Create Spherical Image from a Planar or Equirectangular image

Question

It´s obvious that to have a good and properly panorama image it has to be done with the appropriate equipment and format, but my question is this:

• Is it possible to transform an standard Equirectangular or the typical Planar picture in an approximately Panorama image that could be used in standard Panorama viewers??

In other words, is there some tool/Photoshop plug-in, etc. to make the appropriate spheric distortions to a planar image to "convert it" in an image that could be used as an "Approximate Panorama Image"?

I guess this could be used to download high resolution images from distant places, where you cannot access using this images as panoramas.

Answer 1

This is exactly what panorama creation apps (or plugins) do - transform regular images into spherical images (btw. equirectangular is just another name for the most common panoramic image projection, you don't transform between them because they are the same).

Typically you add a lot of planar images and stitch them into the single spherical image, but of course you can choose to process only one input image (and obviously, only get a fraction of the sphere).