... arrgh!

ifthethunderdontgetya™³²®© said...

I had no idea that it was so easy to embed an animated GIF file into a PowerPoint display.

I see a blank screen. But you know, it's easy to pour wine into the keyboard.
~

tigris said...

I'm just going to pretend the helpfully attached animation is made of peeps on an enormous chessboard, and filmed from a great distance.

fish said...

moving the black-square pattern one step leftward after each photograph and the white-square pattern one step rightward

The same effect could be achieved by moving both the black and the white squares one step leftward and that would avoid the jostling and hurt feelings that occur when one of the black squares inevitably makes some darkly sarcastic remark to one of the white squares.

fish said...

related

Another Kiwi said...

Damn you fish, what are you on about??

merc said...

When we surf, we become part of the food chain, and not at the apex...thus we never curse The Fish...

oonvers, William Blake's Paradise Found.