viewing stereo images on the web site

The Art of Stereoscopic Photo questions and tutorials
Post Reply
gtoal
Posts: 9
Joined: Thu Apr 25, 2019 8:58 pm

viewing stereo images on the web site

Post by gtoal » Thu Jun 06, 2019 5:34 am

I've noticed that the stereo images that are posted here are usually in "wall-eyed" or "side-by-side" format.

At lot of us - possibly the majority from surveys I've seen - find it very hard to freeview in side-by-side format, and much easier to view in 'cross-eyed' format. Consequently when I view stereo pairs that are posted here, I see the depth inverted which ruins the effect for me.

It would be nice if the web site had some sort of live javascript that allowed left and right images to be swapped in-situ by the reader, to allow either type of viewing, but that may be too much to ask for - an easier solution that doesn't involve server side support but just some effort on our part when posting images is to use left-right-left (or right-left-right :-) ) triples of images, so you choose when viewing to look at the leftmost two or the rightmost two depending on which style of viewing you are capable of.

Some examples of triple images can be seen at http://minerbits.com/how-to-view-3D.html

Graham

User avatar
Realizator
Site Admin
Posts: 140
Joined: Tue Apr 16, 2019 9:23 am
Contact:

Re: viewing stereo images on the web site

Post by Realizator » Thu Jun 06, 2019 7:53 am

Hi Graham,
gtoal wrote:
Thu Jun 06, 2019 5:34 am
At lot of us - possibly the majority from surveys I've seen - find it very hard to freeview in side-by-side format, and much easier to view in 'cross-eyed' format. Consequently when I view stereo pairs that are posted here, I see the depth inverted which ruins the effect for me.
Hmm, it's fun, but while viewing photos posted here I look them without Cardboard or other devices, and depth effect is not ruined. Also I can view these photos on my phone via Color Cross device:

Image

Am I right understand you, that, say, with this green bear image, and also with this Jan's (Stereomii) photo you have inverted depth effect?

Image

Image
gtoal wrote:
Thu Jun 06, 2019 5:34 am
It would be nice if the web site had some sort of live javascript that allowed left and right images to be swapped in-situ by the reader, to allow either type of viewing, but that may be too much to ask for - an easier solution that doesn't involve server side support but just some effort on our part when posting images is to use left-right-left (or right-left-right :-) ) triples of images, so you choose when viewing to look at the leftmost two or the rightmost two depending on which style of viewing you are capable of.

Some examples of triple images can be seen at http://minerbits.com/how-to-view-3D.html

Graham
You see, I'm really stuck with this perception paradox. I did this triple-bear edition for you. I can see full 3D effect while looking at 1st and 2nd image. But with 2nd and 3rd my 3D perception is broken. Could you please tell me your opinion on this triple image?

Image
Eugene a.k.a. Realizator

gtoal
Posts: 9
Joined: Thu Apr 25, 2019 8:58 pm

Re: viewing stereo images on the web site

Post by gtoal » Thu Jun 06, 2019 3:12 pm

Yes, I can confirm that the first big image does indeed have depth inversion for me, and on the triple image, I see it correctly only when using the two on the right. I presume you see it properly using the two on the left. That style works for 'wall-eyed' free viewing or when using a Holmes-like viewer. I can't do that myself, I've tried a lot but never managed, I can only do it with cross-eyed free viewing.

PS Now that I have the StereoPi image working (re other thread) I see that the first tutorial example also displays only in side-by-side mode. I don't know if this assumption applies to all your software - if it does, having the option to swap images for freeviewing is even more important in the software than on the website! In the meantime I have a pair of 3d lorgnettes ( https://www.berezin.com/3d/cardvwr.htm ) from way back that I can use to view the screen with. (Holding up a Holmes viewer ( https://www.berezin.com/3d/holmes.htm ) in front of an LCD is not very practical ;-) )

Graham

User avatar
Realizator
Site Admin
Posts: 140
Joined: Tue Apr 16, 2019 9:23 am
Contact:

Re: viewing stereo images on the web site

Post by Realizator » Fri Jun 07, 2019 6:55 am

Hi Graham,
I'm still in paradox mode. :shock: I suggest that actual left camera image has specific features, as it "sees" more features at the left part of an object. The same with the right, as it is projection to the plane from other point of view. So it is a quest for me to understand, how your brain can assemble smooth 3D image with swapped stereopair. :-) I want to dig this perception question. Looks like we need to do a poll with users opinions and approaches, to understand all possible scenarios.

As for swapping images in the software - yes, you can do it easilly. This question already appears here in a several places (1,2,3, etc.)

We plan to add "swap" option in S.L.P. administration panel in the nearest update, so users can do it without any code changes.
Eugene a.k.a. Realizator

gtoal
Posts: 9
Joined: Thu Apr 25, 2019 8:58 pm

Re: viewing stereo images on the web site

Post by gtoal » Sat Jun 08, 2019 9:54 pm

Realizator wrote:
Fri Jun 07, 2019 6:55 am
Hi Graham,
I'm still in paradox mode. :shock: I suggest that actual left camera image has specific features, as it "sees" more features at the left part of an object. The same with the right, as it is projection to the plane from other point of view. So it is a quest for me to understand, how your brain can assemble smooth 3D image with swapped stereopair. :-) I want to dig this perception question. Looks like we need to do a poll with users opinions and approaches, to understand all possible scenarios.
What you are not getting is that the two different modes of viewing put the images in the center of vision on different eyes.

When you freeview, the left image is seen by the left eye and the right image by the right eye. You do this by avoiding the normal convergence of eyes to an object at a distance, and looking straight ahead with each eye - the path between eyes and images being parallel, or at least less converged as in the attached diagram.

When I freeview, I cross my eyes and accentuate the normal convergence, with the result that I concentrate on the left image with my right eye and vice versa.

Image

rather accentuated, this is what you you have to do to do either of the freeviewing techniques!

Image

by the way, wall-eyed vs cross-eyed freeviewing is a religious war in the stereo photography community :-)

User avatar
Realizator
Site Admin
Posts: 140
Joined: Tue Apr 16, 2019 9:23 am
Contact:

Re: viewing stereo images on the web site

Post by Realizator » Thu Jun 13, 2019 6:46 am

Gtoal, thank you for expanding my erudition! Now I understand the difference, and can use both approaches for viewing stereoscopic photos!
Eugene a.k.a. Realizator

User avatar
stereomii
Posts: 27
Joined: Mon May 13, 2019 3:11 pm
Location: Apeldoorn, The Netherlands
Contact:

Re: viewing stereo images on the web site

Post by stereomii » Thu Jun 13, 2019 1:18 pm

Thank you for starting this nice discussion on stereo viewing Gtoal.

Let me add my little bit to this.

Considering parallel viewing : personally I can not actually diverge my eyes, I understand that most people cannot do this. This implies that the far points in a parallel stereopair for most people can not be further separated than the distance between their eyes, for adults some 6 cm. This limits the size of a P-viewable stereopair to 2 times 6 cm.

A lot of people experience a Cross-eyed viewed image as closer by and smaller than a Parallel-eyed viewed image. This is no surprise if we see the lines of sight in the image Gtol included. But I found that this difference is not noticed by all viewers.

Despite all tutorials on viewing techniques some people still struggle to learn freeviewing. A little bit more than 9 years ago I developed an easy tool to make cross-viewing a bit easier. Using a mask cut out of a sheet of paper can guide the line of sight and also block the two images left- and right from the perceived 3D view. (I think that I invented this as I could not find any references to this method but I am curious to know if other people found this before.) You can find it on my no longer maintained site on 3D: http://slakje.jvonline.nl/3d/javimask.html

For picture enhancement I stumbled across ImageMagick (https://www.imagemagick.org). It turns out to be a very versatile tool also for the manipulation of stereo pairs. In another part of this board I shared the windows batch files I use, including one to create LRL views from LR stereopairs: viewtopic.php?f=16&t=35&start=20#p314
Jan a.k.a. stereomii
StereoPi with Waveshare 160deg cams

stereomaton
Posts: 23
Joined: Tue May 21, 2019 12:33 pm
Location: France

Re: viewing stereo images on the web site

Post by stereomaton » Fri Jun 14, 2019 12:18 am

Personally, I was happy that parallel version was used here because I can easily fuse in parallel view, but I have hard time with cross view.
However, I can use sView software to swap the images on the fly on Android (long press the image in the browser and choose open with sView) + in bonus it is configured for my autostereoscopic screen so I can see it without eyes gymnastics ^^.
The LRL version is less convenient for conversions (at least direct conversions like with sView) which might be an issue for users that prefer anaglyph for example (or column interleaved as for my 3d display)

Stereo formats is an endless source of discussions. The best practical answer is to use a software able to convert différent formats to the way you prefer to watch it.
Stereophotographer and hacker
StereoPi Standard Edition + CM3Lite module

User avatar
Realizator
Site Admin
Posts: 140
Joined: Tue Apr 16, 2019 9:23 am
Contact:

Re: viewing stereo images on the web site

Post by Realizator » Fri Jun 14, 2019 7:58 am

As this topic touches important stereoscopic discussion, I moved it to Stereoscopic section. :D
Eugene a.k.a. Realizator

Post Reply