OT: Science question

[H. Kellerman]

I am a seventh grade student attempting to perform a science project. I
have noticed that when you take a photo and reduce the number of pixels it
unrecognizable from near but recognizable from a distance.

Does anyone know why, and can they recommend some books that I could read up
on?

Thank you.

S. Kellerman

[Don Stauffer]

Yes, this fact was recognized in seventies, and much was written about
it. Do you have access to a library at a college? Do searches in
Journal of Imformation Display, Optical Engineering journals.

You may also find info online with a good search. Unfortunately, I
forget the keywords you need to search. Try pixels, recognition, and a
few other words. Spatial filtering is also a term to use, but not by
itself as it will get too many hits.

--
Don Stauffer in Minnesota
stau...@usfamily.net
webpage- http://www.usfamily.net/web/stauffer

[Larry Miracle]

Have you seen these photos that are made up of smaller photos.
I am suprised how real they look from far away.
Our brains must be playing a trick on us.

Larry

On Tue, 10 Dec 2002 05:05:20 GMT, "H. Kellerman" <hjk...@pacbell.net>
wrote:

[Dave Martindale]

Larry Miracle <larrym...@earthlink.net> writes:

>Have you seen these photos that are made up of smaller photos.
>I am suprised how real they look from far away.
>Our brains must be playing a trick on us.

No trick, really. When you look at the mosaic from far away, you can't
see most details of the individual little pictures that make it up.
What you *do* see, mostly, is the overall brightness of each little
picture. The little pictures have been chosen to make each little
picture's brightness correct for one pixel of the larger low-res picture
that you see from far away.

In more technical terms, the low-frequency components of the overall
image, the ones you see when you're far away, are those of the larger
image, and they can be quite accurate. The high-frequency components
of the image, the ones you see when you're close, are taken from a bunch
of independent small images.

The "trick" is really just in how the small images are selected.

Dave

[Anthony S. Poulos]

Check www.howstuffworks.com/tv1.htm

In the section on How Television Works there is a section labeled "Two
amazing things about the brain."

It confirms the principle and provides an image for demonstration.
Unfortunately, there are no links to more detailed info.

A Google search using "brain reassemble image pixels" turned up some
potential web sites for more info. Try that.

Tony

On Tue, 10 Dec 2002 05:05:20 GMT, "H. Kellerman" <hjk...@pacbell.net>
wrote:

>I am a seventh grade student attempting to perform a science project. I

[Robert E. Williams]

In Fine Art oil painting, there is a technique called "Pointillism"
The artist just makes gazillions of little dots of colored paint. Up close, it
looks a mess. However, as you move back from the painting, it magically becomes
more and more recognizable and beautiful. These little dots of paint are really
pixels before we had a name for them. The technique was introduced and perfected
by Georges Seurat , a 19th Century French impressionist painter.
You may want to do a search on GOOGLE to see examples of Seurat's and other's
works.
Bob Williams

[print_maker]

While you are at it, look up Chuck Close for a modern take on a painterly
'pixel'.

"Robert E. Williams" <myt...@cox.net> wrote in message
news:3DF6C541...@cox.net...

[Robert E. Williams]

Chuck Close is WAY COOL!! What a Talent.
Bob Williams

[J...@no.komm]

In message <at5dge$pu4$2...@mughi.cs.ubc.ca>,
da...@cs.ubc.ca (Dave Martindale) wrote:

>Larry Miracle <larrym...@earthlink.net> writes:
>
>>Have you seen these photos that are made up of smaller photos.
>>I am suprised how real they look from far away.
>>Our brains must be playing a trick on us.
>
>No trick, really. When you look at the mosaic from far away, you can't
>see most details of the individual little pictures that make it up.
>What you *do* see, mostly, is the overall brightness of each little
>picture. The little pictures have been chosen to make each little
>picture's brightness correct for one pixel of the larger low-res picture
>that you see from far away.

I don't think each little picture represents a pixel for the large
scene; there is usually sub-big-pixel content as well, such as diagonal
lines, gradients, etc, in the little pictures. If you took one that was
well-done, and replaced each little picture with a solid tile that was
the mean of the little picture, it would lose a lot of detail.
--

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John P Sheehy <J...@no.komm>
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