3-d anaglyph glasses - sam

7/31/2019 3-D Anaglyph Glasses - Sam

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Explanation of how 3-D Glasses work.


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Because we have two eyes located side-by-side, weare able to see the world in three dimensions. Eacheye will see a slightly different image from the other,but our brain will merge them to perceive the depth.

This is called stereo-vision.


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As stereo-visionenables 3-Dviewing, a processwas developed thatwould allow 2-D

images to appear in3-D.

By showing a picture to one eye and a

slightly different picture to the other,the brain renders them and we perceivedepth in the image.


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The hardest part of this process is making sure thateach image gets to the intended eye, this can bedone using colour filters, polarisation, evenmicroscopic channels that direct light to the right

eye.

I will explain the process that uses colour filters.


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We must first understand what happens to lightwhen it passes through filters. We also need toremember that we have stereo-vision. As we saw inour prac light filters work as follows:

ROYGBIV

ROYGBIV

The filter absorbs allof the ROYGBIV, andtransmits the colour

it is.

A red filter will absorb whitelight, except for red, andpossibly a little bit of orange

and yellow.


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An Anaglyph Image is a moving or still pictureconsisting of two slightly different perspectives of thesame object in contrasting colors that aresuperimposed on each other.


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Once the anaglyphs havebeen made, this produces

a three-dimensional effectwhen viewed through 3-DGlasses. Without theglasses they will look

slightly discoloured andsomewhat blurry.
http://upload.wikimedia.org/wikipedia/commons/0/0c/Stereograph_as_an_educator_-_anaglyph.jpg


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To make still 3-D images the artist will take (or draw) 2slightly different pictures, apply a red filter to one(so it isred), a cyan/blue/green filter to the other(so it is cyan)and super-impose them on each other.


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When recording a normal 2-D movie they use onecamera, and get one perspective.

For 3-D movies, they use two slightly separated

cameras, and get the two perspectives.

Each camera will have a different lens filter, and then

To watch the movie the two images aresuperimposed.


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Viewing anaglyphs through appropriately coloredglasses results in each eye seeing a slightly different

picture.

The brain blendstogether the image itreceives from eacheye, and interprets

the differences asbeing the result ofdifferent distances,and we see this as a

3-D image.


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Here is a typical example:

Left eye Right eye

Looks through: Red lens Cyan Lens

What you see: The Red Image

(other imageappearsblack/grey)

The Green/Blue

Image (otherimage appearsblack/grey)

A pair of glasses with two filters of the same colors,once used on the camera/s (or now simulated by

image processing software manipulations) is worn bythe viewer.

The black parts give us the perception of depth.


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hen using the red/blue filters the image was always monochrome (in one colour)

y one colour was getting to each eye. For us to see in colour we need at least onee at least two colours, this was made possible by using a cyan filter instead of b

RO

YGB

IV

Red Filter used whenshooting for left eye

Incombination

with

Blue Filter used whenshooting for right eye

RO

YGB

IV

RO

YGBIV

Red Filter used whenshooting for left eye

Incombination

with

Cyan Filter used whenshooting for right eye

RO

YGBIV

One

colour toone eye

Twocolours toone eye

But it still only allows minimal colour, and therefore images are still not of the


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A major problem of anaglyphimages is 'ghosting', where eacheye perceives some of the other-eye's view. This happens because the filters used

in the glasses are not of good quality.

The simple solution to this problem istoo buybetter quality glasses, or you adjustthe anaglyph to suit the glasses youhave, which is considerably harderand involves decompiling the

anaglyph and recompiling it slightlydifferently.


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Internet Sites:

http://en.wikipedia.org/wiki/Anaglyph_image

http://nzphoto.tripod.com/sterea/anaglyphs.htm

http://www.physics.org/article-questions.asp?id=56

http://www.jyi.org/features/ft.php?id=987
http://nzphoto.tripod.com/sterea/anaglyphs.htmhttp://www.physics.org/article-questions.asp?id=56http://www.jyi.org/features/ft.php?id=987http://www.jyi.org/features/ft.php?id=987http://www.physics.org/article-questions.asp?id=56http://nzphoto.tripod.com/sterea/anaglyphs.htm

3-d anaglyph glasses - sam

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