My pareidolia knows no bounds.

All the reasons why the above post(s) (by rd) are non-arguments have been stated many times.

One of the sister subjects to pareidolia is the subject of illusions. I'd like to post a few from time to time, that I think help to shed some light on the subject of this topic. I'll try to avoid just posting for the sake of posting, and restrict it to the ones that I think are related in some way to pareidolia.

I find this illusion to be particularly interesting. There are a number of variants on it, and to me it illustrates how all is not necessarily what it appears to be. Sure there are reasons for it, and once explained we can sort of understand, but it still flies in the face of the notion that what we see is what we get, or that "because we see it, it must be so."

This is the famous Checkershadow Illusion. I've seen so many variants of this, that it's hard to be sure who created it, but this site says, Edward H. Adelson. www.equationlab.com/mtp/quantumblog/archives/2006/02/

Note: I added the "C", for my proof.

Now, I doubt if there is a person alive (I could be wrong, though) who would conclude anything other than that A is one of the dark squares, and that B=C are light squares. But, the truth of the matter is that A=B are dark, and C is light. There are a number of animations that prove this, but I decided to prove it to myself, the old fashion way, by slicing a little piece of all three in PaintShop, and looking at the histograms.

Here's A:

Here's B:

Here's C:

Once they are removed from the simulated shadow of the green cylinder, it's easy to see them for what they really are. Here's how it works:

======================================================
<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Why does the illusion work?



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. - See above link<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

If you're unconvinced, try it for your self. One thing that helps one understand this is the fact that all 4 dark squares bordering B are significantly darker than A, even though they look the same.

rd

Thought you might be interested in these illusions in case you haven't seen them and would like to post them.
cvcl.mit.edu/hybridimage.htm

Illusions

Rd .. I would just like to thank you.. You have been fantastic in your determination of answering some key questions, that others have overlooked for 45 years.. You in my view are and have been the "only one" on target ..

Your pareidolia thread has been absolutely essential and is great for even the " thinks he knows it all" like me. You have great perceptions and I have been rooting for your success all the way..

For I know without any doubt that Mars is a construct artistically created (with a Facial multi dimensional holographic theme) And it is only your work that will bring us closer to that reality in the mainstream..

Lava Flows and basins, etc. etc. etc ( in my opinion are a total waste of grey matter..)
I may share this opinion with only myself. But I have come to my conclusions from the thousands of Images I have studied.. And I could not expect others to understand why I feel so sure, since they weren't sitting next to me during my image journey..


But again keep up the fantastic work ... and thanks again..


www.cs.dartmouth.edu/farid/illusions/monster.html

Thanks guys. Yes, I have seen those. "Bump" in the link Trinket posted is the Light Inversion Effect that we talked about alot in the T or E topic.

Here's another one that I think is relevant to our discussion. A while ago we debated the validity of posting negative images of faces (I was against it). But this animation, not only proves that they are valid, but also shows that the mind does a quick flip, and converts the negative to a positive. I have to just post a link, though. It uses Quicktime, so I hope you can view it.

It's called "Rotating Face Mask":

www.michaelbach.de/ot/fcs_hollow-face/index.html

rd

Let me state this one more time for the sake of clarity. Since pareidolia is such a new word (approx. 10 years old) it's not in the old time dictionaries, and it has more than one meaning, like many other words in our language. I don't know if the definition I'm using will end up being (1),(2), or (3) when all is said and done, but this is the crux of the meaning as I'm using it:

Pareidolia, as it relates to faces is simply a perceived face that is not man-made. It can be an illusive wispy face in the clouds or smoke, totally transient, or a pattern in a cliff wall (or marble column-Fred), which is essentially eternal. It can be easy to see as the face, where more than one person readily sees it, all the way to being very obscure, and needing to be pointed out from one observer to another. The only thing that would make the face NOT be pareidolia, is if someone (presumably a human, but could be a Martian) created the image of the face, as art, pastime, mischief, or whatever. Shadows may or may not play into the face, from one extreme (like with Fred's art) where it's all shadows, all the way to the other extreme where their are no shadows involved. The only other clarification needed is that it can't be man-made in the sense that a man made a face, but it could be man-made in the sense that it merely appears as a face later, even though that was never the intent.

I'm exclusively dealing with the kind that have no human intervention at all though, and am not really considering the accidental faces that were man made as something else. But many people do use the word to refer to things that are man-made, but not made to be faces intentionally.

rd