There is a bit of bleeding due to compression artifacts, but it’s insignificant because the objective colours that do creep in are inverts of the induced colour.
To show you that it works beyond a doubt, though, I’ve altered the image a bit and saved it as a .gif, so the colours won’t “run” at all.
Every single pixel on both crosspieces is a shade of grey. They are both 50% grey at the “base,” and equally shaded. They are both represented by the exact same pixels, just rotated.
Now I am really confused. Your new image looks absolutely nothing like the images in the original picture. I’m comparing them side by side and the originals, cropped and taken away from the rest of the picture, are filled with color. Your FIRST image is significantly changed, in fact. I took the original picture from the Web site, blew up the crosspeices, cut everything else out, and they absolutely are not made up of all grey pixels.
Perhaps there is something I am missing technically, but if you blow up the original Web site image, is is plainly obvious that the pixels are not all grey. MOST of them are not grey. If this is the result of “image bleeding” the fact remains that in the original illusion, in terms of what actually is sending light to the observer’s eyes, the image is not all grey; most of the pixels are various shades of pale yellow. Even in your first attempt at isolation, “broken_illusion,” which is not a very good representation of how the original appears, I can see green, blue, red… The images simply aren’t identical except in your all-grey version.
Maybe the original has some artifact of computer graphics causing color to bleed into the grey, but there is color there.
Incidentally, of course the illusion DOES still work, albiet not quite as convincingly, after you changed the pixels to gray (or made them gray by changing it into a gif, whatever.) I liked your illusion better, though.
You might be surprised to see how little they vary from grey, objectively. If you use the colorpicker, you can explore all the pixels in the crosspieces and see what colours they actually are. They are never visibly yellow when taken out of context. When they do visibly vary from grey, they take on the colour from the surrounding pixels, making a sort of purple. This is the colour of the yellowest pixel from the right crossbar. These pixels are about 1/25th less "blue’ than a perfect grey. Too me, out of context, it looks grey. Does it register as yellow for you? (I wonder how much different people’s thresholds for registering red, blue, or yellow varies?)
Hey, this is weird. Something I stumbled across while trying to sort out some linguistic Tolkieana might lend some insight into the phenomenon exploited in the induced colour illusions.
The words we have for “blue” and “yellow” are connected, if you go back as far as the Proto-Indo-European roots, when the same word was used for both hues. This peculiarity continued for a long time, too. In Old English, it became “blaw”, (“blue.”) In Old Spanish, it became “blavo”, (“yellowish grey.”) In Welsh, blawr, “grey.”
It’s possible the opposition of yellow and blue that we see is something that human beings did not always see.
I find that after going back to the 3rd illusion (which worked for me as intended the first time) I could train myself to see them as grey all the time. I moved the mask over as shown to make my eyes see them both as grey. Then I moved it a little around the blue side cross so that I could see the grey by itself first, then with a little blue next to it. I circled the mask opening around the cross to let myself see the grey with the blue. When I removed the mask, I saw both crosses as the same color grey, even when I briefly looked away and looked back. When I looked away for a few seconds and looked back again, then I saw them as grey and yellow again.
Try it - you’ll feel better that you can really see the colors if you try!
I found a very trippy illusion on this page, which incidentally has Larry’s favorite and the OP’s #1. The one I have in mind is near the bottom, and it’s called Vision Distorter. You watch one of 4 animations of diagonal black and white stripes moving in different ways, then you look at any other object and it appears to warp and change. I find the illusion is strongest with a color photo or painting, but you can also look at your hand and freak out when demons start writhing around under your skin. [sub]OK, not really, but it looks really weird.[/sub]
If there’s a lesson here – and there has to be a lesson, right? – it’s to be careful when choosing paint for your walls. The paint you love at the paint store might look completely different at home, for a variety of reasons involving context, not to mention lighting. (I’ve noticed that different kinds of light bulbs make colors look radically different. Those energy-efficient bulbs give everything a weird greenish tinge, but incandescents makes a lot of colors better.)
Plus I want to give a shout-out to Larry Mudd for going the extra mile.
This thread is kind of amusing, because… stay with me here… there’s this illusion where one grey object looks blue and another one looks yellow, even though they are actually the same colour, or as near as dammit, but the funny part is that (unless I’m just misunderstanding what they’re saying) we’ve got people saying it doesn’t work because one looks blue and the other looks yellow.
No, what we are saying is that we don’t see the supposed effect. Both cross-pieces look grey, although the one on the left is a slightly darker shade of grey.
Huh? Isn’t the idea to see the illusion without the mask. The mask is used to cover all the irrelevant parts that make the illusion work, i.e., the mask will take away the illusion. In my case, with or without the mask, no illusion for #3.
Some people are more susceptible to illusions for some reason. available light for example seems to take longer to observe their effects compared to me, and they seem to be less striking for her.
I assume that none of you had basic color theory in high school art class. Joseph Albers, who taught at the Bauhaus, wrote a really great book with fantastic examples on how color is affected by other color. These are things taught (or should be) in basic design classes and some students do some incredible work while learning these basic concepts.
