3-D effect with Stereoptical pairs from monoptical images: While futzing around with making hand-held stereo pairs for 3-D perception by unaided viewing, It occurred to me that it may...

Uuglypher Loc: South Dakota (East River)

While futzing around with making hand-held stereo pairs for 3-D perception by unaided viewing, It occurred to me that it may be possible to prepare stereoptical pairs from a single monoptical image.
And, voila! It would seem I was right!

Of course, it's all based on illusion, but I find it amazing the extent to which our mind can purposefully self-attune to accept illusions!

Herewith be two examples of the 3-D illusion generated by a "stereo pair" produced from a single monoptical image.

For some hints on the techniques of viewing stereo pairs, see the previous thread on preparing stereo pairs:

http://www.uglyhedgehog.com/t-395113-2.html

Let me know how they work for you and which viewing system ( parallel gase versus crossed eyes) works best for you.

Dave

(Download)

mcveed Loc: Kelowna, British Columbia (between trips)

Dave, This is very interesting. When viewing your stereo pairs, both parallel gaze and crossed eyes using parallel gaze technique (learned a long time ago viewing stereo pairs of air photographs) the scenes seem normal - the fence recedes into the distance and the sage brush is closer than the hills. However, when viewing the electrical plug and wires at the link you provided, the blue arrow is behind the plug in parallel gaze arrangement and in front of it in crossed eyes arrangement. In addition, the wires appear different, as if we were seeing it from the other side with the nearer wires now further away. I recall now that, with air photographs, you had to know the direction of flight so you could check the time hack on the photo and get them oriented correctly, otherwise the rivers looked like elevated roads and the hills looked like holes. It would seem that, with your landscape shots, the brain corrects for the very obvious anomaly of the fence getting smaller as it gets closer and the hills appearing in front of the bush.Weird!
Don

Uuglypher Loc: South Dakota (East River)

mcveed wrote:

Dave, This is very interesting. When viewing your ... (show quote)

Hi, Don,
I wondered if anyone experienced with topographic photo recon images would show up. Sure glad to get your input. There are aspects of these images that are fascinating, but that I don't completely understand.

I'm particularly curious if you got the 3-D effect from the receding fence pair and the " sage brush" with Monument Valley in the BG.

As for the plug-and-wires image the lens offset was only about 1 1/2". I'm not at all sure about why the shift in arrow position in depth...

Also curious if you are using parallel gaze or crossed eyes when viewing these.

Any input appreciated. This is all new to me and gun to experiment with.

Dave

selmslie Loc: Fernandina Beach, FL, USA

Uuglypher wrote:

... I wondered if anyone experienced with topographic photo recon images would show up. ...

I remember looking at images in my fathers's office taken before WW II over the mountains of Eastern Cuba as well as similar images taken in southern Ontario.

Both were secondary reconnaissance flights done while looking for potential iron mining locations that were initially detected by magnetic reconnaissance.

Stereo pairs were commonly used for reconnaissance going back to WW I and possibly from balloons even earlier.

Uuglypher Loc: South Dakota (East River)

To clarify:

A traditional stereo pair is comprised of two views of the same scene. The distance between the "eyes" perceiving the scene varies from one to a few inches for relatively close scenes to fifty yards or much more for distant aerial views of Earth's surface from airplanes, outer atmosphere, or near space (from orbiting satellites).

The purpose of this thread is to provide examples of, and to discuss modifying a single image by altering the proportions of a copy of that original image in order to produce a pair of images that serve as a "stereo pair" when viewed as if they were a true stereo pair with one image representing the left-eye view and a second image representing the right-eye view.

The posted images are not a true "stereo pair" because they are derived from a single view of the scene.

If you have an image in which there are strong illusory cues to depth perception, particularly relying on proportionate size regression with distance, it may be a candidate for production of a "stereo pair" such as was produced from the single fence-line image and the single Monument Valley image.

Dave

winterrose Loc: Kyneton, Victoria, Australia

I know that I have no need to articulate the fact that as a true stereo pair is made up of two entirely differing images, the attainment of a true stereo illusion is not possible simply by altering the vanishing point of a single image.

I can achieve some semblance of a feeling of depth from your examples with crossed eyes but I find myself able to maintain that only fleetingly before feeling compelled to apply several sharp blows to the side of my head with the heel of my hand in order to rattle eyes and brain back to normality.

Rob.

Uuglypher Loc: South Dakota (East River)

winterrose wrote:

I know that I have no need to articulate the fact ... (show quote)

The degree of alteration of the referent monocular image to form the other member of "the pair" can be exercised over a considerable range while still providing a 3-D effect of greater or lesser difficulty in its perception.
Here are three other examples. The alterations can be finely controlled, so,I'm very curious about responses to these images.

Dave

(Download)

selmslie Loc: Fernandina Beach, FL, USA

Uuglypher wrote:

The degree of alteration of the referent monocular image to form the other member of "the pair" can be exercised over a considerable range while still providing a 3-D effect of greater or lesser difficulty in its perception.
Here are three other examples. The alterations can be finely controlled, so,I'm very curious about responses to these images.

Dave

As Rob pointed out, you cannot simulate a stereo illusion from a single image. It requires the simultaneous capture from two horizontally separated viewpoints.

To make matters worse, in each these three "pairs", the upper left and lower right frames are the exact same cropped and leveled image and the same applies to the upper right and lower left frames. For example, see the leveling of the horizon for the eagle, the crop of the upper edge for the trees and of the lower edge for the fist.

There is no point in straining the eyes since the result cannot be 3-D unless your mind is under some serious chemical influence.

selmslie Loc: Fernandina Beach, FL, USA

selmslie wrote:

... It requires the simultaneous capture from two horizontally separated viewpoints. ...

Relatively simultaneous in the case of aerial reconnaissance.

Uuglypher Loc: South Dakota (East River)

[quote=winterrose]I know that I have no need to articulate the fact that as a true stereo pair is made up of two entirely differing images, the attainment of a true stereo illusion is not possible simply by altering the vanishing point of a single image.

I can achieve some semblance of a feeling of depth from your examples with crossed eyes but I find myself able to maintain that only fleetingly before feeling compelled to apply several sharp blows to the side of my head with the heel of my hand in order to rattle eyes and brain back to normality.

Rob.[/quote

Hi, Rob,
In fact, there was no alteration in the vanishing points, only in the lines of perspective leading to those vanishing points, which occurs in normal binocular viewing.

I hope you'll examine the subsequent examples being posted.

Dave

Uuglypher Loc: South Dakota (East River)

selmslie wrote:

As Rob pointed out, you cannot simulate a stereo i... (show quote)

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Hi, Scotty, thanks for your interest.

[quote=selmslie]As Rob pointed out, you cannot simulate a stereo illusion from a single image. It requires the simultaneous capture from two horizontally separated viewpoints.

yes, indeed. That is the commonly accepted premise, which I had stated in the post to which Rob had responded.

[quote]To make matters worse, in each these three "pairs", the upper left and lower right frames are the exact same cropped and leveled image and the same applies to the upper right and lower left frames. For example, see the leveling of the horizon for the eagle, the crop of the upper edge for the trees and of the lower edge for the fist.

In each of the pairs submitted, the same pair is shown in the upper row and the lower row.
In the upper row the left-eye image is on the left, and is to be viewed by parallel gaze.
In the lower row, the images are reversed and are to be viewed by crossed eyes.
Some people prefer one technique to the other, so I provide the option to you as to which you prefer to view.

Alas, some people are unable to view either arrangement by "free fusion" (without use of a stereoscope)

Quote:

There is no point in straining the eyes since the result cannot be 3-D unless your mind is under some serious chemical influence.

So, Scotty, no knowing if you even tried to view the pairs in an appropriate manner, perhaps you'd give it a try now an tell us, of these three pairs, which are "real" (left-eye and right-eye) views and which are prepared from a single image?
And I'm hoping Rob and others may respond as well.

Dave

(Download)

Uuglypher Loc: South Dakota (East River)

Rob,
I have to admit that your phrase "... a true stereo illusion ..." elicited a chuckle. Considering that every photograph, in attempting to render three dimensions on a two-dimensional surface, is, itself, an illusion, and, as such, requires the viewer's acquiescence in accepting that illususion as a representation of reality. So does the simultaneous viewing of a pair of images capable of delivering, to an acquiescing mind, a sensation of a three-dimensional view require a willingness on the part of the viewer to accept yet another illusory experience.
I hope I have illustrated that there is more than one way to accomplish a stereoptic pair of images that can, to the willing, open, and accepting mind, deliver a three-dimensional viewing experience.

I might also suggest that the stereo pairs I've posted are likely more easily viewed using a tablet's or a smartphone's display rather than your computer display. The portable display can be held easily at a closer or more distant position to facilitate either parallel gaze viewing or crossed eye viewing.

Your thoughts?

And here's another pair: is this a binocular pair or made from a monocular image?
If you'd rather not pick which, how does it do in delivering 3-D?

Dave

(Download)

mcveed Loc: Kelowna, British Columbia (between trips)

Uuglypher wrote:

Hi, Don, br I wondered if anyone experienced with ... (show quote)

Uuglypher Loc: South Dakota (East River)

Don,
Your comment/message didn't come through.
Dave

selmslie Loc: Fernandina Beach, FL, USA

Uuglypher wrote:

So, Scotty, no knowing if you even tried to view the pairs in an appropriate manner, perhaps you'd give it a try now an tell us, of these three pairs, which are "real" (left-eye and right-eye) views and which are prepared from a single image?
And I'm hoping Rob and others may respond as well.

Dave

My parents owned a Stereo Realist in the late 1940's along with the corresponding stereo viwer. I believe it took half frame 35mm Kodachrome image pairs which were mounted between two glass slides. The effect was realistic 3-D. I also saw The House Of Wax in 3-D through polarised glasses.

Please don't take offence but novelty soon wore off so I am not inclined to consider a lesser, unreal 3-D experiment.