Cross eyed to parallel

I can view parallel images without any problem; I also have a parallel viewer (3D inlife??) so i can see large parallels on screen.

However most posts are cross eyed. I see on odd view; reversed front to back?

I can bring an image into Photoshop and swap the left and right but is there a way to swap within a browser?

Yes, it can be done but the problem is that the images posted are a single JPG image. You would have to very carefully select one image and copy it to a new layer, do the same for the other image, then move each image across to the other side and align them carefully at just the right distances.  Move with the right/left arrow keys and Shift + arrow keys so you don't move the images vertically.

A better alternative is to extract the two images as above then save each individually before combining them in StereoPhoto Maker (free) as a parallel 3D image.  StereoPhoto Maker can do an alignment if needed.

StereoPhoto Maker (English)

Thank you.

I wonder why cross eyed is the preferred option for publishing?

Actually, you can open the combined jpeg in StereoPhotomaker as a stereo image and click on "swap" to reverse them.  No need to extract them first.

Stereophotomaker will "break them apart".

Many of us post crosseye here (and elsewhere) to permit "freeviewing" of a pair (no viewer aid required).

A significant portion of the population can freeview crosseye with a small amount of practice, and there is no practical limit to image size when freeviewing in that manner.  Normal vision requires crosseye control to converge on close objects.  The practice requires getting skillful at "decoupling" convergence and focus.   Once you accomplish this, it's like riding a bicycle, you don't forget how.

Freeviewing parallel is constrained by image separation not much larger than 2.5", or 65mm, otherwise vision has to diverge, which is NEVER done in normal vision and is quite uncomfortable, or even painful, for a huge percentage of the population.

The separation restriction limits the size of a parallel stereo pair capable of being freeviewed.

That said, it is possible to withstand and accommodate larger parallel separations with practice, but it can be very distressing at first. And it does not get easier with increasingly wider separations

Turbguy1 wrote:

Actually, you can open the combined jpeg in StereoPhotomaker as a stereo image and click on "swap" to reverse them. No need to extract them first.

Stereophotomaker will "break them apart".

Thanks for your post Turbguy 1.

I didn't know you could do that with StereoPhoto Maker.  I just tried it, using the Swap Left and Right command when opening a cross eyed JPG, and it worked perfectly.

Thank you all for your information

Athegn wrote:

Thank you.

I wonder why cross eyed is the preferred option for publishing?

Like Turbguy pointed out, cross-eyed is the standard for "zero cost" viewing. That had something to do with why it was chosen for the JPS (side by side JPEG) and PNS (side  by side PNG, not to be confused with the PMS standard, which you really want to avoid).

The purpose of having "a standard" is so a lot of programs can process it. As long as the standard is easy to read (side by side JPEG qualifies), it serves as a useful input to a "conversion chain" that may output anaglyphs, left-right, crosseye, horizontal or vertical interleaves, or even top-bottom or two  separate monitors with one flipped for certain mirror viewers.

Problem is, they build a standard and nobody came. More on this in a reply to the main post...

Athegn wrote:

I can view parallel images without any problem; I also have a parallel viewer (3D inlife??) so i can see large parallels on screen.

However most posts are cross eyed. I see on odd view; reversed front to back?

I can bring an image into Photoshop and swap the left and right but is there a way to swap within a browser?

There used to be, but I don't think there is, any more.

The standard for stereo images is a cross-eyed side-by-side, or "RL" JPEG or PNG, with JPS and PNS (respectively) extensions and MIME types.

Once you know what image format you've got (LR "parallel" JPEG, RL "cross eyed" JPEG, odd or even vertically or horizontally interlaced JPEG, etc) it's a simple matter to convert it to any other viewing format (Anaglyph, LR, RL, compressed LR, interlaced, dual screen, etc) and apply any necessary lens corrections, etc). That's how RL became the standard: it's not "the best", it just serves as a "known starting point".

Back 10-15 years ago, during a 3D renaissance that never happened, people started releasing browser plugins that would allow you to set your viewing preference (anaglyph in various color combinations, LR, RL, interlaced, etc) and have any JPS or PNS display automatically.

Some of these included NuVision 3D, Schillr, and VRex DepthCharge. I haven't tried installing one of these plugins in a modern browser.

At least one of these (don't ask me which one) added a right context menu to allow it to process stereo images that were not properly tagged as JPS or PNS. That was very handy, as you could use it on all the images that people post in this forum.